Added backlight support for some samsung laptops #11

xonatius · 2011-09-06T22:35:53Z

Models:

N120
R468/R418
X320/X420/X520
R510/P510
N350
R470/R420
R528/R728
SQ1S

Models: * N120 * R468/R418 * X320/X420/X520 * R510/P510 * N350 * R470/R420 * R528/R728 * SQ1S

torvalds · 2011-09-06T23:14:27Z

I'm not doing github pulls. The pull requests are seriously
misdesigned, and github does horrible things to the commits.

Please don't press the "pull request" github button. Do proper kernel
pull request with diffstat, git source tree (which can be on github,
of course), branch, commit information etc etc etc.

                  Linus

nils-werner · 2011-09-07T07:18:06Z

How are pullrequest seriously misdesigned (apart from that you might be used to a different kind of workflow)?

valpackett · 2011-09-07T12:10:31Z

I'm not doing linux kernel pulls. The kernel pulls are seriously
misdesigned, and linux does horrible things to the commits.

Please don't press the "pull request" kernel button. Do proper github
pull request with diffstat, git source tree (which can be on linux,
of course), branch, commit information etc etc etc.

GitHub

tilsammans · 2011-09-07T21:07:51Z

I honestly would like to know why github pull requests are misdesigned. I'll grant that I didn't actually create git but they seem to work just fine, is there something I am missing?

hotwoofy · 2011-09-07T22:26:13Z

See https://github.com/torvalds/diveclog/pull/18#issuecomment-2023552

nils-werner · 2011-09-09T07:49:03Z

See https://github.com/torvalds/diveclog/pull/18#issuecomment-2023552

Wow, great discussion went on there. Shacon raised perfectly valid points and Torvalds was basically "f this, I don't care, you're crazy". Great response!

torvalds · 2011-09-09T18:35:15Z

On Fri, Sep 9, 2011 at 12:49 AM, Nils Werner
[email protected]
wrote:

Wow, great discussion went on there. Shacon raised perfectly valid points and Torvalds was basically "f this, I don't care, you're crazy". Great response!

Can you read?

"If the merge message doesn't tell me who the merge is from and what
branch it was, the merge message is totally useless."

If you can't understand that, then yes, you're crazy. Or just terminally stupid.

The quality of github "issues" and comments really is very low. This
being just another example of it.

                          Linus

nils-werner · 2011-09-09T19:10:19Z

First, I agree with Scott: In many cases people delete their fork (or at least the branch). So where would the message point you to? The pull request of the pulling repository will much more likely be around for a long time.

Also, what if the branch you'll pull from has changed in the meantime? You'd end up with changes that are not documented in the pull request and thus not reviewed by the ones discussing the pull request. As soon as the PR is posted you must put them out of reach of the author to keep them from sneaking in changes.

Great response!

Can you read?

Also, you did notice that you've proven my point right there, right?

torvalds · 2011-09-09T19:19:43Z

On Fri, Sep 9, 2011 at 12:10 PM, Nils Werner
[email protected]
wrote:

First, I agree with Scott: In many cases people delete their fork (or at least the branch). So where would the message point you to? The pull request of the pulling repository will much more likely be around for a long time.

That's a "implementation problem". It's not an argument for doing crap.

Simple solution: if people delete the branch or repository, consider
the pull request dead.

You can make the "pull request" namespace separate from the branch
namespace, but do it on the source side, instead of on the
destination side like you do now. So if somebody says "please pull by
branch xyzzy", you turn it into a pull request for

git pull git://github.com/ pull/xyzzy

and then if there i a previous pull request, add a number to it (so it
becomes "pull/xyzzy-2" or whatever).

Or something along those lines. The important part is that YOU MUST
NOT THROW AWAY THE SOURCE INFORMATION!

Also, what if the branch you'll pull from has changed in the meantime?

We actually do this in the kernel on purpose sometimes - people fix up
their stuff.

That said, again, you could do the same thing: if somebody changes a
branch after created a pull request off it, just invalidate the pull
request and refuse to honor it. Again, if you do a separate
"pull/xyzzy" namespace, you should be able to validate that trivially
(save off the commit ID at the time of the pull, and refuse to serve
"pull/xyzzy" if the commit ID doesn't match the branch "xyzzy" any
more).

You'd end up with changes that are not documented in the pull request and thus not reviewed by the ones discussing the pull request.

Umm, considering that the pull requests used to have no documentation
what-so-ever before I even complained about it, that's a pretty damn
weak argument, isn't it?

As soon as the PR is posted you must put them out of reach of the
author to keep them from sneaking in changes.

Can you read?

Also, you did notice that you've proven my point right there, right?

Umm. I'm not polite. Big news. I'd rather be acerbic than stupid.

                       Linus

nils-werner · 2011-09-09T20:28:42Z

That's a "implementation problem".

A decentralized system that doesn't accept disappearing nodes sounds more like a design problem.

Simple solution: if people delete the branch or repository, consider the pull request dead.

Years after the branch has been merged? Is that a problem we wanted to solve?

Also, what if the branch you'll pull from has changed in the meantime?

We actually do this in the kernel on purpose sometimes - people fix up their stuff.

I meant malicuous changes. Hierarchies are shallow, elite circles basically nonexistant so that's a real issue. And the biggest strength of GitHub.

save off the commit ID at the time of the pull, and refuse to serve "pull/xyzzy" if the commit ID doesn't match the branch "xyzzy" any more

Thats the first constructive comment to this discussion. And sounds like a good idea, apart from the problem that you'd lose the link to the PR wich, to many, is more useful than being able to immediately recognise the source.

Also it would probably require lots of modifications to the deamon though.And very disciplined contributors (always make sure to use dead-end topic-branches, not everybody does that). Separating the two simply improves the workflow a lot.

It'd be interesting what @schacon has to say about it.

Umm, considering that the pull requests used to have no documentation what-so-ever before I even complained about it, that's a pretty damn weak argument, isn't it?

When was that? Months ago? I am talking about your comment 2 days ago.

nils-werner · 2011-09-09T20:32:56Z

Umm. I'm not polite. Big news. I'd rather be acerbic than stupid.

A personal, unrelated note: Being unable to lead an objective discussion. Judging people, then insulting them just to prove a point. Recognising ones flaws but being unwilling to change them, instead bragging about them. Missing the ability to reflect on ones actions during interactions with others.

That sounds pretty stupid to me. Anyways, I'm moving on.

jeffWelling · 2011-09-09T20:45:58Z

@nils-werner

A decentralized system that doesn't accept disappearing nodes sounds more like a design problem.

I thought we were talking about pull requests and branches? When did a branch become a node?
Perhaps I'm missing something but this sounds simple; if you have a change and you want someone else to pull it, it sounds reasonable to expect you to keep the change published at least until it is pulled.

I meant malicuous changes. Hierarchies are shallow, elite circles basically nonexistant so that's a real issue. And the biggest strength of GitHub.

Except that, as indicated by Scott Chacon [0], the most common scenario is to perform the pull request locally on your machine, allowing you to pull the code and then review it without said code being changed before merging. I can understand your argument in relation to pull requests done using the button on the website though.

