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mptcp: bugFix: Subtract large value from small value. #21
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Subtract large value from small value. This may occur more long searching time to insert skb.
Very nice catch! Thanks. I merged the patch, but modified the commit-message to be a bit more explicit. |
Thanks reply and merge. I will take care that and would you add following tag? Signed-off-by: Takumi Shinkai [email protected] I am beginner to coding with using git. |
Also, update your git-config with the correct info so that commits have the correct author-field: git config --global user.name "Takumi Shinkai" For sending patches, I personally prefer an e-mail to the mptcp-dev mailing list (git send-email makes this really easy). But if it is easier for you to create pull-request, this is possible too. Just make sure that your tree is rebased to the latest head of the mptcp-tree. |
When booting secondary CPUs, announce_cpu() is called to show which cpu has been brought up. For example: [ 0.402751] smpboot: Booting Node 0, Processors multipath-tcp#1 multipath-tcp#2 multipath-tcp#3 multipath-tcp#4 multipath-tcp#5 OK [ 0.525667] smpboot: Booting Node 1, Processors multipath-tcp#6 multipath-tcp#7 multipath-tcp#8 multipath-tcp#9 multipath-tcp#10 multipath-tcp#11 OK [ 0.755592] smpboot: Booting Node 0, Processors multipath-tcp#12 multipath-tcp#13 multipath-tcp#14 multipath-tcp#15 multipath-tcp#16 multipath-tcp#17 OK [ 0.890495] smpboot: Booting Node 1, Processors multipath-tcp#18 multipath-tcp#19 multipath-tcp#20 multipath-tcp#21 multipath-tcp#22 multipath-tcp#23 But the last "OK" is lost, because 'nr_cpu_ids-1' represents the maximum possible cpu id. It should use the maximum present cpu id in case not all CPUs booted up. Signed-off-by: Libin <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/r/[email protected] [ tweaked the changelog, removed unnecessary line break, tweaked the format to align the fields vertically. ] Signed-off-by: Ingo Molnar <[email protected]>
We call cpu_cluster_pm_enter for dev->cpu == 0 only, but cpu_cluster_pm_exit called without that check. Because of that unhandled page fault may happen: [ 3.803405] Unable to handle kernel paging request at virtual address 00002500 [ 3.810974] pgd = c0004000 [ 3.813812] [00002500] *pgd=00000000 [ 3.817596] Internal error: Oops: 5 [multipath-tcp#1] SMP ARM [ 3.822418] Modules linked in: [ 3.825653] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.11.0-rc6+ multipath-tcp#21 [ 3.832397] task: ed86ef40 ti: ed896000 task.ti: ed896000 [ 3.838073] PC is at irq_notifier+0x234/0x25c [ 3.842651] LR is at irq_notifier+0x218/0x25c [ 3.847229] pc : [<c0029ed8>] lr : [<c0029ebc>] psr: 80000193 [ 3.847229] sp : ed897ee8 ip : 00000005 fp : 00000001 [ 3.859283] r10: c0b395f0 r9 : c0b30594 r8 : c0b8c2ac [ 3.864776] r7 : ffffffff r6 : 00000000 r5 : 00000005 r4 : 00000000 [ 3.871643] r3 : 00002500 r2 : 00000000 r1 : 00000005 r0 : 44302244 [ 3.878479] Flags: Nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 3.886260] Control: 10c5387d Table: 8000404a DAC: 00000015 [ 3.892272] Process swapper/1 (pid: 0, stack limit = 0xed896240) [ 3.898590] Stack: (0xed897ee8 to 0xed898000) [ 3.903167] 7ee0: c0979c3a 00000001 ed897ef8 ed896000 c0014f7c 00000000 [ 3.911743] 7f00: 00000005 00000000 ffffffff c0b8c2ac c0b395f0 c077c04c c0c94b48 c0b3953c [ 3.920318] 7f20: c0bcd928 00000002 c0b39524 c00cfad8 00000000 ffffffff 00000000 c00cfb10 [ 3.928924] 7f40: c14e62c0 c002c1c8 c002c0ac c14e62c0 00000002 e251c37d 00000000 c0b39548 [ 3.937499] 7f60: c0b395f0 c05a1bc4 e251c37d 00000000 00000005 c05a3870 edc90380 edc90380 [ 3.946105] 7f80: edc90394 c14e62c0 c0b39548 00000002 c0784064 c05a3c78 c0b395e0 c14e62c0 [ 3.954681] 7fa0: 00000002 c0b39548 c0bc9db8 00000000 00000001 c05a1dc0 ed896000 00000015 [ 3.963287] 7fc0: c0bc9db8 ed896000 8000406a c0b30594 c0784064 c000e504 00000746 c007a528 [ 3.971862] 7fe0: 00000001 0000001d 600001d3 c0bcc004 00000000 800086c4 ee0aa6a7 d2aabaa9 [ 3.980499] [<c0029ed8>] (irq_notifier+0x234/0x25c) from [<c077c04c>] (notifier_call_chain+0x38/0x68) [ 3.990173] [<c077c04c>] (notifier_call_chain+0x38/0x68) from [<c00cfad8>] (cpu_pm_notify+0x20/0x38) [ 3.999786] [<c00cfad8>] (cpu_pm_notify+0x20/0x38) from [<c00cfb10>] (cpu_cluster_pm_exit+0x20/0x50) [ 4.009399] [<c00cfb10>] (cpu_cluster_pm_exit+0x20/0x50) from [<c002c1c8>] (omap_enter_idle_coupled+0x11c/0x14c) [ 4.020111] [<c002c1c8>] (omap_enter_idle_coupled+0x11c/0x14c) from [<c05a1bc4>] (cpuidle_enter_state+0x40/0xec) [ 4.030822] [<c05a1bc4>] (cpuidle_enter_state+0x40/0xec) from [<c05a3c78>] (cpuidle_enter_state_coupled+0x1f4/0x240) [ 4.041870] [<c05a3c78>] (cpuidle_enter_state_coupled+0x1f4/0x240) from [<c05a1dc0>] (cpuidle_idle_call+0x150/0x228) [ 4.052947] [<c05a1dc0>] (cpuidle_idle_call+0x150/0x228) from [<c000e504>] (arch_cpu_idle+0x8/0x38) [ 4.062499] [<c000e504>] (arch_cpu_idle+0x8/0x38) from [<c007a528>] (cpu_startup_entry+0x178/0x1e4) [ 4.071990] [<c007a528>] (cpu_startup_entry+0x178/0x1e4) from [<800086c4>] (0x800086c4) [ 4.080383] Code: e5922288 03a03b0a 13a03c25 e0823003 (e5932000) [ 4.086791] ---[ end trace d83954a84a6fa69e ]--- It is supposed that sar_base is initialized in irq_save_context, which is called on CPU_CLUSTER_PM_ENTER notification. If this notification has been missed and CPU_CLUSTER_PM_EXIT is received sar_base is NULL. Fix it by calling CPU_CLUSTER_PM_{ENTER,EXIT} under the same condition. Signed-off-by: Vladimir Murzin <[email protected]> Acked-by: Kevin Hilman <[email protected]> Signed-off-by: Tony Lindgren <[email protected]>
As the new x86 CPU bootup printout format code maintainer, I am taking immediate action to improve and clean (and thus indulge my OCD) the reporting of the cores when coming up online. Fix padding to a right-hand alignment, cleanup code and bind reporting width to the max number of supported CPUs on the system, like this: [ 0.074509] smpboot: Booting Node 0, Processors: multipath-tcp#1 multipath-tcp#2 multipath-tcp#3 multipath-tcp#4 multipath-tcp#5 multipath-tcp#6 multipath-tcp#7 OK [ 0.644008] smpboot: Booting Node 1, Processors: multipath-tcp#8 multipath-tcp#9 multipath-tcp#10 multipath-tcp#11 multipath-tcp#12 multipath-tcp#13 multipath-tcp#14 multipath-tcp#15 OK [ 1.245006] smpboot: Booting Node 2, Processors: multipath-tcp#16 multipath-tcp#17 multipath-tcp#18 multipath-tcp#19 multipath-tcp#20 multipath-tcp#21 multipath-tcp#22 multipath-tcp#23 OK [ 1.864005] smpboot: Booting Node 3, Processors: multipath-tcp#24 multipath-tcp#25 multipath-tcp#26 multipath-tcp#27 multipath-tcp#28 multipath-tcp#29 multipath-tcp#30 multipath-tcp#31 OK [ 2.489005] smpboot: Booting Node 4, Processors: multipath-tcp#32 multipath-tcp#33 multipath-tcp#34 multipath-tcp#35 multipath-tcp#36 multipath-tcp#37 multipath-tcp#38 multipath-tcp#39 OK [ 3.093005] smpboot: Booting Node 5, Processors: multipath-tcp#40 multipath-tcp#41 multipath-tcp#42 multipath-tcp#43 multipath-tcp#44 multipath-tcp#45 multipath-tcp#46 multipath-tcp#47 OK [ 3.698005] smpboot: Booting Node 6, Processors: multipath-tcp#48 multipath-tcp#49 multipath-tcp#50 multipath-tcp#51 multipath-tcp#52 multipath-tcp#53 multipath-tcp#54 multipath-tcp#55 OK [ 4.304005] smpboot: Booting Node 7, Processors: multipath-tcp#56 multipath-tcp#57 multipath-tcp#58 multipath-tcp#59 multipath-tcp#60 multipath-tcp#61 multipath-tcp#62 multipath-tcp#63 OK [ 4.961413] Brought up 64 CPUs and this: [ 0.072367] smpboot: Booting Node 0, Processors: multipath-tcp#1 multipath-tcp#2 multipath-tcp#3 multipath-tcp#4 multipath-tcp#5 multipath-tcp#6 multipath-tcp#7 OK [ 0.686329] Brought up 8 CPUs Signed-off-by: Borislav Petkov <[email protected]> Cc: Libin <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
Turn it into (for example): [ 0.073380] x86: Booting SMP configuration: [ 0.074005] .... node #0, CPUs: multipath-tcp#1 multipath-tcp#2 multipath-tcp#3 multipath-tcp#4 multipath-tcp#5 multipath-tcp#6 multipath-tcp#7 [ 0.603005] .... node multipath-tcp#1, CPUs: multipath-tcp#8 multipath-tcp#9 multipath-tcp#10 multipath-tcp#11 multipath-tcp#12 multipath-tcp#13 multipath-tcp#14 multipath-tcp#15 [ 1.200005] .... node multipath-tcp#2, CPUs: multipath-tcp#16 multipath-tcp#17 multipath-tcp#18 multipath-tcp#19 multipath-tcp#20 multipath-tcp#21 multipath-tcp#22 multipath-tcp#23 [ 1.796005] .... node multipath-tcp#3, CPUs: multipath-tcp#24 multipath-tcp#25 multipath-tcp#26 multipath-tcp#27 multipath-tcp#28 multipath-tcp#29 multipath-tcp#30 multipath-tcp#31 [ 2.393005] .... node multipath-tcp#4, CPUs: multipath-tcp#32 multipath-tcp#33 multipath-tcp#34 multipath-tcp#35 multipath-tcp#36 multipath-tcp#37 multipath-tcp#38 multipath-tcp#39 [ 2.996005] .... node multipath-tcp#5, CPUs: multipath-tcp#40 multipath-tcp#41 multipath-tcp#42 multipath-tcp#43 multipath-tcp#44 multipath-tcp#45 multipath-tcp#46 multipath-tcp#47 [ 3.600005] .... node multipath-tcp#6, CPUs: multipath-tcp#48 multipath-tcp#49 multipath-tcp#50 multipath-tcp#51 multipath-tcp#52 multipath-tcp#53 multipath-tcp#54 multipath-tcp#55 [ 4.202005] .... node multipath-tcp#7, CPUs: multipath-tcp#56 multipath-tcp#57 multipath-tcp#58 multipath-tcp#59 multipath-tcp#60 multipath-tcp#61 multipath-tcp#62 multipath-tcp#63 [ 4.811005] .... node multipath-tcp#8, CPUs: multipath-tcp#64 multipath-tcp#65 multipath-tcp#66 multipath-tcp#67 multipath-tcp#68 multipath-tcp#69 multipath-tcp#70 multipath-tcp#71 [ 5.421006] .... node multipath-tcp#9, CPUs: multipath-tcp#72 multipath-tcp#73 multipath-tcp#74 multipath-tcp#75 multipath-tcp#76 multipath-tcp#77 multipath-tcp#78 multipath-tcp#79 [ 6.032005] .... node multipath-tcp#10, CPUs: multipath-tcp#80 multipath-tcp#81 multipath-tcp#82 multipath-tcp#83 multipath-tcp#84 multipath-tcp#85 multipath-tcp#86 multipath-tcp#87 [ 6.648006] .... node multipath-tcp#11, CPUs: multipath-tcp#88 multipath-tcp#89 multipath-tcp#90 multipath-tcp#91 multipath-tcp#92 multipath-tcp#93 multipath-tcp#94 multipath-tcp#95 [ 7.262005] .... node multipath-tcp#12, CPUs: multipath-tcp#96 multipath-tcp#97 multipath-tcp#98 multipath-tcp#99 multipath-tcp#100 multipath-tcp#101 multipath-tcp#102 multipath-tcp#103 [ 7.865005] .... node multipath-tcp#13, CPUs: multipath-tcp#104 multipath-tcp#105 multipath-tcp#106 multipath-tcp#107 multipath-tcp#108 multipath-tcp#109 multipath-tcp#110 multipath-tcp#111 [ 8.466005] .... node multipath-tcp#14, CPUs: multipath-tcp#112 multipath-tcp#113 multipath-tcp#114 multipath-tcp#115 multipath-tcp#116 multipath-tcp#117 multipath-tcp#118 multipath-tcp#119 [ 9.073006] .... node multipath-tcp#15, CPUs: multipath-tcp#120 multipath-tcp#121 multipath-tcp#122 multipath-tcp#123 multipath-tcp#124 multipath-tcp#125 multipath-tcp#126 multipath-tcp#127 [ 9.679901] x86: Booted up 16 nodes, 128 CPUs and drop useless elements. Change num_digits() to hpa's division-avoiding, cell-phone-typed version which he went at great lengths and pains to submit on a Saturday evening. Signed-off-by: Borislav Petkov <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
clk_disable_unprepare in remove causes an imbalance and hence gives the below crash on module remove. While at it also remove some duplicate code from probe. / $ rmmod i2c-exynos5 [ 6.996374] ------------[ cut here ]------------ [ 6.999523] WARNING: CPU: 2 PID: 1137 at drivers/clk/clk.c:842 clk_disable+0x18/0x24() [ 7.007403] Modules linked in: i2c_exynos5(-) [ 7.011747] CPU: 2 PID: 1137 Comm: rmmod Not tainted 3.12.0-next-20131105-00083-g16f4799-dirty multipath-tcp#21 [ 7.020696] [<c0014e0c>] (unwind_backtrace+0x0/0xf4) from [<c0011784>] (show_stack+0x10/0x14) [ 7.029190] [<c0011784>] (show_stack+0x10/0x14) from [<c037acd4>] (dump_stack+0x7c/0xb0) [ 7.037255] [<c037acd4>] (dump_stack+0x7c/0xb0) from [<c001e0ac>] (warn_slowpath_common+0x6c/0x88) [ 7.046190] [<c001e0ac>] (warn_slowpath_common+0x6c/0x88) from [<c001e164>] (warn_slowpath_null+0x1c/0x24) [ 7.055818] [<c001e164>] (warn_slowpath_null+0x1c/0x24) from [<c02dcde4>] (clk_disable+0x18/0x24) [ 7.064670] [<c02dcde4>] (clk_disable+0x18/0x24) from [<bf0002d4>] (exynos5_i2c_remove+0x1c/0x34 [i2c_exynos5]) [ 7.074736] [<bf0002d4>] (exynos5_i2c_remove+0x1c/0x34 [i2c_exynos5]) from [<c02274a8>] (__device_release_driver+0x58/0xb0) [ 7.085836] [<c02274a8>] (__device_release_driver+0x58/0xb0) from [<c0227b88>] (driver_detach+0xac/0xb0) [ 7.095291] [<c0227b88>] (driver_detach+0xac/0xb0) from [<c02271c0>] (bus_remove_driver+0x4c/0xa0) [ 7.104227] [<c02271c0>] (bus_remove_driver+0x4c/0xa0) from [<c00725dc>] (SyS_delete_module+0x124/0x194) [ 7.113682] [<c00725dc>] (SyS_delete_module+0x124/0x194) from [<c000e2e0>] (ret_fast_syscall+0x0/0x30) [ 7.122957] ---[ end trace 23bb6e4e0bf52196 ]--- Signed-off-by: Sachin Kamat <[email protected]> Acked-by: Naveen Krishna Chatradhi <[email protected]> Signed-off-by: Wolfram Sang <[email protected]>
