Would you please turn on the issue? #1

koumaza · 2020-05-29T03:10:57Z

In my environment, this Kernel doesn't start.
I'd like to solve it with Issue.
Thanks.

nathanchance · 2020-05-31T04:06:15Z

I provide this kernel with no sort of support, hence no issues. There is no easy way for me to debug things. Sorry that it does not work for you.

xen_failsafe_callback() is invoked from XEN for two cases: 1. Fault while reloading DS, ES, FS or GS 2. Fault while executing IRET #1 retries the IRET after XEN has fixed up the segments. #2 injects a #GP which kills the task For #1 there is no reason to go through the full exception return path because the tasks TIF state is still the same. So just going straight to the IRET path is good enough. Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lore.kernel.org/r/[email protected]

When k_ascii is invoked several times in a row there is a potential for signed integer overflow: UBSAN: Undefined behaviour in drivers/tty/vt/keyboard.c:888:19 signed integer overflow: 10 * 1111111111 cannot be represented in type 'int' CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.11 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xce/0x128 lib/dump_stack.c:118 ubsan_epilogue+0xe/0x30 lib/ubsan.c:154 handle_overflow+0xdc/0xf0 lib/ubsan.c:184 __ubsan_handle_mul_overflow+0x2a/0x40 lib/ubsan.c:205 k_ascii+0xbf/0xd0 drivers/tty/vt/keyboard.c:888 kbd_keycode drivers/tty/vt/keyboard.c:1477 [inline] kbd_event+0x888/0x3be0 drivers/tty/vt/keyboard.c:1495 While it can be worked around by using check_mul_overflow()/ check_add_overflow(), it is better to introduce a separate flag to signal that number pad is being used to compose a symbol, and change type of the accumulator from signed to unsigned, thus avoiding undefined behavior when it overflows. Reported-by: Kyungtae Kim <[email protected]> Signed-off-by: Dmitry Torokhov <[email protected]> Cc: stable <[email protected]> Link: https://lore.kernel.org/r/20200525232740.GA262061@dtor-ws Signed-off-by: Greg Kroah-Hartman <[email protected]>

Be there a platform with the following layout: Regular NIC | +----> DSA master for switch port | +----> DSA master for another switch port After changing DSA back to static lockdep class keys in commit 1a33e10 ("net: partially revert dynamic lockdep key changes"), this kernel splat can be seen: [ 13.361198] ============================================ [ 13.366524] WARNING: possible recursive locking detected [ 13.371851] 5.7.0-rc4-02121-gc32a05ecd7af-dirty #988 Not tainted [ 13.377874] -------------------------------------------- [ 13.383201] swapper/0/0 is trying to acquire lock: [ 13.388004] ffff0000668ff298 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.397879] [ 13.397879] but task is already holding lock: [ 13.403727] ffff0000661a1698 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.413593] [ 13.413593] other info that might help us debug this: [ 13.420140] Possible unsafe locking scenario: [ 13.420140] [ 13.426075] CPU0 [ 13.428523] ---- [ 13.430969] lock(&dsa_slave_netdev_xmit_lock_key); [ 13.435946] lock(&dsa_slave_netdev_xmit_lock_key); [ 13.440924] [ 13.440924] *** DEADLOCK *** [ 13.440924] [ 13.446860] May be due to missing lock nesting notation [ 13.446860] [ 13.453668] 6 locks held by swapper/0/0: [ 13.457598] #0: ffff800010003de0 ((&idev->mc_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x0/0x400 [ 13.466593] #1: ffffd4d3fb478700 (rcu_read_lock){....}-{1:2}, at: mld_sendpack+0x0/0x560 [ 13.474803] #2: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x64/0xb10 [ 13.483886] #3: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x6c/0xbe0 [ 13.492793] #4: ffff0000661a1698 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.503094] #5: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x6c/0xbe0 [ 13.512000] [ 13.512000] stack backtrace: [ 13.516369] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc4-02121-gc32a05ecd7af-dirty #988 [ 13.530421] Call trace: [ 13.532871] dump_backtrace+0x0/0x1d8 [ 13.536539] show_stack+0x24/0x30 [ 13.539862] dump_stack+0xe8/0x150 [ 13.543271] __lock_acquire+0x1030/0x1678 [ 13.547290] lock_acquire+0xf8/0x458 [ 13.550873] _raw_spin_lock+0x44/0x58 [ 13.554543] __dev_queue_xmit+0x84c/0xbe0 [ 13.558562] dev_queue_xmit+0x24/0x30 [ 13.562232] dsa_slave_xmit+0xe0/0x128 [ 13.565988] dev_hard_start_xmit+0xf4/0x448 [ 13.570182] __dev_queue_xmit+0x808/0xbe0 [ 13.574200] dev_queue_xmit+0x24/0x30 [ 13.577869] neigh_resolve_output+0x15c/0x220 [ 13.582237] ip6_finish_output2+0x244/0xb10 [ 13.586430] __ip6_finish_output+0x1dc/0x298 [ 13.590709] ip6_output+0x84/0x358 [ 13.594116] mld_sendpack+0x2bc/0x560 [ 13.597786] mld_ifc_timer_expire+0x210/0x390 [ 13.602153] call_timer_fn+0xcc/0x400 [ 13.605822] run_timer_softirq+0x588/0x6e0 [ 13.609927] __do_softirq+0x118/0x590 [ 13.613597] irq_exit+0x13c/0x148 [ 13.616918] __handle_domain_irq+0x6c/0xc0 [ 13.621023] gic_handle_irq+0x6c/0x160 [ 13.624779] el1_irq+0xbc/0x180 [ 13.627927] cpuidle_enter_state+0xb4/0x4d0 [ 13.632120] cpuidle_enter+0x3c/0x50 [ 13.635703] call_cpuidle+0x44/0x78 [ 13.639199] do_idle+0x228/0x2c8 [ 13.642433] cpu_startup_entry+0x2c/0x48 [ 13.646363] rest_init+0x1ac/0x280 [ 13.649773] arch_call_rest_init+0x14/0x1c [ 13.653878] start_kernel+0x490/0x4bc Lockdep keys themselves were added in commit ab92d68 ("net: core: add generic lockdep keys"), and it's very likely that this splat existed since then, but I have no real way to check, since this stacked platform wasn't supported by mainline back then. >From Taehee's own words: This patch was considered that all stackable devices have LLTX flag. But the dsa doesn't have LLTX, so this splat happened. After this patch, dsa shares the same lockdep class key. On the nested dsa interface architecture, which you illustrated, the same lockdep class key will be used in __dev_queue_xmit() because dsa doesn't have LLTX. So that lockdep detects deadlock because the same lockdep class key is used recursively although actually the different locks are used. There are some ways to fix this problem. 1. using NETIF_F_LLTX flag. If possible, using the LLTX flag is a very clear way for it. But I'm so sorry I don't know whether the dsa could have LLTX or not. 2. using dynamic lockdep again. It means that each interface uses a separate lockdep class key. So, lockdep will not detect recursive locking. But this way has a problem that it could consume lockdep class key too many. Currently, lockdep can have 8192 lockdep class keys. - you can see this number with the following command. cat /proc/lockdep_stats lock-classes: 1251 [max: 8192] ... The [max: 8192] means that the maximum number of lockdep class keys. If too many lockdep class keys are registered, lockdep stops to work. So, using a dynamic(separated) lockdep class key should be considered carefully. In addition, updating lockdep class key routine might have to be existing. (lockdep_register_key(), lockdep_set_class(), lockdep_unregister_key()) 3. Using lockdep subclass. A lockdep class key could have 8 subclasses. The different subclass is considered different locks by lockdep infrastructure. But "lock-classes" is not counted by subclasses. So, it could avoid stopping lockdep infrastructure by an overflow of lockdep class keys. This approach should also have an updating lockdep class key routine. (lockdep_set_subclass()) 4. Using nonvalidate lockdep class key. The lockdep infrastructure supports nonvalidate lockdep class key type. It means this lockdep is not validated by lockdep infrastructure. So, the splat will not happen but lockdep couldn't detect real deadlock case because lockdep really doesn't validate it. I think this should be used for really special cases. (lockdep_set_novalidate_class()) Further discussion here: https://patchwork.ozlabs.org/project/netdev/patch/[email protected]/ There appears to be no negative side-effect to declaring lockless TX for the DSA virtual interfaces, which means they handle their own locking. So that's what we do to make the splat go away. Patch tested in a wide variety of cases: unicast, multicast, PTP, etc. Fixes: ab92d68 ("net: core: add generic lockdep keys") Suggested-by: Taehee Yoo <[email protected]> Signed-off-by: Vladimir Oltean <[email protected]> Reviewed-by: Florian Fainelli <[email protected]> Signed-off-by: David S. Miller <[email protected]>

Replace superfluous VM_BUG_ON() with comment about correct usage. Technically reverts commit 1d148e2 ("mm: add VM_BUG_ON_PAGE() to page_mapcount()"), but context lines have changed. Function isolate_migratepages_block() runs some checks out of lru_lock when choose pages for migration. After checking PageLRU() it checks extra page references by comparing page_count() and page_mapcount(). Between these two checks page could be removed from lru, freed and taken by slab. As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount(). Race window is tiny. For certain workload this happens around once a year. page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0 flags: 0x500000000008100(slab|head) raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:628! invalid opcode: 0000 [#1] SMP NOPTI CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G W 4.19.109-27 #1 Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019 RIP: 0010:isolate_migratepages_block+0x986/0x9b0 The code in isolate_migratepages_block() was added in commit 119d6d5 ("mm, compaction: avoid isolating pinned pages") before adding VM_BUG_ON into page_mapcount(). This race has been predicted in 2015 by Vlastimil Babka (see link below). [[email protected]: comment tweaks, per Hugh] Fixes: 1d148e2 ("mm: add VM_BUG_ON_PAGE() to page_mapcount()") Signed-off-by: Konstantin Khlebnikov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Acked-by: Hugh Dickins <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Cc: David Rientjes <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/r/159032779896.957378.7852761411265662220.stgit@buzz Link: https://lore.kernel.org/lkml/[email protected]/ Link: https://lore.kernel.org/linux-mm/158937872515.474360.5066096871639561424.stgit@buzz/T/ (v1) Signed-off-by: Linus Torvalds <[email protected]>

On a HP-PARISC rp3440 machine with this memory layout: Memory Ranges: 0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB 1) Start 0x0000004040000000 End 0x00000040ffdfffff Size 3070 MB the Debian kernel v5.6 triggers a kernel panic: Kernel panic - not syncing: Bad Address (null pointer deref?) Backtrace: [<0000000040101ab4>] start_kernel+0x6c8/0x1190 [<0000000040108574>] start_parisc+0x158/0x1b8 Bad Address (null pointer deref?): Code=26 (Data memory access rights trap) at addr 0000000000000000 CPU: 0 PID: 0 Comm: swapper Not tainted 5.6.0-2-parisc64 #1 Debian 5.6.14-1 Hardware name: 9000/800/rp3440 IAOQ[0]: mem_init+0xb0/0x150 IAOQ[1]: mem_init+0xb4/0x150 RP(r2): start_kernel+0x6c8/0x1190 Backtrace: [<0000000040101ab4>] start_kernel+0x6c8/0x1190 [<0000000040108574>] start_parisc+0x158/0x1b8 During memory initialization in mem_init() the memory zomes have not been set up yet, so avoid using virt_to_page() and similar functions. Signed-off-by: Helge Deller <[email protected]> Cc: [email protected] # v5.0+

A kernel panic was observed during reading /proc/kpageflags for first few pfns allocated by pmem namespace: BUG: unable to handle page fault for address: fffffffffffffffe [ 114.495280] #PF: supervisor read access in kernel mode [ 114.495738] #PF: error_code(0x0000) - not-present page [ 114.496203] PGD 17120e067 P4D 17120e067 PUD 171210067 PMD 0 [ 114.496713] Oops: 0000 [#1] SMP PTI [ 114.497037] CPU: 9 PID: 1202 Comm: page-types Not tainted 5.3.0-rc1 #1 [ 114.497621] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014 [ 114.498706] RIP: 0010:stable_page_flags+0x27/0x3f0 [ 114.499142] Code: 82 66 90 66 66 66 66 90 48 85 ff 0f 84 d1 03 00 00 41 54 55 48 89 fd 53 48 8b 57 08 48 8b 1f 48 8d 42 ff 83 e2 01 48 0f 44 c7 <48> 8b 00 f6 c4 02 0f 84 57 03 00 00 45 31 e4 48 8b 55 08 48 89 ef [ 114.500788] RSP: 0018:ffffa5e601a0fe60 EFLAGS: 00010202 [ 114.501373] RAX: fffffffffffffffe RBX: ffffffffffffffff RCX: 0000000000000000 [ 114.502009] RDX: 0000000000000001 RSI: 00007ffca13a7310 RDI: ffffd07489000000 [ 114.502637] RBP: ffffd07489000000 R08: 0000000000000001 R09: 0000000000000000 [ 114.503270] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000240000 [ 114.503896] R13: 0000000000080000 R14: 00007ffca13a7310 R15: ffffa5e601a0ff08 [ 114.504530] FS: 00007f0266c7f540(0000) GS:ffff962dbbac0000(0000) knlGS:0000000000000000 [ 114.505245] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 114.505754] CR2: fffffffffffffffe CR3: 000000023a204000 CR4: 00000000000006e0 [ 114.506401] Call Trace: [ 114.506660] kpageflags_read+0xb1/0x130 [ 114.507051] proc_reg_read+0x39/0x60 [ 114.507387] vfs_read+0x8a/0x140 [ 114.507686] ksys_pread64+0x61/0xa0 [ 114.508021] do_syscall_64+0x5f/0x1a0 [ 114.508372] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 114.508844] RIP: 0033:0x7f0266ba426b The reason for the panic is that stable_page_flags() which parses the page flags uses uninitialized struct pages reserved by the ZONE_DEVICE driver. Earlier approach to fix this was discussed here: https://marc.info/?l=linux-mm&m=152964770000672&w=2 This is another approach. To avoid using the uninitialized struct page, immediately return with KPF_RESERVED at the beginning of stable_page_flags() if the page is reserved by ZONE_DEVICE driver. Dan said: : The nvdimm implementation uses vmem_altmap to arrange for the 'struct : page' array to be allocated from a reservation of a pmem namespace. A : namespace in this mode contains an info-block that consumes the first : 8K of the namespace capacity, capacity designated for page mapping, : capacity for padding the start of data to optionally 4K, 2MB, or 1GB : (on x86), and then the namespace data itself. The implementation : specifies a section aligned (now sub-section aligned) address to : arch_add_memory() to establish the linear mapping to map the metadata, : and then vmem_altmap indicates to memmap_init_zone() which pfns : represent data. The implementation only specifies enough 'struct page' : capacity for pfn_to_page() to operate on the data space, not the : namespace metadata space. : : The proposal to validate ZONE_DEVICE pfns against the altmap seems the : right approach to me. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Toshiki Fukasawa <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Dan Williams <[email protected]> Cc: Junichi Nomura <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Naoya Horiguchi <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

isolate_migratepages_block() runs some checks out of lru_lock when choosing pages for migration. After checking PageLRU() it checks extra page references by comparing page_count() and page_mapcount(). Between these two checks page could be removed from lru, freed and taken by slab. As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount(). Race window is tiny. For certain workload this happens around once a year. page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0 flags: 0x500000000008100(slab|head) raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:628! invalid opcode: 0000 [#1] SMP NOPTI CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G W 4.19.109-27 #1 Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019 RIP: 0010:isolate_migratepages_block+0x986/0x9b0 To fix just opencode page_mapcount() in racy check for 0-order case and recheck carefully under lru_lock when page cannot escape from lru. Also add checking extra references for file pages and swap cache. Link: http://lkml.kernel.org/r/158937872515.474360.5066096871639561424.stgit@buzz Fixes: 119d6d5 ("mm, compaction: avoid isolating pinned pages") Fixes: 1d148e2 ("mm: add VM_BUG_ON_PAGE() to page_mapcount()") Signed-off-by: Konstantin Khlebnikov <[email protected]> Cc: Minchan Kim <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: David Rientjes <[email protected]> Cc: Mel Gorman <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

The slub_debug is able to fix the corrupted slab freelist/page. However, alloc_debug_processing() only checks the validity of current and next freepointer during allocation path. As a result, once some objects have their freepointers corrupted, deactivate_slab() may lead to page fault. Below is from a test kernel module when 'slub_debug=PUF,kmalloc-128 slub_nomerge'. The test kernel corrupts the freepointer of one free object on purpose. Unfortunately, deactivate_slab() does not detect it when iterating the freechain. [ 92.665260] BUG: unable to handle page fault for address: 00000000123456f8 [ 92.671597] #PF: supervisor read access in kernel mode [ 92.676159] #PF: error_code(0x0000) - not-present page [ 92.681666] PGD 0 P4D 0 [ 92.684923] Oops: 0000 [#1] SMP PTI ... ... [ 92.706684] RIP: 0010:deactivate_slab.isra.92+0xed/0x490 ... ... [ 92.819781] Call Trace: [ 92.823129] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.829488] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.834852] ? stack_trace_save+0x46/0x70 [ 92.839342] ? init_object+0x66/0x80 [ 92.843729] ? ___slab_alloc+0x536/0x570 [ 92.847664] ___slab_alloc+0x536/0x570 [ 92.851696] ? __find_get_block+0x23d/0x2c0 [ 92.856763] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.862258] ? _cond_resched+0x10/0x40 [ 92.866925] ? __getblk_gfp+0x27/0x2a0 [ 92.872136] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.878394] ? __slab_alloc+0x17/0x30 [ 92.883222] __slab_alloc+0x17/0x30 [ 92.887210] __kmalloc+0x1d9/0x200 [ 92.891448] ext4_htree_store_dirent+0x30/0xf0 [ 92.896748] htree_dirblock_to_tree+0xcb/0x1c0 [ 92.902398] ext4_htree_fill_tree+0x1bc/0x2d0 [ 92.907749] ext4_readdir+0x54f/0x920 [ 92.912725] iterate_dir+0x88/0x190 [ 92.917072] __x64_sys_getdents+0xa6/0x140 [ 92.922760] ? fillonedir+0xb0/0xb0 [ 92.927020] ? do_syscall_64+0x49/0x170 [ 92.931603] ? __ia32_sys_getdents+0x130/0x130 [ 92.937012] do_syscall_64+0x49/0x170 [ 92.940754] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Therefore, this patch adds extra consistency check in deactivate_slab(). Once an object's freepointer is corrupted, all following objects starting at this object are isolated. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Dongli Zhang <[email protected]> Cc: Joe Jin <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