[0] https://github.com/torvalds/diveclog/pull/18

* Ingo Molnar <[email protected]> wrote: > The patch below addresses these concerns, serializes the output, tidies up the > printout, resulting in this new output: There's one bug remaining that my patch does not address: the vCPUs are not printed in order: # vCPU #0's dump: # vCPU #2's dump: # vCPU torvalds#24's dump: # vCPU #5's dump: # vCPU torvalds#39's dump: # vCPU torvalds#38's dump: # vCPU torvalds#51's dump: # vCPU torvalds#11's dump: # vCPU torvalds#10's dump: # vCPU torvalds#12's dump: This is undesirable as the order of printout is highly random, so successive dumps are difficult to compare. The patch below serializes the signalling itself. (this is on top of the previous patch) The patch also tweaks the vCPU printout line a bit so that it does not start with '#', which is discarded if such messages are pasted into Git commit messages. Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Pekka Enberg <[email protected]>

If the pte mapping in generic_perform_write() is unmapped between iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the "copied" parameter to ->end_write can be zero. ext4 couldn't cope with it with delayed allocations enabled. This skips the i_disksize enlargement logic if copied is zero and no new data was appeneded to the inode. gdb> bt #0 0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\ 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467 #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 #2 0xffffffff810d97f1 in generic_perform_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value o\ ptimized out>, pos=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2440 #3 generic_file_buffered_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value optimized out>, p\ os=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2482 #4 0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\ xffff88001e26be40) at mm/filemap.c:2600 #5 0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=<value optimi\ zed out>, pos=<value optimized out>) at mm/filemap.c:2632 #6 0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\ t fs/ext4/file.c:136 #7 0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=<value optimized out>, len=<value optimized out>, \ ppos=0xffff88001e26bf48) at fs/read_write.c:406 #8 0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x4\ 000, pos=0xffff88001e26bf48) at fs/read_write.c:435 #9 0xffffffff8113816c in sys_write (fd=<value optimized out>, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x\ 4000) at fs/read_write.c:487 #10 <signal handler called> #11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ () #12 0x0000000000000000 in ?? () gdb> print offset $22 = 0xffffffffffffffff gdb> print idx $23 = 0xffffffff gdb> print inode->i_blkbits $24 = 0xc gdb> up #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 2512 if (ext4_da_should_update_i_disksize(page, end)) { gdb> print start $25 = 0x0 gdb> print end $26 = 0xffffffffffffffff gdb> print pos $27 = 0x108000 gdb> print new_i_size $28 = 0x108000 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize $29 = 0xd9000 gdb> down 2467 for (i = 0; i < idx; i++) gdb> print i $30 = 0xd44acbee This is 100% reproducible with some autonuma development code tuned in a very aggressive manner (not normal way even for knumad) which does "exotic" changes to the ptes. It wouldn't normally trigger but I don't see why it can't happen normally if the page is added to swap cache in between the two faults leading to "copied" being zero (which then hangs in ext4). So it should be fixed. Especially possible with lumpy reclaim (albeit disabled if compaction is enabled) as that would ignore the young bits in the ptes. Signed-off-by: Andrea Arcangeli <[email protected]> Signed-off-by: "Theodore Ts'o" <[email protected]> Cc: [email protected]

If the netdev is already in NETREG_UNREGISTERING/_UNREGISTERED state, do not update the real num tx queues. netdev_queue_update_kobjects() is already called via remove_queue_kobjects() at NETREG_UNREGISTERING time. So, when upper layer driver, e.g., FCoE protocol stack is monitoring the netdev event of NETDEV_UNREGISTER and calls back to LLD ndo_fcoe_disable() to remove extra queues allocated for FCoE, the associated txq sysfs kobjects are already removed, and trying to update the real num queues would cause something like below: ... PID: 25138 TASK: ffff88021e64c440 CPU: 3 COMMAND: "kworker/3:3" #0 [ffff88021f007760] machine_kexec at ffffffff810226d9 #1 [ffff88021f0077d0] crash_kexec at ffffffff81089d2d #2 [ffff88021f0078a0] oops_end at ffffffff813bca78 #3 [ffff88021f0078d0] no_context at ffffffff81029e72 #4 [ffff88021f007920] __bad_area_nosemaphore at ffffffff8102a155 #5 [ffff88021f0079f0] bad_area_nosemaphore at ffffffff8102a23e torvalds#6 [ffff88021f007a00] do_page_fault at ffffffff813bf32e torvalds#7 [ffff88021f007b10] page_fault at ffffffff813bc045 [exception RIP: sysfs_find_dirent+17] RIP: ffffffff81178611 RSP: ffff88021f007bc0 RFLAGS: 00010246 RAX: ffff88021e64c440 RBX: ffffffff8156cc63 RCX: 0000000000000004 RDX: ffffffff8156cc63 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88021f007be0 R8: 0000000000000004 R9: 0000000000000008 R10: ffffffff816fed00 R11: 0000000000000004 R12: 0000000000000000 R13: ffffffff8156cc63 R14: 0000000000000000 R15: ffff8802222a0000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#8 [ffff88021f007be8] sysfs_get_dirent at ffffffff81178c07 torvalds#9 [ffff88021f007c18] sysfs_remove_group at ffffffff8117ac27 torvalds#10 [ffff88021f007c48] netdev_queue_update_kobjects at ffffffff813178f9 torvalds#11 [ffff88021f007c88] netif_set_real_num_tx_queues at ffffffff81303e38 torvalds#12 [ffff88021f007cc8] ixgbe_set_num_queues at ffffffffa0249763 [ixgbe] torvalds#13 [ffff88021f007cf8] ixgbe_init_interrupt_scheme at ffffffffa024ea89 [ixgbe] torvalds#14 [ffff88021f007d48] ixgbe_fcoe_disable at ffffffffa0267113 [ixgbe] torvalds#15 [ffff88021f007d68] vlan_dev_fcoe_disable at ffffffffa014fef5 [8021q] torvalds#16 [ffff88021f007d78] fcoe_interface_cleanup at ffffffffa02b7dfd [fcoe] torvalds#17 [ffff88021f007df8] fcoe_destroy_work at ffffffffa02b7f08 [fcoe] torvalds#18 [ffff88021f007e18] process_one_work at ffffffff8105d7ca torvalds#19 [ffff88021f007e68] worker_thread at ffffffff81060513 torvalds#20 [ffff88021f007ee8] kthread at ffffffff810648b6 torvalds#21 [ffff88021f007f48] kernel_thread_helper at ffffffff813c40f4 Signed-off-by: Yi Zou <[email protected]> Tested-by: Ross Brattain <[email protected]> Tested-by: Stephen Ko <[email protected]> Signed-off-by: Jeff Kirsher <[email protected]>

…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72ec #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a torvalds#7 [d72d3d1] zone_watermark_ok at c02d26cb torvalds#8 [d72d3d2c] compact_zone at c030b8de torvalds#9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb0] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <[email protected]> Tested-by: Herbert van den Bergh <[email protected]> Signed-off-by: Mel Gorman <[email protected]> Acked-by: Michal Nazarewicz <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

fixed: WARNING: please, no space before tabs torvalds#11: FILE: adt7411.c:11: + * ^I use power-down mode for suspend?, interrupt handling?$ not fixed as all other macros around it are the same structure and this one is only 2 chars longer: WARNING: line over 80 characters torvalds#229: FILE: adt7411.c:229: +static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225); Signed-off-by: Frans Meulenbroeks <[email protected]> Signed-off-by: Guenter Roeck <[email protected]>

…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72ec #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d1] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8de #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb0] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <[email protected]> Tested-by: Herbert van den Bergh <[email protected]> Signed-off-by: Mel Gorman <[email protected]> Acked-by: Michal Nazarewicz <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

BugLink: http://bugs.launchpad.net/bugs/907778 commit ea51d13 upstream. If the pte mapping in generic_perform_write() is unmapped between iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the "copied" parameter to ->end_write can be zero. ext4 couldn't cope with it with delayed allocations enabled. This skips the i_disksize enlargement logic if copied is zero and no new data was appeneded to the inode. gdb> bt #0 0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\ 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467 #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 #2 0xffffffff810d97f1 in generic_perform_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value o\ ptimized out>, pos=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2440 #3 generic_file_buffered_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value optimized out>, p\ os=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2482 #4 0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\ xffff88001e26be40) at mm/filemap.c:2600 #5 0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=<value optimi\ zed out>, pos=<value optimized out>) at mm/filemap.c:2632 torvalds#6 0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\ t fs/ext4/file.c:136 torvalds#7 0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=<value optimized out>, len=<value optimized out>, \ ppos=0xffff88001e26bf48) at fs/read_write.c:406 torvalds#8 0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x4\ 000, pos=0xffff88001e26bf48) at fs/read_write.c:435 torvalds#9 0xffffffff8113816c in sys_write (fd=<value optimized out>, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x\ 4000) at fs/read_write.c:487 torvalds#10 <signal handler called> torvalds#11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ () torvalds#12 0x0000000000000000 in ?? () gdb> print offset $22 = 0xffffffffffffffff gdb> print idx $23 = 0xffffffff gdb> print inode->i_blkbits $24 = 0xc gdb> up #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 2512 if (ext4_da_should_update_i_disksize(page, end)) { gdb> print start $25 = 0x0 gdb> print end $26 = 0xffffffffffffffff gdb> print pos $27 = 0x108000 gdb> print new_i_size $28 = 0x108000 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize $29 = 0xd9000 gdb> down 2467 for (i = 0; i < idx; i++) gdb> print i $30 = 0xd44acbee This is 100% reproducible with some autonuma development code tuned in a very aggressive manner (not normal way even for knumad) which does "exotic" changes to the ptes. It wouldn't normally trigger but I don't see why it can't happen normally if the page is added to swap cache in between the two faults leading to "copied" being zero (which then hangs in ext4). So it should be fixed. Especially possible with lumpy reclaim (albeit disabled if compaction is enabled) as that would ignore the young bits in the ptes. Signed-off-by: Andrea Arcangeli <[email protected]> Signed-off-by: "Theodore Ts'o" <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Tim Gardner <[email protected]> Signed-off-by: Brad Figg <[email protected]>