cond_resched_lock(cinfo->lock) is called everywhere else while holding the cinfo->lock spinlock. Not holding this lock while calling transfer_commit_list in filelayout_recover_commit_reqs causes the BUG below. It's true that we can't hold this lock while calling pnfs_put_lseg, because that might try to lock the inode lock - which might be the same lock as cinfo->lock. To reproduce, mount a 2 DS pynfs server and run an O_DIRECT command that crosses a stripe boundary and is not page aligned, such as: dd if=/dev/zero of=/mnt/f bs=17000 count=1 oflag=direct BUG: sleeping function called from invalid context at linux/fs/nfs/nfs4filelayout.c:1161 in_atomic(): 0, irqs_disabled(): 0, pid: 27, name: kworker/0:1 2 locks held by kworker/0:1/27: #0: (events){.+.+.+}, at: [<ffffffff810501d7>] process_one_work+0x175/0x3a5 multipath-tcp#1: ((&dreq->work)){+.+...}, at: [<ffffffff810501d7>] process_one_work+0x175/0x3a5 CPU: 0 PID: 27 Comm: kworker/0:1 Not tainted 3.13.0-rc3-branch-dros_testing+ multipath-tcp#21 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 Workqueue: events nfs_direct_write_schedule_work [nfs] 0000000000000000 ffff88007a39bbb8 ffffffff81491256 ffff88007b87a130 ffff88007a39bbd8 ffffffff8105f103 ffff880079614000 ffff880079617d40 ffff88007a39bc20 ffffffffa011603e ffff880078988b98 0000000000000000 Call Trace: [<ffffffff81491256>] dump_stack+0x4d/0x66 [<ffffffff8105f103>] __might_sleep+0x100/0x105 [<ffffffffa011603e>] transfer_commit_list+0x94/0xf1 [nfs_layout_nfsv41_files] [<ffffffffa01160d6>] filelayout_recover_commit_reqs+0x3b/0x68 [nfs_layout_nfsv41_files] [<ffffffffa00ba53a>] nfs_direct_write_reschedule+0x9f/0x1d6 [nfs] [<ffffffff810705df>] ? mark_lock+0x1df/0x224 [<ffffffff8106e617>] ? trace_hardirqs_off_caller+0x37/0xa4 [<ffffffff8106e691>] ? trace_hardirqs_off+0xd/0xf [<ffffffffa00ba8f8>] nfs_direct_write_schedule_work+0x9d/0xb7 [nfs] [<ffffffff810501d7>] ? process_one_work+0x175/0x3a5 [<ffffffff81050258>] process_one_work+0x1f6/0x3a5 [<ffffffff810501d7>] ? process_one_work+0x175/0x3a5 [<ffffffff8105187e>] worker_thread+0x149/0x1f5 [<ffffffff81051735>] ? rescuer_thread+0x28d/0x28d [<ffffffff81056d74>] kthread+0xd2/0xda [<ffffffff81056ca2>] ? __kthread_parkme+0x61/0x61 [<ffffffff8149e66c>] ret_from_fork+0x7c/0xb0 [<ffffffff81056ca2>] ? __kthread_parkme+0x61/0x61 Signed-off-by: Weston Andros Adamson <[email protected]> Signed-off-by: Trond Myklebust <[email protected]>
commit 086ba77 upstream. ARM has some private syscalls (for example, set_tls(2)) which lie outside the range of NR_syscalls. If any of these are called while syscall tracing is being performed, out-of-bounds array access will occur in the ftrace and perf sys_{enter,exit} handlers. # trace-cmd record -e raw_syscalls:* true && trace-cmd report ... true-653 [000] 384.675777: sys_enter: NR 192 (0, 1000, 3, 4000022, ffffffff, 0) true-653 [000] 384.675812: sys_exit: NR 192 = 1995915264 true-653 [000] 384.675971: sys_enter: NR 983045 (76f74480, 76f74000, 76f74b28, 76f74480, 76f76f74, 1) true-653 [000] 384.675988: sys_exit: NR 983045 = 0 ... # trace-cmd record -e syscalls:* true [ 17.289329] Unable to handle kernel paging request at virtual address aaaaaace [ 17.289590] pgd = 9e71c000 [ 17.289696] [aaaaaace] *pgd=00000000 [ 17.289985] Internal error: Oops: 5 [#1] PREEMPT SMP ARM [ 17.290169] Modules linked in: [ 17.290391] CPU: 0 PID: 704 Comm: true Not tainted 3.18.0-rc2+ #21 [ 17.290585] task: 9f4dab00 ti: 9e710000 task.ti: 9e710000 [ 17.290747] PC is at ftrace_syscall_enter+0x48/0x1f8 [ 17.290866] LR is at syscall_trace_enter+0x124/0x184 Fix this by ignoring out-of-NR_syscalls-bounds syscall numbers. Commit cd0980f "tracing: Check invalid syscall nr while tracing syscalls" added the check for less than zero, but it should have also checked for greater than NR_syscalls. Link: http://lkml.kernel.org/p/[email protected] Fixes: cd0980f "tracing: Check invalid syscall nr while tracing syscalls" Signed-off-by: Rabin Vincent <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
[ Upstream commit ecf5fc6 ] Nikolay has reported a hang when a memcg reclaim got stuck with the following backtrace: PID: 18308 TASK: ffff883d7c9b0a30 CPU: 1 COMMAND: "rsync" #0 __schedule at ffffffff815ab152 #1 schedule at ffffffff815ab76e #2 schedule_timeout at ffffffff815ae5e5 #3 io_schedule_timeout at ffffffff815aad6a #4 bit_wait_io at ffffffff815abfc6 #5 __wait_on_bit at ffffffff815abda5 #6 wait_on_page_bit at ffffffff8111fd4f #7 shrink_page_list at ffffffff81135445 #8 shrink_inactive_list at ffffffff81135845 #9 shrink_lruvec at ffffffff81135ead #10 shrink_zone at ffffffff811360c3 #11 shrink_zones at ffffffff81136eff #12 do_try_to_free_pages at ffffffff8113712f #13 try_to_free_mem_cgroup_pages at ffffffff811372be #14 try_charge at ffffffff81189423 #15 mem_cgroup_try_charge at ffffffff8118c6f5 #16 __add_to_page_cache_locked at ffffffff8112137d #17 add_to_page_cache_lru at ffffffff81121618 #18 pagecache_get_page at ffffffff8112170b #19 grow_dev_page at ffffffff811c8297 #20 __getblk_slow at ffffffff811c91d6 #21 __getblk_gfp at ffffffff811c92c1 #22 ext4_ext_grow_indepth at ffffffff8124565c #23 ext4_ext_create_new_leaf at ffffffff81246ca8 #24 ext4_ext_insert_extent at ffffffff81246f09 #25 ext4_ext_map_blocks at ffffffff8124a848 #26 ext4_map_blocks at ffffffff8121a5b7 #27 mpage_map_one_extent at ffffffff8121b1fa #28 mpage_map_and_submit_extent at ffffffff8121f07b #29 ext4_writepages at ffffffff8121f6d5 #30 do_writepages at ffffffff8112c490 #31 __filemap_fdatawrite_range at ffffffff81120199 #32 filemap_flush at ffffffff8112041c #33 ext4_alloc_da_blocks at ffffffff81219da1 #34 ext4_rename at ffffffff81229b91 #35 ext4_rename2 at ffffffff81229e32 #36 vfs_rename at ffffffff811a08a5 #37 SYSC_renameat2 at ffffffff811a3ffc #38 sys_renameat2 at ffffffff811a408e #39 sys_rename at ffffffff8119e51e #40 system_call_fastpath at ffffffff815afa89 Dave Chinner has properly pointed out that this is a deadlock in the reclaim code because ext4 doesn't submit pages which are marked by PG_writeback right away. The heuristic was introduced by commit e62e384 ("memcg: prevent OOM with too many dirty pages") and it was applied only when may_enter_fs was specified. The code has been changed by c3b94f4 ("memcg: further prevent OOM with too many dirty pages") which has removed the __GFP_FS restriction with a reasoning that we do not get into the fs code. But this is not sufficient apparently because the fs doesn't necessarily submit pages marked PG_writeback for IO right away. ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily submit the bio. Instead it tries to map more pages into the bio and mpage_map_one_extent might trigger memcg charge which might end up waiting on a page which is marked PG_writeback but hasn't been submitted yet so we would end up waiting for something that never finishes. Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2) before we go to wait on the writeback. The page fault path, which is the only path that triggers memcg oom killer since 3.12, shouldn't require GFP_NOFS and so we shouldn't reintroduce the premature OOM killer issue which was originally addressed by the heuristic. As per David Chinner the xfs is doing similar thing since 2.6.15 already so ext4 is not the only affected filesystem. Moreover he notes: : For example: IO completion might require unwritten extent conversion : which executes filesystem transactions and GFP_NOFS allocations. The : writeback flag on the pages can not be cleared until unwritten : extent conversion completes. Hence memory reclaim cannot wait on : page writeback to complete in GFP_NOFS context because it is not : safe to do so, memcg reclaim or otherwise. Cc: [email protected] # 3.9+ [[email protected]: corrected the control flow] Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages") Reported-by: Nikolay Borisov <[email protected]> Signed-off-by: Michal Hocko <[email protected]> Signed-off-by: Hugh Dickins <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
commit ecf5fc6 upstream. Nikolay has reported a hang when a memcg reclaim got stuck with the following backtrace: PID: 18308 TASK: ffff883d7c9b0a30 CPU: 1 COMMAND: "rsync" #0 __schedule at ffffffff815ab152 #1 schedule at ffffffff815ab76e #2 schedule_timeout at ffffffff815ae5e5 #3 io_schedule_timeout at ffffffff815aad6a #4 bit_wait_io at ffffffff815abfc6 #5 __wait_on_bit at ffffffff815abda5 #6 wait_on_page_bit at ffffffff8111fd4f #7 shrink_page_list at ffffffff81135445 #8 shrink_inactive_list at ffffffff81135845 #9 shrink_lruvec at ffffffff81135ead #10 shrink_zone at ffffffff811360c3 #11 shrink_zones at ffffffff81136eff #12 do_try_to_free_pages at ffffffff8113712f #13 try_to_free_mem_cgroup_pages at ffffffff811372be #14 try_charge at ffffffff81189423 #15 mem_cgroup_try_charge at ffffffff8118c6f5 #16 __add_to_page_cache_locked at ffffffff8112137d #17 add_to_page_cache_lru at ffffffff81121618 #18 pagecache_get_page at ffffffff8112170b #19 grow_dev_page at ffffffff811c8297 #20 __getblk_slow at ffffffff811c91d6 #21 __getblk_gfp at ffffffff811c92c1 #22 ext4_ext_grow_indepth at ffffffff8124565c #23 ext4_ext_create_new_leaf at ffffffff81246ca8 #24 ext4_ext_insert_extent at ffffffff81246f09 #25 ext4_ext_map_blocks at ffffffff8124a848 #26 ext4_map_blocks at ffffffff8121a5b7 #27 mpage_map_one_extent at ffffffff8121b1fa #28 mpage_map_and_submit_extent at ffffffff8121f07b #29 ext4_writepages at ffffffff8121f6d5 #30 do_writepages at ffffffff8112c490 #31 __filemap_fdatawrite_range at ffffffff81120199 #32 filemap_flush at ffffffff8112041c #33 ext4_alloc_da_blocks at ffffffff81219da1 #34 ext4_rename at ffffffff81229b91 #35 ext4_rename2 at ffffffff81229e32 #36 vfs_rename at ffffffff811a08a5 #37 SYSC_renameat2 at ffffffff811a3ffc #38 sys_renameat2 at ffffffff811a408e #39 sys_rename at ffffffff8119e51e #40 system_call_fastpath at ffffffff815afa89 Dave Chinner has properly pointed out that this is a deadlock in the reclaim code because ext4 doesn't submit pages which are marked by PG_writeback right away. The heuristic was introduced by commit e62e384 ("memcg: prevent OOM with too many dirty pages") and it was applied only when may_enter_fs was specified. The code has been changed by c3b94f4 ("memcg: further prevent OOM with too many dirty pages") which has removed the __GFP_FS restriction with a reasoning that we do not get into the fs code. But this is not sufficient apparently because the fs doesn't necessarily submit pages marked PG_writeback for IO right away. ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily submit the bio. Instead it tries to map more pages into the bio and mpage_map_one_extent might trigger memcg charge which might end up waiting on a page which is marked PG_writeback but hasn't been submitted yet so we would end up waiting for something that never finishes. Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2) before we go to wait on the writeback. The page fault path, which is the only path that triggers memcg oom killer since 3.12, shouldn't require GFP_NOFS and so we shouldn't reintroduce the premature OOM killer issue which was originally addressed by the heuristic. As per David Chinner the xfs is doing similar thing since 2.6.15 already so ext4 is not the only affected filesystem. Moreover he notes: : For example: IO completion might require unwritten extent conversion : which executes filesystem transactions and GFP_NOFS allocations. The : writeback flag on the pages can not be cleared until unwritten : extent conversion completes. Hence memory reclaim cannot wait on : page writeback to complete in GFP_NOFS context because it is not : safe to do so, memcg reclaim or otherwise. Cc: [email protected] # 3.9+ [[email protected]: corrected the control flow] Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages") Reported-by: Nikolay Borisov <[email protected]> Signed-off-by: Michal Hocko <[email protected]> Signed-off-by: Hugh Dickins <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