We have seen a following problem on a RPi4 with 1G RAM: BUG: Bad page state in process systemd-hwdb pfn:35601 page:ffff7e0000d58040 refcount:15 mapcount:131221 mapping:efd8fe765bc80080 index:0x1 compound_mapcount: -32767 Unable to handle kernel paging request at virtual address efd8fe765bc80080 Mem abort info: ESR = 0x96000004 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [efd8fe765bc80080] address between user and kernel address ranges Internal error: Oops: 96000004 [#1] SMP Modules linked in: btrfs libcrc32c xor xor_neon zlib_deflate raid6_pq mmc_block xhci_pci xhci_hcd usbcore sdhci_iproc sdhci_pltfm sdhci mmc_core clk_raspberrypi gpio_raspberrypi_exp pcie_brcmstb bcm2835_dma gpio_regulator phy_generic fixed sg scsi_mod efivarfs Supported: No, Unreleased kernel CPU: 3 PID: 408 Comm: systemd-hwdb Not tainted 5.3.18-8-default #1 SLE15-SP2 (unreleased) Hardware name: raspberrypi rpi/rpi, BIOS 2020.01 02/21/2020 pstate: 40000085 (nZcv daIf -PAN -UAO) pc : __dump_page+0x268/0x368 lr : __dump_page+0xc4/0x368 sp : ffff000012563860 x29: ffff000012563860 x28: ffff80003ddc4300 x27: 0000000000000010 x26: 000000000000003f x25: ffff7e0000d58040 x24: 000000000000000f x23: efd8fe765bc80080 x22: 0000000000020095 x21: efd8fe765bc80080 x20: ffff000010ede8b0 x19: ffff7e0000d58040 x18: ffffffffffffffff x17: 0000000000000001 x16: 0000000000000007 x15: ffff000011689708 x14: 3030386362353637 x13: 6566386466653a67 x12: 6e697070616d2031 x11: 32323133313a746e x10: 756f6370616d2035 x9 : ffff00001168a840 x8 : ffff00001077a670 x7 : 000000000000013d x6 : ffff0000118a43b5 x5 : 0000000000000001 x4 : ffff80003dd9e2c8 x3 : ffff80003dd9e2c8 x2 : 911c8d7c2f483500 x1 : dead000000000100 x0 : efd8fe765bc80080 Call trace: __dump_page+0x268/0x368 bad_page+0xd4/0x168 check_new_page_bad+0x80/0xb8 rmqueue_bulk.constprop.26+0x4d8/0x788 get_page_from_freelist+0x4d4/0x1228 __alloc_pages_nodemask+0x134/0xe48 alloc_pages_vma+0x198/0x1c0 do_anonymous_page+0x1a4/0x4d8 __handle_mm_fault+0x4e8/0x560 handle_mm_fault+0x104/0x1e0 do_page_fault+0x1e8/0x4c0 do_translation_fault+0xb0/0xc0 do_mem_abort+0x50/0xb0 el0_da+0x24/0x28 Code: f9401025 8b8018a0 9a851005 17ffffca (f94002a0) ---[ end trace 703ac54becfd8094 ]--- Besides the underlying issue with page->mapping containing a bogus value for some reason, we can see that __dump_page() crashed by trying to read the pointer at mapping->host, turning a recoverable warning into full Oops. It can be expected that when page is reported as bad state for some reason, the pointers there should not be trusted blindly. So this patch treats all data in __dump_page() that depends on page->mapping as lava, using probe_kernel_read_strict(). Ideally this would include the dentry->d_parent recursively, but that would mean changing printk handler for %pd. Chances of reaching the dentry printing part with an initially bogus mapping pointer should be rather low, though. Also prefix printing mapping->a_ops with a description of what is being printed. In case the value is bogus, %ps will print raw value instead of the symbol name and then it's not obvious at all that it's printing a_ops. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Vlastimil Babka <[email protected]> Reported-by: Petr Tesarik <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: John Hubbard <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Fix crash with cgroup_disable=memory: > > > > + mkfs -t ext4 /dev/disk/by-id/ata-TOSHIBA_MG04ACA100N_Y8NRK0BPF6XF > > > > mke2fs 1.43.8 (1-Jan-2018) > > > > Creating filesystem with 244190646 4k blocks and 61054976 inodes > > > > Filesystem UUID: 3bb1a285-2cb4-44b4-b6e8-62548f3ac620 > > > > Superblock backups stored on blocks: > > > > 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, > > > > 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, > > > > 102400000, 214990848 > > > > Allocating group tables: 0/7453 done > > > > Writing inode tables: 0/7453 done > > > > Creating journal (262144 blocks): [ 35.502102] BUG: kernel NULL > > > > pointer dereference, address: 000000c8 > > > > [ 35.508372] #PF: supervisor read access in kernel mode > > > > [ 35.513506] #PF: error_code(0x0000) - not-present page > > > > [ 35.518638] *pde = 00000000 > > > > [ 35.521514] Oops: 0000 [#1] SMP > > > > [ 35.524652] CPU: 0 PID: 145 Comm: kswapd0 Not tainted > > > > 5.7.0-rc6-next-20200519+ #1 > > > > [ 35.532121] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS > > > > 2.2 05/23/2018 > > > > [ 35.539507] EIP: mem_cgroup_get_nr_swap_pages+0x28/0x60 Swap accounting used to be implied-disabled when the cgroup controller was disabled. Restore that for the new cgroup_memory_noswap, so that we bail out of this function instead of dereferencing a NULL memcg. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Johannes Weiner <[email protected]> Reported-by: Naresh Kamboju <[email protected]> Debugged-by: Hugh Dickins <[email protected]> Debugged-by: Michal Hocko <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Now that deferred pages are initialized with interrupts enabled we can replace touch_nmi_watchdog() with cond_resched(), as it was before 3a2d7fa. For now, we cannot do the same in deferred_grow_zone() as it is still initializes pages with interrupts disabled. This change fixes RCU problem described in https://lkml.kernel.org/r/[email protected] [ 60.474005] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 60.475000] rcu: 1-...0: (0 ticks this GP) idle=02a/1/0x4000000000000000 softirq=1/1 fqs=15000 [ 60.475000] rcu: (detected by 0, t=60002 jiffies, g=-1199, q=1) [ 60.475000] Sending NMI from CPU 0 to CPUs 1: [ 1.760091] NMI backtrace for cpu 1 [ 1.760091] CPU: 1 PID: 20 Comm: pgdatinit0 Not tainted 4.18.0-147.9.1.el8_1.x86_64 #1 [ 1.760091] Hardware name: Red Hat KVM, BIOS 1.13.0-1.module+el8.2.0+5520+4e5817f3 04/01/2014 [ 1.760091] RIP: 0010:__init_single_page.isra.65+0x10/0x4f [ 1.760091] Code: 48 83 cf 63 48 89 f8 0f 1f 40 00 48 89 c6 48 89 d7 e8 6b 18 80 ff 66 90 5b c3 31 c0 b9 10 00 00 00 49 89 f8 48 c1 e6 33 f3 ab <b8> 07 00 00 00 48 c1 e2 36 41 c7 40 34 01 00 00 00 48 c1 e0 33 41 [ 1.760091] RSP: 0000:ffffba783123be40 EFLAGS: 00000006 [ 1.760091] RAX: 0000000000000000 RBX: fffffad34405e300 RCX: 0000000000000000 [ 1.760091] RDX: 0000000000000000 RSI: 0010000000000000 RDI: fffffad34405e340 [ 1.760091] RBP: 0000000033f3177e R08: fffffad34405e300 R09: 0000000000000002 [ 1.760091] R10: 000000000000002b R11: ffff98afb691a500 R12: 0000000000000002 [ 1.760091] R13: 0000000000000000 R14: 000000003f03ea00 R15: 000000003e10178c [ 1.760091] FS: 0000000000000000(0000) GS:ffff9c9ebeb00000(0000) knlGS:0000000000000000 [ 1.760091] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.760091] CR2: 00000000ffffffff CR3: 000000a1cf20a001 CR4: 00000000003606e0 [ 1.760091] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1.760091] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1.760091] Call Trace: [ 1.760091] deferred_init_pages+0x8f/0xbf [ 1.760091] deferred_init_memmap+0x184/0x29d [ 1.760091] ? deferred_free_pages.isra.97+0xba/0xba [ 1.760091] kthread+0x112/0x130 [ 1.760091] ? kthread_flush_work_fn+0x10/0x10 [ 1.760091] ret_from_fork+0x35/0x40 [ 89.123011] node 0 initialised, 1055935372 pages in 88650ms Link: http://lkml.kernel.org/r/[email protected] Fixes: 3a2d7fa ("mm: disable interrupts while initializing deferred pages") Reported-by: Yiqian Wei <[email protected]> Tested-by: David Hildenbrand <[email protected]> Signed-off-by: Pavel Tatashin <[email protected]> Reviewed-by: Daniel Jordan <[email protected]> Acked-by: Michal Hocko <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Reviewed-by: Pankaj Gupta <[email protected]> Cc: Dan Williams <[email protected]> Cc: James Morris <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Sasha Levin <[email protected]> Cc: Shile Zhang <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: <[email protected]> [4.17+] Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

The reclaim code that balances between swapping and cache reclaim tries to predict likely reuse based on in-memory reference patterns alone. This works in many cases, but when it fails it cannot detect when the cache is thrashing pathologically, or when we're in the middle of a swap storm. The high seek cost of rotational drives under which the algorithm evolved also meant that mistakes could quickly result in lockups from too aggressive swapping (which is predominantly random IO). As a result, the balancing code has been tuned over time to a point where it mostly goes for page cache and defers swapping until the VM is under significant memory pressure. The resulting strategy doesn't make optimal caching decisions - where optimal is the least amount of IO required to execute the workload. The proliferation of fast random IO devices such as SSDs, in-memory compression such as zswap, and persistent memory technologies on the horizon, has made this undesirable behavior very noticable: Even in the presence of large amounts of cold anonymous memory and a capable swap device, the VM refuses to even seriously scan these pages, and can leave the page cache thrashing needlessly. This series sets out to address this. Since commit ("a528910e12ec mm: thrash detection-based file cache sizing") we have exact tracking of refault IO - the ultimate cost of reclaiming the wrong pages. This allows us to use an IO cost based balancing model that is more aggressive about scanning anonymous memory when the cache is thrashing, while being able to avoid unnecessary swap storms. These patches base the LRU balance on the rate of refaults on each list, times the relative IO cost between swap device and filesystem (swappiness), in order to optimize reclaim for least IO cost incurred. History I floated these changes in 2016. At the time they were incomplete and full of workarounds due to a lack of infrastructure in the reclaim code: We didn't have PageWorkingset, we didn't have hierarchical cgroup statistics, and problems with the cgroup swap controller. As swapping wasn't too high a priority then, the patches stalled out. With all dependencies in place now, here we are again with much cleaner, feature-complete patches. I kept the acks for patches that stayed materially the same :-) Below is a series of test results that demonstrate certain problematic behavior of the current code, as well as showcase the new code's more predictable and appropriate balancing decisions. Test #1: No convergence This test shows an edge case where the VM currently doesn't converge at all on a new file workingset with a stale anon/tmpfs set. The test sets up a cold anon set the size of 3/4 RAM, then tries to establish a new file set half the size of RAM (flat access pattern). The vanilla kernel refuses to even scan anon pages and never converges. The file set is perpetually served from the filesystem. The first test kernel is with the series up to the workingset patch applied. This allows thrashing page cache to challenge the anonymous workingset. The VM then scans the lists based on the current scanned/rotated balancing algorithm. It converges on a stable state where all cold anon pages are pushed out and the fileset is served entirely from cache: noconverge/5.7-rc5-mm noconverge/5.7-rc5-mm-workingset Scanned 417719308.00 ( +0.00%) 64091155.00 ( -84.66%) Reclaimed 417711094.00 ( +0.00%) 61640308.00 ( -85.24%) Reclaim efficiency % 100.00 ( +0.00%) 96.18 ( -3.78%) Scanned file 417719308.00 ( +0.00%) 59211118.00 ( -85.83%) Scanned anon 0.00 ( +0.00%) 4880037.00 ( ) Swapouts 0.00 ( +0.00%) 2439957.00 ( ) Swapins 0.00 ( +0.00%) 257.00 ( ) Refaults 415246605.00 ( +0.00%) 59183722.00 ( -85.75%) Restore refaults 0.00 ( +0.00%) 54988252.00 ( ) The second test kernel is with the full patch series applied, which replaces the scanned/rotated ratios with refault/swapin rate-based balancing. It evicts the cold anon pages more aggressively in the presence of a thrashing cache and the absence of swapins, and so converges with about 60% of the IO and reclaim activity: noconverge/5.7-rc5-mm-workingset noconverge/5.7-rc5-mm-lrubalance Scanned 64091155.00 ( +0.00%) 37579741.00 ( -41.37%) Reclaimed 61640308.00 ( +0.00%) 35129293.00 ( -43.01%) Reclaim efficiency % 96.18 ( +0.00%) 93.48 ( -2.78%) Scanned file 59211118.00 ( +0.00%) 32708385.00 ( -44.76%) Scanned anon 4880037.00 ( +0.00%) 4871356.00 ( -0.18%) Swapouts 2439957.00 ( +0.00%) 2435565.00 ( -0.18%) Swapins 257.00 ( +0.00%) 262.00 ( +1.94%) Refaults 59183722.00 ( +0.00%) 32675667.00 ( -44.79%) Restore refaults 54988252.00 ( +0.00%) 28480430.00 ( -48.21%) We're triggering this case in host sideloading scenarios: When a host's primary workload is not saturating the machine (primary load is usually driven by user activity), we can optimistically sideload a batch job; if user activity picks up and the primary workload needs the whole host during this time, we freeze the sideload and rely on it getting pushed to swap. Frequently that swapping doesn't happen and the completely inactive sideload simply stays resident while the expanding primary worklad is struggling to gain ground. Test #2: Kernel build This test is a a kernel build that is slightly memory-restricted (make -j4 inside a 400M cgroup). Despite the very aggressive swapping of cold anon pages in test #1, this test shows that the new kernel carefully balances swap against cache refaults when both the file and the cache set are pressured. It shows the patched kernel to be slightly better at finding the coldest memory from the combined anon and file set to evict under pressure. The result is lower aggregate reclaim and paging activity: z 5.7-rc5-mm 5.7-rc5-mm-lrubalance Real time 210.60 ( +0.00%) 210.97 ( +0.18%) User time 745.42 ( +0.00%) 746.48 ( +0.14%) System time 69.78 ( +0.00%) 69.79 ( +0.02%) Scanned file 354682.00 ( +0.00%) 293661.00 ( -17.20%) Scanned anon 465381.00 ( +0.00%) 378144.00 ( -18.75%) Swapouts 185920.00 ( +0.00%) 147801.00 ( -20.50%) Swapins 34583.00 ( +0.00%) 32491.00 ( -6.05%) Refaults 212664.00 ( +0.00%) 172409.00 ( -18.93%) Restore refaults 48861.00 ( +0.00%) 80091.00 ( +63.91%) Total paging IO 433167.00 ( +0.00%) 352701.00 ( -18.58%) Test #3: Overload This next test is not about performance, but rather about the predictability of the algorithm. The current balancing behavior doesn't always lead to comprehensible results, which makes performance analysis and parameter tuning (swappiness e.g.) very difficult. The test shows the balancing behavior under equivalent anon and file input. Anon and file sets are created of equal size (3/4 RAM), have the same access patterns (a hot-cold gradient), and synchronized access rates. Swappiness is raised from the default of 60 to 100 to indicate equal IO cost between swap and cache. With the vanilla balancing code, anon scans make up around 9% of the total pages scanned, or a ~1:10 ratio. This is a surprisingly skewed ratio, and it's an outcome that is hard to explain given the input parameters to the VM. The new balancing model targets a 1:2 balance: All else being equal, reclaiming a file page costs one page IO - the refault; reclaiming an anon page costs two IOs - the swapout and the swapin. In the test we observe a ~1:3 balance. The scanned and paging IO numbers indicate that the anon LRU algorithm we have in place right now does a slightly worse job at picking the coldest pages compared to the file algorithm. There is ongoing work to improve this, like Joonsoo's anon workingset patches; however, it's difficult to compare the two aging strategies when the balancing between them is behaving unintuitively. The slightly less efficient anon reclaim results in a deviation from the optimal 1:2 scan ratio we would like to see here - however, 1:3 is much closer to what we'd want to see in this test than the vanilla kernel's aging of 10+ cache pages for every anonymous one: overload-100/5.7-rc5-mm-workingset overload-100/5.7-rc5-mm-lrubalance-realfile Scanned 533633725.00 ( +0.00%) 595687785.00 ( +11.63%) Reclaimed 494325440.00 ( +0.00%) 518154380.00 ( +4.82%) Reclaim efficiency % 92.63 ( +0.00%) 86.98 ( -6.03%) Scanned file 484532894.00 ( +0.00%) 456937722.00 ( -5.70%) Scanned anon 49100831.00 ( +0.00%) 138750063.00 ( +182.58%) Swapouts 8096423.00 ( +0.00%) 48982142.00 ( +504.98%) Swapins 10027384.00 ( +0.00%) 62325044.00 ( +521.55%) Refaults 479819973.00 ( +0.00%) 451309483.00 ( -5.94%) Restore refaults 426422087.00 ( +0.00%) 399914067.00 ( -6.22%) Total paging IO 497943780.00 ( +0.00%) 562616669.00 ( +12.99%) Test #4: Parallel IO It's important to note that these patches only affect the situation where the kernel has to reclaim workingset memory, which is usually a transitionary period. The vast majority of page reclaim occuring in a system is from trimming the ever-expanding page cache. These patches don't affect cache trimming behavior. We never swap as long as we only have use-once cache moving through the file LRU, we only consider swapping when the cache is actively thrashing. The following test demonstrates this. It has an anon workingset that takes up half of RAM and then writes a file that is twice the size of RAM out to disk. As the cache is funneled through the inactive file list, no anon pages are scanned (aside from apparently some background noise of 10 pages): 5.7-rc5-mm 5.7-rc5-mm-lrubalance Scanned 10714722.00 ( +0.00%) 10723445.00 ( +0.08%) Reclaimed 10703596.00 ( +0.00%) 10712166.00 ( +0.08%) Reclaim efficiency % 99.90 ( +0.00%) 99.89 ( -0.00%) Scanned file 10714722.00 ( +0.00%) 10723435.00 ( +0.08%) Scanned anon 0.00 ( +0.00%) 10.00 ( ) Swapouts 0.00 ( +0.00%) 7.00 ( ) Swapins 0.00 ( +0.00%) 0.00 ( +0.00%) Refaults 92.00 ( +0.00%) 41.00 ( -54.84%) Restore refaults 0.00 ( +0.00%) 0.00 ( +0.00%) Total paging IO 92.00 ( +0.00%) 48.00 ( -47.31%) This patch (of 14): Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless. Always account THP by the number of basepages, and remove the fixup from the splitting path. Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Johannes Weiner <[email protected]> Reviewed-by: Rik van Riel <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Minchan Kim <[email protected]> Cc: Joonsoo Kim <[email protected]>, Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

A misbehaving qemu created a situation where the ACPI SRAT table advertised one fewer proximity domains than intended. The NFIT table did describe all the expected proximity domains. This caused the device dax driver to assign an impossible target_node to the device, and when hotplugged as system memory, this would fail with the following signature: [ +0.001627] BUG: kernel NULL pointer dereference, address: 0000000000000088 [ +0.001331] #PF: supervisor read access in kernel mode [ +0.000975] #PF: error_code(0x0000) - not-present page [ +0.000976] PGD 80000001767d4067 P4D 80000001767d4067 PUD 10e0c4067 PMD 0 [ +0.001338] Oops: 0000 [#1] SMP PTI [ +0.000676] CPU: 4 PID: 22737 Comm: kswapd3 Tainted: G O 5.6.0-rc5 #9 [ +0.001457] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ +0.001990] RIP: 0010:prepare_kswapd_sleep+0x7c/0xc0 [ +0.000780] Code: 89 df e8 87 fd ff ff 89 c2 31 c0 84 d2 74 e6 0f 1f 44 00 00 48 8b 05 fb af 7a 01 48 63 93 88 1d 01 00 48 8b 84 d0 20 0f 00 00 <48> 3b 98 88 00 00 00 75 28 f0 80 a0 80 00 00 00 fe f0 80 a3 38 20 [ +0.002877] RSP: 0018:ffffc900017a3e78 EFLAGS: 00010202 [ +0.000805] RAX: 0000000000000000 RBX: ffff8881209e0000 RCX: 0000000000000000 [ +0.001115] RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff8881209e0e80 [ +0.001098] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000008000 [ +0.001092] R10: 0000000000000000 R11: 0000000000000003 R12: 0000000000000003 [ +0.001092] R13: 0000000000000003 R14: 0000000000000000 R15: ffffc900017a3ec8 [ +0.001091] FS: 0000000000000000(0000) GS:ffff888318c00000(0000) knlGS:0000000000000000 [ +0.001275] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000882] CR2: 0000000000000088 CR3: 0000000120b50002 CR4: 00000000001606e0 [ +0.001095] Call Trace: [ +0.000388] kswapd+0x103/0x520 [ +0.000494] ? finish_wait+0x80/0x80 [ +0.000547] ? balance_pgdat+0x5a0/0x5a0 [ +0.000607] kthread+0x120/0x140 [ +0.000508] ? kthread_create_on_node+0x60/0x60 [ +0.000706] ret_from_fork+0x3a/0x50 Add a check in the add_memory path to fail if the node to which we are adding memory is in the node_possible_map Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Vishal Verma <[email protected]> Acked-by: David Hildenbrand <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Dan Williams <[email protected]> Cc: Dave Hansen <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Patch series "mm/memory_hotplug: Interface to add driver-managed system ram", v4. kexec (via kexec_load()) can currently not properly handle memory added via dax/kmem, and will have similar issues with virtio-mem. kexec-tools will currently add all memory to the fixed-up initial firmware memmap. In case of dax/kmem, this means that - in contrast to a proper reboot - how that persistent memory will be used can no longer be configured by the kexec'd kernel. In case of virtio-mem it will be harmful, because that memory might contain inaccessible pieces that require coordination with hypervisor first. In both cases, we want to let the driver in the kexec'd kernel handle detecting and adding the memory, like during an ordinary reboot. Introduce add_memory_driver_managed(). More on the samentics are in patch #1. In the future, we might want to make this behavior configurable for dax/kmem- either by configuring it in the kernel (which would then also allow to configure kexec_file_load()) or in kexec-tools by also adding "System RAM (kmem)" memory from /proc/iomem to the fixed-up initial firmware memmap. More on the motivation can be found in [1] and [2]. [1] https://lkml.kernel.org/r/[email protected] [2] https://lkml.kernel.org/r/[email protected] This patch (of 3): Some device drivers rely on memory they managed to not get added to the initial (firmware) memmap as system RAM - so it's not used as initial system RAM by the kernel and the driver is under control. While this is the case during cold boot and after a reboot, kexec is not aware of that and might add such memory to the initial (firmware) memmap of the kexec kernel. We need ways to teach kernel and userspace that this system ram is different. For example, dax/kmem allows to decide at runtime if persistent memory is to be used as system ram. Another future user is virtio-mem, which has to coordinate with its hypervisor to deal with inaccessible parts within memory resources. We want to let users in the kernel (esp. kexec) but also user space (esp. kexec-tools) know that this memory has different semantics and needs to be handled differently: 1. Don't create entries in /sys/firmware/memmap/ 2. Name the memory resource "System RAM ($DRIVER)" (exposed via /proc/iomem) ($DRIVER might be "kmem", "virtio_mem"). 3. Flag the memory resource IORESOURCE_MEM_DRIVER_MANAGED /sys/firmware/memmap/ [1] represents the "raw firmware-provided memory map" because "on most architectures that firmware-provided memory map is modified afterwards by the kernel itself". The primary user is kexec on x86-64. Since commit d96ae53 ("memory-hotplug: create /sys/firmware/memmap entry for new memory"), we add all hotplugged memory to that firmware memmap - which makes perfect sense for traditional memory hotplug on x86-64, where real HW will also add hotplugged DIMMs to the firmware memmap. We replicate what the "raw firmware-provided memory map" looks like after hot(un)plug. To keep things simple, let the user provide the full resource name instead of only the driver name - this way, we don't have to manually allocate/craft strings for memory resources. Also use the resource name to make decisions, to avoid passing additional flags. In case the name isn't "System RAM", it's special. We don't have to worry about firmware_map_remove() on the removal path. If there is no entry, it will simply return with -EINVAL. We'll adapt dax/kmem in a follow-up patch. [1] https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-memmap Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: David Hildenbrand <[email protected]> Acked-by: Pankaj Gupta <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Pankaj Gupta <[email protected]> Cc: Wei Yang <[email protected]> Cc: Baoquan He <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Eric Biederman <[email protected]> Cc: Pavel Tatashin <[email protected]> Cc: Dan Williams <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Since free_bprm(bprm) always calls allow_write_access(bprm->file) and fput(bprm->file) if bprm->file is set to non-NULL, __do_execve_file() must call deny_write_access(file) and get_file(file) if called from do_execve_file() path. Otherwise, use-after-free access can happen at fput(file) in fork_usermode_blob(). general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] SMP DEBUG_PAGEALLOC CPU: 3 PID: 4131 Comm: insmod Tainted: G O 5.6.0-rc5+ #978 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/29/2019 RIP: 0010:fork_usermode_blob+0xaa/0x190 Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Tetsuo Handa <[email protected]> Fixes: 449325b ("umh: introduce fork_usermode_blob() helper") Cc: <[email protected]> [4.18+] Cc: Alexei Starovoitov <[email protected]> Cc: David S. Miller <[email protected]> Cc: Alexander Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