Disable strict aliasing, as has been done in the kernel proper for decades (literally since before git history) to fix issues where gcc will optimize away loads in code that looks 100% correct, but is _technically_ undefined behavior, and thus can be thrown away by the compiler. E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long) pointer to a u64 (unsigned long long) pointer when setting PMCR.N via u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores the result and uses the original PMCR. The issue is most easily observed by making set_pmcr_n() noinline and wrapping the call with printf(), e.g. sans comments, for this code: printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); set_pmcr_n(&pmcr, pmcr_n); printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); gcc-13 generates: 0000000000401c90 <set_pmcr_n>: 401c90: f9400002 ldr x2, [x0] 401c94: b3751022 bfi x2, x1, torvalds#11, #5 401c98: f9000002 str x2, [x0] 401c9c: d65f03c0 ret 0000000000402660 <test_create_vpmu_vm_with_pmcr_n>: 402724: aa1403e3 mov x3, x20 402728: aa1503e2 mov x2, x21 40272c: aa1603e0 mov x0, x22 402730: aa1503e1 mov x1, x21 402734: 940060ff bl 41ab30 <_IO_printf> 402738: aa1403e1 mov x1, x20 40273c: 910183e0 add x0, sp, #0x60 402740: 97fffd54 bl 401c90 <set_pmcr_n> 402744: aa1403e3 mov x3, x20 402748: aa1503e2 mov x2, x21 40274c: aa1503e1 mov x1, x21 402750: aa1603e0 mov x0, x22 402754: 940060f7 bl 41ab30 <_IO_printf> with the value stored in [sp + 0x60] ignored by both printf() above and in the test proper, resulting in a false failure due to vcpu_set_reg() simply storing the original value, not the intended value. $ ./vpmu_counter_access Random seed: 0x6b8b4567 orig = 3040, next = 3040, want = 0 orig = 3040, next = 3040, want = 0 ==== Test Assertion Failure ==== aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr) pid=71578 tid=71578 errno=9 - Bad file descriptor 1 0x400673: run_access_test at vpmu_counter_access.c:522 2 (inlined by) main at vpmu_counter_access.c:643 3 0x4132d7: __libc_start_call_main at libc-start.o:0 4 0x413653: __libc_start_main at ??:0 5 0x40106f: _start at ??:0 Failed to update PMCR.N to 0 (received: 6) Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n() is inlined in its sole caller. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912 Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]>

Disable strict aliasing, as has been done in the kernel proper for decades (literally since before git history) to fix issues where gcc will optimize away loads in code that looks 100% correct, but is _technically_ undefined behavior, and thus can be thrown away by the compiler. E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long) pointer to a u64 (unsigned long long) pointer when setting PMCR.N via u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores the result and uses the original PMCR. The issue is most easily observed by making set_pmcr_n() noinline and wrapping the call with printf(), e.g. sans comments, for this code: printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); set_pmcr_n(&pmcr, pmcr_n); printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); gcc-13 generates: 0000000000401c90 <set_pmcr_n>: 401c90: f9400002 ldr x2, [x0] 401c94: b3751022 bfi x2, x1, torvalds#11, #5 401c98: f9000002 str x2, [x0] 401c9c: d65f03c0 ret 0000000000402660 <test_create_vpmu_vm_with_pmcr_n>: 402724: aa1403e3 mov x3, x20 402728: aa1503e2 mov x2, x21 40272c: aa1603e0 mov x0, x22 402730: aa1503e1 mov x1, x21 402734: 940060ff bl 41ab30 <_IO_printf> 402738: aa1403e1 mov x1, x20 40273c: 910183e0 add x0, sp, #0x60 402740: 97fffd54 bl 401c90 <set_pmcr_n> 402744: aa1403e3 mov x3, x20 402748: aa1503e2 mov x2, x21 40274c: aa1503e1 mov x1, x21 402750: aa1603e0 mov x0, x22 402754: 940060f7 bl 41ab30 <_IO_printf> with the value stored in [sp + 0x60] ignored by both printf() above and in the test proper, resulting in a false failure due to vcpu_set_reg() simply storing the original value, not the intended value. $ ./vpmu_counter_access Random seed: 0x6b8b4567 orig = 3040, next = 3040, want = 0 orig = 3040, next = 3040, want = 0 ==== Test Assertion Failure ==== aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr) pid=71578 tid=71578 errno=9 - Bad file descriptor 1 0x400673: run_access_test at vpmu_counter_access.c:522 2 (inlined by) main at vpmu_counter_access.c:643 3 0x4132d7: __libc_start_call_main at libc-start.o:0 4 0x413653: __libc_start_main at ??:0 5 0x40106f: _start at ??:0 Failed to update PMCR.N to 0 (received: 6) Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n() is inlined in its sole caller. Cc: [email protected] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912 Signed-off-by: Sean Christopherson <[email protected]>

commit e972b08 upstream. We're seeing crashes from rq_qos_wake_function that look like this: BUG: unable to handle page fault for address: ffffafe180a40084 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 100000067 P4D 100000067 PUD 10027c067 PMD 10115d067 PTE 0 Oops: Oops: 0002 [#1] PREEMPT SMP PTI CPU: 17 UID: 0 PID: 0 Comm: swapper/17 Not tainted 6.12.0-rc3-00013-geca631b8fe80 torvalds#11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:_raw_spin_lock_irqsave+0x1d/0x40 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 9c 41 5c fa 65 ff 05 62 97 30 4c 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 0a 4c 89 e0 41 5c c3 cc cc cc cc 89 c6 e8 2c 0b 00 RSP: 0018:ffffafe180580ca0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffafe180a3f7a8 RCX: 0000000000000011 RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffafe180a40084 RBP: 0000000000000000 R08: 00000000001e7240 R09: 0000000000000011 R10: 0000000000000028 R11: 0000000000000888 R12: 0000000000000002 R13: ffffafe180a40084 R14: 0000000000000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff9aaf1f280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffafe180a40084 CR3: 000000010e428002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> try_to_wake_up+0x5a/0x6a0 rq_qos_wake_function+0x71/0x80 __wake_up_common+0x75/0xa0 __wake_up+0x36/0x60 scale_up.part.0+0x50/0x110 wb_timer_fn+0x227/0x450 ... So rq_qos_wake_function() calls wake_up_process(data->task), which calls try_to_wake_up(), which faults in raw_spin_lock_irqsave(&p->pi_lock). p comes from data->task, and data comes from the waitqueue entry, which is stored on the waiter's stack in rq_qos_wait(). Analyzing the core dump with drgn, I found that the waiter had already woken up and moved on to a completely unrelated code path, clobbering what was previously data->task. Meanwhile, the waker was passing the clobbered garbage in data->task to wake_up_process(), leading to the crash. What's happening is that in between rq_qos_wake_function() deleting the waitqueue entry and calling wake_up_process(), rq_qos_wait() is finding that it already got a token and returning. The race looks like this: rq_qos_wait() rq_qos_wake_function() ============================================================== prepare_to_wait_exclusive() data->got_token = true; list_del_init(&curr->entry); if (data.got_token) break; finish_wait(&rqw->wait, &data.wq); ^- returns immediately because list_empty_careful(&wq_entry->entry) is true ... return, go do something else ... wake_up_process(data->task) (NO LONGER VALID!)-^ Normally, finish_wait() is supposed to synchronize against the waker. But, as noted above, it is returning immediately because the waitqueue entry has already been removed from the waitqueue. The bug is that rq_qos_wake_function() is accessing the waitqueue entry AFTER deleting it. Note that autoremove_wake_function() wakes the waiter and THEN deletes the waitqueue entry, which is the proper order. Fix it by swapping the order. We also need to use list_del_init_careful() to match the list_empty_careful() in finish_wait(). Fixes: 38cfb5a ("blk-wbt: improve waking of tasks") Cc: [email protected] Signed-off-by: Omar Sandoval <[email protected]> Acked-by: Tejun Heo <[email protected]> Reviewed-by: Johannes Thumshirn <[email protected]> Link: https://lore.kernel.org/r/d3bee2463a67b1ee597211823bf7ad3721c26e41.1729014591.git.osandov@fb.com Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> (cherry picked from commit 4c5b123)