commit 4dfce57 upstream. There have been several reports over the years of NULL pointer dereferences in xfs_trans_log_inode during xfs_fsr processes, when the process is doing an fput and tearing down extents on the temporary inode, something like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 PID: 29439 TASK: ffff880550584fa0 CPU: 6 COMMAND: "xfs_fsr" [exception RIP: xfs_trans_log_inode+0x10] #9 [ffff8800a57bbbe0] xfs_bunmapi at ffffffffa037398e [xfs] #10 [ffff8800a57bbce8] xfs_itruncate_extents at ffffffffa0391b29 [xfs] #11 [ffff8800a57bbd88] xfs_inactive_truncate at ffffffffa0391d0c [xfs] #12 [ffff8800a57bbdb8] xfs_inactive at ffffffffa0392508 [xfs] #13 [ffff8800a57bbdd8] xfs_fs_evict_inode at ffffffffa035907e [xfs] #14 [ffff8800a57bbe00] evict at ffffffff811e1b67 #15 [ffff8800a57bbe28] iput at ffffffff811e23a5 #16 [ffff8800a57bbe58] dentry_kill at ffffffff811dcfc8 #17 [ffff8800a57bbe88] dput at ffffffff811dd06c #18 [ffff8800a57bbea8] __fput at ffffffff811c823b #19 [ffff8800a57bbef0] ____fput at ffffffff811c846e #20 [ffff8800a57bbf00] task_work_run at ffffffff81093b27 #21 [ffff8800a57bbf30] do_notify_resume at ffffffff81013b0c #22 [ffff8800a57bbf50] int_signal at ffffffff8161405d As it turns out, this is because the i_itemp pointer, along with the d_ops pointer, has been overwritten with zeros when we tear down the extents during truncate. When the in-core inode fork on the temporary inode used by xfs_fsr was originally set up during the extent swap, we mistakenly looked at di_nextents to determine whether all extents fit inline, but this misses extents generated by speculative preallocation; we should be using if_bytes instead. This mistake corrupts the in-memory inode, and code in xfs_iext_remove_inline eventually gets bad inputs, causing it to memmove and memset incorrect ranges; this became apparent because the two values in ifp->if_u2.if_inline_ext[1] contained what should have been in d_ops and i_itemp; they were memmoved due to incorrect array indexing and then the original locations were zeroed with memset, again due to an array overrun. Fix this by properly using i_df.if_bytes to determine the number of extents, not di_nextents. Thanks to dchinner for looking at this with me and spotting the root cause. [nborisov: backported to 4.4] Cc: [email protected] Signed-off-by: Eric Sandeen <[email protected]> Reviewed-by: Brian Foster <[email protected]> Signed-off-by: Dave Chinner <[email protected]> Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> -- fs/xfs/xfs_bmap_util.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
commit 613bd1e upstream. Commit 9b61e30 (spi: Pick spi bus number from Linux idr or spi alias) ceased to unregister SPI buses with fixed bus numbers. Moreover this is visible only if CONFIG_SPI_DEBUG=y is set or when trying to re-register the same SPI controller. rmmod spi_pxa2xx_platform (with CONFIG_SPI_DEBUG=y): [ 26.788362] spi_master spi1: attempting to delete unregistered controller [spi1] modprobe spi_pxa2xx_platform: [ 37.883137] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:19.0/pxa2xx-spi.12/spi_master/spi1' [ 37.894984] CPU: 1 PID: 1467 Comm: modprobe Not tainted 4.16.0-rc4+ multipath-tcp#21 [ 37.902384] Call Trace: ... [ 38.122680] kobject_add_internal failed for spi1 with -EEXIST, don't try to register things with the same name in the same directory. [ 38.136154] WARNING: CPU: 1 PID: 1467 at lib/kobject.c:238 kobject_add_internal+0x2a5/0x2f0 ... [ 38.513817] pxa2xx-spi pxa2xx-spi.12: problem registering spi master [ 38.521036] pxa2xx-spi: probe of pxa2xx-spi.12 failed with error -17 Fix this by not returning immediately from spi_unregister_controller() if idr_find() doesn't find controller with given ID/bus number. It finds only those controllers that were registered with dynamic SPI bus numbers. Only conditional cleanup between dynamic and fixed bus numbers is to remove allocated IDR. Fixes: 9b61e30 (spi: Pick spi bus number from Linux idr or spi alias) Cc: [email protected] Signed-off-by: Jarkko Nikula <[email protected]> Signed-off-by: Mark Brown <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
commit 613bd1e upstream. Commit 9b61e30 (spi: Pick spi bus number from Linux idr or spi alias) ceased to unregister SPI buses with fixed bus numbers. Moreover this is visible only if CONFIG_SPI_DEBUG=y is set or when trying to re-register the same SPI controller. rmmod spi_pxa2xx_platform (with CONFIG_SPI_DEBUG=y): [ 26.788362] spi_master spi1: attempting to delete unregistered controller [spi1] modprobe spi_pxa2xx_platform: [ 37.883137] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:19.0/pxa2xx-spi.12/spi_master/spi1' [ 37.894984] CPU: 1 PID: 1467 Comm: modprobe Not tainted 4.16.0-rc4+ #21 [ 37.902384] Call Trace: ... [ 38.122680] kobject_add_internal failed for spi1 with -EEXIST, don't try to register things with the same name in the same directory. [ 38.136154] WARNING: CPU: 1 PID: 1467 at lib/kobject.c:238 kobject_add_internal+0x2a5/0x2f0 ... [ 38.513817] pxa2xx-spi pxa2xx-spi.12: problem registering spi master [ 38.521036] pxa2xx-spi: probe of pxa2xx-spi.12 failed with error -17 Fix this by not returning immediately from spi_unregister_controller() if idr_find() doesn't find controller with given ID/bus number. It finds only those controllers that were registered with dynamic SPI bus numbers. Only conditional cleanup between dynamic and fixed bus numbers is to remove allocated IDR. Fixes: 9b61e30 (spi: Pick spi bus number from Linux idr or spi alias) Cc: [email protected] Signed-off-by: Jarkko Nikula <[email protected]> Signed-off-by: Mark Brown <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
[ Upstream commit af50e4b ] syzbot caught an infinite recursion in nsh_gso_segment(). Problem here is that we need to make sure the NSH header is of reasonable length. BUG: MAX_LOCK_DEPTH too low! turning off the locking correctness validator. depth: 48 max: 48! 48 locks held by syz-executor0/10189: #0: (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517 #1: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] #1: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#2: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#2: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#3: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#3: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#4: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#4: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#5: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#5: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#6: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#6: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#7: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#7: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#8: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#8: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#9: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#9: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#10: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#10: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#11: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#11: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#12: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#12: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#13: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#13: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#14: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#14: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#15: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#15: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#16: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#16: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#17: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#17: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#18: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#18: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#19: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#19: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#20: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#20: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#21: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#21: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#22: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#22: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#23: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#23: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#24: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#24: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#25: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#25: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#26: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#26: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#27: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#27: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#28: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#28: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#29: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#29: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#30: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#30: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#31: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#31: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 dccp_close: ABORT with 65423 bytes unread multipath-tcp#32: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#32: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#33: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#33: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#34: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#34: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#35: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#35: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#36: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#36: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#37: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#37: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#38: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#38: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#39: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#39: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#40: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#40: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#41: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#41: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#42: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#42: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#43: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#43: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#44: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#44: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#45: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#45: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#46: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#46: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 multipath-tcp#47: (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline] multipath-tcp#47: (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787 INFO: lockdep is turned off. CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ multipath-tcp#26 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 rcu_lock_acquire include/linux/rcupdate.h:246 [inline] rcu_read_lock include/linux/rcupdate.h:632 [inline] skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865 skb_gso_segment include/linux/netdevice.h:4025 [inline] validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312 qdisc_restart net/sched/sch_generic.c:399 [inline] __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410 __dev_xmit_skb net/core/dev.c:3243 [inline] __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616 packet_snd net/packet/af_packet.c:2951 [inline] packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 __sys_sendto+0x3d7/0x670 net/socket.c:1789 __do_sys_sendto net/socket.c:1801 [inline] __se_sys_sendto net/socket.c:1797 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: c411ed8 ("nsh: add GSO support") Signed-off-by: Eric Dumazet <[email protected]> Cc: Jiri Benc <[email protected]> Reported-by: syzbot <[email protected]> Acked-by: Jiri Benc <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