struct file_ra_state ra.mmap_miss could be accessed concurrently during page faults as noticed by KCSAN, BUG: KCSAN: data-race in filemap_fault / filemap_map_pages write to 0xffff9b1700a2c1b4 of 4 bytes by task 3292 on cpu 30: filemap_fault+0x920/0xfc0 do_sync_mmap_readahead at mm/filemap.c:2384 (inlined by) filemap_fault at mm/filemap.c:2486 __xfs_filemap_fault+0x112/0x3e0 [xfs] xfs_filemap_fault+0x74/0x90 [xfs] __do_fault+0x9e/0x220 do_fault+0x4a0/0x920 __handle_mm_fault+0xc69/0xd00 handle_mm_fault+0xfc/0x2f0 do_page_fault+0x263/0x6f9 page_fault+0x34/0x40 read to 0xffff9b1700a2c1b4 of 4 bytes by task 3313 on cpu 32: filemap_map_pages+0xc2e/0xd80 filemap_map_pages at mm/filemap.c:2625 do_fault+0x3da/0x920 __handle_mm_fault+0xc69/0xd00 handle_mm_fault+0xfc/0x2f0 do_page_fault+0x263/0x6f9 page_fault+0x34/0x40 Reported by Kernel Concurrency Sanitizer on: CPU: 32 PID: 3313 Comm: systemd-udevd Tainted: G W L 5.5.0-next-20200210+ #1 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 ra.mmap_miss is used to contribute the readahead decisions, a data race could be undesirable. Both the read and write is only under non-exclusive mmap_sem, two concurrent writers could even underflow the counter. Fix the underflow by writing to a local variable before committing a final store to ra.mmap_miss given a small inaccuracy of the counter should be acceptable. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Kirill A. Shutemov <[email protected]> Signed-off-by: Qian Cai <[email protected]> Tested-by: Qian Cai <[email protected]> Reviewed-by: Matthew Wilcox (Oracle) <[email protected]> Cc: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Read to lru_add_pvec->nr could be interrupted and then write to the same variable. The write has local interrupt disabled, but the plain reads result in data races. However, it is unlikely the compilers could do much damage here given that lru_add_pvec->nr is a "unsigned char" and there is an existing compiler barrier. Thus, annotate the reads using the data_race() macro. The data races were reported by KCSAN, BUG: KCSAN: data-race in lru_add_drain_cpu / rotate_reclaimable_page write to 0xffff9291ebcb8a40 of 1 bytes by interrupt on cpu 23: rotate_reclaimable_page+0x2df/0x490 pagevec_add at include/linux/pagevec.h:81 (inlined by) rotate_reclaimable_page at mm/swap.c:259 end_page_writeback+0x1b5/0x2b0 end_swap_bio_write+0x1d0/0x280 bio_endio+0x297/0x560 dec_pending+0x218/0x430 [dm_mod] clone_endio+0xe4/0x2c0 [dm_mod] bio_endio+0x297/0x560 blk_update_request+0x201/0x920 scsi_end_request+0x6b/0x4a0 scsi_io_completion+0xb7/0x7e0 scsi_finish_command+0x1ed/0x2a0 scsi_softirq_done+0x1c9/0x1d0 blk_done_softirq+0x181/0x1d0 __do_softirq+0xd9/0x57c irq_exit+0xa2/0xc0 do_IRQ+0x8b/0x190 ret_from_intr+0x0/0x42 delay_tsc+0x46/0x80 __const_udelay+0x3c/0x40 __udelay+0x10/0x20 kcsan_setup_watchpoint+0x202/0x3a0 __tsan_read1+0xc2/0x100 lru_add_drain_cpu+0xb8/0x3f0 lru_add_drain+0x25/0x40 shrink_active_list+0xe1/0xc80 shrink_lruvec+0x766/0xb70 shrink_node+0x2d6/0xca0 do_try_to_free_pages+0x1f7/0x9a0 try_to_free_pages+0x252/0x5b0 __alloc_pages_slowpath+0x458/0x1290 __alloc_pages_nodemask+0x3bb/0x450 alloc_pages_vma+0x8a/0x2c0 do_anonymous_page+0x16e/0x6f0 __handle_mm_fault+0xcd5/0xd40 handle_mm_fault+0xfc/0x2f0 do_page_fault+0x263/0x6f9 page_fault+0x34/0x40 read to 0xffff9291ebcb8a40 of 1 bytes by task 37761 on cpu 23: lru_add_drain_cpu+0xb8/0x3f0 lru_add_drain_cpu at mm/swap.c:602 lru_add_drain+0x25/0x40 shrink_active_list+0xe1/0xc80 shrink_lruvec+0x766/0xb70 shrink_node+0x2d6/0xca0 do_try_to_free_pages+0x1f7/0x9a0 try_to_free_pages+0x252/0x5b0 __alloc_pages_slowpath+0x458/0x1290 __alloc_pages_nodemask+0x3bb/0x450 alloc_pages_vma+0x8a/0x2c0 do_anonymous_page+0x16e/0x6f0 __handle_mm_fault+0xcd5/0xd40 handle_mm_fault+0xfc/0x2f0 do_page_fault+0x263/0x6f9 page_fault+0x34/0x40 2 locks held by oom02/37761: #0: ffff9281e5928808 (&mm->mmap_sem#2){++++}, at: do_page_fault #1: ffffffffb3ade380 (fs_reclaim){+.+.}, at: fs_reclaim_acquire.part irq event stamp: 1949217 trace_hardirqs_on_thunk+0x1a/0x1c __do_softirq+0x2e7/0x57c __do_softirq+0x34c/0x57c irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 23 PID: 37761 Comm: oom02 Not tainted 5.6.0-rc3-next-20200226+ #6 Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018 Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Qian Cai <[email protected]> Acked-by: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

syzkaller is picking up a bunch of crashes that look like this: Unrecoverable exception 380 at c00000000037ed60 (msr=8000000000001031) Oops: Unrecoverable exception, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 874 Comm: syz-executor.0 Not tainted 5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e #0 NIP: c00000000037ed60 LR: c00000000004bac8 CTR: c000000000030990 REGS: c0000000555a7230 TRAP: 0380 Not tainted (5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e) MSR: 8000000000001031 <SF,ME,IR,DR,LE> CR: 48222882 XER: 20000000 CFAR: c00000000004bac4 IRQMASK: 0 GPR00: c00000000004bb68 c0000000555a74c0 c0000000024b3500 0000000000000005 GPR04: 0000000000000000 0000000000000000 c00000000004bb88 c008000000910000 GPR08: 00000000000b0000 c00000000004bac8 0000000000016000 c000000002503500 GPR12: c000000000030990 c000000003190000 00000000106a5898 00000000106a0000 GPR16: 00000000106a5890 c000000007a92000 c000000008180e00 c000000007a8f700 GPR20: c000000007a904b0 0000000010110000 c00000000259d318 5deadbeef0000100 GPR24: 5deadbeef0000122 c000000078422700 c000000009ee88b8 c000000078422778 GPR28: 0000000000000001 800000000280b033 0000000000000000 c0000000555a75a0 NIP [c00000000037ed60] __sanitizer_cov_trace_pc+0x40/0x50 LR [c00000000004bac8] interrupt_exit_kernel_prepare+0x118/0x310 Call Trace: [c0000000555a74c0] [c00000000004bb68] interrupt_exit_kernel_prepare+0x1b8/0x310 (unreliable) [c0000000555a7530] [c00000000000f9a8] interrupt_return+0x118/0x1c0 --- interrupt: 900 at __sanitizer_cov_trace_pc+0x0/0x50 ...<random previous call chain>... This is caused by __sanitizer_cov_trace_pc() causing an SLB fault after MSR[RI] has been cleared by __hard_EE_RI_disable(), which we can not recover from. Do not instrument the new syscall/interrupt entry/exit code with KCOV, GCOV or UBSAN. Reported-by: syzbot-ppc64 <[email protected]> Fixes: 68b3458 ("powerpc/64/sycall: Implement syscall entry/exit logic in C") Signed-off-by: Daniel Axtens <[email protected]> Acked-by: Andrew Donnellan <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>

The Debian kernel v5.6 triggers this kernel panic: Kernel panic - not syncing: Bad Address (null pointer deref?) Bad Address (null pointer deref?): Code=26 (Data memory access rights trap) at addr 0000000000000000 CPU: 0 PID: 0 Comm: swapper Not tainted 5.6.0-2-parisc64 #1 Debian 5.6.14-1 IAOQ[0]: mem_init+0xb0/0x150 IAOQ[1]: mem_init+0xb4/0x150 RP(r2): start_kernel+0x6c8/0x1190 Backtrace: [<0000000040101ab4>] start_kernel+0x6c8/0x1190 [<0000000040108574>] start_parisc+0x158/0x1b8 on a HP-PARISC rp3440 machine with this memory layout: Memory Ranges: 0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB 1) Start 0x0000004040000000 End 0x00000040ffdfffff Size 3070 MB Fix the crash by avoiding virt_to_page() and similar functions in mem_init() until the memory zones have been fully set up. Signed-off-by: Helge Deller <[email protected]> Cc: [email protected] # v5.0+

A kernel panic was observed during reading /proc/kpageflags for first few pfns allocated by pmem namespace: BUG: unable to handle page fault for address: fffffffffffffffe [ 114.495280] #PF: supervisor read access in kernel mode [ 114.495738] #PF: error_code(0x0000) - not-present page [ 114.496203] PGD 17120e067 P4D 17120e067 PUD 171210067 PMD 0 [ 114.496713] Oops: 0000 [#1] SMP PTI [ 114.497037] CPU: 9 PID: 1202 Comm: page-types Not tainted 5.3.0-rc1 #1 [ 114.497621] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014 [ 114.498706] RIP: 0010:stable_page_flags+0x27/0x3f0 [ 114.499142] Code: 82 66 90 66 66 66 66 90 48 85 ff 0f 84 d1 03 00 00 41 54 55 48 89 fd 53 48 8b 57 08 48 8b 1f 48 8d 42 ff 83 e2 01 48 0f 44 c7 <48> 8b 00 f6 c4 02 0f 84 57 03 00 00 45 31 e4 48 8b 55 08 48 89 ef [ 114.500788] RSP: 0018:ffffa5e601a0fe60 EFLAGS: 00010202 [ 114.501373] RAX: fffffffffffffffe RBX: ffffffffffffffff RCX: 0000000000000000 [ 114.502009] RDX: 0000000000000001 RSI: 00007ffca13a7310 RDI: ffffd07489000000 [ 114.502637] RBP: ffffd07489000000 R08: 0000000000000001 R09: 0000000000000000 [ 114.503270] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000240000 [ 114.503896] R13: 0000000000080000 R14: 00007ffca13a7310 R15: ffffa5e601a0ff08 [ 114.504530] FS: 00007f0266c7f540(0000) GS:ffff962dbbac0000(0000) knlGS:0000000000000000 [ 114.505245] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 114.505754] CR2: fffffffffffffffe CR3: 000000023a204000 CR4: 00000000000006e0 [ 114.506401] Call Trace: [ 114.506660] kpageflags_read+0xb1/0x130 [ 114.507051] proc_reg_read+0x39/0x60 [ 114.507387] vfs_read+0x8a/0x140 [ 114.507686] ksys_pread64+0x61/0xa0 [ 114.508021] do_syscall_64+0x5f/0x1a0 [ 114.508372] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 114.508844] RIP: 0033:0x7f0266ba426b The reason for the panic is that stable_page_flags() which parses the page flags uses uninitialized struct pages reserved by the ZONE_DEVICE driver. Earlier approach to fix this was discussed here: https://marc.info/?l=linux-mm&m=152964770000672&w=2 This is another approach. To avoid using the uninitialized struct page, immediately return with KPF_RESERVED at the beginning of stable_page_flags() if the page is reserved by ZONE_DEVICE driver. Dan said: : The nvdimm implementation uses vmem_altmap to arrange for the 'struct : page' array to be allocated from a reservation of a pmem namespace. A : namespace in this mode contains an info-block that consumes the first : 8K of the namespace capacity, capacity designated for page mapping, : capacity for padding the start of data to optionally 4K, 2MB, or 1GB : (on x86), and then the namespace data itself. The implementation : specifies a section aligned (now sub-section aligned) address to : arch_add_memory() to establish the linear mapping to map the metadata, : and then vmem_altmap indicates to memmap_init_zone() which pfns : represent data. The implementation only specifies enough 'struct page' : capacity for pfn_to_page() to operate on the data space, not the : namespace metadata space. : : The proposal to validate ZONE_DEVICE pfns against the altmap seems the : right approach to me. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Toshiki Fukasawa <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Dan Williams <[email protected]> Cc: Junichi Nomura <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Naoya Horiguchi <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

isolate_migratepages_block() runs some checks out of lru_lock when choosing pages for migration. After checking PageLRU() it checks extra page references by comparing page_count() and page_mapcount(). Between these two checks page could be removed from lru, freed and taken by slab. As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount(). Race window is tiny. For certain workload this happens around once a year. page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0 flags: 0x500000000008100(slab|head) raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:628! invalid opcode: 0000 [#1] SMP NOPTI CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G W 4.19.109-27 #1 Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019 RIP: 0010:isolate_migratepages_block+0x986/0x9b0 To fix just opencode page_mapcount() in racy check for 0-order case and recheck carefully under lru_lock when page cannot escape from lru. Also add checking extra references for file pages and swap cache. Link: http://lkml.kernel.org/r/158937872515.474360.5066096871639561424.stgit@buzz Fixes: 119d6d5 ("mm, compaction: avoid isolating pinned pages") Fixes: 1d148e2 ("mm: add VM_BUG_ON_PAGE() to page_mapcount()") Signed-off-by: Konstantin Khlebnikov <[email protected]> Cc: Minchan Kim <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: David Rientjes <[email protected]> Cc: Mel Gorman <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Replace superfluous VM_BUG_ON() with comment about correct usage. Technically reverts commit 1d148e2 ("mm: add VM_BUG_ON_PAGE() to page_mapcount()"), but context have changed. Function isolate_migratepages_block() runs some checks out of lru_lock when choose pages for migration. After checking PageLRU() it checks extra page references by comparing page_count() and page_mapcount(). Between these two checks page could be removed from lru, freed and taken by slab. As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount(). Race window is tiny. For certain workload this happens around once a year. page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0 flags: 0x500000000008100(slab|head) raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:628! invalid opcode: 0000 [#1] SMP NOPTI CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G W 4.19.109-27 #1 Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019 RIP: 0010:isolate_migratepages_block+0x986/0x9b0 Code in isolate_migratepages_block() was added in commit 119d6d5 ("mm, compaction: avoid isolating pinned pages") before adding VM_BUG_ON into page_mapcount(). This race has been predicted in 2015 by Vlastimil Babka (see link below). Link: http://lkml.kernel.org/r/159032779896.957378.7852761411265662220.stgit@buzz Link: https://lore.kernel.org/lkml/[email protected]/ Link: https://lore.kernel.org/linux-mm/158937872515.474360.5066096871639561424.stgit@buzz/T/ (v1) Fixes: 1d148e2 ("mm: add VM_BUG_ON_PAGE() to page_mapcount()") Signed-off-by: Konstantin Khlebnikov <[email protected]> Acked-by: Hugh Dickins <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: David Rientjes <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

The slub_debug is able to fix the corrupted slab freelist/page. However, alloc_debug_processing() only checks the validity of current and next freepointer during allocation path. As a result, once some objects have their freepointers corrupted, deactivate_slab() may lead to page fault. Below is from a test kernel module when 'slub_debug=PUF,kmalloc-128 slub_nomerge'. The test kernel corrupts the freepointer of one free object on purpose. Unfortunately, deactivate_slab() does not detect it when iterating the freechain. [ 92.665260] BUG: unable to handle page fault for address: 00000000123456f8 [ 92.671597] #PF: supervisor read access in kernel mode [ 92.676159] #PF: error_code(0x0000) - not-present page [ 92.681666] PGD 0 P4D 0 [ 92.684923] Oops: 0000 [#1] SMP PTI ... ... [ 92.706684] RIP: 0010:deactivate_slab.isra.92+0xed/0x490 ... ... [ 92.819781] Call Trace: [ 92.823129] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.829488] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.834852] ? stack_trace_save+0x46/0x70 [ 92.839342] ? init_object+0x66/0x80 [ 92.843729] ? ___slab_alloc+0x536/0x570 [ 92.847664] ___slab_alloc+0x536/0x570 [ 92.851696] ? __find_get_block+0x23d/0x2c0 [ 92.856763] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.862258] ? _cond_resched+0x10/0x40 [ 92.866925] ? __getblk_gfp+0x27/0x2a0 [ 92.872136] ? ext4_htree_store_dirent+0x30/0xf0 [ 92.878394] ? __slab_alloc+0x17/0x30 [ 92.883222] __slab_alloc+0x17/0x30 [ 92.887210] __kmalloc+0x1d9/0x200 [ 92.891448] ext4_htree_store_dirent+0x30/0xf0 [ 92.896748] htree_dirblock_to_tree+0xcb/0x1c0 [ 92.902398] ext4_htree_fill_tree+0x1bc/0x2d0 [ 92.907749] ext4_readdir+0x54f/0x920 [ 92.912725] iterate_dir+0x88/0x190 [ 92.917072] __x64_sys_getdents+0xa6/0x140 [ 92.922760] ? fillonedir+0xb0/0xb0 [ 92.927020] ? do_syscall_64+0x49/0x170 [ 92.931603] ? __ia32_sys_getdents+0x130/0x130 [ 92.937012] do_syscall_64+0x49/0x170 [ 92.940754] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Therefore, this patch adds extra consistency check in deactivate_slab(). Once an object's freepointer is corrupted, all following objects starting at this object are isolated. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Dongli Zhang <[email protected]> Cc: Joe Jin <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