[ Upstream commit 3deb12c ] Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT creates this splat when an MPTCP socket is created: ============================= WARNING: suspicious RCU usage 6.12.0-rc2+ torvalds#11 Not tainted ----------------------------- net/mptcp/sched.c:44 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by mptcp_connect/176. stack backtrace: CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ torvalds#11 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7)) mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1)) ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28) inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386) ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1)) __sock_create (net/socket.c:1576) __sys_socket (net/socket.c:1671) ? __pfx___sys_socket (net/socket.c:1712) ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1)) __x64_sys_socket (net/socket.c:1728) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) That's because when the socket is initialised, rcu_read_lock() is not used despite the explicit comment written above the declaration of mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the warning. Fixes: 1730b2b ("mptcp: add sched in mptcp_sock") Cc: [email protected] Closes: multipath-tcp/mptcp_net-next#523 Reviewed-by: Geliang Tang <[email protected]> Signed-off-by: Matthieu Baerts (NGI0) <[email protected]> Reviewed-by: Simon Horman <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

commit e972b08 upstream. We're seeing crashes from rq_qos_wake_function that look like this: BUG: unable to handle page fault for address: ffffafe180a40084 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 100000067 P4D 100000067 PUD 10027c067 PMD 10115d067 PTE 0 Oops: Oops: 0002 [#1] PREEMPT SMP PTI CPU: 17 UID: 0 PID: 0 Comm: swapper/17 Not tainted 6.12.0-rc3-00013-geca631b8fe80 torvalds#11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:_raw_spin_lock_irqsave+0x1d/0x40 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 9c 41 5c fa 65 ff 05 62 97 30 4c 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 0a 4c 89 e0 41 5c c3 cc cc cc cc 89 c6 e8 2c 0b 00 RSP: 0018:ffffafe180580ca0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffafe180a3f7a8 RCX: 0000000000000011 RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffafe180a40084 RBP: 0000000000000000 R08: 00000000001e7240 R09: 0000000000000011 R10: 0000000000000028 R11: 0000000000000888 R12: 0000000000000002 R13: ffffafe180a40084 R14: 0000000000000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff9aaf1f280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffafe180a40084 CR3: 000000010e428002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> try_to_wake_up+0x5a/0x6a0 rq_qos_wake_function+0x71/0x80 __wake_up_common+0x75/0xa0 __wake_up+0x36/0x60 scale_up.part.0+0x50/0x110 wb_timer_fn+0x227/0x450 ... So rq_qos_wake_function() calls wake_up_process(data->task), which calls try_to_wake_up(), which faults in raw_spin_lock_irqsave(&p->pi_lock). p comes from data->task, and data comes from the waitqueue entry, which is stored on the waiter's stack in rq_qos_wait(). Analyzing the core dump with drgn, I found that the waiter had already woken up and moved on to a completely unrelated code path, clobbering what was previously data->task. Meanwhile, the waker was passing the clobbered garbage in data->task to wake_up_process(), leading to the crash. What's happening is that in between rq_qos_wake_function() deleting the waitqueue entry and calling wake_up_process(), rq_qos_wait() is finding that it already got a token and returning. The race looks like this: rq_qos_wait() rq_qos_wake_function() ============================================================== prepare_to_wait_exclusive() data->got_token = true; list_del_init(&curr->entry); if (data.got_token) break; finish_wait(&rqw->wait, &data.wq); ^- returns immediately because list_empty_careful(&wq_entry->entry) is true ... return, go do something else ... wake_up_process(data->task) (NO LONGER VALID!)-^ Normally, finish_wait() is supposed to synchronize against the waker. But, as noted above, it is returning immediately because the waitqueue entry has already been removed from the waitqueue. The bug is that rq_qos_wake_function() is accessing the waitqueue entry AFTER deleting it. Note that autoremove_wake_function() wakes the waiter and THEN deletes the waitqueue entry, which is the proper order. Fix it by swapping the order. We also need to use list_del_init_careful() to match the list_empty_careful() in finish_wait(). Fixes: 38cfb5a ("blk-wbt: improve waking of tasks") Cc: [email protected] Signed-off-by: Omar Sandoval <[email protected]> Acked-by: Tejun Heo <[email protected]> Reviewed-by: Johannes Thumshirn <[email protected]> Link: https://lore.kernel.org/r/d3bee2463a67b1ee597211823bf7ad3721c26e41.1729014591.git.osandov@fb.com Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 3deb12c ] Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT creates this splat when an MPTCP socket is created: ============================= WARNING: suspicious RCU usage 6.12.0-rc2+ torvalds#11 Not tainted ----------------------------- net/mptcp/sched.c:44 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by mptcp_connect/176. stack backtrace: CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ torvalds#11 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7)) mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1)) ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28) inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386) ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1)) __sock_create (net/socket.c:1576) __sys_socket (net/socket.c:1671) ? __pfx___sys_socket (net/socket.c:1712) ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1)) __x64_sys_socket (net/socket.c:1728) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) That's because when the socket is initialised, rcu_read_lock() is not used despite the explicit comment written above the declaration of mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the warning. Fixes: 1730b2b ("mptcp: add sched in mptcp_sock") Cc: [email protected] Closes: multipath-tcp/mptcp_net-next#523 Reviewed-by: Geliang Tang <[email protected]> Signed-off-by: Matthieu Baerts (NGI0) <[email protected]> Reviewed-by: Simon Horman <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

This commit provides a watchdog timer that sets a limit of how long a single sub-test could run: - if sub-test runs for 10 seconds, the name of the test is printed (currently the name of the test is printed only after it finishes); - if sub-test runs for 120 seconds, the running thread is terminated with SIGSEGV (to trigger crash_handler() and get a stack trace). Specifically: - the timer is armed on each call to run_one_test(); - re-armed at each call to test__start_subtest(); - is stopped when exiting run_one_test(). Default timeout could be overridden using '-w' or '--watchdog-timeout' options. Value 0 can be used to turn the timer off. Here is an example execution: $ ./ssh-exec.sh ./test_progs -w 5 -t \ send_signal/send_signal_perf_thread_remote,send_signal/send_signal_nmi_thread_remote WATCHDOG: test case send_signal/send_signal_nmi_thread_remote executes for 5 seconds, terminating with SIGSEGV Caught signal torvalds#11! Stack trace: ./test_progs(crash_handler+0x1f)[0x9049ef] /lib64/libc.so.6(+0x40d00)[0x7f1f1184fd00] /lib64/libc.so.6(read+0x4a)[0x7f1f1191cc4a] ./test_progs[0x720dd3] ./test_progs[0x71ef7a] ./test_progs(test_send_signal+0x1db)[0x71edeb] ./test_progs[0x9066c5] ./test_progs(main+0x5ed)[0x9054ad] /lib64/libc.so.6(+0x2a088)[0x7f1f11839088] /lib64/libc.so.6(__libc_start_main+0x8b)[0x7f1f1183914b] ./test_progs(_start+0x25)[0x527385] torvalds#292 send_signal:FAIL test_send_signal_common:PASS:reading pipe 0 nsec test_send_signal_common:PASS:reading pipe error: size 0 0 nsec test_send_signal_common:PASS:incorrect result 0 nsec test_send_signal_common:PASS:pipe_write 0 nsec test_send_signal_common:PASS:setpriority 0 nsec Timer is implemented using timer_{create,start} librt API. Internally librt uses pthreads for SIGEV_THREAD timers, so this change adds a background timer thread to the test process. Because of this a few checks in tests 'bpf_iter' and 'iters' need an update to account for an extra thread. For parallelized scenario the watchdog is also created for each worker fork. If one of the workers gets stuck, it would be terminated by a watchdog. In theory, this might lead to a scenario when all worker threads are exhausted, however this should not be a problem for server_main(), as it would exit with some of the tests not run. Signed-off-by: Eduard Zingerman <[email protected]>