[ Upstream commit 2bbea6e ] when mounting an ISO filesystem sometimes (very rarely) the system hangs because of a race condition between two tasks. PID: 6766 TASK: ffff88007b2a6dd0 CPU: 0 COMMAND: "mount" #0 [ffff880078447ae0] __schedule at ffffffff8168d605 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49 multipath-tcp#2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995 multipath-tcp#3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef multipath-tcp#4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod] multipath-tcp#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50 multipath-tcp#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3 multipath-tcp#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs] multipath-tcp#8 [ffff880078447da8] mount_bdev at ffffffff81202570 multipath-tcp#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs] multipath-tcp#10 [ffff880078447e28] mount_fs at ffffffff81202d09 multipath-tcp#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f multipath-tcp#12 [ffff880078447ea8] do_mount at ffffffff81220fee multipath-tcp#13 [ffff880078447f28] sys_mount at ffffffff812218d6 multipath-tcp#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49 RIP: 00007fd9ea914e9a RSP: 00007ffd5d9bf648 RFLAGS: 00010246 RAX: 00000000000000a5 RBX: ffffffff81698c49 RCX: 0000000000000010 RDX: 00007fd9ec2bc210 RSI: 00007fd9ec2bc290 RDI: 00007fd9ec2bcf30 RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000010 R10: 00000000c0ed0001 R11: 0000000000000206 R12: 00007fd9ec2bc040 R13: 00007fd9eb6b2380 R14: 00007fd9ec2bc210 R15: 00007fd9ec2bcf30 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b This task was trying to mount the cdrom. It allocated and configured a super_block struct and owned the write-lock for the super_block->s_umount rwsem. While exclusively owning the s_umount lock, it called sr_block_ioctl and waited to acquire the global sr_mutex lock. PID: 6785 TASK: ffff880078720fb0 CPU: 0 COMMAND: "systemd-udevd" #0 [ffff880078417898] __schedule at ffffffff8168d605 #1 [ffff880078417900] schedule at ffffffff8168dc59 multipath-tcp#2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605 multipath-tcp#3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838 multipath-tcp#4 [ffff8800784179d0] down_read at ffffffff8168cde0 multipath-tcp#5 [ffff8800784179e8] get_super at ffffffff81201cc7 multipath-tcp#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de multipath-tcp#7 [ffff880078417a40] flush_disk at ffffffff8123a94b multipath-tcp#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50 multipath-tcp#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom] multipath-tcp#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod] multipath-tcp#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86 multipath-tcp#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65 multipath-tcp#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b multipath-tcp#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7 multipath-tcp#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf multipath-tcp#16 [ffff880078417d00] do_last at ffffffff8120d53d multipath-tcp#17 [ffff880078417db0] path_openat at ffffffff8120e6b2 multipath-tcp#18 [ffff880078417e48] do_filp_open at ffffffff8121082b multipath-tcp#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33 multipath-tcp#20 [ffff880078417f70] sys_open at ffffffff811fde4e multipath-tcp#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49 RIP: 00007f29438b0c20 RSP: 00007ffc76624b78 RFLAGS: 00010246 RAX: 0000000000000002 RBX: ffffffff81698c49 RCX: 0000000000000000 RDX: 00007f2944a5fa70 RSI: 00000000000a0800 RDI: 00007f2944a5fa70 RBP: 00007f2944a5f540 R8: 0000000000000000 R9: 0000000000000020 R10: 00007f2943614c40 R11: 0000000000000246 R12: ffffffff811fde4e R13: ffff880078417f78 R14: 000000000000000c R15: 00007f2944a4b010 ORIG_RAX: 0000000000000002 CS: 0033 SS: 002b This task tried to open the cdrom device, the sr_block_open function acquired the global sr_mutex lock. The call to check_disk_change() then saw an event flag indicating a possible media change and tried to flush any cached data for the device. As part of the flush, it tried to acquire the super_block->s_umount lock associated with the cdrom device. This was the same super_block as created and locked by the previous task. The first task acquires the s_umount lock and then the sr_mutex_lock; the second task acquires the sr_mutex_lock and then the s_umount lock. This patch fixes the issue by moving check_disk_change() out of cdrom_open() and let the caller take care of it. Signed-off-by: Maurizio Lombardi <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
commit a5ba1d9 upstream. We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 #2 [ffff88085c6db830] oops_end at ffffffff81008ae7 #3 [ffff88085c6db860] no_context at ffffffff81050b8f #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d #20 [ffff88085c6dbeb0] kthread at ffffffff81096384 #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
commit a5ba1d9 upstream. We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 multipath-tcp#2 [ffff88085c6db830] oops_end at ffffffff81008ae7 multipath-tcp#3 [ffff88085c6db860] no_context at ffffffff81050b8f multipath-tcp#4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 multipath-tcp#5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 multipath-tcp#6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e multipath-tcp#7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c multipath-tcp#8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 multipath-tcp#9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 multipath-tcp#10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c multipath-tcp#11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b multipath-tcp#12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 multipath-tcp#13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b multipath-tcp#14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a multipath-tcp#15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 multipath-tcp#16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 multipath-tcp#17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a multipath-tcp#18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 multipath-tcp#19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d multipath-tcp#20 [ffff88085c6dbeb0] kthread at ffffffff81096384 multipath-tcp#21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
commit a5ba1d9 upstream. We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 #2 [ffff88085c6db830] oops_end at ffffffff81008ae7 #3 [ffff88085c6db860] no_context at ffffffff81050b8f #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d #20 [ffff88085c6dbeb0] kthread at ffffffff81096384 #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
[ Upstream commit 8425843 ] pid_task() dereferences rcu protected tasks array. But there is no rcu_read_lock() in shutdown_umh() routine so that rcu_read_lock() is needed. get_pid_task() is wrapper function of pid_task. it holds rcu_read_lock() then calls pid_task(). if task isn't NULL, it increases reference count of task. test commands: %modprobe bpfilter %modprobe -rv bpfilter splat looks like: [15102.030932] ============================= [15102.030957] WARNING: suspicious RCU usage [15102.030985] 4.19.0-rc7+ multipath-tcp#21 Not tainted [15102.031010] ----------------------------- [15102.031038] kernel/pid.c:330 suspicious rcu_dereference_check() usage! [15102.031063] other info that might help us debug this: [15102.031332] rcu_scheduler_active = 2, debug_locks = 1 [15102.031363] 1 lock held by modprobe/1570: [15102.031389] #0: 00000000580ef2b0 (bpfilter_lock){+.+.}, at: stop_umh+0x13/0x52 [bpfilter] [15102.031552] stack backtrace: [15102.031583] CPU: 1 PID: 1570 Comm: modprobe Not tainted 4.19.0-rc7+ multipath-tcp#21 [15102.031607] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015 [15102.031628] Call Trace: [15102.031676] dump_stack+0xc9/0x16b [15102.031723] ? show_regs_print_info+0x5/0x5 [15102.031801] ? lockdep_rcu_suspicious+0x117/0x160 [15102.031855] pid_task+0x134/0x160 [15102.031900] ? find_vpid+0xf0/0xf0 [15102.032017] shutdown_umh.constprop.1+0x1e/0x53 [bpfilter] [15102.032055] stop_umh+0x46/0x52 [bpfilter] [15102.032092] __x64_sys_delete_module+0x47e/0x570 [ ... ] Fixes: d2ba09c ("net: add skeleton of bpfilter kernel module") Signed-off-by: Taehee Yoo <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
[ Upstream commit 0fbcc5b ] xt_rateest_net_exit() was added to check whether rules are flushed successfully. but ->net_exit() callback is called earlier than ->destroy() callback. So that ->net_exit() callback can't check that. test commands: %ip netns add vm1 %ip netns exec vm1 iptables -t mangle -I PREROUTING -p udp \ --dport 1111 -j RATEEST --rateest-name ap \ --rateest-interval 250ms --rateest-ewma 0.5s %ip netns del vm1 splat looks like: [ 668.813518] WARNING: CPU: 0 PID: 87 at net/netfilter/xt_RATEEST.c:210 xt_rateest_net_exit+0x210/0x340 [xt_RATEEST] [ 668.813518] Modules linked in: xt_RATEEST xt_tcpudp iptable_mangle bpfilter ip_tables x_tables [ 668.813518] CPU: 0 PID: 87 Comm: kworker/u4:2 Not tainted 4.19.0-rc7+ multipath-tcp#21 [ 668.813518] Workqueue: netns cleanup_net [ 668.813518] RIP: 0010:xt_rateest_net_exit+0x210/0x340 [xt_RATEEST] [ 668.813518] Code: 00 48 8b 85 30 ff ff ff 4c 8b 23 80 38 00 0f 85 24 01 00 00 48 8b 85 30 ff ff ff 4d 85 e4 4c 89 a5 58 ff ff ff c6 00 f8 74 b2 <0f> 0b 48 83 c3 08 4c 39 f3 75 b0 48 b8 00 00 00 00 00 fc ff df 49 [ 668.813518] RSP: 0018:ffff8801156c73f8 EFLAGS: 00010282 [ 668.813518] RAX: ffffed0022ad8e85 RBX: ffff880118928e98 RCX: 5db8012a00000000 [ 668.813518] RDX: ffff8801156c7428 RSI: 00000000cb1d185f RDI: ffff880115663b74 [ 668.813518] RBP: ffff8801156c74d0 R08: ffff8801156633c0 R09: 1ffff100236440be [ 668.813518] R10: 0000000000000001 R11: ffffed002367d852 R12: ffff880115142b08 [ 668.813518] R13: 1ffff10022ad8e81 R14: ffff880118928ea8 R15: dffffc0000000000 [ 668.813518] FS: 0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000 [ 668.813518] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 668.813518] CR2: 0000563aa69f4f28 CR3: 0000000105a16000 CR4: 00000000001006f0 [ 668.813518] Call Trace: [ 668.813518] ? unregister_netdevice_many+0xe0/0xe0 [ 668.813518] ? xt_rateest_net_init+0x2c0/0x2c0 [xt_RATEEST] [ 668.813518] ? default_device_exit+0x1ca/0x270 [ 