We have seen a following problem on a RPi4 with 1G RAM: BUG: Bad page state in process systemd-hwdb pfn:35601 page:ffff7e0000d58040 refcount:15 mapcount:131221 mapping:efd8fe765bc80080 index:0x1 compound_mapcount: -32767 Unable to handle kernel paging request at virtual address efd8fe765bc80080 Mem abort info: ESR = 0x96000004 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [efd8fe765bc80080] address between user and kernel address ranges Internal error: Oops: 96000004 [#1] SMP Modules linked in: btrfs libcrc32c xor xor_neon zlib_deflate raid6_pq mmc_block xhci_pci xhci_hcd usbcore sdhci_iproc sdhci_pltfm sdhci mmc_core clk_raspberrypi gpio_raspberrypi_exp pcie_brcmstb bcm2835_dma gpio_regulator phy_generic fixed sg scsi_mod efivarfs Supported: No, Unreleased kernel CPU: 3 PID: 408 Comm: systemd-hwdb Not tainted 5.3.18-8-default #1 SLE15-SP2 (unreleased) Hardware name: raspberrypi rpi/rpi, BIOS 2020.01 02/21/2020 pstate: 40000085 (nZcv daIf -PAN -UAO) pc : __dump_page+0x268/0x368 lr : __dump_page+0xc4/0x368 sp : ffff000012563860 x29: ffff000012563860 x28: ffff80003ddc4300 x27: 0000000000000010 x26: 000000000000003f x25: ffff7e0000d58040 x24: 000000000000000f x23: efd8fe765bc80080 x22: 0000000000020095 x21: efd8fe765bc80080 x20: ffff000010ede8b0 x19: ffff7e0000d58040 x18: ffffffffffffffff x17: 0000000000000001 x16: 0000000000000007 x15: ffff000011689708 x14: 3030386362353637 x13: 6566386466653a67 x12: 6e697070616d2031 x11: 32323133313a746e x10: 756f6370616d2035 x9 : ffff00001168a840 x8 : ffff00001077a670 x7 : 000000000000013d x6 : ffff0000118a43b5 x5 : 0000000000000001 x4 : ffff80003dd9e2c8 x3 : ffff80003dd9e2c8 x2 : 911c8d7c2f483500 x1 : dead000000000100 x0 : efd8fe765bc80080 Call trace: __dump_page+0x268/0x368 bad_page+0xd4/0x168 check_new_page_bad+0x80/0xb8 rmqueue_bulk.constprop.26+0x4d8/0x788 get_page_from_freelist+0x4d4/0x1228 __alloc_pages_nodemask+0x134/0xe48 alloc_pages_vma+0x198/0x1c0 do_anonymous_page+0x1a4/0x4d8 __handle_mm_fault+0x4e8/0x560 handle_mm_fault+0x104/0x1e0 do_page_fault+0x1e8/0x4c0 do_translation_fault+0xb0/0xc0 do_mem_abort+0x50/0xb0 el0_da+0x24/0x28 Code: f9401025 8b8018a0 9a851005 17ffffca (f94002a0) ---[ end trace 703ac54becfd8094 ]--- Besides the underlying issue with page->mapping containing a bogus value for some reason, we can see that __dump_page() crashed by trying to read the pointer at mapping->host, turning a recoverable warning into full Oops. It can be expected that when page is reported as bad state for some reason, the pointers there should not be trusted blindly. So this patch treats all data in __dump_page() that depends on page->mapping as lava, using probe_kernel_read_strict(). Ideally this would include the dentry->d_parent recursively, but that would mean changing printk handler for %pd. Chances of reaching the dentry printing part with an initially bogus mapping pointer should be rather low, though. Also prefix printing mapping->a_ops with a description of what is being printed. In case the value is bogus, %ps will print raw value instead of the symbol name and then it's not obvious at all that it's printing a_ops. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Vlastimil Babka <[email protected]> Reported-by: Petr Tesarik <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: John Hubbard <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Fix crash with cgroup_disable=memory: > > > > + mkfs -t ext4 /dev/disk/by-id/ata-TOSHIBA_MG04ACA100N_Y8NRK0BPF6XF > > > > mke2fs 1.43.8 (1-Jan-2018) > > > > Creating filesystem with 244190646 4k blocks and 61054976 inodes > > > > Filesystem UUID: 3bb1a285-2cb4-44b4-b6e8-62548f3ac620 > > > > Superblock backups stored on blocks: > > > > 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, > > > > 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, > > > > 102400000, 214990848 > > > > Allocating group tables: 0/7453 done > > > > Writing inode tables: 0/7453 done > > > > Creating journal (262144 blocks): [ 35.502102] BUG: kernel NULL > > > > pointer dereference, address: 000000c8 > > > > [ 35.508372] #PF: supervisor read access in kernel mode > > > > [ 35.513506] #PF: error_code(0x0000) - not-present page > > > > [ 35.518638] *pde = 00000000 > > > > [ 35.521514] Oops: 0000 [#1] SMP > > > > [ 35.524652] CPU: 0 PID: 145 Comm: kswapd0 Not tainted > > > > 5.7.0-rc6-next-20200519+ #1 > > > > [ 35.532121] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS > > > > 2.2 05/23/2018 > > > > [ 35.539507] EIP: mem_cgroup_get_nr_swap_pages+0x28/0x60 Swap accounting used to be implied-disabled when the cgroup controller was disabled. Restore that for the new cgroup_memory_noswap, so that we bail out of this function instead of dereferencing a NULL memcg. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Johannes Weiner <[email protected]> Reported-by: Naresh Kamboju <[email protected]> Debugged-by: Hugh Dickins <[email protected]> Debugged-by: Michal Hocko <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Now that deferred pages are initialized with interrupts enabled we can replace touch_nmi_watchdog() with cond_resched(), as it was before 3a2d7fa. For now, we cannot do the same in deferred_grow_zone() as it is still initializes pages with interrupts disabled. This change fixes RCU problem described in https://lkml.kernel.org/r/[email protected] [ 60.474005] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 60.475000] rcu: 1-...0: (0 ticks this GP) idle=02a/1/0x4000000000000000 softirq=1/1 fqs=15000 [ 60.475000] rcu: (detected by 0, t=60002 jiffies, g=-1199, q=1) [ 60.475000] Sending NMI from CPU 0 to CPUs 1: [ 1.760091] NMI backtrace for cpu 1 [ 1.760091] CPU: 1 PID: 20 Comm: pgdatinit0 Not tainted 4.18.0-147.9.1.el8_1.x86_64 #1 [ 1.760091] Hardware name: Red Hat KVM, BIOS 1.13.0-1.module+el8.2.0+5520+4e5817f3 04/01/2014 [ 1.760091] RIP: 0010:__init_single_page.isra.65+0x10/0x4f [ 1.760091] Code: 48 83 cf 63 48 89 f8 0f 1f 40 00 48 89 c6 48 89 d7 e8 6b 18 80 ff 66 90 5b c3 31 c0 b9 10 00 00 00 49 89 f8 48 c1 e6 33 f3 ab <b8> 07 00 00 00 48 c1 e2 36 41 c7 40 34 01 00 00 00 48 c1 e0 33 41 [ 1.760091] RSP: 0000:ffffba783123be40 EFLAGS: 00000006 [ 1.760091] RAX: 0000000000000000 RBX: fffffad34405e300 RCX: 0000000000000000 [ 1.760091] RDX: 0000000000000000 RSI: 0010000000000000 RDI: fffffad34405e340 [ 1.760091] RBP: 0000000033f3177e R08: fffffad34405e300 R09: 0000000000000002 [ 1.760091] R10: 000000000000002b R11: ffff98afb691a500 R12: 0000000000000002 [ 1.760091] R13: 0000000000000000 R14: 000000003f03ea00 R15: 000000003e10178c [ 1.760091] FS: 0000000000000000(0000) GS:ffff9c9ebeb00000(0000) knlGS:0000000000000000 [ 1.760091] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.760091] CR2: 00000000ffffffff CR3: 000000a1cf20a001 CR4: 00000000003606e0 [ 1.760091] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1.760091] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1.760091] Call Trace: [ 1.760091] deferred_init_pages+0x8f/0xbf [ 1.760091] deferred_init_memmap+0x184/0x29d [ 1.760091] ? deferred_free_pages.isra.97+0xba/0xba [ 1.760091] kthread+0x112/0x130 [ 1.760091] ? kthread_flush_work_fn+0x10/0x10 [ 1.760091] ret_from_fork+0x35/0x40 [ 89.123011] node 0 initialised, 1055935372 pages in 88650ms Link: http://lkml.kernel.org/r/[email protected] Fixes: 3a2d7fa ("mm: disable interrupts while initializing deferred pages") Reported-by: Yiqian Wei <[email protected]> Tested-by: David Hildenbrand <[email protected]> Signed-off-by: Pavel Tatashin <[email protected]> Reviewed-by: Daniel Jordan <[email protected]> Acked-by: Michal Hocko <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Reviewed-by: Pankaj Gupta <[email protected]> Cc: Dan Williams <[email protected]> Cc: James Morris <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Sasha Levin <[email protected]> Cc: Shile Zhang <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: <[email protected]> [4.17+] Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

The reclaim code that balances between swapping and cache reclaim tries to predict likely reuse based on in-memory reference patterns alone. This works in many cases, but when it fails it cannot detect when the cache is thrashing pathologically, or when we're in the middle of a swap storm. The high seek cost of rotational drives under which the algorithm evolved also meant that mistakes could quickly result in lockups from too aggressive swapping (which is predominantly random IO). As a result, the balancing code has been tuned over time to a point where it mostly goes for page cache and defers swapping until the VM is under significant memory pressure. The resulting strategy doesn't make optimal caching decisions - where optimal is the least amount of IO required to execute the workload. The proliferation of fast random IO devices such as SSDs, in-memory compression such as zswap, and persistent memory technologies on the horizon, has made this undesirable behavior very noticable: Even in the presence of large amounts of cold anonymous memory and a capable swap device, the VM refuses to even seriously scan these pages, and can leave the page cache thrashing needlessly. This series sets out to address this. Since commit ("a528910e12ec mm: thrash detection-based file cache sizing") we have exact tracking of refault IO - the ultimate cost of reclaiming the wrong pages. This allows us to use an IO cost based balancing model that is more aggressive about scanning anonymous memory when the cache is thrashing, while being able to avoid unnecessary swap storms. These patches base the LRU balance on the rate of refaults on each list, times the relative IO cost between swap device and filesystem (swappiness), in order to optimize reclaim for least IO cost incurred. History I floated these changes in 2016. At the time they were incomplete and full of workarounds due to a lack of infrastructure in the reclaim code: We didn't have PageWorkingset, we didn't have hierarchical cgroup statistics, and problems with the cgroup swap controller. As swapping wasn't too high a priority then, the patches stalled out. With all dependencies in place now, here we are again with much cleaner, feature-complete patches. I kept the acks for patches that stayed materially the same :-) Below is a series of test results that demonstrate certain problematic behavior of the current code, as well as showcase the new code's more predictable and appropriate balancing decisions. Test #1: No convergence This test shows an edge case where the VM currently doesn't converge at all on a new file workingset with a stale anon/tmpfs set. The test sets up a cold anon set the size of 3/4 RAM, then tries to establish a new file set half the size of RAM (flat access pattern). The vanilla kernel refuses to even scan anon pages and never converges. The file set is perpetually served from the filesystem. The first test kernel is with the series up to the workingset patch applied. This allows thrashing page cache to challenge the anonymous workingset. The VM then scans the lists based on the current scanned/rotated balancing algorithm. It converges on a stable state where all cold anon pages are pushed out and the fileset is served entirely from cache: noconverge/5.7-rc5-mm noconverge/5.7-rc5-mm-workingset Scanned 417719308.00 ( +0.00%) 64091155.00 ( -84.66%) Reclaimed 417711094.00 ( +0.00%) 61640308.00 ( -85.24%) Reclaim efficiency % 100.00 ( +0.00%) 96.18 ( -3.78%) Scanned file 417719308.00 ( +0.00%) 59211118.00 ( -85.83%) Scanned anon 0.00 ( +0.00%) 4880037.00 ( ) Swapouts 0.00 ( +0.00%) 2439957.00 ( ) Swapins 0.00 ( +0.00%) 257.00 ( ) Refaults 415246605.00 ( +0.00%) 59183722.00 ( -85.75%) Restore refaults 0.00 ( +0.00%) 54988252.00 ( ) The second test kernel is with the full patch series applied, which replaces the scanned/rotated ratios with refault/swapin rate-based balancing. It evicts the cold anon pages more aggressively in the presence of a thrashing cache and the absence of swapins, and so converges with about 60% of the IO and reclaim activity: noconverge/5.7-rc5-mm-workingset noconverge/5.7-rc5-mm-lrubalance Scanned 64091155.00 ( +0.00%) 37579741.00 ( -41.37%) Reclaimed 61640308.00 ( +0.00%) 35129293.00 ( -43.01%) Reclaim efficiency % 96.18 ( +0.00%) 93.48 ( -2.78%) Scanned file 59211118.00 ( +0.00%) 32708385.00 ( -44.76%) Scanned anon 4880037.00 ( +0.00%) 4871356.00 ( -0.18%) Swapouts 2439957.00 ( +0.00%) 2435565.00 ( -0.18%) Swapins 257.00 ( +0.00%) 262.00 ( +1.94%) Refaults 59183722.00 ( +0.00%) 32675667.00 ( -44.79%) Restore refaults 54988252.00 ( +0.00%) 28480430.00 ( -48.21%) We're triggering this case in host sideloading scenarios: When a host's primary workload is not saturating the machine (primary load is usually driven by user activity), we can optimistically sideload a batch job; if user activity picks up and the primary workload needs the whole host during this time, we freeze the sideload and rely on it getting pushed to swap. Frequently that swapping doesn't happen and the completely inactive sideload simply stays resident while the expanding primary worklad is struggling to gain ground. Test #2: Kernel build This test is a a kernel build that is slightly memory-restricted (make -j4 inside a 400M cgroup). Despite the very aggressive swapping of cold anon pages in test #1, this test shows that the new kernel carefully balances swap against cache refaults when both the file and the cache set are pressured. It shows the patched kernel to be slightly better at finding the coldest memory from the combined anon and file set to evict under pressure. The result is lower aggregate reclaim and paging activity: z 5.7-rc5-mm 5.7-rc5-mm-lrubalance Real time 210.60 ( +0.00%) 210.97 ( +0.18%) User time 745.42 ( +0.00%) 746.48 ( +0.14%) System time 69.78 ( +0.00%) 69.79 ( +0.02%) Scanned file 354682.00 ( +0.00%) 293661.00 ( -17.20%) Scanned anon 465381.00 ( +0.00%) 378144.00 ( -18.75%) Swapouts 185920.00 ( +0.00%) 147801.00 ( -20.50%) Swapins 34583.00 ( +0.00%) 32491.00 ( -6.05%) Refaults 212664.00 ( +0.00%) 172409.00 ( -18.93%) Restore refaults 48861.00 ( +0.00%) 80091.00 ( +63.91%) Total paging IO 433167.00 ( +0.00%) 352701.00 ( -18.58%) Test #3: Overload This next test is not about performance, but rather about the predictability of the algorithm. The current balancing behavior doesn't always lead to comprehensible results, which makes performance analysis and parameter tuning (swappiness e.g.) very difficult. The test shows the balancing behavior under equivalent anon and file input. Anon and file sets are created of equal size (3/4 RAM), have the same access patterns (a hot-cold gradient), and synchronized access rates. Swappiness is raised from the default of 60 to 100 to indicate equal IO cost between swap and cache. With the vanilla balancing code, anon scans make up around 9% of the total pages scanned, or a ~1:10 ratio. This is a surprisingly skewed ratio, and it's an outcome that is hard to explain given the input parameters to the VM. The new balancing model targets a 1:2 balance: All else being equal, reclaiming a file page costs one page IO - the refault; reclaiming an anon page costs two IOs - the swapout and the swapin. In the test we observe a ~1:3 balance. The scanned and paging IO numbers indicate that the anon LRU algorithm we have in place right now does a slightly worse job at picking the coldest pages compared to the file algorithm. There is ongoing work to improve this, like Joonsoo's anon workingset patches; however, it's difficult to compare the two aging strategies when the balancing between them is behaving unintuitively. The slightly less efficient anon reclaim results in a deviation from the optimal 1:2 scan ratio we would like to see here - however, 1:3 is much closer to what we'd want to see in this test than the vanilla kernel's aging of 10+ cache pages for every anonymous one: overload-100/5.7-rc5-mm-workingset overload-100/5.7-rc5-mm-lrubalance-realfile Scanned 533633725.00 ( +0.00%) 595687785.00 ( +11.63%) Reclaimed 494325440.00 ( +0.00%) 518154380.00 ( +4.82%) Reclaim efficiency % 92.63 ( +0.00%) 86.98 ( -6.03%) Scanned file 484532894.00 ( +0.00%) 456937722.00 ( -5.70%) Scanned anon 49100831.00 ( +0.00%) 138750063.00 ( +182.58%) Swapouts 8096423.00 ( +0.00%) 48982142.00 ( +504.98%) Swapins 10027384.00 ( +0.00%) 62325044.00 ( +521.55%) Refaults 479819973.00 ( +0.00%) 451309483.00 ( -5.94%) Restore refaults 426422087.00 ( +0.00%) 399914067.00 ( -6.22%) Total paging IO 497943780.00 ( +0.00%) 562616669.00 ( +12.99%) Test #4: Parallel IO It's important to note that these patches only affect the situation where the kernel has to reclaim workingset memory, which is usually a transitionary period. The vast majority of page reclaim occuring in a system is from trimming the ever-expanding page cache. These patches don't affect cache trimming behavior. We never swap as long as we only have use-once cache moving through the file LRU, we only consider swapping when the cache is actively thrashing. The following test demonstrates this. It has an anon workingset that takes up half of RAM and then writes a file that is twice the size of RAM out to disk. As the cache is funneled through the inactive file list, no anon pages are scanned (aside from apparently some background noise of 10 pages): 5.7-rc5-mm 5.7-rc5-mm-lrubalance Scanned 10714722.00 ( +0.00%) 10723445.00 ( +0.08%) Reclaimed 10703596.00 ( +0.00%) 10712166.00 ( +0.08%) Reclaim efficiency % 99.90 ( +0.00%) 99.89 ( -0.00%) Scanned file 10714722.00 ( +0.00%) 10723435.00 ( +0.08%) Scanned anon 0.00 ( +0.00%) 10.00 ( ) Swapouts 0.00 ( +0.00%) 7.00 ( ) Swapins 0.00 ( +0.00%) 0.00 ( +0.00%) Refaults 92.00 ( +0.00%) 41.00 ( -54.84%) Restore refaults 0.00 ( +0.00%) 0.00 ( +0.00%) Total paging IO 92.00 ( +0.00%) 48.00 ( -47.31%) This patch (of 14): Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless. Always account THP by the number of basepages, and remove the fixup from the splitting path. Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Johannes Weiner <[email protected]> Reviewed-by: Rik van Riel <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Minchan Kim <[email protected]> Cc: Joonsoo Kim <[email protected]>, Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>

Currently, RISC-V sets up reserved memory using the "early" copy of the device tree. As a result, when trying to get a reserved memory region using of_reserved_mem_lookup(), the pointer to reserved memory regions is using the early, pre-virtual-memory address which causes a kernel panic when trying to use the buffer's name: Unable to handle kernel paging request at virtual address 00000000401c31ac Oops [#1] Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc1-00001-g0d9d6953d834 #1 Hardware name: Microchip PolarFire-SoC Icicle Kit (DT) epc : string+0x4a/0xea ra : vsnprintf+0x1e4/0x336 epc : ffffffff80335ea0 ra : ffffffff80338936 sp : ffffffff81203be0 gp : ffffffff812e0a98 tp : ffffffff8120de40 t0 : 0000000000000000 t1 : ffffffff81203e28 t2 : 7265736572203a46 s0 : ffffffff81203c20 s1 : ffffffff81203e28 a0 : ffffffff81203d22 a1 : 0000000000000000 a2 : ffffffff81203d08 a3 : 0000000081203d21 a4 : ffffffffffffffff a5 : 00000000401c31ac a6 : ffff0a00ffffff04 a7 : ffffffffffffffff s2 : ffffffff81203d08 s3 : ffffffff81203d00 s4 : 0000000000000008 s5 : ffffffff000000ff s6 : 0000000000ffffff s7 : 00000000ffffff00 s8 : ffffffff80d9821a s9 : ffffffff81203d22 s10: 0000000000000002 s11: ffffffff80d9821c t3 : ffffffff812f3617 t4 : ffffffff812f3617 t5 : ffffffff812f3618 t6 : ffffffff81203d08 status: 0000000200000100 badaddr: 00000000401c31ac cause: 000000000000000d [<ffffffff80338936>] vsnprintf+0x1e4/0x336 [<ffffffff80055ae2>] vprintk_store+0xf6/0x344 [<ffffffff80055d86>] vprintk_emit+0x56/0x192 [<ffffffff80055ed8>] vprintk_default+0x16/0x1e [<ffffffff800563d2>] vprintk+0x72/0x80 [<ffffffff806813b2>] _printk+0x36/0x50 [<ffffffff8068af48>] print_reserved_mem+0x1c/0x24 [<ffffffff808057ec>] paging_init+0x528/0x5bc [<ffffffff808031ae>] setup_arch+0xd0/0x592 [<ffffffff8080070e>] start_kernel+0x82/0x73c early_init_fdt_scan_reserved_mem() takes no arguments as it operates on initial_boot_params, which is populated by early_init_dt_verify(). On RISC-V, early_init_dt_verify() is called twice. Once, directly, in setup_arch() if CONFIG_BUILTIN_DTB is not enabled and once indirectly, very early in the boot process, by parse_dtb() when it calls early_init_dt_scan_nodes(). This first call uses dtb_early_va to set initial_boot_params, which is not usable later in the boot process when early_init_fdt_scan_reserved_mem() is called. On arm64 for example, the corresponding call to early_init_dt_scan_nodes() uses fixmap addresses and doesn't suffer the same fate. Move early_init_fdt_scan_reserved_mem() further along the boot sequence, after the direct call to early_init_dt_verify() in setup_arch() so that the names use the correct virtual memory addresses. The above supposed that CONFIG_BUILTIN_DTB was not set, but should work equally in the case where it is - unflatted_and_copy_device_tree() also updates initial_boot_params. Reported-by: Valentina Fernandez <[email protected]> Reported-by: Evgenii Shatokhin <[email protected]> Link: https://lore.kernel.org/linux-riscv/[email protected]/ Fixes: 922b037 ("riscv: Fix memblock reservation for device tree blob") Signed-off-by: Conor Dooley <[email protected]> Tested-by: Evgenii Shatokhin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>