This commit provides a watchdog timer that sets a limit of how long a single sub-test could run: - if sub-test runs for 10 seconds, the name of the test is printed (currently the name of the test is printed only after it finishes); - if sub-test runs for 120 seconds, the running thread is terminated with SIGSEGV (to trigger crash_handler() and get a stack trace). Specifically: - the timer is armed on each call to run_one_test(); - re-armed at each call to test__start_subtest(); - is stopped when exiting run_one_test(). Default timeout could be overridden using '-w' or '--watchdog-timeout' options. Value 0 can be used to turn the timer off. Here is an example execution: $ ./ssh-exec.sh ./test_progs -w 5 -t \ send_signal/send_signal_perf_thread_remote,send_signal/send_signal_nmi_thread_remote WATCHDOG: test case send_signal/send_signal_nmi_thread_remote executes for 5 seconds, terminating with SIGSEGV Caught signal torvalds#11! Stack trace: ./test_progs(crash_handler+0x1f)[0x9049ef] /lib64/libc.so.6(+0x40d00)[0x7f1f1184fd00] /lib64/libc.so.6(read+0x4a)[0x7f1f1191cc4a] ./test_progs[0x720dd3] ./test_progs[0x71ef7a] ./test_progs(test_send_signal+0x1db)[0x71edeb] ./test_progs[0x9066c5] ./test_progs(main+0x5ed)[0x9054ad] /lib64/libc.so.6(+0x2a088)[0x7f1f11839088] /lib64/libc.so.6(__libc_start_main+0x8b)[0x7f1f1183914b] ./test_progs(_start+0x25)[0x527385] torvalds#292 send_signal:FAIL test_send_signal_common:PASS:reading pipe 0 nsec test_send_signal_common:PASS:reading pipe error: size 0 0 nsec test_send_signal_common:PASS:incorrect result 0 nsec test_send_signal_common:PASS:pipe_write 0 nsec test_send_signal_common:PASS:setpriority 0 nsec Timer is implemented using timer_{create,start} librt API. Internally librt uses pthreads for SIGEV_THREAD timers, so this change adds a background timer thread to the test process. Because of this a few checks in tests 'bpf_iter' and 'iters' need an update to account for an extra thread. For parallelized scenario the watchdog is also created for each worker fork. If one of the workers gets stuck, it would be terminated by a watchdog. In theory, this might lead to a scenario when all worker threads are exhausted, however this should not be a problem for server_main(), as it would exit with some of the tests not run. Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>

[ Upstream commit 3deb12c ] Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT creates this splat when an MPTCP socket is created: ============================= WARNING: suspicious RCU usage 6.12.0-rc2+ torvalds#11 Not tainted ----------------------------- net/mptcp/sched.c:44 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by mptcp_connect/176. stack backtrace: CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ torvalds#11 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7)) mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1)) ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28) inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386) ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1)) __sock_create (net/socket.c:1576) __sys_socket (net/socket.c:1671) ? __pfx___sys_socket (net/socket.c:1712) ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1)) __x64_sys_socket (net/socket.c:1728) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) That's because when the socket is initialised, rcu_read_lock() is not used despite the explicit comment written above the declaration of mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the warning. Fixes: 1730b2b ("mptcp: add sched in mptcp_sock") Cc: [email protected] Closes: multipath-tcp/mptcp_net-next#523 Reviewed-by: Geliang Tang <[email protected]> Signed-off-by: Matthieu Baerts (NGI0) <[email protected]> Reviewed-by: Simon Horman <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ 123.491737][ T1] Unexpected kernel BRK exception at EL1 [ 123.497593][ T1] Internal error: ptrace BRK handler: f20003e8 [#1] PREEMPT SMP [ 123.500785][ T1] Modules linked in: [ 123.502567][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.8.0-rc3-next-20200630-00003-g15e24419c239-dirty torvalds#11 [ 123.507468][ T1] Hardware name: linux,dummy-virt (DT) [ 123.509826][ T1] pstate: 80400005 (Nzcv daif +PAN -UAO BTYPE=--) [ 123.512609][ T1] pc : of_unittest_untrack_overlay+0x64/0x134 [ 123.515245][ T1] lr : of_unittest_untrack_overlay+0x64/0x134 [ 123.517848][ T1] sp : ffff00006a65fb30 [ 123.519668][ T1] x29: ffff00006a65fb30 x28: 0000000000000000 [ 123.522295][ T1] x27: ffff00006a65fc30 x26: ffffa00016b86f00 [ 123.524937][ T1] x25: 0000000000000000 x24: 0000000000000000 [ 123.527592][ T1] x23: ffffa00014c72540 x22: ffffa00016b86000 [ 123.530191][ T1] x21: 0000000000000000 x20: 00000000ffffffff [ 123.532845][ T1] x19: 00000000ffffffff x18: 0000000000002690 [ 123.535547][ T1] x17: 0000000000002718 x16: 00000000000014b8 [ 123.538299][ T1] x15: 0000000000000001 x14: 0080000000000000 [ 123.541055][ T1] x13: 0000000000000002 x12: ffff94000298d209 [ 123.543801][ T1] x11: 1ffff4000298d208 x10: ffff94000298d208 [ 123.546580][ T1] x9 : dfffa00000000000 x8 : ffffa00014c69047 [ 123.549247][ T1] x7 : 0000000000000001 x6 : ffffa00014c69040 [ 123.552026][ T1] x5 : ffff00006a654040 x4 : 0000000000000000 [ 123.554799][ T1] x3 : ffffa00011d59d04 x2 : 00000000ffffffff [ 123.557541][ T1] x1 : ffff00006a654040 x0 : 0000000000000000 [ 123.560390][ T1] Call trace: [ 123.561935][ T1] of_unittest_untrack_overlay+0x64/0x134 [ 123.564469][ T1] of_unittest+0x2220/0x2438 [ 123.566585][ T1] do_one_initcall+0x470/0xa10 [ 123.568751][ T1] kernel_init_freeable+0x510/0x5f0 [ 123.571123][ T1] kernel_init+0x18/0x1e8 [ 123.573078][ T1] ret_from_fork+0x10/0x18 [ 123.575119][ T1] Code: 97978a9c d4210000 14000024 97978a99 (d4207d00) [ 123.578138][ T1] ---[ end trace c4e049fb5e3b0ba0 ]--- [ 123.580449][ T1] Kernel panic - not syncing: Fatal exception [ 123.583116][ T1] Kernel Offset: disabled [ 123.585066][ T1] CPU features: 0x240002,20002004 [ 123.587259][ T1] Memory Limit: none [ 123.588986][ T1] ---[ end Kernel panic - not syncing: Fatal exception ]--- Signed-off-by: Anders Roxell <[email protected]>