668.813518] ? remove_proc_entry+0x1cd/0x390 [ 668.813518] ? dev_change_net_namespace+0xd00/0xd00 [ 668.813518] ? __init_waitqueue_head+0x130/0x130 [ 668.813518] ops_exit_list.isra.10+0x94/0x140 [ 668.813518] cleanup_net+0x45b/0x900 [ 668.813518] ? net_drop_ns+0x110/0x110 [ 668.813518] ? swapgs_restore_regs_and_return_to_usermode+0x3c/0x80 [ 668.813518] ? save_trace+0x300/0x300 [ 668.813518] ? lock_acquire+0x196/0x470 [ 668.813518] ? lock_acquire+0x196/0x470 [ 668.813518] ? process_one_work+0xb60/0x1de0 [ 668.813518] ? _raw_spin_unlock_irq+0x29/0x40 [ 668.813518] ? _raw_spin_unlock_irq+0x29/0x40 [ 668.813518] ? __lock_acquire+0x4500/0x4500 [ 668.813518] ? __lock_is_held+0xb4/0x140 [ 668.813518] process_one_work+0xc13/0x1de0 [ 668.813518] ? pwq_dec_nr_in_flight+0x3c0/0x3c0 [ 668.813518] ? set_load_weight+0x270/0x270 [ ... ] Fixes: 3427b2a ("netfilter: make xt_rateest hash table per net") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit b058809 ] A bug is present in GDB which causes early string termination when parsing variables. This has been reported [0], but we should ensure that we can support at least basic printing of the core kernel strings. For current gdb version (has been tested with 7.3 and 8.1), 'lx-version' only prints one character. (gdb) lx-version L(gdb) This can be fixed by casting 'linux_banner' as (char *). (gdb) lx-version Linux version 4.19.0-rc1+ (changbin@acer) (gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)) multipath-tcp#21 SMP Sat Sep 1 21:43:30 CST 2018 [0] https://sourceware.org/bugzilla/show_bug.cgi?id=20077 [[email protected]: add detail to commit message] Link: http://lkml.kernel.org/r/[email protected] Fixes: 2d061d9 ("scripts/gdb: add version command") Signed-off-by: Du Changbin <[email protected]> Signed-off-by: Kieran Bingham <[email protected]> Acked-by: Jan Kiszka <[email protected]> Cc: Jan Kiszka <[email protected]> Cc: Jason Wessel <[email protected]> Cc: Daniel Thompson <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit b058809 ] A bug is present in GDB which causes early string termination when parsing variables. This has been reported [0], but we should ensure that we can support at least basic printing of the core kernel strings. For current gdb version (has been tested with 7.3 and 8.1), 'lx-version' only prints one character. (gdb) lx-version L(gdb) This can be fixed by casting 'linux_banner' as (char *). (gdb) lx-version Linux version 4.19.0-rc1+ (changbin@acer) (gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)) #21 SMP Sat Sep 1 21:43:30 CST 2018 [0] https://sourceware.org/bugzilla/show_bug.cgi?id=20077 [[email protected]: add detail to commit message] Link: http://lkml.kernel.org/r/[email protected] Fixes: 2d061d9 ("scripts/gdb: add version command") Signed-off-by: Du Changbin <[email protected]> Signed-off-by: Kieran Bingham <[email protected]> Acked-by: Jan Kiszka <[email protected]> Cc: Jan Kiszka <[email protected]> Cc: Jason Wessel <[email protected]> Cc: Daniel Thompson <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
pid_task() dereferences rcu protected tasks array. But there is no rcu_read_lock() in shutdown_umh() routine so that rcu_read_lock() is needed. get_pid_task() is wrapper function of pid_task. it holds rcu_read_lock() then calls pid_task(). if task isn't NULL, it increases reference count of task. test commands: %modprobe bpfilter %modprobe -rv bpfilter splat looks like: [15102.030932] ============================= [15102.030957] WARNING: suspicious RCU usage [15102.030985] 4.19.0-rc7+ multipath-tcp#21 Not tainted [15102.031010] ----------------------------- [15102.031038] kernel/pid.c:330 suspicious rcu_dereference_check() usage! [15102.031063] other info that might help us debug this: [15102.031332] rcu_scheduler_active = 2, debug_locks = 1 [15102.031363] 1 lock held by modprobe/1570: [15102.031389] #0: 00000000580ef2b0 (bpfilter_lock){+.+.}, at: stop_umh+0x13/0x52 [bpfilter] [15102.031552] stack backtrace: [15102.031583] CPU: 1 PID: 1570 Comm: modprobe Not tainted 4.19.0-rc7+ multipath-tcp#21 [15102.031607] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015 [15102.031628] Call Trace: [15102.031676] dump_stack+0xc9/0x16b [15102.031723] ? show_regs_print_info+0x5/0x5 [15102.031801] ? lockdep_rcu_suspicious+0x117/0x160 [15102.031855] pid_task+0x134/0x160 [15102.031900] ? find_vpid+0xf0/0xf0 [15102.032017] shutdown_umh.constprop.1+0x1e/0x53 [bpfilter] [15102.032055] stop_umh+0x46/0x52 [bpfilter] [15102.032092] __x64_sys_delete_module+0x47e/0x570 [ ... ] Fixes: d2ba09c ("net: add skeleton of bpfilter kernel module") Signed-off-by: Taehee Yoo <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Extend test_btf with various positive and negative tests around BTF verification of kind Var and DataSec. All passing as well: # ./test_btf [...] BTF raw test[4] (global data test multipath-tcp#1): OK BTF raw test[5] (global data test multipath-tcp#2): OK BTF raw test[6] (global data test multipath-tcp#3): OK BTF raw test[7] (global data test multipath-tcp#4, unsupported linkage): OK BTF raw test[8] (global data test multipath-tcp#5, invalid var type): OK BTF raw test[9] (global data test multipath-tcp#6, invalid var type (fwd type)): OK BTF raw test[10] (global data test multipath-tcp#7, invalid var type (fwd type)): OK BTF raw test[11] (global data test multipath-tcp#8, invalid var size): OK BTF raw test[12] (global data test multipath-tcp#9, invalid var size): OK BTF raw test[13] (global data test multipath-tcp#10, invalid var size): OK BTF raw test[14] (global data test multipath-tcp#11, multiple section members): OK BTF raw test[15] (global data test multipath-tcp#12, invalid offset): OK BTF raw test[16] (global data test multipath-tcp#13, invalid offset): OK BTF raw test[17] (global data test multipath-tcp#14, invalid offset): OK BTF raw test[18] (global data test multipath-tcp#15, not var kind): OK BTF raw test[19] (global data test multipath-tcp#16, invalid var referencing sec): OK BTF raw test[20] (global data test multipath-tcp#17, invalid var referencing var): OK BTF raw test[21] (global data test multipath-tcp#18, invalid var loop): OK BTF raw test[22] (global data test multipath-tcp#19, invalid var referencing var): OK BTF raw test[23] (global data test multipath-tcp#20, invalid ptr referencing var): OK BTF raw test[24] (global data test multipath-tcp#21, var included in struct): OK BTF raw test[25] (global data test multipath-tcp#22, array of var): OK [...] PASS:167 SKIP:0 FAIL:0 Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
[ Upstream commit 30f3312 ] ttm_bo_glob and ttm_mem_glob are defined as structure instance, while not allocated by kzalloc, so kfree should not be invoked to release them anymore. Otherwise, it will cause the following kernel BUG when unloading amdgpu module [ 48.419294] kernel BUG at /build/linux-5s7Xkn/linux-4.15.0/mm/slub.c:3894! [ 48.419352] invalid opcode: 0000 [#1] SMP PTI [ 48.419387] Modules linked in: amdgpu(OE-) amdchash(OE) amdttm(OE) amd_sched(OE) amdkcl(OE) amd_iommu_v2 drm_kms_helper drm i2c_algo_bit fb_sys_fops syscopyarea sysfillrect sysimgblt snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi pcbc snd_seq snd_seq_device snd_timer aesni_intel snd soundcore joydev aes_x86_64 crypto_simd glue_helper cryptd input_leds mac_hid serio_raw binfmt_misc nfsd auth_rpcgss nfs_acl lockd grace sunrpc sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 8139too psmouse i2c_piix4 8139cp mii floppy pata_acpi [ 48.419782] CPU: 1 PID: 1281 Comm: modprobe Tainted: G OE 4.15.0-20-generic #21-Ubuntu [ 48.419838] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 48.419901] RIP: 0010:kfree+0x137/0x180 [ 48.419934] RSP: 0018:ffffb02101273bf8 EFLAGS: 00010246 [ 48.419974] RAX: ffffeee1418ad7e0 RBX: ffffffffc075f100 RCX: ffff8fed7fca7ed0 [ 48.420025] RDX: 0000000000000000 RSI: 000000000003440e RDI: 0000000022400000 [ 48.420073] RBP: ffffb02101273c10 R08: 0000000000000010 R09: ffff8fed7ffd3680 [ 48.420121] R10: ffffeee1418ad7c0 R11: ffff8fed7ffd3000 R12: ffffffffc075e2c0 [ 48.420169] R13: ffffffffc074ec10 R14: ffff8fed73063900 R15: ffff8fed737428e8 [ 48.420216] FS: 00007fdc912ec540(0000) GS:ffff8fed7fc80000(0000) knlGS:0000000000000000 [ 48.420267] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 48.420308] CR2: 000055fa40c30060 CR3: 000000023470a006 CR4: 00000000003606e0 [ 48.420358] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 48.420405] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 48.420452] Call Trace: [ 48.420485] ttm_bo_global_kobj_release+0x20/0x30 [amdttm] [ 48.420528] kobject_release+0x6a/0x180 [ 48.420562] kobject_put+0x28/0x50 [ 48.420595] ttm_bo_global_release+0x36/0x50 [amdttm] [ 48.420636] amdttm_bo_device_release+0x119/0x180 [amdttm] [ 48.420678] ? amdttm_bo_clean_mm+0xa6/0xf0 [amdttm] [ 48.420760] amdgpu_ttm_fini+0xc9/0x180 [amdgpu] [ 48.420821] amdgpu_bo_fini+0x12/0x40 [amdgpu] [ 48.420889] gmc_v9_0_sw_fini+0x40/0x50 [amdgpu] [ 48.420947] amdgpu_device_fini+0x36f/0x4c0 [amdgpu] [ 48.421007] amdgpu_driver_unload_kms+0xb4/0x150 [amdgpu] [ 48.421058] drm_dev_unregister+0x46/0xf0 [drm] [ 48.421102] drm_dev_unplug+0x12/0x70 [drm] Signed-off-by: Trigger Huang <[email protected]> Reviewed-by: Christian König <[email protected]> Signed-off-by: Alex Deucher <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
commit d0a255e upstream. A deadlock with this stacktrace was observed. The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio shrinker and the shrinker depends on I/O completion in the dm-bufio subsystem. In order to fix the deadlock (and other similar ones), we set the flag PF_MEMALLOC_NOIO at loop thread entry. PID: 474 TASK: ffff8813e11f4600 CPU: 10 COMMAND: "kswapd0" #0 [ffff8813dedfb938] __schedule at ffffffff8173f405 #1 [ffff8813dedfb990] schedule at ffffffff8173fa27 #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186 #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8 #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81 #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio] #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio] #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio] #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778 #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f #13 [ffff8813dedfbec0] kthread at ffffffff810a8428 #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242 PID: 14127 TASK: ffff881455749c00 CPU: 11 COMMAND: "loop1" #0 [ffff88272f5af228] __schedule at ffffffff8173f405 #1 [ffff88272f5af280] schedule at ffffffff8173fa27 #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5 #4 [ffff88272f5af330] mutex_lock at ffffffff81742133 #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio] #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778 #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34 #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8 #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3 #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71 #12 [ffff88272f5af760] new_slab at ffffffff811f4523 #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5 #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3 #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3 #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs] #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994 #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs] #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop] #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop] #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c #23 [ffff88272f5afec0] kthread at ffffffff810a8428 #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242 Signed-off-by: Mikulas Patocka <[email protected]> Cc: [email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