When doing a nowait buffered write we can trigger the following assertion: [11138.437027] assertion failed: !path->nowait, in fs/btrfs/ctree.c:4658 [11138.438251] ------------[ cut here ]------------ [11138.438254] kernel BUG at fs/btrfs/messages.c:259! [11138.438762] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [11138.439450] CPU: 4 PID: 1091021 Comm: fsstress Not tainted 6.1.0-rc4-btrfs-next-128 #1 [11138.440611] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [11138.442553] RIP: 0010:btrfs_assertfail+0x19/0x1b [btrfs] [11138.443583] Code: 5b 41 5a 41 (...) [11138.446437] RSP: 0018:ffffbaf0cf05b840 EFLAGS: 00010246 [11138.447235] RAX: 0000000000000039 RBX: ffffbaf0cf05b938 RCX: 0000000000000000 [11138.448303] RDX: 0000000000000000 RSI: ffffffffb2ef59f6 RDI: 00000000ffffffff [11138.449370] RBP: ffff9165f581eb68 R08: 00000000ffffffff R09: 0000000000000001 [11138.450493] R10: ffff9167a88421f8 R11: 0000000000000000 R12: ffff9164981b1000 [11138.451661] R13: 000000008c8f1000 R14: ffff9164991d4000 R15: ffff9164981b1000 [11138.452225] FS: 00007f1438a66440(0000) GS:ffff9167ad600000(0000) knlGS:0000000000000000 [11138.452949] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [11138.453394] CR2: 00007f1438a64000 CR3: 0000000100c36002 CR4: 0000000000370ee0 [11138.454057] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [11138.454879] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [11138.455779] Call Trace: [11138.456211] <TASK> [11138.456598] btrfs_next_old_leaf.cold+0x18/0x1d [btrfs] [11138.457827] ? kmem_cache_alloc+0x18d/0x2a0 [11138.458516] btrfs_lookup_csums_range+0x149/0x4d0 [btrfs] [11138.459407] csum_exist_in_range+0x56/0x110 [btrfs] [11138.460271] can_nocow_file_extent+0x27c/0x310 [btrfs] [11138.461155] can_nocow_extent+0x1ec/0x2e0 [btrfs] [11138.461672] btrfs_check_nocow_lock+0x114/0x1c0 [btrfs] [11138.462951] btrfs_buffered_write+0x44c/0x8e0 [btrfs] [11138.463482] btrfs_do_write_iter+0x42b/0x5f0 [btrfs] [11138.463982] ? lock_release+0x153/0x4a0 [11138.464347] io_write+0x11b/0x570 [11138.464660] ? lock_release+0x153/0x4a0 [11138.465213] ? lock_is_held_type+0xe8/0x140 [11138.466003] io_issue_sqe+0x63/0x4a0 [11138.466339] io_submit_sqes+0x238/0x770 [11138.466741] __do_sys_io_uring_enter+0x37b/0xb10 [11138.467206] ? lock_is_held_type+0xe8/0x140 [11138.467879] ? syscall_enter_from_user_mode+0x1d/0x50 [11138.468688] do_syscall_64+0x38/0x90 [11138.469265] entry_SYSCALL_64_after_hwframe+0x63/0xcd [11138.470017] RIP: 0033:0x7f1438c539e6 This is because to check if we can NOCOW, we check that if we can NOCOW into an extent (it's prealloc extent or the inode has NOCOW attribute), and then check if there are csums for the extent's range in the csum tree. The search may leave us beyond the last slot of a leaf, and then when we call btrfs_next_leaf() we end up at btrfs_next_old_leaf() with a time_seq of 0. This triggers a failure of the first assertion at btrfs_next_old_leaf(), since we have a nowait path. With assertions disabled, we simply don't respect the NOWAIT semantics, allowing the write to block on locks or blocking on IO for reading an extent buffer from disk. Fix this by: 1) Triggering the assertion only if time_seq is not 0, which means that search is being done by a tree mod log user, and in the buffered and direct IO write paths we don't use the tree mod log; 2) Implementing NOWAIT semantics at btrfs_next_old_leaf(). Any failure to lock an extent buffer should return immediately and not retry the search, as well as if we need to do IO to read an extent buffer from disk. Fixes: c922b01 ("btrfs: assert nowait mode is not used for some btree search functions") Signed-off-by: Filipe Manana <[email protected]> Signed-off-by: David Sterba <[email protected]>

Syzbot reported the following lockdep splat ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted ------------------------------------------------------ syz-executor307/3029 is trying to acquire lock: ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576 but task is already holding lock: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (btrfs-root-00){++++}-{3:3}: down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624 __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637 btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944 btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132 commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459 btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343 flush_space+0x66c/0x738 fs/btrfs/space-info.c:786 btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 -> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline] start_transaction+0x248/0x944 fs/btrfs/transaction.c:752 btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781 btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651 btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x804/0x11c4 fs/namei.c:3688 do_filp_open+0xdc/0x1b8 fs/namei.c:3718 do_sys_openat2+0xb8/0x22c fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #1 (sb_internal#2){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x360/0x944 fs/btrfs/transaction.c:683 btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795 btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103 btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145 inode_update_time fs/inode.c:1872 [inline] touch_atime+0x1f0/0x4a8 fs/inode.c:1945 file_accessed include/linux/fs.h:2516 [inline] btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407 call_mmap include/linux/fs.h:2192 [inline] mmap_region+0x7fc/0xc14 mm/mmap.c:1752 do_mmap+0x644/0x97c mm/mmap.c:1540 vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552 ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 other info that might help us debug this: Chain exists of: &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-root-00); lock(&fs_info->reloc_mutex); lock(btrfs-root-00); lock(&mm->mmap_lock); *** DEADLOCK *** 1 lock held by syz-executor307/3029: #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 stack backtrace: CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 We do generally the right thing here, copying the references into a temporary buffer, however we are still holding the path when we do copy_to_user from the temporary buffer. Fix this by freeing the path before we copy to user space. Reported-by: [email protected] CC: [email protected] # 4.19+ Reviewed-by: Anand Jain <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>

Wei Chen reports a kernel bug as blew: INFO: task syz-executor.0:29056 blocked for more than 143 seconds. Not tainted 5.15.0-rc5 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:14632 pid:29056 ppid: 6574 flags:0x00000004 Call Trace: __schedule+0x4a1/0x1720 schedule+0x36/0xe0 rwsem_down_write_slowpath+0x322/0x7a0 fscrypt_ioctl_set_policy+0x11f/0x2a0 __f2fs_ioctl+0x1a9f/0x5780 f2fs_ioctl+0x89/0x3a0 __x64_sys_ioctl+0xe8/0x140 do_syscall_64+0x34/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae Eric did some investigation on this issue, quoted from reply of Eric: "Well, the quality of this bug report has a lot to be desired (not on upstream kernel, reproducer is full of totally irrelevant stuff, not sent to the mailing list of the filesystem whose disk image is being fuzzed, etc.). But what is going on is that f2fs_empty_dir() doesn't consider the case of a directory with an extremely large i_size on a malicious disk image. Specifically, the reproducer mounts an f2fs image with a directory that has an i_size of 14814520042850357248, then calls FS_IOC_SET_ENCRYPTION_POLICY on it. That results in a call to f2fs_empty_dir() to check whether the directory is empty. f2fs_empty_dir() then iterates through all 3616826182336513 blocks the directory allegedly contains to check whether any contain anything. i_rwsem is held during this, so anything else that tries to take it will hang." In order to solve this issue, let's use f2fs_get_next_page_offset() to speed up iteration by skipping holes for all below functions: - f2fs_empty_dir - f2fs_readdir - find_in_level The way why we can speed up iteration was described in 'commit 3cf4574 ("f2fs: introduce get_next_page_offset to speed up SEEK_DATA")'. Meanwhile, in f2fs_empty_dir(), let's use f2fs_find_data_page() instead f2fs_get_lock_data_page(), due to i_rwsem was held in caller of f2fs_empty_dir(), there shouldn't be any races, so it's fine to not lock dentry page during lookuping dirents in the page. Link: https://lore.kernel.org/lkml/[email protected]/T/ Reported-by: Wei Chen <[email protected]> Cc: Eric Biggers <[email protected]> Signed-off-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]>

Currently, in clang version of gcov code when module is getting removed gcov_info_add() incorrectly adds the sfn_ptr->counter to all the dst->functions and it result in the kernel panic in below crash report. Fix this by properly handling it. [ 8.899094][ T599] Unable to handle kernel write to read-only memory at virtual address ffffff80461cc000 [ 8.899100][ T599] Mem abort info: [ 8.899102][ T599] ESR = 0x9600004f [ 8.899103][ T599] EC = 0x25: DABT (current EL), IL = 32 bits [ 8.899105][ T599] SET = 0, FnV = 0 [ 8.899107][ T599] EA = 0, S1PTW = 0 [ 8.899108][ T599] FSC = 0x0f: level 3 permission fault [ 8.899110][ T599] Data abort info: [ 8.899111][ T599] ISV = 0, ISS = 0x0000004f [ 8.899113][ T599] CM = 0, WnR = 1 [ 8.899114][ T599] swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000ab8de000 [ 8.899116][ T599] [ffffff80461cc000] pgd=18000009ffcde003, p4d=18000009ffcde003, pud=18000009ffcde003, pmd=18000009ffcad003, pte=00600000c61cc787 [ 8.899124][ T599] Internal error: Oops: 9600004f [#1] PREEMPT SMP [ 8.899265][ T599] Skip md ftrace buffer dump for: 0x1609e0 .... .., [ 8.899544][ T599] CPU: 7 PID: 599 Comm: modprobe Tainted: G S OE 5.15.41-android13-8-g38e9b1af6bce #1 [ 8.899547][ T599] Hardware name: XXX (DT) [ 8.899549][ T599] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) [ 8.899551][ T599] pc : gcov_info_add+0x9c/0xb8 [ 8.899557][ T599] lr : gcov_event+0x28c/0x6b8 [ 8.899559][ T599] sp : ffffffc00e733b00 [ 8.899560][ T599] x29: ffffffc00e733b00 x28: ffffffc00e733d30 x27: ffffffe8dc297470 [ 8.899563][ T599] x26: ffffffe8dc297000 x25: ffffffe8dc297000 x24: ffffffe8dc297000 [ 8.899566][ T599] x23: ffffffe8dc0a6200 x22: ffffff880f68bf20 x21: 0000000000000000 [ 8.899569][ T599] x20: ffffff880f68bf00 x19: ffffff8801babc00 x18: ffffffc00d7f9058 [ 8.899572][ T599] x17: 0000000000088793 x16: ffffff80461cbe00 x15: 9100052952800785 [ 8.899575][ T599] x14: 0000000000000200 x13: 0000000000000041 x12: 9100052952800785 [ 8.899577][ T599] x11: ffffffe8dc297000 x10: ffffffe8dc297000 x9 : ffffff80461cbc80 [ 8.899580][ T599] x8 : ffffff8801babe80 x7 : ffffffe8dc2ec000 x6 : ffffffe8dc2ed000 [ 8.899583][ T599] x5 : 000000008020001f x4 : fffffffe2006eae0 x3 : 000000008020001f [ 8.899586][ T599] x2 : ffffff8027c49200 x1 : ffffff8801babc20 x0 : ffffff80461cb3a0 [ 8.899589][ T599] Call trace: [ 8.899590][ T599] gcov_info_add+0x9c/0xb8 [ 8.899592][ T599] gcov_module_notifier+0xbc/0x120 [ 8.899595][ T599] blocking_notifier_call_chain+0xa0/0x11c [ 8.899598][ T599] do_init_module+0x2a8/0x33c [ 8.899600][ T599] load_module+0x23cc/0x261c [ 8.899602][ T599] __arm64_sys_finit_module+0x158/0x194 [ 8.899604][ T599] invoke_syscall+0x94/0x2bc [ 8.899607][ T599] el0_svc_common+0x1d8/0x34c [ 8.899609][ T599] do_el0_svc+0x40/0x54 [ 8.899611][ T599] el0_svc+0x94/0x2f0 [ 8.899613][ T599] el0t_64_sync_handler+0x88/0xec [ 8.899615][ T599] el0t_64_sync+0x1b4/0x1b8 [ 8.899618][ T599] Code: f905f56c f86e69ec f86e6a0f 8b0c01ec (f82e6a0c) [ 8.899620][ T599] ---[ end trace ed5218e9e5b6e2e6 ]--- Link: https://lkml.kernel.org/r/[email protected] Fixes: e178a5b ("gcov: clang support") Signed-off-by: Mukesh Ojha <[email protected]> Reviewed-by: Peter Oberparleiter <[email protected]> Tested-by: Peter Oberparleiter <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Tom Rix <[email protected]> Cc: <[email protected]> [5.2+] Signed-off-by: Andrew Morton <[email protected]>

…x/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: - Force the use of SetVirtualAddressMap() on Ampera Altra arm64 machines, which crash in SetTime() if no virtual remapping is used This is the first time we've added an SMBIOS based quirk on arm64, but fortunately, we can just call a EFI protocol to grab the type #1 SMBIOS record when running in the stub, so we don't need all the machinery we have in the kernel proper to parse SMBIOS data. - Drop a spurious warning on misaligned runtime regions when using 16k or 64k pages on arm64 * tag 'efi-fixes-for-v6.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: arm64: efi: Fix handling of misaligned runtime regions and drop warning arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines

CQE compression feature improves performance by reducing PCI bandwidth bottleneck on CQEs write. Enhanced CQE compression introduced in ConnectX-6 and it aims to reduce CPU utilization of SW side packets decompression by eliminating the need to rewrite ownership bit, which is likely to cost a cache-miss, is replaced by validity byte handled solely by HW. Another advantage of the enhanced feature is that session packets are available to SW as soon as a single CQE slot is filled, instead of waiting for session to close, this improves packet latency from NIC to host. Performance: Following are tested scenarios and reults comparing basic and enahnced CQE compression. setup: IXIA 100GbE connected directly to port 0 and port 1 of ConnectX-6 Dx 100GbE dual port. Case #1 RX only, single flow goes to single queue: IRQ rate reduced by ~ 30%, CPU utilization improved by 2%. Case #2 IP forwarding from port 1 to port 0 single flow goes to single queue: Avg latency improved from 60us to 21us, frame loss improved from 0.5% to 0.0%. Case #3 IP forwarding from port 1 to port 0 Max Throughput IXIA sends 100%, 8192 UDP flows, goes to 24 queues: Enhanced is equal or slightly better than basic. Testing the basic compression feature with this patch shows there is no perfrormance degradation of the basic compression feature. Signed-off-by: Ofer Levi <[email protected]> Reviewed-by: Tariq Toukan <[email protected]> Signed-off-by: Saeed Mahameed <[email protected]>

There's a crash in mempool_free when running the lvm test shell/lvchange-rebuild-raid.sh. The reason for the crash is this: * super_written calls atomic_dec_and_test(&mddev->pending_writes) and wake_up(&mddev->sb_wait). Then it calls rdev_dec_pending(rdev, mddev) and bio_put(bio). * so, the process that waited on sb_wait and that is woken up is racing with bio_put(bio). * if the process wins the race, it calls bioset_exit before bio_put(bio) is executed. * bio_put(bio) attempts to free a bio into a destroyed bio set - causing a crash in mempool_free. We fix this bug by moving bio_put before atomic_dec_and_test. We also move rdev_dec_pending before atomic_dec_and_test as suggested by Neil Brown. The function md_end_flush has a similar bug - we must call bio_put before we decrement the number of in-progress bios. BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 11557f0067 P4D 11557f0067 PUD 0 Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 73 Comm: kworker/0:1 Not tainted 6.1.0-rc3 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: kdelayd flush_expired_bios [dm_delay] RIP: 0010:mempool_free+0x47/0x80 Code: 48 89 ef 5b 5d ff e0 f3 c3 48 89 f7 e8 32 45 3f 00 48 63 53 08 48 89 c6 3b 53 04 7d 2d 48 8b 43 10 8d 4a 01 48 89 df 89 4b 08 <48> 89 2c d0 e8 b0 45 3f 00 48 8d 7b 30 5b 5d 31 c9 ba 01 00 00 00 RSP: 0018:ffff88910036bda8 EFLAGS: 00010093 RAX: 0000000000000000 RBX: ffff8891037b65d8 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000202 RDI: ffff8891037b65d8 RBP: ffff8891447ba240 R08: 0000000000012908 R09: 00000000003d0900 R10: 0000000000000000 R11: 0000000000173544 R12: ffff889101a14000 R13: ffff8891562ac300 R14: ffff889102b41440 R15: ffffe8ffffa00d05 FS: 0000000000000000(0000) GS:ffff88942fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000001102e99000 CR4: 00000000000006b0 Call Trace: <TASK> clone_endio+0xf4/0x1c0 [dm_mod] clone_endio+0xf4/0x1c0 [dm_mod] __submit_bio+0x76/0x120 submit_bio_noacct_nocheck+0xb6/0x2a0 flush_expired_bios+0x28/0x2f [dm_delay] process_one_work+0x1b4/0x300 worker_thread+0x45/0x3e0 ? rescuer_thread+0x380/0x380 kthread+0xc2/0x100 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> Modules linked in: brd dm_delay dm_raid dm_mod af_packet uvesafb cfbfillrect cfbimgblt cn cfbcopyarea fb font fbdev tun autofs4 binfmt_misc configfs ipv6 virtio_rng virtio_balloon rng_core virtio_net pcspkr net_failover failover qemu_fw_cfg button mousedev raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod sd_mod t10_pi crc64_rocksoft crc64 virtio_scsi scsi_mod evdev psmouse bsg scsi_common [last unloaded: brd] CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- Signed-off-by: Mikulas Patocka <[email protected]> Cc: [email protected] Signed-off-by: Song Liu <[email protected]>

fail run raid1 array when we assemble array with the inactive disk only, but the mdx_raid1 thread were not stop, Even if the associated resources have been released. it will caused a NULL dereference when we do poweroff. This causes the following Oops: [ 287.587787] BUG: kernel NULL pointer dereference, address: 0000000000000070 [ 287.594762] #PF: supervisor read access in kernel mode [ 287.599912] #PF: error_code(0x0000) - not-present page [ 287.605061] PGD 0 P4D 0 [ 287.607612] Oops: 0000 [#1] SMP NOPTI [ 287.611287] CPU: 3 PID: 5265 Comm: md0_raid1 Tainted: G U 5.10.146 #0 [ 287.619029] Hardware name: xxxxxxx/To be filled by O.E.M, BIOS 5.19 06/16/2022 [ 287.626775] RIP: 0010:md_check_recovery+0x57/0x500 [md_mod] [ 287.632357] Code: fe 01 00 00 48 83 bb 10 03 00 00 00 74 08 48 89 ...... [ 287.651118] RSP: 0018:ffffc90000433d78 EFLAGS: 00010202 [ 287.656347] RAX: 0000000000000000 RBX: ffff888105986800 RCX: 0000000000000000 [ 287.663491] RDX: ffffc90000433bb0 RSI: 00000000ffffefff RDI: ffff888105986800 [ 287.670634] RBP: ffffc90000433da0 R08: 0000000000000000 R09: c0000000ffffefff [ 287.677771] R10: 0000000000000001 R11: ffffc90000433ba8 R12: ffff888105986800 [ 287.684907] R13: 0000000000000000 R14: fffffffffffffe00 R15: ffff888100b6b500 [ 287.692052] FS: 0000000000000000(0000) GS:ffff888277f80000(0000) knlGS:0000000000000000 [ 287.700149] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 287.705897] CR2: 0000000000000070 CR3: 000000000320a000 CR4: 0000000000350ee0 [ 287.713033] Call Trace: [ 287.715498] raid1d+0x6c/0xbbb [raid1] [ 287.719256] ? __schedule+0x1ff/0x760 [ 287.722930] ? schedule+0x3b/0xb0 [ 287.726260] ? schedule_timeout+0x1ed/0x290 [ 287.730456] ? __switch_to+0x11f/0x400 [ 287.734219] md_thread+0xe9/0x140 [md_mod] [ 287.738328] ? md_thread+0xe9/0x140 [md_mod] [ 287.742601] ? wait_woken+0x80/0x80 [ 287.746097] ? md_register_thread+0xe0/0xe0 [md_mod] [ 287.751064] kthread+0x11a/0x140 [ 287.754300] ? kthread_park+0x90/0x90 [ 287.757974] ret_from_fork+0x1f/0x30 In fact, when raid1 array run fail, we need to do md_unregister_thread() before raid1_free(). Signed-off-by: Jiang Li <[email protected]> Signed-off-by: Song Liu <[email protected]>