commit 5b188cc upstream. Disable strict aliasing, as has been done in the kernel proper for decades (literally since before git history) to fix issues where gcc will optimize away loads in code that looks 100% correct, but is _technically_ undefined behavior, and thus can be thrown away by the compiler. E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long) pointer to a u64 (unsigned long long) pointer when setting PMCR.N via u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores the result and uses the original PMCR. The issue is most easily observed by making set_pmcr_n() noinline and wrapping the call with printf(), e.g. sans comments, for this code: printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); set_pmcr_n(&pmcr, pmcr_n); printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); gcc-13 generates: 0000000000401c90 <set_pmcr_n>: 401c90: f9400002 ldr x2, [x0] 401c94: b3751022 bfi x2, x1, torvalds#11, #5 401c98: f9000002 str x2, [x0] 401c9c: d65f03c0 ret 0000000000402660 <test_create_vpmu_vm_with_pmcr_n>: 402724: aa1403e3 mov x3, x20 402728: aa1503e2 mov x2, x21 40272c: aa1603e0 mov x0, x22 402730: aa1503e1 mov x1, x21 402734: 940060ff bl 41ab30 <_IO_printf> 402738: aa1403e1 mov x1, x20 40273c: 910183e0 add x0, sp, #0x60 402740: 97fffd54 bl 401c90 <set_pmcr_n> 402744: aa1403e3 mov x3, x20 402748: aa1503e2 mov x2, x21 40274c: aa1503e1 mov x1, x21 402750: aa1603e0 mov x0, x22 402754: 940060f7 bl 41ab30 <_IO_printf> with the value stored in [sp + 0x60] ignored by both printf() above and in the test proper, resulting in a false failure due to vcpu_set_reg() simply storing the original value, not the intended value. $ ./vpmu_counter_access Random seed: 0x6b8b4567 orig = 3040, next = 3040, want = 0 orig = 3040, next = 3040, want = 0 ==== Test Assertion Failure ==== aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr) pid=71578 tid=71578 errno=9 - Bad file descriptor 1 0x400673: run_access_test at vpmu_counter_access.c:522 2 (inlined by) main at vpmu_counter_access.c:643 3 0x4132d7: __libc_start_call_main at libc-start.o:0 4 0x413653: __libc_start_main at ??:0 5 0x40106f: _start at ??:0 Failed to update PMCR.N to 0 (received: 6) Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n() is inlined in its sole caller. Cc: [email protected] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912 Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ 123.491737][ T1] Unexpected kernel BRK exception at EL1 [ 123.497593][ T1] Internal error: ptrace BRK handler: f20003e8 [#1] PREEMPT SMP [ 123.500785][ T1] Modules linked in: [ 123.502567][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.8.0-rc3-next-20200630-00003-g15e24419c239-dirty torvalds#11 [ 123.507468][ T1] Hardware name: linux,dummy-virt (DT) [ 123.509826][ T1] pstate: 80400005 (Nzcv daif +PAN -UAO BTYPE=--) [ 123.512609][ T1] pc : of_unittest_untrack_overlay+0x64/0x134 [ 123.515245][ T1] lr : of_unittest_untrack_overlay+0x64/0x134 [ 123.517848][ T1] sp : ffff00006a65fb30 [ 123.519668][ T1] x29: ffff00006a65fb30 x28: 0000000000000000 [ 123.522295][ T1] x27: ffff00006a65fc30 x26: ffffa00016b86f00 [ 123.524937][ T1] x25: 0000000000000000 x24: 0000000000000000 [ 123.527592][ T1] x23: ffffa00014c72540 x22: ffffa00016b86000 [ 123.530191][ T1] x21: 0000000000000000 x20: 00000000ffffffff [ 123.532845][ T1] x19: 00000000ffffffff x18: 0000000000002690 [ 123.535547][ T1] x17: 0000000000002718 x16: 00000000000014b8 [ 123.538299][ T1] x15: 0000000000000001 x14: 0080000000000000 [ 123.541055][ T1] x13: 0000000000000002 x12: ffff94000298d209 [ 123.543801][ T1] x11: 1ffff4000298d208 x10: ffff94000298d208 [ 123.546580][ T1] x9 : dfffa00000000000 x8 : ffffa00014c69047 [ 123.549247][ T1] x7 : 0000000000000001 x6 : ffffa00014c69040 [ 123.552026][ T1] x5 : ffff00006a654040 x4 : 0000000000000000 [ 123.554799][ T1] x3 : ffffa00011d59d04 x2 : 00000000ffffffff [ 123.557541][ T1] x1 : ffff00006a654040 x0 : 0000000000000000 [ 123.560390][ T1] Call trace: [ 123.561935][ T1] of_unittest_untrack_overlay+0x64/0x134 [ 123.564469][ T1] of_unittest+0x2220/0x2438 [ 123.566585][ T1] do_one_initcall+0x470/0xa10 [ 123.568751][ T1] kernel_init_freeable+0x510/0x5f0 [ 123.571123][ T1] kernel_init+0x18/0x1e8 [ 123.573078][ T1] ret_from_fork+0x10/0x18 [ 123.575119][ T1] Code: 97978a9c d4210000 14000024 97978a99 (d4207d00) [ 123.578138][ T1] ---[ end trace c4e049fb5e3b0ba0 ]--- [ 123.580449][ T1] Kernel panic - not syncing: Fatal exception [ 123.583116][ T1] Kernel Offset: disabled [ 123.585066][ T1] CPU features: 0x240002,20002004 [ 123.587259][ T1] Memory Limit: none [ 123.588986][ T1] ---[ end Kernel panic - not syncing: Fatal exception ]--- Signed-off-by: Anders Roxell <[email protected]>