commit d0a255e upstream. A deadlock with this stacktrace was observed. The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio shrinker and the shrinker depends on I/O completion in the dm-bufio subsystem. In order to fix the deadlock (and other similar ones), we set the flag PF_MEMALLOC_NOIO at loop thread entry. PID: 474 TASK: ffff8813e11f4600 CPU: 10 COMMAND: "kswapd0" #0 [ffff8813dedfb938] __schedule at ffffffff8173f405 #1 [ffff8813dedfb990] schedule at ffffffff8173fa27 #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186 #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8 #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81 #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio] #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio] #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio] #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778 #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f #13 [ffff8813dedfbec0] kthread at ffffffff810a8428 #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242 PID: 14127 TASK: ffff881455749c00 CPU: 11 COMMAND: "loop1" #0 [ffff88272f5af228] __schedule at ffffffff8173f405 #1 [ffff88272f5af280] schedule at ffffffff8173fa27 #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5 #4 [ffff88272f5af330] mutex_lock at ffffffff81742133 #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio] #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778 #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34 #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8 #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3 #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71 #12 [ffff88272f5af760] new_slab at ffffffff811f4523 #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5 #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3 #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3 #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs] #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994 #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs] #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop] #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop] #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c #23 [ffff88272f5afec0] kthread at ffffffff810a8428 #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242 Signed-off-by: Mikulas Patocka <[email protected]> Cc: [email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
Some QPs (e.g. XRC QP) are not tracked in kernel, in this case they have an invalid res and should not be bound to any dynamically-allocated counter in auto mode. This fixes below call trace: BUG: kernel NULL pointer dereference, address: 0000000000000390 PGD 80000001a7233067 P4D 80000001a7233067 PUD 1a7215067 PMD 0 Oops: 0000 [multipath-tcp#1] SMP PTI CPU: 2 PID: 24822 Comm: ibv_xsrq_pingpo Not tainted 5.4.0-rc5+ multipath-tcp#21 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 RIP: 0010:rdma_counter_bind_qp_auto+0x142/0x270 [ib_core] Code: e1 48 85 c0 48 89 c2 0f 84 bc 00 00 00 49 8b 06 48 39 42 48 75 d6 40 3a aa 90 00 00 00 75 cd 49 8b 86 00 01 00 00 48 8b 4a 28 <8b> 80 90 03 00 00 39 81 90 03 00 00 75 b4 85 c0 74 b0 48 8b 04 24 RSP: 0018:ffffc900003f39c0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88820020ec00 RSI: 0000000000000004 RDI: ffffffffffffffc0 RBP: 0000000000000001 R08: ffff888224149ff0 R09: ffffc900003f3968 R10: ffffffffffffffff R11: ffff8882249c5848 R12: ffffffffffffffff R13: ffff88821d5aca50 R14: ffff8881f7690800 R15: ffff8881ff890000 FS: 00007fe53a3e1740(0000) GS:ffff888237b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000390 CR3: 00000001a7292006 CR4: 00000000003606a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _ib_modify_qp+0x3a4/0x3f0 [ib_core] ? lookup_get_idr_uobject.part.8+0x23/0x40 [ib_uverbs] modify_qp+0x322/0x3e0 [ib_uverbs] ib_uverbs_modify_qp+0x43/0x70 [ib_uverbs] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xb1/0xf0 [ib_uverbs] ib_uverbs_run_method+0x6be/0x760 [ib_uverbs] ? uverbs_disassociate_api+0xd0/0xd0 [ib_uverbs] ib_uverbs_cmd_verbs+0x18d/0x3a0 [ib_uverbs] ? get_acl+0x1a/0x120 ? __alloc_pages_nodemask+0x15d/0x2c0 ib_uverbs_ioctl+0xa7/0x110 [ib_uverbs] do_vfs_ioctl+0xa5/0x610 ksys_ioctl+0x60/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x48/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 99fa331 ("RDMA/counter: Add "auto" configuration mode support") Signed-off-by: Mark Zhang <[email protected]> Reviewed-by: Maor Gottlieb <[email protected]> Reviewed-by: Ido Kalir <[email protected]> Signed-off-by: Leon Romanovsky <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Doug Ledford <[email protected]>
[ Upstream commit 2b81f81 ] af_inet sets sock->sk to NULL which trips strparser over: BUG: kernel NULL pointer dereference, address: 0000000000000012 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.2.0-rc1-00139-g14629453a6d3 multipath-tcp#21 RIP: 0010:tcp_peek_len+0x10/0x60 RSP: 0018:ffffc02e41c54b98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff9cf924c4e030 RCX: 0000000000000051 RDX: 0000000000000000 RSI: 000000000000000c RDI: ffff9cf97128f480 RBP: ffff9cf9365e0300 R08: ffff9cf94fe7d2c0 R09: 0000000000000000 R10: 000000000000036b R11: ffff9cf939735e00 R12: ffff9cf91ad9ae40 R13: ffff9cf924c4e000 R14: ffff9cf9a8fcbaae R15: 0000000000000020 FS: 0000000000000000(0000) GS:ffff9cf9af7c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000012 CR3: 000000013920a003 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> strp_data_ready+0x48/0x90 tls_data_ready+0x22/0xd0 [tls] tcp_rcv_established+0x569/0x620 tcp_v4_do_rcv+0x127/0x1e0 tcp_v4_rcv+0xad7/0xbf0 ip_protocol_deliver_rcu+0x2c/0x1c0 ip_local_deliver_finish+0x41/0x50 ip_local_deliver+0x6b/0xe0 ? ip_protocol_deliver_rcu+0x1c0/0x1c0 ip_rcv+0x52/0xd0 ? ip_rcv_finish_core.isra.20+0x380/0x380 __netif_receive_skb_one_core+0x7e/0x90 netif_receive_skb_internal+0x42/0xf0 napi_gro_receive+0xed/0x150 nfp_net_poll+0x7a2/0xd30 [nfp] ? kmem_cache_free_bulk+0x286/0x310 net_rx_action+0x149/0x3b0 __do_softirq+0xe3/0x30a ? handle_irq_event_percpu+0x6a/0x80 irq_exit+0xe8/0xf0 do_IRQ+0x85/0xd0 common_interrupt+0xf/0xf </IRQ> RIP: 0010:cpuidle_enter_state+0xbc/0x450 To avoid this issue set sock->sk after sk_prot->close. My grepping and testing did not discover any code which would depend on the current behaviour. Fixes: c46234e ("tls: RX path for ktls") Reported-by: David Beckett <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]> Reviewed-by: Dirk van der Merwe <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
I compiled with AddressSanitizer and I had these memory leaks while I was using the tep_parse_format function: Direct leak of 28 byte(s) in 4 object(s) allocated from: #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe) multipath-tcp#1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985 multipath-tcp#2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140 multipath-tcp#3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206 multipath-tcp#4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291 multipath-tcp#5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299 multipath-tcp#6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849 multipath-tcp#7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161 multipath-tcp#8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207 multipath-tcp#9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786 multipath-tcp#10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285 multipath-tcp#11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369 multipath-tcp#12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335 multipath-tcp#13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389 multipath-tcp#14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431 multipath-tcp#15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251 multipath-tcp#16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284 multipath-tcp#17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593 multipath-tcp#18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727 multipath-tcp#19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048 multipath-tcp#20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127 multipath-tcp#21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152 multipath-tcp#22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252 multipath-tcp#23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347 multipath-tcp#24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461 multipath-tcp#25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673 multipath-tcp#26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2) The token variable in the process_dynamic_array_len function is allocated in the read_expect_type function, but is not freed before calling the read_token function. Free the token variable before calling read_token in order to plug the leak. Signed-off-by: Philippe Duplessis-Guindon <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Link: https://lore.kernel.org/linux-trace-devel/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
[ Upstream commit e24c644 ] I compiled with AddressSanitizer and I had these memory leaks while I was using the tep_parse_format function: Direct leak of 28 byte(s) in 4 object(s) allocated from: #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe) #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985 multipath-tcp#2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140 multipath-tcp#3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206 multipath-tcp#4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291 multipath-tcp#5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299 multipath-tcp#6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849 multipath-tcp#7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161 multipath-tcp#8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207 multipath-tcp#9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786 multipath-tcp#10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285 multipath-tcp#11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369 multipath-tcp#12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335 multipath-tcp#13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389 multipath-tcp#14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431 multipath-tcp#15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251 multipath-tcp#16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284 multipath-tcp#17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593 multipath-tcp#18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727 multipath-tcp#19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048 multipath-tcp#20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127 multipath-tcp#21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152 multipath-tcp#22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252 multipath-tcp#23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347 multipath-tcp#24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461 multipath-tcp#25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673 multipath-tcp#26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2) The token variable in the process_dynamic_array_len function is allocated in the read_expect_type function, but is not freed before calling the read_token function. Free the token variable before calling read_token in order to plug the leak. Signed-off-by: Philippe Duplessis-Guindon <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Link: https://lore.kernel.org/linux-trace-devel/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 43e8f76 ] When using kprobe on powerpc booke series processor, Oops happens as show bellow: / # echo "p:myprobe do_nanosleep" > /sys/kernel/debug/tracing/kprobe_events / # echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable / # sleep 1 [ 50.076730] Oops: Exception in kernel mode, sig: 5 [#1] [ 50.077017] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 [ 50.077221] Modules linked in: [ 50.077462] CPU: 0 PID: 77 Comm: sleep Not tainted 5.14.0-rc4-00022-g251a1524293d #21 [ 50.077887] NIP: c0b9c4e0 LR: c00ebecc CTR: 00000000 [ 50.078067] REGS: c3883de0 TRAP: 0700 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.078349] MSR: 00029000 <CE,EE,ME> CR: 24000228 XER: 20000000 [ 50.078675] [ 50.078675] GPR00: c00ebdf0 c3883e90 c313e300 c3883ea0 00000001 00000000 c3883ecc 00000001 [ 50.078675] GPR08: c100598c c00ea250 00000004 00000000 24000222 102490c2 bff4180c 101e60d4 [ 50.078675] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.078675] GPR24: 00000002 00000000 c3883ea0 00000001 00000000 0000c350 3b9b8d50 00000000 [ 50.080151] NIP [c0b9c4e0] do_nanosleep+0x0/0x190 [ 50.080352] LR [c00ebecc] hrtimer_nanosleep+0x14c/0x1e0 [ 50.080638] Call Trace: [ 50.080801] [c3883e90] [c00ebdf0] hrtimer_nanosleep+0x70/0x1e0 (unreliable) [ 50.081110] [c3883f00] [c00ec004] sys_nanosleep_time32+0xa4/0x110 [ 50.081336] [c3883f40] [c001509c] ret_from_syscall+0x0/0x28 [ 50.081541] --- interrupt: c00 at 0x100a4d08 [ 50.081749] NIP: 100a4d08 LR: 101b5234 CTR: 00000003 [ 50.081931] REGS: c3883f50 TRAP: 0c00 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.082183] MSR: 0002f902 <CE,EE,PR,FP,ME> CR: 24000222 XER: 00000000 [ 50.082457] [ 50.082457] GPR00: 000000a2 bf980040 1024b4d0 bf980084 bf980084 64000000 00555345 fefefeff [ 50.082457] GPR08: 7f7f7f7f 101e0000 00000069 00000003 28000422 102490c2 bff4180c 101e60d4 [ 50.082457] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.082457] GPR24: 00000002 bf9803f4 10240000 00000000 00000000 100039e0 00000000 102444e8 [ 50.083789] NIP [100a4d08] 0x100a4d08 [ 50.083917] LR [101b5234] 0x101b5234 [ 50.084042] --- interrupt: c00 [ 50.084238] Instruction dump: [ 50.084483] 4bfffc40 60000000 60000000 60000000 9421fff0 39400402 914200c0 38210010 [ 50.084841] 4bfffc20 00000000 00000000 00000000 <7fe00008> 7c0802a6 7c892378 93c10048 [ 50.085487] ---[ end trace f6fffe98e2fa8f3e ]--- [ 50.085678] Trace/breakpoint trap There is no real mode for booke arch and the MMU translation is always on. The corresponding MSR_IS/MSR_DS bit in booke is used to switch the address space, but not for real mode judgment. Fixes: 21f8b2f ("powerpc/kprobes: Ignore traps that happened in real mode") Signed-off-by: Pu Lehui <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 43e8f76 ] When using kprobe on powerpc booke series processor, Oops happens as show bellow: / # echo "p:myprobe do_nanosleep" > /sys/kernel/debug/tracing/kprobe_events / # echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable / # sleep 1 [ 50.076730] Oops: Exception in kernel mode, sig: 5 [#1] [ 50.077017] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 [ 50.077221] Modules linked in: [ 50.077462] CPU: 0 PID: 77 Comm: sleep Not tainted 5.14.0-rc4-00022-g251a1524293d #21 [ 50.077887] NIP: c0b9c4e0 LR: c00ebecc CTR: 00000000 [ 50.078067] REGS: c3883de0 TRAP: 0700 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.078349] MSR: 00029000 <CE,EE,ME> CR: 24000228 XER: 20000000 [ 50.078675] [ 50.078675] GPR00: c00ebdf0 c3883e90 c313e300 c3883ea0 00000001 00000000 c3883ecc 00000001 [ 50.078675] GPR08: c100598c c00ea250 00000004 00000000 24000222 102490c2 bff4180c 101e60d4 [ 50.078675] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.078675] GPR24: 00000002 00000000 c3883ea0 00000001 00000000 0000c350 3b9b8d50 00000000 [ 50.080151] NIP [c0b9c4e0] do_nanosleep+0x0/0x190 [ 50.080352] LR [c00ebecc] hrtimer_nanosleep+0x14c/0x1e0 [ 50.080638] Call Trace: [ 50.080801] [c3883e90] [c00ebdf0] hrtimer_nanosleep+0x70/0x1e0 (unreliable) [ 50.081110] [c3883f00] [c00ec004] sys_nanosleep_time32+0xa4/0x110 [ 50.081336] [c3883f40] [c001509c] ret_from_syscall+0x0/0x28 [ 50.081541] --- interrupt: c00 at 0x100a4d08 [ 50.081749] NIP: 100a4d08 LR: 101b5234 CTR: 00000003 [ 50.081931] REGS: c3883f50 TRAP: 0c00 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.082183] MSR: 0002f902 <CE,EE,PR,FP,ME> CR: 24000222 XER: 00000000 [ 50.082457] [ 50.082457] GPR00: 000000a2 bf980040 1024b4d0 bf980084 bf980084 64000000 00555345 fefefeff [ 50.082457] GPR08: 7f7f7f7f 101e0000 00000069 00000003 28000422 102490c2 bff4180c 101e60d4 [ 50.082457] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.082457] GPR24: 00000002 bf9803f4 10240000 00000000 00000000 100039e0 00000000 102444e8 [ 50.083789] NIP [100a4d08] 0x100a4d08 [ 50.083917] LR [101b5234] 0x101b5234 [ 50.084042] --- interrupt: c00 [ 50.084238] Instruction dump: [ 50.084483] 4bfffc40 60000000 60000000 60000000 9421fff0 39400402 914200c0 38210010 [ 50.084841] 4bfffc20 00000000 00000000 00000000 <7fe00008> 7c0802a6 7c892378 93c10048 [ 50.085487] ---[ end trace f6fffe98e2fa8f3e ]--- [ 50.085678] Trace/breakpoint trap There is no real mode for booke arch and the MMU translation is always on. The corresponding MSR_IS/MSR_DS bit in booke is used to switch the address space, but not for real mode judgment. Fixes: 21f8b2f ("powerpc/kprobes: Ignore traps that happened in real mode") Signed-off-by: Pu Lehui <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 43e8f76 ] When using kprobe on powerpc booke series processor, Oops happens as show bellow: / # echo "p:myprobe do_nanosleep" > /sys/kernel/debug/tracing/kprobe_events / # echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable / # sleep 1 [ 50.076730] Oops: Exception in kernel mode, sig: 5 [#1] [ 50.077017] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 [ 50.077221] Modules linked in: [ 50.077462] CPU: 0 PID: 77 Comm: sleep Not tainted 5.14.0-rc4-00022-g251a1524293d #21 [ 50.077887] NIP: c0b9c4e0 LR: c00ebecc CTR: 00000000 [ 50.078067] REGS: c3883de0 TRAP: 0700 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.078349] MSR: 00029000 <CE,EE,ME> CR: 24000228 XER: 20000000 [ 50.078675] [ 50.078675] GPR00: c00ebdf0 c3883e90 c313e300 c3883ea0 00000001 00000000 c3883ecc 00000001 [ 50.078675] GPR08: c100598c c00ea250 00000004 00000000 24000222 102490c2 bff4180c 101e60d4 [ 50.078675] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.078675] GPR24: 00000002 00000000 c3883ea0 00000001 00000000 0000c350 3b9b8d50 00000000 [ 50.080151] NIP [c0b9c4e0] do_nanosleep+0x0/0x190 [ 50.080352] LR [c00ebecc] hrtimer_nanosleep+0x14c/0x1e0 [ 50.080638] Call Trace: [ 50.080801] [c3883e90] [c00ebdf0] hrtimer_nanosleep+0x70/0x1e0 (unreliable) [ 50.081110] [c3883f00] [c00ec004] sys_nanosleep_time32+0xa4/0x110 [ 50.081336] [c3883f40] [c001509c] ret_from_syscall+0x0/0x28 [ 50.081541] --- interrupt: c00 at 0x100a4d08 [ 50.081749] NIP: 100a4d08 LR: 101b5234 CTR: 00000003 [ 50.081931] REGS: c3883f50 TRAP: 0c00 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.082183] MSR: 0002f902 <CE,EE,PR,FP,ME> CR: 24000222 XER: 00000000 [ 50.082457] [ 50.082457] GPR00: 000000a2 bf980040 1024b4d0 bf980084 bf980084 64000000 00555345 fefefeff [ 50.082457] GPR08: 7f7f7f7f 101e0000 00000069 00000003 28000422 102490c2 bff4180c 101e60d4 [ 50.082457] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.082457] GPR24: 00000002 bf9803f4 10240000 00000000 00000000 100039e0 00000000 102444e8 [ 50.083789] NIP [100a4d08] 0x100a4d08 [ 50.083917] LR [101b5234] 0x101b5234 [ 50.084042] --- interrupt: c00 [ 50.084238] Instruction dump: [ 50.084483] 4bfffc40 60000000 60000000 60000000 9421fff0 39400402 914200c0 38210010 [ 50.084841] 4bfffc20 00000000 00000000 00000000 <7fe00008> 7c0802a6 7c892378 93c10048 [ 50.085487] ---[ end trace f6fffe98e2fa8f3e ]--- [ 50.085678] Trace/breakpoint trap There is no real mode for booke arch and the MMU translation is always on. The corresponding MSR_IS/MSR_DS bit in booke is used to switch the address space, but not for real mode judgment. Fixes: 21f8b2f ("powerpc/kprobes: Ignore traps that happened in real mode") Signed-off-by: Pu Lehui <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 4224cfd7fb6523f7a9d1c8bb91bb5df1e38eb624 ] When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... multipath-tcp#9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 multipath-tcp#10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] multipath-tcp#11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] multipath-tcp#12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] multipath-tcp#13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] multipath-tcp#14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] multipath-tcp#15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] multipath-tcp#16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] multipath-tcp#17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 multipath-tcp#18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 multipath-tcp#19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 multipath-tcp#20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf multipath-tcp#21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 multipath-tcp#22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 multipath-tcp#23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 multipath-tcp#24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff multipath-tcp#25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f multipath-tcp#26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 4224cfd7fb6523f7a9d1c8bb91bb5df1e38eb624 ] When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... multipath-tcp#9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 multipath-tcp#10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] multipath-tcp#11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] multipath-tcp#12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] multipath-tcp#13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] multipath-tcp#14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] multipath-tcp#15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] multipath-tcp#16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] multipath-tcp#17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 multipath-tcp#18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 multipath-tcp#19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 multipath-tcp#20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf multipath-tcp#21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 multipath-tcp#22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 multipath-tcp#23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 multipath-tcp#24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff multipath-tcp#25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f multipath-tcp#26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 4224cfd7fb6523f7a9d1c8bb91bb5df1e38eb624 ] When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 9de255c461d1b3f0242b3ad1450c3323a3e00b34 ] Commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") started calling disable_irq() without holding the spinlock because it can sleep. However, that fix introduced another bug: if interrupt is already disabled and a new disable request comes in, then the spinlock is not unlocked: root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0 root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0 root@localhost:~# [ 14.851538] BUG: scheduling while atomic: bash/223/0x00000002 [ 14.851991] Modules linked in: uio_dmem_genirq uio myfpga(OE) bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm snd_pcm ppdev joydev psmouse snd_timer snd e1000fb_sys_fops syscopyarea parport sysfillrect soundcore sysimgblt input_leds pcspkr i2c_piix4 serio_raw floppy evbug qemu_fw_cfg mac_hid pata_acpi ip_tables x_tables autofs4 [last unloaded: parport_pc] [ 14.854206] CPU: 0 PID: 223 Comm: bash Tainted: G OE 6.0.0-rc7 #21 [ 14.854786] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 14.855664] Call Trace: [ 14.855861] <TASK> [ 14.856025] dump_stack_lvl+0x4d/0x67 [ 14.856325] dump_stack+0x14/0x1a [ 14.856583] __schedule_bug.cold+0x4b/0x5c [ 14.856915] __schedule+0xe81/0x13d0 [ 14.857199] ? idr_find+0x13/0x20 [ 14.857456] ? get_work_pool+0x2d/0x50 [ 14.857756] ? __flush_work+0x233/0x280 [ 14.858068] ? __schedule+0xa95/0x13d0 [ 14.858307] ? idr_find+0x13/0x20 [ 14.858519] ? get_work_pool+0x2d/0x50 [ 14.858798] schedule+0x6c/0x100 [ 14.859009] schedule_hrtimeout_range_clock+0xff/0x110 [ 14.859335] ? tty_write_room+0x1f/0x30 [ 14.859598] ? n_tty_poll+0x1ec/0x220 [ 14.859830] ? tty_ldisc_deref+0x1a/0x20 [ 14.860090] schedule_hrtimeout_range+0x17/0x20 [ 14.860373] do_select+0x596/0x840 [ 14.860627] ? __kernel_text_address+0x16/0x50 [ 14.860954] ? poll_freewait+0xb0/0xb0 [ 14.861235] ? poll_freewait+0xb0/0xb0 [ 14.861517] ? rpm_resume+0x49d/0x780 [ 14.861798] ? common_interrupt+0x59/0xa0 [ 14.862127] ? asm_common_interrupt+0x2b/0x40 [ 14.862511] ? __uart_start.isra.0+0x61/0x70 [ 14.862902] ? __check_object_size+0x61/0x280 [ 14.863255] core_sys_select+0x1c6/0x400 [ 14.863575] ? vfs_write+0x1c9/0x3d0 [ 14.863853] ? vfs_write+0x1c9/0x3d0 [ 14.864121] ? _copy_from_user+0x45/0x70 [ 14.864526] do_pselect.constprop.0+0xb3/0xf0 [ 14.864893] ? do_syscall_64+0x6d/0x90 [ 14.865228] ? do_syscall_64+0x6d/0x90 [ 14.865556] __x64_sys_pselect6+0x76/0xa0 [ 14.865906] do_syscall_64+0x60/0x90 [ 14.866214] ? syscall_exit_to_user_mode+0x2a/0x50 [ 14.866640] ? do_syscall_64+0x6d/0x90 [ 14.866972] ? do_syscall_64+0x6d/0x90 [ 14.867286] ? do_syscall_64+0x6d/0x90 [ 14.867626] entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] stripped [ 14.872959] </TASK> ('myfpga' is a simple 'uio_dmem_genirq' driver I wrote to test this) The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and it is used in a similar manner to the "uio_pdrv_genirq" driver with respect to interrupt configuration and handling. At the time "uio_dmem_genirq" was introduced, both had the same implementation of the 'uio_info' handlers irqcontrol() and handler(). Then commit 34cb275 ("UIO: Fix concurrency issue"), which was only applied to "uio_pdrv_genirq", ended up making them a little different. That commit, among other things, changed disable_irq() to disable_irq_nosync() in the implementation of irqcontrol(). The motivation there was to avoid a deadlock between irqcontrol() and handler(), since it added a spinlock in the irq handler, and disable_irq() waits for the completion of the irq handler. By changing disable_irq() to disable_irq_nosync() in irqcontrol(), we also avoid the sleeping-while-atomic bug that commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") was trying to fix. Thus, this fixes the missing unlock in irqcontrol() by importing the implementation of irqcontrol() handler from the "uio_pdrv_genirq" driver. In the end, it reverts commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") and change disable_irq() to disable_irq_nosync(). It is worth noting that this still does not address the concurrency issue fixed by commit 34cb275 ("UIO: Fix concurrency issue"). It will be addressed separately in the next commits. Split out from commit 34cb275 ("UIO: Fix concurrency issue"). Fixes: b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") Signed-off-by: Rafael Mendonca <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 9de255c461d1b3f0242b3ad1450c3323a3e00b34 ] Commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") started calling disable_irq() without holding the spinlock because it can sleep. However, that fix introduced another bug: if interrupt is already disabled and a new disable request comes in, then the spinlock is not unlocked: root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0 root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0 root@localhost:~# [ 14.851538] BUG: scheduling while atomic: bash/223/0x00000002 [ 14.851991] Modules linked in: uio_dmem_genirq uio myfpga(OE) bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm snd_pcm ppdev joydev psmouse snd_timer snd e1000fb_sys_fops syscopyarea parport sysfillrect soundcore sysimgblt input_leds pcspkr i2c_piix4 serio_raw floppy evbug qemu_fw_cfg mac_hid pata_acpi ip_tables x_tables autofs4 [last unloaded: parport_pc] [ 14.854206] CPU: 0 PID: 223 Comm: bash Tainted: G OE 6.0.0-rc7 #21 [ 14.854786] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 14.855664] Call Trace: [ 14.855861] <TASK> [ 14.856025] dump_stack_lvl+0x4d/0x67 [ 14.856325] dump_stack+0x14/0x1a [ 14.856583] __schedule_bug.cold+0x4b/0x5c [ 14.856915] __schedule+0xe81/0x13d0 [ 14.857199] ? idr_find+0x13/0x20 [ 14.857456] ? get_work_pool+0x2d/0x50 [ 14.857756] ? __flush_work+0x233/0x280 [ 14.858068] ? __schedule+0xa95/0x13d0 [ 14.858307] ? idr_find+0x13/0x20 [ 14.858519] ? get_work_pool+0x2d/0x50 [ 14.858798] schedule+0x6c/0x100 [ 14.859009] schedule_hrtimeout_range_clock+0xff/0x110 [ 14.859335] ? tty_write_room+0x1f/0x30 [ 14.859598] ? n_tty_poll+0x1ec/0x220 [ 14.859830] ? tty_ldisc_deref+0x1a/0x20 [ 14.860090] schedule_hrtimeout_range+0x17/0x20 [ 14.860373] do_select+0x596/0x840 [ 14.860627] ? __kernel_text_address+0x16/0x50 [ 14.860954] ? poll_freewait+0xb0/0xb0 [ 14.861235] ? poll_freewait+0xb0/0xb0 [ 14.861517] ? rpm_resume+0x49d/0x780 [ 14.861798] ? common_interrupt+0x59/0xa0 [ 14.862127] ? asm_common_interrupt+0x2b/0x40 [ 14.862511] ? __uart_start.isra.0+0x61/0x70 [ 14.862902] ? __check_object_size+0x61/0x280 [ 14.863255] core_sys_select+0x1c6/0x400 [ 14.863575] ? vfs_write+0x1c9/0x3d0 [ 14.863853] ? vfs_write+0x1c9/0x3d0 [ 14.864121] ? _copy_from_user+0x45/0x70 [ 14.864526] do_pselect.constprop.0+0xb3/0xf0 [ 14.864893] ? do_syscall_64+0x6d/0x90 [ 14.865228] ? do_syscall_64+0x6d/0x90 [ 14.865556] __x64_sys_pselect6+0x76/0xa0 [ 14.865906] do_syscall_64+0x60/0x90 [ 14.866214] ? syscall_exit_to_user_mode+0x2a/0x50 [ 14.866640] ? do_syscall_64+0x6d/0x90 [ 14.866972] ? do_syscall_64+0x6d/0x90 [ 14.867286] ? do_syscall_64+0x6d/0x90 [ 14.867626] entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] stripped [ 14.872959] </TASK> ('myfpga' is a simple 'uio_dmem_genirq' driver I wrote to test this) The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and it is used in a similar manner to the "uio_pdrv_genirq" driver with respect to interrupt configuration and handling. At the time "uio_dmem_genirq" was introduced, both had the same implementation of the 'uio_info' handlers irqcontrol() and handler(). Then commit 34cb275 ("UIO: Fix concurrency issue"), which was only applied to "uio_pdrv_genirq", ended up making them a little different. That commit, among other things, changed disable_irq() to disable_irq_nosync() in the implementation of irqcontrol(). The motivation there was to avoid a deadlock between irqcontrol() and handler(), since it added a spinlock in the irq handler, and disable_irq() waits for the completion of the irq handler. By changing disable_irq() to disable_irq_nosync() in irqcontrol(), we also avoid the sleeping-while-atomic bug that commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") was trying to fix. Thus, this fixes the missing unlock in irqcontrol() by importing the implementation of irqcontrol() handler from the "uio_pdrv_genirq" driver. In the end, it reverts commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") and change disable_irq() to disable_irq_nosync(). It is worth noting that this still does not address the concurrency issue fixed by commit 34cb275 ("UIO: Fix concurrency issue"). It will be addressed separately in the next commits. Split out from commit 34cb275 ("UIO: Fix concurrency issue"). Fixes: b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") Signed-off-by: Rafael Mendonca <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
[ Upstream commit 9de255c461d1b3f0242b3ad1450c3323a3e00b34 ] Commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") started calling disable_irq() without holding the spinlock because it can sleep. However, that fix introduced another bug: if interrupt is already disabled and a new disable request comes in, then the spinlock is not unlocked: root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0 root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0 root@localhost:~# [ 14.851538] BUG: scheduling while atomic: bash/223/0x00000002 [ 14.851991] Modules linked in: uio_dmem_genirq uio myfpga(OE) bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm snd_pcm ppdev joydev psmouse snd_timer snd e1000fb_sys_fops syscopyarea parport sysfillrect soundcore sysimgblt input_leds pcspkr i2c_piix4 serio_raw floppy evbug qemu_fw_cfg mac_hid pata_acpi ip_tables x_tables autofs4 [last unloaded: parport_pc] [ 14.854206] CPU: 0 PID: 223 Comm: bash Tainted: G OE 6.0.0-rc7 #21 [ 14.854786] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 14.855664] Call Trace: [ 14.855861] <TASK> [ 14.856025] dump_stack_lvl+0x4d/0x67 [ 14.856325] dump_stack+0x14/0x1a [ 14.856583] __schedule_bug.cold+0x4b/0x5c [ 14.856915] __schedule+0xe81/0x13d0 [ 14.857199] ? idr_find+0x13/0x20 [ 14.857456] ? get_work_pool+0x2d/0x50 [ 14.857756] ? __flush_work+0x233/0x280 [ 14.858068] ? __schedule+0xa95/0x13d0 [ 14.858307] ? idr_find+0x13/0x20 [ 14.858519] ? get_work_pool+0x2d/0x50 [ 14.858798] schedule+0x6c/0x100 [ 14.859009] schedule_hrtimeout_range_clock+0xff/0x110 [ 14.859335] ? tty_write_room+0x1f/0x30 [ 14.859598] ? n_tty_poll+0x1ec/0x220 [ 14.859830] ? tty_ldisc_deref+0x1a/0x20 [ 14.860090] schedule_hrtimeout_range+0x17/0x20 [ 14.860373] do_select+0x596/0x840 [ 14.860627] ? __kernel_text_address+0x16/0x50 [ 14.860954] ? poll_freewait+0xb0/0xb0 [ 14.861235] ? poll_freewait+0xb0/0xb0 [ 14.861517] ? rpm_resume+0x49d/0x780 [ 14.861798] ? common_interrupt+0x59/0xa0 [ 14.862127] ? asm_common_interrupt+0x2b/0x40 [ 14.862511] ? __uart_start.isra.0+0x61/0x70 [ 14.862902] ? __check_object_size+0x61/0x280 [ 14.863255] core_sys_select+0x1c6/0x400 [ 14.863575] ? vfs_write+0x1c9/0x3d0 [ 14.863853] ? vfs_write+0x1c9/0x3d0 [ 14.864121] ? _copy_from_user+0x45/0x70 [ 14.864526] do_pselect.constprop.0+0xb3/0xf0 [ 14.864893] ? do_syscall_64+0x6d/0x90 [ 14.865228] ? do_syscall_64+0x6d/0x90 [ 14.865556] __x64_sys_pselect6+0x76/0xa0 [ 14.865906] do_syscall_64+0x60/0x90 [ 14.866214] ? syscall_exit_to_user_mode+0x2a/0x50 [ 14.866640] ? do_syscall_64+0x6d/0x90 [ 14.866972] ? do_syscall_64+0x6d/0x90 [ 14.867286] ? do_syscall_64+0x6d/0x90 [ 14.867626] entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] stripped [ 14.872959] </TASK> ('myfpga' is a simple 'uio_dmem_genirq' driver I wrote to test this) The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and it is used in a similar manner to the "uio_pdrv_genirq" driver with respect to interrupt configuration and handling. At the time "uio_dmem_genirq" was introduced, both had the same implementation of the 'uio_info' handlers irqcontrol() and handler(). Then commit 34cb275 ("UIO: Fix concurrency issue"), which was only applied to "uio_pdrv_genirq", ended up making them a little different. That commit, among other things, changed disable_irq() to disable_irq_nosync() in the implementation of irqcontrol(). The motivation there was to avoid a deadlock between irqcontrol() and handler(), since it added a spinlock in the irq handler, and disable_irq() waits for the completion of the irq handler. By changing disable_irq() to disable_irq_nosync() in irqcontrol(), we also avoid the sleeping-while-atomic bug that commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") was trying to fix. Thus, this fixes the missing unlock in irqcontrol() by importing the implementation of irqcontrol() handler from the "uio_pdrv_genirq" driver. In the end, it reverts commit b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") and change disable_irq() to disable_irq_nosync(). It is worth noting that this still does not address the concurrency issue fixed by commit 34cb275 ("UIO: Fix concurrency issue"). It will be addressed separately in the next commits. Split out from commit 34cb275 ("UIO: Fix concurrency issue"). Fixes: b743512 ("uio: fix a sleep-in-atomic-context bug in uio_dmem_genirq_irqcontrol()") Signed-off-by: Rafael Mendonca <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
Subtract large value from small value.
The far distance shortcut is chosen.
This may occur more long searching time to insert skb.