Currently, in clang version of gcov code when module is getting removed gcov_info_add() incorrectly adds the sfn_ptr->counter to all the dst->functions and it result in the kernel panic in below crash report. Fix this by properly handling it. [ 8.899094][ T599] Unable to handle kernel write to read-only memory at virtual address ffffff80461cc000 [ 8.899100][ T599] Mem abort info: [ 8.899102][ T599] ESR = 0x9600004f [ 8.899103][ T599] EC = 0x25: DABT (current EL), IL = 32 bits [ 8.899105][ T599] SET = 0, FnV = 0 [ 8.899107][ T599] EA = 0, S1PTW = 0 [ 8.899108][ T599] FSC = 0x0f: level 3 permission fault [ 8.899110][ T599] Data abort info: [ 8.899111][ T599] ISV = 0, ISS = 0x0000004f [ 8.899113][ T599] CM = 0, WnR = 1 [ 8.899114][ T599] swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000ab8de000 [ 8.899116][ T599] [ffffff80461cc000] pgd=18000009ffcde003, p4d=18000009ffcde003, pud=18000009ffcde003, pmd=18000009ffcad003, pte=00600000c61cc787 [ 8.899124][ T599] Internal error: Oops: 9600004f [#1] PREEMPT SMP [ 8.899265][ T599] Skip md ftrace buffer dump for: 0x1609e0 .... .., [ 8.899544][ T599] CPU: 7 PID: 599 Comm: modprobe Tainted: G S OE 5.15.41-android13-8-g38e9b1af6bce #1 [ 8.899547][ T599] Hardware name: XXX (DT) [ 8.899549][ T599] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) [ 8.899551][ T599] pc : gcov_info_add+0x9c/0xb8 [ 8.899557][ T599] lr : gcov_event+0x28c/0x6b8 [ 8.899559][ T599] sp : ffffffc00e733b00 [ 8.899560][ T599] x29: ffffffc00e733b00 x28: ffffffc00e733d30 x27: ffffffe8dc297470 [ 8.899563][ T599] x26: ffffffe8dc297000 x25: ffffffe8dc297000 x24: ffffffe8dc297000 [ 8.899566][ T599] x23: ffffffe8dc0a6200 x22: ffffff880f68bf20 x21: 0000000000000000 [ 8.899569][ T599] x20: ffffff880f68bf00 x19: ffffff8801babc00 x18: ffffffc00d7f9058 [ 8.899572][ T599] x17: 0000000000088793 x16: ffffff80461cbe00 x15: 9100052952800785 [ 8.899575][ T599] x14: 0000000000000200 x13: 0000000000000041 x12: 9100052952800785 [ 8.899577][ T599] x11: ffffffe8dc297000 x10: ffffffe8dc297000 x9 : ffffff80461cbc80 [ 8.899580][ T599] x8 : ffffff8801babe80 x7 : ffffffe8dc2ec000 x6 : ffffffe8dc2ed000 [ 8.899583][ T599] x5 : 000000008020001f x4 : fffffffe2006eae0 x3 : 000000008020001f [ 8.899586][ T599] x2 : ffffff8027c49200 x1 : ffffff8801babc20 x0 : ffffff80461cb3a0 [ 8.899589][ T599] Call trace: [ 8.899590][ T599] gcov_info_add+0x9c/0xb8 [ 8.899592][ T599] gcov_module_notifier+0xbc/0x120 [ 8.899595][ T599] blocking_notifier_call_chain+0xa0/0x11c [ 8.899598][ T599] do_init_module+0x2a8/0x33c [ 8.899600][ T599] load_module+0x23cc/0x261c [ 8.899602][ T599] __arm64_sys_finit_module+0x158/0x194 [ 8.899604][ T599] invoke_syscall+0x94/0x2bc [ 8.899607][ T599] el0_svc_common+0x1d8/0x34c [ 8.899609][ T599] do_el0_svc+0x40/0x54 [ 8.899611][ T599] el0_svc+0x94/0x2f0 [ 8.899613][ T599] el0t_64_sync_handler+0x88/0xec [ 8.899615][ T599] el0t_64_sync+0x1b4/0x1b8 [ 8.899618][ T599] Code: f905f56c f86e69ec f86e6a0f 8b0c01ec (f82e6a0c) [ 8.899620][ T599] ---[ end trace ed5218e9e5b6e2e6 ]--- Link: https://lkml.kernel.org/r/[email protected] Fixes: e178a5b ("gcov: clang support") Signed-off-by: Mukesh Ojha <[email protected]> Reviewed-by: Peter Oberparleiter <[email protected]> Tested-by: Peter Oberparleiter <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Tom Rix <[email protected]> Cc: <[email protected]> [5.2+] Signed-off-by: Andrew Morton <[email protected]>

Patch series "rapidio: fix three possible memory leaks". This patchset fixes three name leaks in error handling. - patch #1 fixes two name leaks while rio_add_device() fails. - patch #2 fixes a name leak while rio_register_mport() fails. This patch (of 2): If rio_add_device() returns error, the name allocated by dev_set_name() need be freed. It should use put_device() to give up the reference in the error path, so that the name can be freed in kobject_cleanup(), and the 'rdev' can be freed in rio_release_dev(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: e8de370 ("rapidio: add mport char device driver") Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array") Signed-off-by: Yang Yingliang <[email protected]> Cc: Alexandre Bounine <[email protected]> Cc: Matt Porter <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

syzkaller found a bug: BUG: unable to handle page fault for address: ffffc9000a3b1000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 100000067 P4D 100000067 PUD 10015f067 PMD 1121ca067 PTE 0 Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 23489 Comm: vivid-000-vid-c Not tainted 6.1.0-rc1+ #512 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:memcpy_erms+0x6/0x10 [...] Call Trace: <TASK> ? tpg_fill_plane_buffer+0x856/0x15b0 vivid_fillbuff+0x8ac/0x1110 vivid_thread_vid_cap_tick+0x361/0xc90 vivid_thread_vid_cap+0x21a/0x3a0 kthread+0x143/0x180 ret_from_fork+0x1f/0x30 </TASK> This is because we forget to check boundary after adjust compose->height int V4L2_SEL_TGT_CROP case. Add v4l2_rect_map_inside() to fix this problem for this case. Fixes: ef834f7 ("[media] vivid: add the video capture and output parts") Signed-off-by: Liu Shixin <[email protected]> Signed-off-by: Hans Verkuil <[email protected]>

When doing a nowait buffered write we can trigger the following assertion: [11138.437027] assertion failed: !path->nowait, in fs/btrfs/ctree.c:4658 [11138.438251] ------------[ cut here ]------------ [11138.438254] kernel BUG at fs/btrfs/messages.c:259! [11138.438762] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [11138.439450] CPU: 4 PID: 1091021 Comm: fsstress Not tainted 6.1.0-rc4-btrfs-next-128 #1 [11138.440611] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [11138.442553] RIP: 0010:btrfs_assertfail+0x19/0x1b [btrfs] [11138.443583] Code: 5b 41 5a 41 (...) [11138.446437] RSP: 0018:ffffbaf0cf05b840 EFLAGS: 00010246 [11138.447235] RAX: 0000000000000039 RBX: ffffbaf0cf05b938 RCX: 0000000000000000 [11138.448303] RDX: 0000000000000000 RSI: ffffffffb2ef59f6 RDI: 00000000ffffffff [11138.449370] RBP: ffff9165f581eb68 R08: 00000000ffffffff R09: 0000000000000001 [11138.450493] R10: ffff9167a88421f8 R11: 0000000000000000 R12: ffff9164981b1000 [11138.451661] R13: 000000008c8f1000 R14: ffff9164991d4000 R15: ffff9164981b1000 [11138.452225] FS: 00007f1438a66440(0000) GS:ffff9167ad600000(0000) knlGS:0000000000000000 [11138.452949] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [11138.453394] CR2: 00007f1438a64000 CR3: 0000000100c36002 CR4: 0000000000370ee0 [11138.454057] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [11138.454879] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [11138.455779] Call Trace: [11138.456211] <TASK> [11138.456598] btrfs_next_old_leaf.cold+0x18/0x1d [btrfs] [11138.457827] ? kmem_cache_alloc+0x18d/0x2a0 [11138.458516] btrfs_lookup_csums_range+0x149/0x4d0 [btrfs] [11138.459407] csum_exist_in_range+0x56/0x110 [btrfs] [11138.460271] can_nocow_file_extent+0x27c/0x310 [btrfs] [11138.461155] can_nocow_extent+0x1ec/0x2e0 [btrfs] [11138.461672] btrfs_check_nocow_lock+0x114/0x1c0 [btrfs] [11138.462951] btrfs_buffered_write+0x44c/0x8e0 [btrfs] [11138.463482] btrfs_do_write_iter+0x42b/0x5f0 [btrfs] [11138.463982] ? lock_release+0x153/0x4a0 [11138.464347] io_write+0x11b/0x570 [11138.464660] ? lock_release+0x153/0x4a0 [11138.465213] ? lock_is_held_type+0xe8/0x140 [11138.466003] io_issue_sqe+0x63/0x4a0 [11138.466339] io_submit_sqes+0x238/0x770 [11138.466741] __do_sys_io_uring_enter+0x37b/0xb10 [11138.467206] ? lock_is_held_type+0xe8/0x140 [11138.467879] ? syscall_enter_from_user_mode+0x1d/0x50 [11138.468688] do_syscall_64+0x38/0x90 [11138.469265] entry_SYSCALL_64_after_hwframe+0x63/0xcd [11138.470017] RIP: 0033:0x7f1438c539e6 This is because to check if we can NOCOW, we check that if we can NOCOW into an extent (it's prealloc extent or the inode has NOCOW attribute), and then check if there are csums for the extent's range in the csum tree. The search may leave us beyond the last slot of a leaf, and then when we call btrfs_next_leaf() we end up at btrfs_next_old_leaf() with a time_seq of 0. This triggers a failure of the first assertion at btrfs_next_old_leaf(), since we have a nowait path. With assertions disabled, we simply don't respect the NOWAIT semantics, allowing the write to block on locks or blocking on IO for reading an extent buffer from disk. Fix this by: 1) Triggering the assertion only if time_seq is not 0, which means that search is being done by a tree mod log user, and in the buffered and direct IO write paths we don't use the tree mod log; 2) Implementing NOWAIT semantics at btrfs_next_old_leaf(). Any failure to lock an extent buffer should return immediately and not retry the search, as well as if we need to do IO to read an extent buffer from disk. Fixes: c922b01 ("btrfs: assert nowait mode is not used for some btree search functions") Signed-off-by: Filipe Manana <[email protected]> Signed-off-by: David Sterba <[email protected]>

Syzbot reported the following lockdep splat ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted ------------------------------------------------------ syz-executor307/3029 is trying to acquire lock: ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576 but task is already holding lock: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (btrfs-root-00){++++}-{3:3}: down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624 __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637 btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944 btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132 commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459 btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343 flush_space+0x66c/0x738 fs/btrfs/space-info.c:786 btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 -> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline] start_transaction+0x248/0x944 fs/btrfs/transaction.c:752 btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781 btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651 btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x804/0x11c4 fs/namei.c:3688 do_filp_open+0xdc/0x1b8 fs/namei.c:3718 do_sys_openat2+0xb8/0x22c fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #1 (sb_internal#2){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x360/0x944 fs/btrfs/transaction.c:683 btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795 btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103 btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145 inode_update_time fs/inode.c:1872 [inline] touch_atime+0x1f0/0x4a8 fs/inode.c:1945 file_accessed include/linux/fs.h:2516 [inline] btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407 call_mmap include/linux/fs.h:2192 [inline] mmap_region+0x7fc/0xc14 mm/mmap.c:1752 do_mmap+0x644/0x97c mm/mmap.c:1540 vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552 ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 other info that might help us debug this: Chain exists of: &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-root-00); lock(&fs_info->reloc_mutex); lock(btrfs-root-00); lock(&mm->mmap_lock); *** DEADLOCK *** 1 lock held by syz-executor307/3029: #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 stack backtrace: CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 We do generally the right thing here, copying the references into a temporary buffer, however we are still holding the path when we do copy_to_user from the temporary buffer. Fix this by freeing the path before we copy to user space. Reported-by: [email protected] CC: [email protected] # 4.19+ Reviewed-by: Anand Jain <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>

Currently, in clang version of gcov code when module is getting removed gcov_info_add() incorrectly adds the sfn_ptr->counter to all the dst->functions and it result in the kernel panic in below crash report. Fix this by properly handling it. [ 8.899094][ T599] Unable to handle kernel write to read-only memory at virtual address ffffff80461cc000 [ 8.899100][ T599] Mem abort info: [ 8.899102][ T599] ESR = 0x9600004f [ 8.899103][ T599] EC = 0x25: DABT (current EL), IL = 32 bits [ 8.899105][ T599] SET = 0, FnV = 0 [ 8.899107][ T599] EA = 0, S1PTW = 0 [ 8.899108][ T599] FSC = 0x0f: level 3 permission fault [ 8.899110][ T599] Data abort info: [ 8.899111][ T599] ISV = 0, ISS = 0x0000004f [ 8.899113][ T599] CM = 0, WnR = 1 [ 8.899114][ T599] swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000ab8de000 [ 8.899116][ T599] [ffffff80461cc000] pgd=18000009ffcde003, p4d=18000009ffcde003, pud=18000009ffcde003, pmd=18000009ffcad003, pte=00600000c61cc787 [ 8.899124][ T599] Internal error: Oops: 9600004f [#1] PREEMPT SMP [ 8.899265][ T599] Skip md ftrace buffer dump for: 0x1609e0 .... .., [ 8.899544][ T599] CPU: 7 PID: 599 Comm: modprobe Tainted: G S OE 5.15.41-android13-8-g38e9b1af6bce #1 [ 8.899547][ T599] Hardware name: XXX (DT) [ 8.899549][ T599] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) [ 8.899551][ T599] pc : gcov_info_add+0x9c/0xb8 [ 8.899557][ T599] lr : gcov_event+0x28c/0x6b8 [ 8.899559][ T599] sp : ffffffc00e733b00 [ 8.899560][ T599] x29: ffffffc00e733b00 x28: ffffffc00e733d30 x27: ffffffe8dc297470 [ 8.899563][ T599] x26: ffffffe8dc297000 x25: ffffffe8dc297000 x24: ffffffe8dc297000 [ 8.899566][ T599] x23: ffffffe8dc0a6200 x22: ffffff880f68bf20 x21: 0000000000000000 [ 8.899569][ T599] x20: ffffff880f68bf00 x19: ffffff8801babc00 x18: ffffffc00d7f9058 [ 8.899572][ T599] x17: 0000000000088793 x16: ffffff80461cbe00 x15: 9100052952800785 [ 8.899575][ T599] x14: 0000000000000200 x13: 0000000000000041 x12: 9100052952800785 [ 8.899577][ T599] x11: ffffffe8dc297000 x10: ffffffe8dc297000 x9 : ffffff80461cbc80 [ 8.899580][ T599] x8 : ffffff8801babe80 x7 : ffffffe8dc2ec000 x6 : ffffffe8dc2ed000 [ 8.899583][ T599] x5 : 000000008020001f x4 : fffffffe2006eae0 x3 : 000000008020001f [ 8.899586][ T599] x2 : ffffff8027c49200 x1 : ffffff8801babc20 x0 : ffffff80461cb3a0 [ 8.899589][ T599] Call trace: [ 8.899590][ T599] gcov_info_add+0x9c/0xb8 [ 8.899592][ T599] gcov_module_notifier+0xbc/0x120 [ 8.899595][ T599] blocking_notifier_call_chain+0xa0/0x11c [ 8.899598][ T599] do_init_module+0x2a8/0x33c [ 8.899600][ T599] load_module+0x23cc/0x261c [ 8.899602][ T599] __arm64_sys_finit_module+0x158/0x194 [ 8.899604][ T599] invoke_syscall+0x94/0x2bc [ 8.899607][ T599] el0_svc_common+0x1d8/0x34c [ 8.899609][ T599] do_el0_svc+0x40/0x54 [ 8.899611][ T599] el0_svc+0x94/0x2f0 [ 8.899613][ T599] el0t_64_sync_handler+0x88/0xec [ 8.899615][ T599] el0t_64_sync+0x1b4/0x1b8 [ 8.899618][ T599] Code: f905f56c f86e69ec f86e6a0f 8b0c01ec (f82e6a0c) [ 8.899620][ T599] ---[ end trace ed5218e9e5b6e2e6 ]--- Link: https://lkml.kernel.org/r/[email protected] Fixes: e178a5b ("gcov: clang support") Signed-off-by: Mukesh Ojha <[email protected]> Reviewed-by: Peter Oberparleiter <[email protected]> Tested-by: Peter Oberparleiter <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Tom Rix <[email protected]> Cc: <[email protected]> [5.2+] Signed-off-by: Andrew Morton <[email protected]>

Patch series "rapidio: fix three possible memory leaks". This patchset fixes three name leaks in error handling. - patch #1 fixes two name leaks while rio_add_device() fails. - patch #2 fixes a name leak while rio_register_mport() fails. This patch (of 2): If rio_add_device() returns error, the name allocated by dev_set_name() need be freed. It should use put_device() to give up the reference in the error path, so that the name can be freed in kobject_cleanup(), and the 'rdev' can be freed in rio_release_dev(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: e8de370 ("rapidio: add mport char device driver") Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array") Signed-off-by: Yang Yingliang <[email protected]> Cc: Alexandre Bounine <[email protected]> Cc: Matt Porter <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

The TPM code registers put_device() as a devm cleanup handler, and casts the reference to the right function pointer type for this to be permitted by the compiler. However, under kCFI, this is rejected at runtime, resulting in a splat like CFI failure at devm_action_release+0x24/0x3c (target: put_device+0x0/0x24; expected type: 0xa488ebfc) Internal error: Oops - CFI: 0000000000000000 [#1] PREEMPT SMP Modules linked in: ... CPU: 20 PID: 454 Comm: systemd-udevd Not tainted 6.1.0-rc1+ #51 Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Oct 3 2022 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : devm_action_release+0x24/0x3c lr : devres_release_all+0xb4/0x114 sp : ffff800009bb3630 x29: ffff800009bb3630 x28: 0000000000000000 x27: 0000000000000011 x26: ffffaa6f9922c0c8 x25: 0000000000000002 x24: 000000000000000f x23: ffff800009bb3648 x22: ffff7aefc3be2100 x21: ffff7aefc3be2e00 x20: 0000000000000005 x19: ffff7aefc1e1ec10 x18: ffff800009af70a8 x17: 00000000a488ebfc x16: 0000000094ee7df3 x15: 0000000000000000 x14: 4075c5c2ef7affff x13: e46a91c5c5e2ef42 x12: ffff7aefc2c57540 x11: 0000000000000001 x10: 0000000000000001 x9 : 0000000100000000 x8 : ffffaa6fa09b39b4 x7 : 7f7f7f7f7f7f7f7f x6 : 8000000000000000 x5 : 000000008020000e x4 : ffff7aefc2c57500 x3 : ffff800009bb3648 x2 : ffff800009bb3648 x1 : ffff7aefc3be2e80 x0 : ffff7aefc3bb7000 Call trace: devm_action_release+0x24/0x3c devres_release_all+0xb4/0x114 really_probe+0xb0/0x49c __driver_probe_device+0x114/0x180 driver_probe_device+0x48/0x1ec __driver_attach+0x118/0x284 bus_for_each_dev+0x94/0xe4 driver_attach+0x24/0x34 bus_add_driver+0x10c/0x220 driver_register+0x78/0x118 __platform_driver_register+0x24/0x34 init_module+0x20/0xfe4 [tpm_tis_synquacer] do_one_initcall+0xd4/0x248 do_init_module+0x44/0x28c load_module+0x16b4/0x1920 Fix this by going through a helper function of the correct type. Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Kees Cook <[email protected]> Reviewed-by: Jason Gunthorpe <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]>