commit cf96b8e upstream. ASan reports a memory leak caused by evlist not being deleted on exit in perf-report, perf-script and perf-data. The problem is caused by evlist->session not being deleted, which is allocated in perf_session__read_header, called in perf_session__new if perf_data is in read mode. In case of write mode, the session->evlist is filled by the caller. This patch solves the problem by calling evlist__delete in perf_session__delete if perf_data is in read mode. Changes in v2: - call evlist__delete from within perf_session__delete v1: https://lore.kernel.org/lkml/[email protected]/ ASan report follows: $ ./perf script report flamegraph ================================================================= ==227640==ERROR: LeakSanitizer: detected memory leaks <SNIP unrelated> Indirect leak of 2704 byte(s) in 1 object(s) allocated from: #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137) #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9 #2 0x7f999e in evlist__new /home/user/linux/tools/perf/util/evlist.c:77:26 #3 0x8ad938 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3797:20 #4 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6 #5 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10 torvalds#6 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12 torvalds#7 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 torvalds#8 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 torvalds#9 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2 torvalds#10 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3 torvalds#11 0x7f5260654b74 (/lib64/libc.so.6+0x27b74) Indirect leak of 568 byte(s) in 1 object(s) allocated from: #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137) #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9 #2 0x80ce88 in evsel__new_idx /home/user/linux/tools/perf/util/evsel.c:268:24 #3 0x8aed93 in evsel__new /home/user/linux/tools/perf/util/evsel.h:210:9 #4 0x8ae07e in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3853:11 #5 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6 torvalds#6 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10 torvalds#7 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12 torvalds#8 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 torvalds#9 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 torvalds#10 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2 torvalds#11 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3 torvalds#12 0x7f5260654b74 (/lib64/libc.so.6+0x27b74) Indirect leak of 264 byte(s) in 1 object(s) allocated from: #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137) #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9 #2 0xbe3e70 in xyarray__new /home/user/linux/tools/lib/perf/xyarray.c:10:23 #3 0xbd7754 in perf_evsel__alloc_id /home/user/linux/tools/lib/perf/evsel.c:361:21 #4 0x8ae201 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3871:7 #5 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6 torvalds#6 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10 torvalds#7 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12 torvalds#8 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 torvalds#9 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 torvalds#10 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2 torvalds#11 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3 torvalds#12 0x7f5260654b74 (/lib64/libc.so.6+0x27b74) Indirect leak of 32 byte(s) in 1 object(s) allocated from: #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137) #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9 #2 0xbd77e0 in perf_evsel__alloc_id /home/user/linux/tools/lib/perf/evsel.c:365:14 #3 0x8ae201 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3871:7 #4 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6 #5 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10 torvalds#6 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12 torvalds#7 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 torvalds#8 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 torvalds#9 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2 torvalds#10 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3 torvalds#11 0x7f5260654b74 (/lib64/libc.so.6+0x27b74) Indirect leak of 7 byte(s) in 1 object(s) allocated from: #0 0x4b8207 in strdup (/home/user/linux/tools/perf/perf+0x4b8207) #1 0x8b4459 in evlist__set_event_name /home/user/linux/tools/perf/util/header.c:2292:16 #2 0x89d862 in process_event_desc /home/user/linux/tools/perf/util/header.c:2313:3 #3 0x8af319 in perf_file_section__process /home/user/linux/tools/perf/util/header.c:3651:9 #4 0x8aa6e9 in perf_header__process_sections /home/user/linux/tools/perf/util/header.c:3427:9 #5 0x8ae3e7 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3886:2 torvalds#6 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6 torvalds#7 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10 torvalds#8 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12 torvalds#9 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 torvalds#10 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 torvalds#11 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2 torvalds#12 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3 torvalds#13 0x7f5260654b74 (/lib64/libc.so.6+0x27b74) SUMMARY: AddressSanitizer: 3728 byte(s) leaked in 7 allocation(s). Signed-off-by: Riccardo Mancini <[email protected]> Acked-by: Ian Rogers <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Kan Liang <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Cc: [email protected] # 5.10.228 Signed-off-by: Shuai Xue <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit 5b188cc upstream. Disable strict aliasing, as has been done in the kernel proper for decades (literally since before git history) to fix issues where gcc will optimize away loads in code that looks 100% correct, but is _technically_ undefined behavior, and thus can be thrown away by the compiler. E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long) pointer to a u64 (unsigned long long) pointer when setting PMCR.N via u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores the result and uses the original PMCR. The issue is most easily observed by making set_pmcr_n() noinline and wrapping the call with printf(), e.g. sans comments, for this code: printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); set_pmcr_n(&pmcr, pmcr_n); printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); gcc-13 generates: 0000000000401c90 <set_pmcr_n>: 401c90: f9400002 ldr x2, [x0] 401c94: b3751022 bfi x2, x1, torvalds#11, #5 401c98: f9000002 str x2, [x0] 401c9c: d65f03c0 ret 0000000000402660 <test_create_vpmu_vm_with_pmcr_n>: 402724: aa1403e3 mov x3, x20 402728: aa1503e2 mov x2, x21 40272c: aa1603e0 mov x0, x22 402730: aa1503e1 mov x1, x21 402734: 940060ff bl 41ab30 <_IO_printf> 402738: aa1403e1 mov x1, x20 40273c: 910183e0 add x0, sp, #0x60 402740: 97fffd54 bl 401c90 <set_pmcr_n> 402744: aa1403e3 mov x3, x20 402748: aa1503e2 mov x2, x21 40274c: aa1503e1 mov x1, x21 402750: aa1603e0 mov x0, x22 402754: 940060f7 bl 41ab30 <_IO_printf> with the value stored in [sp + 0x60] ignored by both printf() above and in the test proper, resulting in a false failure due to vcpu_set_reg() simply storing the original value, not the intended value. $ ./vpmu_counter_access Random seed: 0x6b8b4567 orig = 3040, next = 3040, want = 0 orig = 3040, next = 3040, want = 0 ==== Test Assertion Failure ==== aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr) pid=71578 tid=71578 errno=9 - Bad file descriptor 1 0x400673: run_access_test at vpmu_counter_access.c:522 2 (inlined by) main at vpmu_counter_access.c:643 3 0x4132d7: __libc_start_call_main at libc-start.o:0 4 0x413653: __libc_start_main at ??:0 5 0x40106f: _start at ??:0 Failed to update PMCR.N to 0 (received: 6) Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n() is inlined in its sole caller. Cc: [email protected] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912 Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ 123.491737][ T1] Unexpected kernel BRK exception at EL1 [ 123.497593][ T1] Internal error: ptrace BRK handler: f20003e8 [#1] PREEMPT SMP [ 123.500785][ T1] Modules linked in: [ 123.502567][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.8.0-rc3-next-20200630-00003-g15e24419c239-dirty torvalds#11 [ 123.507468][ T1] Hardware name: linux,dummy-virt (DT) [ 123.509826][ T1] pstate: 80400005 (Nzcv daif +PAN -UAO BTYPE=--) [ 123.512609][ T1] pc : of_unittest_untrack_overlay+0x64/0x134 [ 123.515245][ T1] lr : of_unittest_untrack_overlay+0x64/0x134 [ 123.517848][ T1] sp : ffff00006a65fb30 [ 123.519668][ T1] x29: ffff00006a65fb30 x28: 0000000000000000 [ 123.522295][ T1] x27: ffff00006a65fc30 x26: ffffa00016b86f00 [ 123.524937][ T1] x25: 0000000000000000 x24: 0000000000000000 [ 123.527592][ T1] x23: ffffa00014c72540 x22: ffffa00016b86000 [ 123.530191][ T1] x21: 0000000000000000 x20: 00000000ffffffff [ 123.532845][ T1] x19: 00000000ffffffff x18: 0000000000002690 [ 123.535547][ T1] x17: 0000000000002718 x16: 00000000000014b8 [ 123.538299][ T1] x15: 0000000000000001 x14: 0080000000000000 [ 123.541055][ T1] x13: 0000000000000002 x12: ffff94000298d209 [ 123.543801][ T1] x11: 1ffff4000298d208 x10: ffff94000298d208 [ 123.546580][ T1] x9 : dfffa00000000000 x8 : ffffa00014c69047 [ 123.549247][ T1] x7 : 0000000000000001 x6 : ffffa00014c69040 [ 123.552026][ T1] x5 : ffff00006a654040 x4 : 0000000000000000 [ 123.554799][ T1] x3 : ffffa00011d59d04 x2 : 00000000ffffffff [ 123.557541][ T1] x1 : ffff00006a654040 x0 : 0000000000000000 [ 123.560390][ T1] Call trace: [ 123.561935][ T1] of_unittest_untrack_overlay+0x64/0x134 [ 123.564469][ T1] of_unittest+0x2220/0x2438 [ 123.566585][ T1] do_one_initcall+0x470/0xa10 [ 123.568751][ T1] kernel_init_freeable+0x510/0x5f0 [ 123.571123][ T1] kernel_init+0x18/0x1e8 [ 123.573078][ T1] ret_from_fork+0x10/0x18 [ 123.575119][ T1] Code: 97978a9c d4210000 14000024 97978a99 (d4207d00) [ 123.578138][ T1] ---[ end trace c4e049fb5e3b0ba0 ]--- [ 123.580449][ T1] Kernel panic - not syncing: Fatal exception [ 123.583116][ T1] Kernel Offset: disabled [ 123.585066][ T1] CPU features: 0x240002,20002004 [ 123.587259][ T1] Memory Limit: none [ 123.588986][ T1] ---[ end Kernel panic - not syncing: Fatal exception ]--- Signed-off-by: Anders Roxell <[email protected]>

Disable strict aliasing, as has been done in the kernel proper for decades (literally since before git history) to fix issues where gcc will optimize away loads in code that looks 100% correct, but is _technically_ undefined behavior, and thus can be thrown away by the compiler. E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long) pointer to a u64 (unsigned long long) pointer when setting PMCR.N via u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores the result and uses the original PMCR. The issue is most easily observed by making set_pmcr_n() noinline and wrapping the call with printf(), e.g. sans comments, for this code: printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); set_pmcr_n(&pmcr, pmcr_n); printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); gcc-13 generates: 0000000000401c90 <set_pmcr_n>: 401c90: f9400002 ldr x2, [x0] 401c94: b3751022 bfi x2, x1, torvalds#11, #5 401c98: f9000002 str x2, [x0] 401c9c: d65f03c0 ret 0000000000402660 <test_create_vpmu_vm_with_pmcr_n>: 402724: aa1403e3 mov x3, x20 402728: aa1503e2 mov x2, x21 40272c: aa1603e0 mov x0, x22 402730: aa1503e1 mov x1, x21 402734: 940060ff bl 41ab30 <_IO_printf> 402738: aa1403e1 mov x1, x20 40273c: 910183e0 add x0, sp, #0x60 402740: 97fffd54 bl 401c90 <set_pmcr_n> 402744: aa1403e3 mov x3, x20 402748: aa1503e2 mov x2, x21 40274c: aa1503e1 mov x1, x21 402750: aa1603e0 mov x0, x22 402754: 940060f7 bl 41ab30 <_IO_printf> with the value stored in [sp + 0x60] ignored by both printf() above and in the test proper, resulting in a false failure due to vcpu_set_reg() simply storing the original value, not the intended value. $ ./vpmu_counter_access Random seed: 0x6b8b4567 orig = 3040, next = 3040, want = 0 orig = 3040, next = 3040, want = 0 ==== Test Assertion Failure ==== aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr) pid=71578 tid=71578 errno=9 - Bad file descriptor 1 0x400673: run_access_test at vpmu_counter_access.c:522 2 (inlined by) main at vpmu_counter_access.c:643 3 0x4132d7: __libc_start_call_main at libc-start.o:0 4 0x413653: __libc_start_main at ??:0 5 0x40106f: _start at ??:0 Failed to update PMCR.N to 0 (received: 6) Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n() is inlined in its sole caller. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912 Signed-off-by: Sean Christopherson <[email protected]>

[ 123.491737][ T1] Unexpected kernel BRK exception at EL1 [ 123.497593][ T1] Internal error: ptrace BRK handler: f20003e8 [#1] PREEMPT SMP [ 123.500785][ T1] Modules linked in: [ 123.502567][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.8.0-rc3-next-20200630-00003-g15e24419c239-dirty torvalds#11 [ 123.507468][ T1] Hardware name: linux,dummy-virt (DT) [ 123.509826][ T1] pstate: 80400005 (Nzcv daif +PAN -UAO BTYPE=--) [ 123.512609][ T1] pc : of_unittest_untrack_overlay+0x64/0x134 [ 123.515245][ T1] lr : of_unittest_untrack_overlay+0x64/0x134 [ 123.517848][ T1] sp : ffff00006a65fb30 [ 123.519668][ T1] x29: ffff00006a65fb30 x28: 0000000000000000 [ 123.522295][ T1] x27: ffff00006a65fc30 x26: ffffa00016b86f00 [ 123.524937][ T1] x25: 0000000000000000 x24: 0000000000000000 [ 123.527592][ T1] x23: ffffa00014c72540 x22: ffffa00016b86000 [ 123.530191][ T1] x21: 0000000000000000 x20: 00000000ffffffff [ 123.532845][ T1] x19: 00000000ffffffff x18: 0000000000002690 [ 123.535547][ T1] x17: 0000000000002718 x16: 00000000000014b8 [ 123.538299][ T1] x15: 0000000000000001 x14: 0080000000000000 [ 123.541055][ T1] x13: 0000000000000002 x12: ffff94000298d209 [ 123.543801][ T1] x11: 1ffff4000298d208 x10: ffff94000298d208 [ 123.546580][ T1] x9 : dfffa00000000000 x8 : ffffa00014c69047 [ 123.549247][ T1] x7 : 0000000000000001 x6 : ffffa00014c69040 [ 123.552026][ T1] x5 : ffff00006a654040 x4 : 0000000000000000 [ 123.554799][ T1] x3 : ffffa00011d59d04 x2 : 00000000ffffffff [ 123.557541][ T1] x1 : ffff00006a654040 x0 : 0000000000000000 [ 123.560390][ T1] Call trace: [ 123.561935][ T1] of_unittest_untrack_overlay+0x64/0x134 [ 123.564469][ T1] of_unittest+0x2220/0x2438 [ 123.566585][ T1] do_one_initcall+0x470/0xa10 [ 123.568751][ T1] kernel_init_freeable+0x510/0x5f0 [ 123.571123][ T1] kernel_init+0x18/0x1e8 [ 123.573078][ T1] ret_from_fork+0x10/0x18 [ 123.575119][ T1] Code: 97978a9c d4210000 14000024 97978a99 (d4207d00) [ 123.578138][ T1] ---[ end trace c4e049fb5e3b0ba0 ]--- [ 123.580449][ T1] Kernel panic - not syncing: Fatal exception [ 123.583116][ T1] Kernel Offset: disabled [ 123.585066][ T1] CPU features: 0x240002,20002004 [ 123.587259][ T1] Memory Limit: none [ 123.588986][ T1] ---[ end Kernel panic - not syncing: Fatal exception ]--- Signed-off-by: Anders Roxell <[email protected]>

[ Upstream commit 5bf1557 ] test_progs uses glibc specific functions backtrace() and backtrace_symbols_fd() to print backtrace in case of SIGSEGV. Recent commit (see fixes) updated test_progs.c to define stub versions of the same functions with attriubte "weak" in order to allow linking test_progs against musl libc. Unfortunately this broke the backtrace handling for glibc builds. As it turns out, glibc defines backtrace() and backtrace_symbols_fd() as weak: $ llvm-readelf --symbols /lib64/libc.so.6 \ | grep -P '( backtrace_symbols_fd| backtrace)$' 4910: 0000000000126b40 161 FUNC WEAK DEFAULT 16 backtrace 6843: 0000000000126f90 852 FUNC WEAK DEFAULT 16 backtrace_symbols_fd So does test_progs: $ llvm-readelf --symbols test_progs \ | grep -P '( backtrace_symbols_fd| backtrace)$' 2891: 00000000006ad190 15 FUNC WEAK DEFAULT 13 backtrace 11215: 00000000006ad1a0 41 FUNC WEAK DEFAULT 13 backtrace_symbols_fd In such situation dynamic linker is not obliged to favour glibc implementation over the one defined in test_progs. Compiling with the following simple modification to test_progs.c demonstrates the issue: $ git diff ... \--- a/tools/testing/selftests/bpf/test_progs.c \+++ b/tools/testing/selftests/bpf/test_progs.c \@@ -1817,6 +1817,7 @@ int main(int argc, char **argv) if (err) return err; + *(int *)0xdeadbeef = 42; err = cd_flavor_subdir(argv[0]); if (err) return err; $ ./test_progs [0]: Caught signal torvalds#11! Stack trace: <backtrace not supported> Segmentation fault (core dumped) Resolve this by hiding stub definitions behind __GLIBC__ macro check instead of using "weak" attribute. Fixes: c9a83e7 ("selftests/bpf: Fix compile if backtrace support missing in libc") Signed-off-by: Eduard Zingerman <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Tested-by: Tony Ambardar <[email protected]> Reviewed-by: Tony Ambardar <[email protected]> Acked-by: Daniel Xu <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Sasha Levin <[email protected]>

Until now the Identification Request command was used to detect devices. The command is not strictly mandatory for displays to implement but should at least result in a valid error response. Some devices seen to not even send back an error/null response but instead only respond with null bytes causing the detection to abort. Now the first chunk of the capability string is requested for the first detection step. As the capabilites request command is effectively mandatory, this should improve compatibility with badly programmed displays. May fix issues torvalds#11 and torvalds#20.

Added backlight support for some samsung laptops

bdb25f1

Models: * N120 * R468/R418 * X320/X420/X520 * R510/P510 * N350 * R470/R420 * R528/R728 * SQ1S

xonatius closed this Sep 7, 2011

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Added backlight support for some samsung laptops #11

Added backlight support for some samsung laptops #11

xonatius commented Sep 6, 2011

torvalds commented Sep 6, 2011

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nils-werner commented Sep 9, 2011

torvalds commented Sep 9, 2011

nils-werner commented Sep 9, 2011

torvalds commented Sep 9, 2011

nils-werner commented Sep 9, 2011

nils-werner commented Sep 9, 2011

jeffWelling commented Sep 9, 2011

Added backlight support for some samsung laptops #11

Added backlight support for some samsung laptops #11

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xonatius commented Sep 6, 2011

torvalds commented Sep 6, 2011

nils-werner commented Sep 7, 2011

valpackett commented Sep 7, 2011

tilsammans commented Sep 7, 2011

hotwoofy commented Sep 7, 2011

nils-werner commented Sep 9, 2011

torvalds commented Sep 9, 2011

nils-werner commented Sep 9, 2011

torvalds commented Sep 9, 2011

nils-werner commented Sep 9, 2011

nils-werner commented Sep 9, 2011

jeffWelling commented Sep 9, 2011