…e_get_temp Calls to thermal_zone_get_temp() are not protected against thermal zone device removal. As result, it is possible that the thermal zone operations callbacks are no longer valid when thermal_zone_get_temp() is called. This may result in crashes such as BUG: unable to handle page fault for address: ffffffffc04ef420 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 5d60e067 P4D 5d60e067 PUD 5d610067 PMD 110197067 PTE 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 3209 Comm: cat Tainted: G W 5.10.136-19389-g615abc6eb807 #1 02df41ac0b12f3a64f4b34245188d8875bb3bce1 Hardware name: Google Coral/Coral, BIOS Google_Coral.10068.92.0 11/27/2018 RIP: 0010:thermal_zone_get_temp+0x26/0x73 Code: 89 c3 eb d3 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 85 ff 74 50 48 89 fb 48 81 ff 00 f0 ff ff 77 44 48 8b 83 98 03 00 00 <48> 83 78 10 00 74 36 49 89 f6 4c 8d bb d8 03 00 00 4c 89 ff e8 9f RSP: 0018:ffffb3758138fd38 EFLAGS: 00010287 RAX: ffffffffc04ef410 RBX: ffff98f14d7fb000 RCX: 0000000000000000 RDX: ffff98f17cf90000 RSI: ffffb3758138fd64 RDI: ffff98f14d7fb000 RBP: ffffb3758138fd50 R08: 0000000000001000 R09: ffff98f17cf90000 R10: 0000000000000000 R11: ffffffff8dacad28 R12: 0000000000001000 R13: ffff98f1793a7d80 R14: ffff98f143231708 R15: ffff98f14d7fb018 FS: 00007ec166097800(0000) GS:ffff98f1bbd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffc04ef420 CR3: 000000010ee9a000 CR4: 00000000003506e0 Call Trace: temp_show+0x31/0x68 dev_attr_show+0x1d/0x4f sysfs_kf_seq_show+0x92/0x107 seq_read_iter+0xf5/0x3f2 vfs_read+0x205/0x379 __x64_sys_read+0x7c/0xe2 do_syscall_64+0x43/0x55 entry_SYSCALL_64_after_hwframe+0x61/0xc6 if a thermal device is removed while accesses to its device attributes are ongoing. The problem is exposed by code in iwl_op_mode_mvm_start(), which registers a thermal zone device only to unregister it shortly afterwards if an unrelated failure is encountered while accessing the hardware. Check if the thermal zone device is registered after acquiring the thermal zone device mutex to ensure this does not happen. The code was tested by triggering the failure in iwl_op_mode_mvm_start() on purpose. Without this patch, the kernel crashes reliably. The crash is no longer observed after applying this and the preceding patches. Signed-off-by: Guenter Roeck <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>

Populate a KASAN shadow for the entire possible per-CPU range of the CPU entry area instead of requiring that each individual chunk map a shadow. Mapping shadows individually is error prone, e.g. the per-CPU GDT mapping was left behind, which can lead to not-present page faults during KASAN validation if the kernel performs a software lookup into the GDT. The DS buffer is also likely affected. The motivation for mapping the per-CPU areas on-demand was to avoid mapping the entire 512GiB range that's reserved for the CPU entry area, shaving a few bytes by not creating shadows for potentially unused memory was not a goal. The bug is most easily reproduced by doing a sigreturn with a garbage CS in the sigcontext, e.g. int main(void) { struct sigcontext regs; syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); memset(&regs, 0, sizeof(regs)); regs.cs = 0x1d0; syscall(__NR_rt_sigreturn); return 0; } to coerce the kernel into doing a GDT lookup to compute CS.base when reading the instruction bytes on the subsequent #GP to determine whether or not the #GP is something the kernel should handle, e.g. to fixup UMIP violations or to emulate CLI/STI for IOPL=3 applications. BUG: unable to handle page fault for address: fffffbc8379ace00 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 16c03a067 P4D 16c03a067 PUD 15b990067 PMD 15b98f067 PTE 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 3 PID: 851 Comm: r2 Not tainted 6.1.0-rc3-next-20221103+ #432 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kasan_check_range+0xdf/0x190 Call Trace: <TASK> get_desc+0xb0/0x1d0 insn_get_seg_base+0x104/0x270 insn_fetch_from_user+0x66/0x80 fixup_umip_exception+0xb1/0x530 exc_general_protection+0x181/0x210 asm_exc_general_protection+0x22/0x30 RIP: 0003:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0003:0000000000000000 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000001d0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Fixes: 9fd429c ("x86/kasan: Map shadow for percpu pages on demand") Reported-by: [email protected] Suggested-by: Andrey Ryabinin <[email protected]> Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Andrey Ryabinin <[email protected]> Link: https://lkml.kernel.org/r/[email protected]

Popuplate the shadow for the shared portion of the CPU entry area, i.e. the read-only IDT mapping, during KASAN initialization. A recent change modified KASAN to map the per-CPU areas on-demand, but forgot to keep a shadow for the common area that is shared amongst all CPUs. Map the common area in KASAN init instead of letting idt_map_in_cea() do the dirty work so that it Just Works in the unlikely event more shared data is shoved into the CPU entry area. The bug manifests as a not-present #PF when software attempts to lookup an IDT entry, e.g. when KVM is handling IRQs on Intel CPUs (KVM performs direct CALL to the IRQ handler to avoid the overhead of INTn): BUG: unable to handle page fault for address: fffffbc0000001d8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 16c03a067 P4D 16c03a067 PUD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 5 PID: 901 Comm: repro Tainted: G W 6.1.0-rc3+ #410 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kasan_check_range+0xdf/0x190 vmx_handle_exit_irqoff+0x152/0x290 [kvm_intel] vcpu_run+0x1d89/0x2bd0 [kvm] kvm_arch_vcpu_ioctl_run+0x3ce/0xa70 [kvm] kvm_vcpu_ioctl+0x349/0x900 [kvm] __x64_sys_ioctl+0xb8/0xf0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: 9fd429c ("x86/kasan: Map shadow for percpu pages on demand") Reported-by: [email protected] Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]

After creating a dm device, then user can reload such dm with itself, and dead loop will be triggered because dm keep looking up to itself. Test procedures: 1) dmsetup create test --table "xxx sda", assume dm-0 is created 2) dmsetup suspend test 3) dmsetup reload test --table "xxx dm-0" 4) dmsetup resume test Test result: BUG: TASK stack guard page was hit at 00000000736a261f (stack is 000000008d12c88d..00000000c8dd82d5) stack guard page: 0000 [#1] PREEMPT SMP CPU: 29 PID: 946 Comm: systemd-udevd Not tainted 6.1.0-rc3-next-20221101-00006-g17640ca3b0ee #1295 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 RIP: 0010:dm_prepare_ioctl+0xf/0x1e0 Code: da 48 83 05 4a 7c 99 0b 01 41 89 c4 eb cd e8 b8 1f 40 00 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 48 83 05 a1 5a 99 0b 01 <41> 56 49 89 d6 41 55 4c 8d af 90 02 00 00 9 RSP: 0018:ffffc90002090000 EFLAGS: 00010206 RAX: ffff8881049d6800 RBX: ffff88817e589000 RCX: 0000000000000000 RDX: ffffc90002090010 RSI: ffffc9000209001c RDI: ffff88817e589000 RBP: 00000000484a101d R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000005331 R13: 0000000000005331 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fddf9609200(0000) GS:ffff889fbfd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc9000208fff8 CR3: 0000000179043000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> dm_blk_ioctl+0x50/0x1c0 ? dm_prepare_ioctl+0xe0/0x1e0 dm_blk_ioctl+0x88/0x1c0 dm_blk_ioctl+0x88/0x1c0 ......(a lot of same lines) dm_blk_ioctl+0x88/0x1c0 dm_blk_ioctl+0x88/0x1c0 blkdev_ioctl+0x184/0x3e0 __x64_sys_ioctl+0xa3/0x110 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fddf7306577 Code: b3 66 90 48 8b 05 11 89 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 88 8 RSP: 002b:00007ffd0b2ec318 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00005634ef478320 RCX: 00007fddf7306577 RDX: 0000000000000000 RSI: 0000000000005331 RDI: 0000000000000007 RBP: 0000000000000007 R08: 00005634ef4843e0 R09: 0000000000000080 R10: 00007fddf75cfb38 R11: 0000000000000246 R12: 00000000030d4000 R13: 0000000000000000 R14: 0000000000000000 R15: 00005634ef48b800 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:dm_prepare_ioctl+0xf/0x1e0 Code: da 48 83 05 4a 7c 99 0b 01 41 89 c4 eb cd e8 b8 1f 40 00 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 48 83 05 a1 5a 99 0b 01 <41> 56 49 89 d6 41 55 4c 8d af 90 02 00 00 9 RSP: 0018:ffffc90002090000 EFLAGS: 00010206 RAX: ffff8881049d6800 RBX: ffff88817e589000 RCX: 0000000000000000 RDX: ffffc90002090010 RSI: ffffc9000209001c RDI: ffff88817e589000 RBP: 00000000484a101d R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000005331 R13: 0000000000005331 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fddf9609200(0000) GS:ffff889fbfd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc9000208fff8 CR3: 0000000179043000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Kernel panic - not syncing: Fatal exception in interrupt Kernel Offset: disabled ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Fix the problem by forbidding a disk to create link to itself. Signed-off-by: Yu Kuai <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>

Currently, in clang version of gcov code when module is getting removed gcov_info_add() incorrectly adds the sfn_ptr->counter to all the dst->functions and it result in the kernel panic in below crash report. Fix this by properly handling it. [ 8.899094][ T599] Unable to handle kernel write to read-only memory at virtual address ffffff80461cc000 [ 8.899100][ T599] Mem abort info: [ 8.899102][ T599] ESR = 0x9600004f [ 8.899103][ T599] EC = 0x25: DABT (current EL), IL = 32 bits [ 8.899105][ T599] SET = 0, FnV = 0 [ 8.899107][ T599] EA = 0, S1PTW = 0 [ 8.899108][ T599] FSC = 0x0f: level 3 permission fault [ 8.899110][ T599] Data abort info: [ 8.899111][ T599] ISV = 0, ISS = 0x0000004f [ 8.899113][ T599] CM = 0, WnR = 1 [ 8.899114][ T599] swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000ab8de000 [ 8.899116][ T599] [ffffff80461cc000] pgd=18000009ffcde003, p4d=18000009ffcde003, pud=18000009ffcde003, pmd=18000009ffcad003, pte=00600000c61cc787 [ 8.899124][ T599] Internal error: Oops: 9600004f [#1] PREEMPT SMP [ 8.899265][ T599] Skip md ftrace buffer dump for: 0x1609e0 .... .., [ 8.899544][ T599] CPU: 7 PID: 599 Comm: modprobe Tainted: G S OE 5.15.41-android13-8-g38e9b1af6bce #1 [ 8.899547][ T599] Hardware name: XXX (DT) [ 8.899549][ T599] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) [ 8.899551][ T599] pc : gcov_info_add+0x9c/0xb8 [ 8.899557][ T599] lr : gcov_event+0x28c/0x6b8 [ 8.899559][ T599] sp : ffffffc00e733b00 [ 8.899560][ T599] x29: ffffffc00e733b00 x28: ffffffc00e733d30 x27: ffffffe8dc297470 [ 8.899563][ T599] x26: ffffffe8dc297000 x25: ffffffe8dc297000 x24: ffffffe8dc297000 [ 8.899566][ T599] x23: ffffffe8dc0a6200 x22: ffffff880f68bf20 x21: 0000000000000000 [ 8.899569][ T599] x20: ffffff880f68bf00 x19: ffffff8801babc00 x18: ffffffc00d7f9058 [ 8.899572][ T599] x17: 0000000000088793 x16: ffffff80461cbe00 x15: 9100052952800785 [ 8.899575][ T599] x14: 0000000000000200 x13: 0000000000000041 x12: 9100052952800785 [ 8.899577][ T599] x11: ffffffe8dc297000 x10: ffffffe8dc297000 x9 : ffffff80461cbc80 [ 8.899580][ T599] x8 : ffffff8801babe80 x7 : ffffffe8dc2ec000 x6 : ffffffe8dc2ed000 [ 8.899583][ T599] x5 : 000000008020001f x4 : fffffffe2006eae0 x3 : 000000008020001f [ 8.899586][ T599] x2 : ffffff8027c49200 x1 : ffffff8801babc20 x0 : ffffff80461cb3a0 [ 8.899589][ T599] Call trace: [ 8.899590][ T599] gcov_info_add+0x9c/0xb8 [ 8.899592][ T599] gcov_module_notifier+0xbc/0x120 [ 8.899595][ T599] blocking_notifier_call_chain+0xa0/0x11c [ 8.899598][ T599] do_init_module+0x2a8/0x33c [ 8.899600][ T599] load_module+0x23cc/0x261c [ 8.899602][ T599] __arm64_sys_finit_module+0x158/0x194 [ 8.899604][ T599] invoke_syscall+0x94/0x2bc [ 8.899607][ T599] el0_svc_common+0x1d8/0x34c [ 8.899609][ T599] do_el0_svc+0x40/0x54 [ 8.899611][ T599] el0_svc+0x94/0x2f0 [ 8.899613][ T599] el0t_64_sync_handler+0x88/0xec [ 8.899615][ T599] el0t_64_sync+0x1b4/0x1b8 [ 8.899618][ T599] Code: f905f56c f86e69ec f86e6a0f 8b0c01ec (f82e6a0c) [ 8.899620][ T599] ---[ end trace ed5218e9e5b6e2e6 ]--- Link: https://lkml.kernel.org/r/[email protected] Fixes: e178a5b ("gcov: clang support") Signed-off-by: Mukesh Ojha <[email protected]> Reviewed-by: Peter Oberparleiter <[email protected]> Tested-by: Peter Oberparleiter <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Tom Rix <[email protected]> Cc: <[email protected]> [5.2+] Signed-off-by: Andrew Morton <[email protected]>

Patch series "rapidio: fix three possible memory leaks". This patchset fixes three name leaks in error handling. - patch #1 fixes two name leaks while rio_add_device() fails. - patch #2 fixes a name leak while rio_register_mport() fails. This patch (of 2): If rio_add_device() returns error, the name allocated by dev_set_name() need be freed. It should use put_device() to give up the reference in the error path, so that the name can be freed in kobject_cleanup(), and the 'rdev' can be freed in rio_release_dev(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: e8de370 ("rapidio: add mport char device driver") Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array") Signed-off-by: Yang Yingliang <[email protected]> Cc: Alexandre Bounine <[email protected]> Cc: Matt Porter <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

The "ib_port" structure must be set before adding the sysfs kobject, and reset after removing it, otherwise it may crash when accessing the sysfs node: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 Mem abort info: ESR = 0x96000006 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000e85f5ba5 [0000000000000050] pgd=0000000848fd9003, pud=000000085b387003, pmd=0000000000000000 Internal error: Oops: 96000006 [#2] PREEMPT SMP Modules linked in: ib_umad(O) mlx5_ib(O) nfnetlink_cttimeout(E) nfnetlink(E) act_gact(E) cls_flower(E) sch_ingress(E) openvswitch(E) nsh(E) nf_nat_ipv6(E) nf_nat_ipv4(E) nf_conncount(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) mst_pciconf(O) ipmi_devintf(E) ipmi_msghandler(E) ipmb_dev_int(OE) mlx5_core(O) mlxfw(O) mlxdevm(O) auxiliary(O) ib_uverbs(O) ib_core(O) mlx_compat(O) psample(E) sbsa_gwdt(E) uio_pdrv_genirq(E) uio(E) mlxbf_pmc(OE) mlxbf_gige(OE) mlxbf_tmfifo(OE) gpio_mlxbf2(OE) pwr_mlxbf(OE) mlx_trio(OE) i2c_mlxbf(OE) mlx_bootctl(OE) bluefield_edac(OE) knem(O) ip_tables(E) ipv6(E) crc_ccitt(E) [last unloaded: mst_pci] Process grep (pid: 3372, stack limit = 0x0000000022055c92) CPU: 5 PID: 3372 Comm: grep Tainted: G D OE 4.19.161-mlnx.47.gadcd9e3 #1 Hardware name: https://www.mellanox.com BlueField SoC/BlueField SoC, BIOS BlueField:3.9.2-15-ga2403ab Sep 8 2022 pstate: 40000005 (nZcv daif -PAN -UAO) pc : hw_stat_port_show+0x4c/0x80 [ib_core] lr : port_attr_show+0x40/0x58 [ib_core] sp : ffff000029f43b50 x29: ffff000029f43b50 x28: 0000000019375000 x27: ffff8007b821a540 x26: ffff000029f43e30 x25: 0000000000008000 x24: ffff000000eaa958 x23: 0000000000001000 x22: ffff8007a4ce3000 x21: ffff8007baff8000 x20: ffff8007b9066ac0 x19: ffff8007bae97578 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : ffff8007a4ce4000 x7 : 0000000000000000 x6 : 000000000000003f x5 : ffff000000e6a280 x4 : ffff8007a4ce3000 x3 : 0000000000000000 x2 : aaaaaaaaaaaaaaab x1 : ffff8007b9066a10 x0 : ffff8007baff8000 Call trace: hw_stat_port_show+0x4c/0x80 [ib_core] port_attr_show+0x40/0x58 [ib_core] sysfs_kf_seq_show+0x8c/0x150 kernfs_seq_show+0x44/0x50 seq_read+0x1b4/0x45c kernfs_fop_read+0x148/0x1d8 __vfs_read+0x58/0x180 vfs_read+0x94/0x154 ksys_read+0x68/0xd8 __arm64_sys_read+0x28/0x34 el0_svc_common+0x88/0x18c el0_svc_handler+0x78/0x94 el0_svc+0x8/0xe8 Code: f2955562 aa1603e4 aa1503e0 f9405683 (f9402861) Fixes: d8a5883 ("RDMA/core: Replace the ib_port_data hw_stats pointers with a ib_port pointer") Signed-off-by: Mark Zhang <[email protected]> Reviewed-by: Michael Guralnik <[email protected]> Link: https://lore.kernel.org/r/88867e705c42c1cd2011e45201c25eecdb9fef94.1667810736.git.leonro@nvidia.com Signed-off-by: Leon Romanovsky <[email protected]>

Commit 994f706 ("srcu: Make Tree SRCU able to operate without snp_node array") assumes that cpu 0 is always online. However, there really are situations when some other CPU is the boot CPU, for example, when booting a kdump kernel with the maxcpus=1 boot parameter. On PowerPC, the kdump kernel can hang as follows: ... [ 1.740036] systemd[1]: Hostname set to <xyz.com> [ 243.686240] INFO: task systemd:1 blocked for more than 122 seconds. [ 243.686264] Not tainted 6.1.0-rc1 #1 [ 243.686272] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 243.686281] task:systemd state:D stack:0 pid:1 ppid:0 flags:0x00042000 [ 243.686296] Call Trace: [ 243.686301] [c000000016657640] [c000000016657670] 0xc000000016657670 (unreliable) [ 243.686317] [c000000016657830] [c00000001001dec0] __switch_to+0x130/0x220 [ 243.686333] [c000000016657890] [c000000010f607b8] __schedule+0x1f8/0x580 [ 243.686347] [c000000016657940] [c000000010f60bb4] schedule+0x74/0x140 [ 243.686361] [c0000000166579b0] [c000000010f699b8] schedule_timeout+0x168/0x1c0 [ 243.686374] [c000000016657a80] [c000000010f61de8] __wait_for_common+0x148/0x360 [ 243.686387] [c000000016657b20] [c000000010176bb0] __flush_work.isra.0+0x1c0/0x3d0 [ 243.686401] [c000000016657bb0] [c0000000105f2768] fsnotify_wait_marks_destroyed+0x28/0x40 [ 243.686415] [c000000016657bd0] [c0000000105f21b8] fsnotify_destroy_group+0x68/0x160 [ 243.686428] [c000000016657c40] [c0000000105f6500] inotify_release+0x30/0xa0 [ 243.686440] [c000000016657cb0] [c0000000105751a8] __fput+0xc8/0x350 [ 243.686452] [c000000016657d00] [c00000001017d524] task_work_run+0xe4/0x170 [ 243.686464] [c000000016657d50] [c000000010020e94] do_notify_resume+0x134/0x140 [ 243.686478] [c000000016657d80] [c00000001002eb18] interrupt_exit_user_prepare_main+0x198/0x270 [ 243.686493] [c000000016657de0] [c00000001002ec60] syscall_exit_prepare+0x70/0x180 [ 243.686505] [c000000016657e10] [c00000001000bf7c] system_call_vectored_common+0xfc/0x280 [ 243.686520] --- interrupt: 3000 at 0x7fffa47d5ba4 [ 243.686528] NIP: 00007fffa47d5ba4 LR: 0000000000000000 CTR: 0000000000000000 [ 243.686538] REGS: c000000016657e80 TRAP: 3000 Not tainted (6.1.0-rc1) [ 243.686548] MSR: 800000000000d033 <SF,EE,PR,ME,IR,DR,RI,LE> CR: 42044440 XER: 00000000 [ 243.686572] IRQMASK: 0 [ 243.686572] GPR00: 0000000000000006 00007ffffa606710 00007fffa48e7200 0000000000000000 [ 243.686572] GPR04: 0000000000000002 000000000000000a 0000000000000000 0000000000000001 [ 243.686572] GPR08: 000001000c172dd0 0000000000000000 0000000000000000 0000000000000000 [ 243.686572] GPR12: 0000000000000000 00007fffa4ff4bc0 0000000000000000 0000000000000000 [ 243.686572] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 243.686572] GPR20: 0000000132dfdc50 000000000000000e 0000000000189375 0000000000000000 [ 243.686572] GPR24: 00007ffffa606ae0 0000000000000005 000001000c185490 000001000c172570 [ 243.686572] GPR28: 000001000c172990 000001000c184850 000001000c172e00 00007fffa4fedd98 [ 243.686683] NIP [00007fffa47d5ba4] 0x7fffa47d5ba4 [ 243.686691] LR [0000000000000000] 0x0 [ 243.686698] --- interrupt: 3000 [ 243.686708] INFO: task kworker/u16:1:24 blocked for more than 122 seconds. [ 243.686717] Not tainted 6.1.0-rc1 #1 [ 243.686724] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 243.686733] task:kworker/u16:1 state:D stack:0 pid:24 ppid:2 flags:0x00000800 [ 243.686747] Workqueue: events_unbound fsnotify_mark_destroy_workfn [ 243.686758] Call Trace: [ 243.686762] [c0000000166736e0] [c00000004fd91000] 0xc00000004fd91000 (unreliable) [ 243.686775] [c0000000166738d0] [c00000001001dec0] __switch_to+0x130/0x220 [ 243.686788] [c000000016673930] [c000000010f607b8] __schedule+0x1f8/0x580 [ 243.686801] [c0000000166739e0] [c000000010f60bb4] schedule+0x74/0x140 [ 243.686814] [c000000016673a50] [c000000010f699b8] schedule_timeout+0x168/0x1c0 [ 243.686827] [c000000016673b20] [c000000010f61de8] __wait_for_common+0x148/0x360 [ 243.686840] [c000000016673bc0] [c000000010210840] __synchronize_srcu.part.0+0xa0/0xe0 [ 243.686855] [c000000016673c30] [c0000000105f2c64] fsnotify_mark_destroy_workfn+0xc4/0x1a0 [ 243.686868] [c000000016673ca0] [c000000010174ea8] process_one_work+0x2a8/0x570 [ 243.686882] [c000000016673d40] [c000000010175208] worker_thread+0x98/0x5e0 [ 243.686895] [c000000016673dc0] [c0000000101828d4] kthread+0x124/0x130 [ 243.686908] [c000000016673e10] [c00000001000cd40] ret_from_kernel_thread+0x5c/0x64 [ 366.566274] INFO: task systemd:1 blocked for more than 245 seconds. [ 366.566298] Not tainted 6.1.0-rc1 #1 [ 366.566305] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 366.566314] task:systemd state:D stack:0 pid:1 ppid:0 flags:0x00042000 [ 366.566329] Call Trace: ... The above splat occurs because PowerPC really does use maxcpus=1 instead of nr_cpus=1 in the kernel command line. Consequently, the (quite possibly non-zero) kdump CPU is the only online CPU in the kdump kernel. SRCU unconditionally queues a sdp->work on cpu 0, for which no worker thread has been created, so sdp->work will be never executed and __synchronize_srcu() will never be completed. This commit therefore replaces CPU ID 0 with get_boot_cpu_id() in key places in Tree SRCU. Since the CPU indicated by get_boot_cpu_id() is guaranteed to be online, this avoids the above splat. Signed-off-by: Pingfan Liu <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Lai Jiangshan <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Mathieu Desnoyers <[email protected]> To: [email protected] Signed-off-by: Paul E. McKenney <[email protected]>

Marek reported a BUG resulting from the recent parallel faults changes, as the hyp stage-1 map walker attempted to allocate table memory while holding the RCU read lock: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 2 locks held by swapper/0/1: #0: ffff80000a8a44d0 (kvm_hyp_pgd_mutex){+.+.}-{3:3}, at: __create_hyp_mappings+0x80/0xc4 #1: ffff80000a927720 (rcu_read_lock){....}-{1:2}, at: kvm_pgtable_walk+0x0/0x1f4 CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc3+ #5918 Hardware name: Raspberry Pi 3 Model B (DT) Call trace: dump_backtrace.part.0+0xe4/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x8c/0xb8 dump_stack+0x18/0x34 __might_resched+0x178/0x220 __might_sleep+0x48/0xa0 prepare_alloc_pages+0x178/0x1a0 __alloc_pages+0x9c/0x109c alloc_page_interleave+0x1c/0xc4 alloc_pages+0xec/0x160 get_zeroed_page+0x1c/0x44 kvm_hyp_zalloc_page+0x14/0x20 hyp_map_walker+0xd4/0x134 kvm_pgtable_visitor_cb.isra.0+0x38/0x5c __kvm_pgtable_walk+0x1a4/0x220 kvm_pgtable_walk+0x104/0x1f4 kvm_pgtable_hyp_map+0x80/0xc4 __create_hyp_mappings+0x9c/0xc4 kvm_mmu_init+0x144/0x1cc kvm_arch_init+0xe4/0xef4 kvm_init+0x3c/0x3d0 arm_init+0x20/0x30 do_one_initcall+0x74/0x400 kernel_init_freeable+0x2e0/0x350 kernel_init+0x24/0x130 ret_from_fork+0x10/0x20 Since the hyp stage-1 table walkers are serialized by kvm_hyp_pgd_mutex, RCU protection really doesn't add anything. Don't acquire the RCU read lock for an exclusive walk. While at it, add a warning which codifies the lack of support for shared walks in the hypervisor code. Reported-by: Marek Szyprowski <[email protected]> Signed-off-by: Oliver Upton <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> Link: https://lore.kernel.org/r/[email protected]

We used to use the wrong type of integer in 'zfcp_fsf_req_send()' to cache the FSF request ID when sending a new FSF request. This is used in case the sending fails and we need to remove the request from our internal hash table again (so we don't keep an invalid reference and use it when we free the request again). In 'zfcp_fsf_req_send()' we used to cache the ID as 'int' (signed and 32 bit wide), but the rest of the zfcp code (and the firmware specification) handles the ID as 'unsigned long'/'u64' (unsigned and 64 bit wide [s390x ELF ABI]). For one this has the obvious problem that when the ID grows past 32 bit (this can happen reasonably fast) it is truncated to 32 bit when storing it in the cache variable and so doesn't match the original ID anymore. The second less obvious problem is that even when the original ID has not yet grown past 32 bit, as soon as the 32nd bit is set in the original ID (0x80000000 = 2'147'483'648) we will have a mismatch when we cast it back to 'unsigned long'. As the cached variable is of a signed type, the compiler will choose a sign-extending instruction to load the 32 bit variable into a 64 bit register (e.g.: 'lgf %r11,188(%r15)'). So once we pass the cached variable into 'zfcp_reqlist_find_rm()' to remove the request again all the leading zeros will be flipped to ones to extend the sign and won't match the original ID anymore (this has been observed in practice). If we can't successfully remove the request from the hash table again after 'zfcp_qdio_send()' fails (this happens regularly when zfcp cannot notify the adapter about new work because the adapter is already gone during e.g. a ChpID toggle) we will end up with a double free. We unconditionally free the request in the calling function when 'zfcp_fsf_req_send()' fails, but because the request is still in the hash table we end up with a stale memory reference, and once the zfcp adapter is either reset during recovery or shutdown we end up freeing the same memory twice. The resulting stack traces vary depending on the kernel and have no direct correlation to the place where the bug occurs. Here are three examples that have been seen in practice: list_del corruption. next->prev should be 00000001b9d13800, but was 00000000dead4ead. (next=00000001bd131a00) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:62! monitor event: 0040 ilc:2 [#1] PREEMPT SMP Modules linked in: ... CPU: 9 PID: 1617 Comm: zfcperp0.0.1740 Kdump: loaded Hardware name: ... Krnl PSW : 0704d00180000000 00000003cbeea1f8 (__list_del_entry_valid+0x98/0x140) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3 Krnl GPRS: 00000000916d12f1 0000000080000000 000000000000006d 00000003cb665cd6 0000000000000001 0000000000000000 0000000000000000 00000000d28d21e8 00000000d3844000 00000380099efd28 00000001bd131a00 00000001b9d13800 00000000d3290100 0000000000000000 00000003cbeea1f4 00000380099efc70 Krnl Code: 00000003cbeea1e8: c020004f68a7 larl %r2,00000003cc8d7336 00000003cbeea1ee: c0e50027fd65 brasl %r14,00000003cc3e9cb8 #00000003cbeea1f4: af000000 mc 0,0 >00000003cbeea1f8: c02000920440 larl %r2,00000003cd12aa78 00000003cbeea1fe: c0e500289c25 brasl %r14,00000003cc3fda48 00000003cbeea204: b9040043 lgr %r4,%r3 00000003cbeea208: b9040051 lgr %r5,%r1 00000003cbeea20c: b9040032 lgr %r3,%r2 Call Trace: [<00000003cbeea1f8>] __list_del_entry_valid+0x98/0x140 ([<00000003cbeea1f4>] __list_del_entry_valid+0x94/0x140) [<000003ff7ff502fe>] zfcp_fsf_req_dismiss_all+0xde/0x150 [zfcp] [<000003ff7ff49cd0>] zfcp_erp_strategy_do_action+0x160/0x280 [zfcp] [<000003ff7ff4a22e>] zfcp_erp_strategy+0x21e/0xca0 [zfcp] [<000003ff7ff4ad34>] zfcp_erp_thread+0x84/0x1a0 [zfcp] [<00000003cb5eece8>] kthread+0x138/0x150 [<00000003cb557f3c>] __ret_from_fork+0x3c/0x60 [<00000003cc4172ea>] ret_from_fork+0xa/0x40 INFO: lockdep is turned off. Last Breaking-Event-Address: [<00000003cc3e9d04>] _printk+0x4c/0x58 Kernel panic - not syncing: Fatal exception: panic_on_oops or: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6803 Fault in home space mode while using kernel ASCE. AS:0000000063b10007 R3:0000000000000024 Oops: 0038 ilc:3 [#1] SMP Modules linked in: ... CPU: 10 PID: 0 Comm: swapper/10 Kdump: loaded Hardware name: ... Krnl PSW : 0404d00180000000 000003ff7febaf8e (zfcp_fsf_reqid_check+0x86/0x158 [zfcp]) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3 Krnl GPRS: 5a6f1cfa89c49ac3 00000000aff2c4c8 6b6b6b6b6b6b6b6b 00000000000002a8 0000000000000000 0000000000000055 0000000000000000 00000000a8515800 0700000000000000 00000000a6e14500 00000000aff2c000 000000008003c44c 000000008093c700 0000000000000010 00000380009ebba8 00000380009ebb48 Krnl Code: 000003ff7febaf7e: a7f4003d brc 15,000003ff7febaff8 000003ff7febaf82: e32020000004 lg %r2,0(%r2) #000003ff7febaf88: ec2100388064 cgrj %r2,%r1,8,000003ff7febaff8 >000003ff7febaf8e: e3b020100020 cg %r11,16(%r2) 000003ff7febaf94: a774fff7 brc 7,000003ff7febaf82 000003ff7febaf98: ec280030007c cgij %r2,0,8,000003ff7febaff8 000003ff7febaf9e: e31020080004 lg %r1,8(%r2) 000003ff7febafa4: e33020000004 lg %r3,0(%r2) Call Trace: [<000003ff7febaf8e>] zfcp_fsf_reqid_check+0x86/0x158 [zfcp] [<000003ff7febbdbc>] zfcp_qdio_int_resp+0x6c/0x170 [zfcp] [<000003ff7febbf90>] zfcp_qdio_irq_tasklet+0xd0/0x108 [zfcp] [<0000000061d90a04>] tasklet_action_common.constprop.0+0xdc/0x128 [<000000006292f300>] __do_softirq+0x130/0x3c0 [<0000000061d906c6>] irq_exit_rcu+0xfe/0x118 [<000000006291e818>] do_io_irq+0xc8/0x168 [<000000006292d516>] io_int_handler+0xd6/0x110 [<000000006292d596>] psw_idle_exit+0x0/0xa ([<0000000061d3be50>] arch_cpu_idle+0x40/0xd0) [<000000006292ceea>] default_idle_call+0x52/0xf8 [<0000000061de4fa4>] do_idle+0xd4/0x168 [<0000000061de51fe>] cpu_startup_entry+0x36/0x40 [<0000000061d4faac>] smp_start_secondary+0x12c/0x138 [<000000006292d88e>] restart_int_handler+0x6e/0x90 Last Breaking-Event-Address: [<000003ff7febaf94>] zfcp_fsf_reqid_check+0x8c/0x158 [zfcp] Kernel panic - not syncing: Fatal exception in interrupt or: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 523b05d3ae76a000 TEID: 523b05d3ae76a803 Fault in home space mode while using kernel ASCE. AS:0000000077c40007 R3:0000000000000024 Oops: 0038 ilc:3 [#1] SMP Modules linked in: ... CPU: 3 PID: 453 Comm: kworker/3:1H Kdump: loaded Hardware name: ... Workqueue: kblockd blk_mq_run_work_fn Krnl PSW : 0404d00180000000 0000000076fc0312 (__kmalloc+0xd2/0x398) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3 Krnl GPRS: ffffffffffffffff 523b05d3ae76abf6 0000000000000000 0000000000092a20 0000000000000002 00000007e49b5cc0 00000007eda8f000 0000000000092a20 00000007eda8f000 00000003b02856b9 00000000000000a8 523b05d3ae76abf6 00000007dd662000 00000007eda8f000 0000000076fc02b2 000003e0037637a0 Krnl Code: 0000000076fc0302: c004000000d4 brcl 0,76fc04aa 0000000076fc0308: b904001b lgr %r1,%r11 #0000000076fc030c: e3106020001a algf %r1,32(%r6) >0000000076fc0312: e31010000082 xg %r1,0(%r1) 0000000076fc0318: b9040001 lgr %r0,%r1 0000000076fc031c: e30061700082 xg %r0,368(%r6) 0000000076fc0322: ec59000100d9 aghik %r5,%r9,1 0000000076fc0328: e34003b80004 lg %r4,952 Call Trace: [<0000000076fc0312>] __kmalloc+0xd2/0x398 [<0000000076f318f2>] mempool_alloc+0x72/0x1f8 [<000003ff8027c5f8>] zfcp_fsf_req_create.isra.7+0x40/0x268 [zfcp] [<000003ff8027f1bc>] zfcp_fsf_fcp_cmnd+0xac/0x3f0 [zfcp] [<000003ff80280f1a>] zfcp_scsi_queuecommand+0x122/0x1d0 [zfcp] [<000003ff800b4218>] scsi_queue_rq+0x778/0xa10 [scsi_mod] [<00000000771782a0>] __blk_mq_try_issue_directly+0x130/0x208 [<000000007717a124>] blk_mq_request_issue_directly+0x4c/0xa8 [<000003ff801302e2>] dm_mq_queue_rq+0x2ea/0x468 [dm_mod] [<0000000077178c12>] blk_mq_dispatch_rq_list+0x33a/0x818 [<000000007717f064>] __blk_mq_do_dispatch_sched+0x284/0x2f0 [<000000007717f44c>] __blk_mq_sched_dispatch_requests+0x1c4/0x218 [<000000007717fa7a>] blk_mq_sched_dispatch_requests+0x52/0x90 [<0000000077176d74>] __blk_mq_run_hw_queue+0x9c/0xc0 [<0000000076da6d74>] process_one_work+0x274/0x4d0 [<0000000076da7018>] worker_thread+0x48/0x560 [<0000000076daef18>] kthread+0x140/0x160 [<000000007751d144>] ret_from_fork+0x28/0x30 Last Breaking-Event-Address: [<0000000076fc0474>] __kmalloc+0x234/0x398 Kernel panic - not syncing: Fatal exception: panic_on_oops To fix this, simply change the type of the cache variable to 'unsigned long', like the rest of zfcp and also the argument for 'zfcp_reqlist_find_rm()'. This prevents truncation and wrong sign extension and so can successfully remove the request from the hash table. Fixes: e60a6d6 ("[SCSI] zfcp: Remove function zfcp_reqlist_find_safe") Cc: <[email protected]> #v2.6.34+ Signed-off-by: Benjamin Block <[email protected]> Link: https://lore.kernel.org/r/979f6e6019d15f91ba56182f1aaf68d61bf37fc6.1668595505.git.bblock@linux.ibm.com Reviewed-by: Steffen Maier <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]>

Currently, in clang version of gcov code when module is getting removed gcov_info_add() incorrectly adds the sfn_ptr->counter to all the dst->functions and it result in the kernel panic in below crash report. Fix this by properly handling it. [ 8.899094][ T599] Unable to handle kernel write to read-only memory at virtual address ffffff80461cc000 [ 8.899100][ T599] Mem abort info: [ 8.899102][ T599] ESR = 0x9600004f [ 8.899103][ T599] EC = 0x25: DABT (current EL), IL = 32 bits [ 8.899105][ T599] SET = 0, FnV = 0 [ 8.899107][ T599] EA = 0, S1PTW = 0 [ 8.899108][ T599] FSC = 0x0f: level 3 permission fault [ 8.899110][ T599] Data abort info: [ 8.899111][ T599] ISV = 0, ISS = 0x0000004f [ 8.899113][ T599] CM = 0, WnR = 1 [ 8.899114][ T599] swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000ab8de000 [ 8.899116][ T599] [ffffff80461cc000] pgd=18000009ffcde003, p4d=18000009ffcde003, pud=18000009ffcde003, pmd=18000009ffcad003, pte=00600000c61cc787 [ 8.899124][ T599] Internal error: Oops: 9600004f [#1] PREEMPT SMP [ 8.899265][ T599] Skip md ftrace buffer dump for: 0x1609e0 .... .., [ 8.899544][ T599] CPU: 7 PID: 599 Comm: modprobe Tainted: G S OE 5.15.41-android13-8-g38e9b1af6bce #1 [ 8.899547][ T599] Hardware name: XXX (DT) [ 8.899549][ T599] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) [ 8.899551][ T599] pc : gcov_info_add+0x9c/0xb8 [ 8.899557][ T599] lr : gcov_event+0x28c/0x6b8 [ 8.899559][ T599] sp : ffffffc00e733b00 [ 8.899560][ T599] x29: ffffffc00e733b00 x28: ffffffc00e733d30 x27: ffffffe8dc297470 [ 8.899563][ T599] x26: ffffffe8dc297000 x25: ffffffe8dc297000 x24: ffffffe8dc297000 [ 8.899566][ T599] x23: ffffffe8dc0a6200 x22: ffffff880f68bf20 x21: 0000000000000000 [ 8.899569][ T599] x20: ffffff880f68bf00 x19: ffffff8801babc00 x18: ffffffc00d7f9058 [ 8.899572][ T599] x17: 0000000000088793 x16: ffffff80461cbe00 x15: 9100052952800785 [ 8.899575][ T599] x14: 0000000000000200 x13: 0000000000000041 x12: 9100052952800785 [ 8.899577][ T599] x11: ffffffe8dc297000 x10: ffffffe8dc297000 x9 : ffffff80461cbc80 [ 8.899580][ T599] x8 : ffffff8801babe80 x7 : ffffffe8dc2ec000 x6 : ffffffe8dc2ed000 [ 8.899583][ T599] x5 : 000000008020001f x4 : fffffffe2006eae0 x3 : 000000008020001f [ 8.899586][ T599] x2 : ffffff8027c49200 x1 : ffffff8801babc20 x0 : ffffff80461cb3a0 [ 8.899589][ T599] Call trace: [ 8.899590][ T599] gcov_info_add+0x9c/0xb8 [ 8.899592][ T599] gcov_module_notifier+0xbc/0x120 [ 8.899595][ T599] blocking_notifier_call_chain+0xa0/0x11c [ 8.899598][ T599] do_init_module+0x2a8/0x33c [ 8.899600][ T599] load_module+0x23cc/0x261c [ 8.899602][ T599] __arm64_sys_finit_module+0x158/0x194 [ 8.899604][ T599] invoke_syscall+0x94/0x2bc [ 8.899607][ T599] el0_svc_common+0x1d8/0x34c [ 8.899609][ T599] do_el0_svc+0x40/0x54 [ 8.899611][ T599] el0_svc+0x94/0x2f0 [ 8.899613][ T599] el0t_64_sync_handler+0x88/0xec [ 8.899615][ T599] el0t_64_sync+0x1b4/0x1b8 [ 8.899618][ T599] Code: f905f56c f86e69ec f86e6a0f 8b0c01ec (f82e6a0c) [ 8.899620][ T599] ---[ end trace ed5218e9e5b6e2e6 ]--- Link: https://lkml.kernel.org/r/[email protected] Fixes: e178a5b ("gcov: clang support") Signed-off-by: Mukesh Ojha <[email protected]> Reviewed-by: Peter Oberparleiter <[email protected]> Tested-by: Peter Oberparleiter <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Tom Rix <[email protected]> Cc: <[email protected]> [5.2+] Signed-off-by: Andrew Morton <[email protected]>

Patch series "rapidio: fix three possible memory leaks". This patchset fixes three name leaks in error handling. - patch #1 fixes two name leaks while rio_add_device() fails. - patch #2 fixes a name leak while rio_register_mport() fails. This patch (of 2): If rio_add_device() returns error, the name allocated by dev_set_name() need be freed. It should use put_device() to give up the reference in the error path, so that the name can be freed in kobject_cleanup(), and the 'rdev' can be freed in rio_release_dev(). Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: e8de370 ("rapidio: add mport char device driver") Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array") Signed-off-by: Yang Yingliang <[email protected]> Cc: Alexandre Bounine <[email protected]> Cc: Matt Porter <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

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nathanchance closed this May 31, 2020

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Would you please turn on the issue? #1

Would you please turn on the issue? #1

koumaza commented May 29, 2020

nathanchance commented May 31, 2020

Would you please turn on the issue? #1

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koumaza commented May 29, 2020

nathanchance commented May 31, 2020