Is instantaneously removing running bandwidth theoretically wrong? #7
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jlelli
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Mar 5, 2018
Commit e936509 ("usb: phy: mxs: add usb charger type detection") causes the following kernel hang on i.MX28: [ 2.207973] usbcore: registered new interface driver usb-storage [ 2.235659] Unable to handle kernel NULL pointer dereference at virtual address 00000188 [ 2.244195] pgd = (ptrval) [ 2.246994] [00000188] *pgd=00000000 [ 2.250676] Internal error: Oops: 5 [#1] ARM [ 2.254979] Modules linked in: [ 2.258089] CPU: 0 PID: 1 Comm: swapper Not tainted 4.15.0-rc8-next-20180117-00002-g75d5f21 #7 [ 2.266724] Hardware name: Freescale MXS (Device Tree) [ 2.271921] PC is at regmap_read+0x0/0x5c [ 2.275977] LR is at mxs_phy_charger_detect+0x34/0x1dc mxs_phy_charger_detect() makes accesses to the anatop registers via regmap, however i.MX23/28 do not have such registers, which causes a NULL pointer dereference. Fix the issue by doing a NULL check on the 'regmap' pointer. Fixes: e936509 ("usb: phy: mxs: add usb charger type detection") Cc: <stable@vger.kernel.org> # v4.15 Reviewed-by: Li Jun <jun.li@nxp.com> Acked-by: Peter Chen <peter.chen@nxp.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
jlelli
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Mar 5, 2018
It was reported by Sergey Senozhatsky that if THP (Transparent Huge Page) and frontswap (via zswap) are both enabled, when memory goes low so that swap is triggered, segfault and memory corruption will occur in random user space applications as follow, kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000] #0 0x00007fc08889ae0d _int_malloc (libc.so.6) #1 0x00007fc08889c2f3 malloc (libc.so.6) #2 0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt) #3 0x0000560e6005e75c n/a (urxvt) #4 0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt) #5 0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt) #6 0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt) #7 0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt) #8 0x0000560e6005cb55 ev_run (urxvt) #9 0x0000560e6003b9b9 main (urxvt) torvalds#10 0x00007fc08883af4a __libc_start_main (libc.so.6) torvalds#11 0x0000560e6003f9da _start (urxvt) After bisection, it was found the first bad commit is bd4c82c ("mm, THP, swap: delay splitting THP after swapped out"). The root cause is as follows: When the pages are written to swap device during swapping out in swap_writepage(), zswap (fontswap) is tried to compress the pages to improve performance. But zswap (frontswap) will treat THP as a normal page, so only the head page is saved. After swapping in, tail pages will not be restored to their original contents, causing memory corruption in the applications. This is fixed by refusing to save page in the frontswap store functions if the page is a THP. So that the THP will be swapped out to swap device. Another choice is to split THP if frontswap is enabled. But it is found that the frontswap enabling isn't flexible. For example, if CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if zswap itself isn't enabled. Frontswap has multiple backends, to make it easy for one backend to enable THP support, the THP checking is put in backend frontswap store functions instead of the general interfaces. Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com Fixes: bd4c82c ("mm, THP, swap: delay splitting THP after swapped out") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> [put THP checking in backend] Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Shaohua Li <shli@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Shakeel Butt <shakeelb@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> [4.14] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
jlelli
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Jan 7, 2019
Increase kasan instrumented kernel stack size from 32k to 64k. Other architectures seems to get away with just doubling kernel stack size under kasan, but on s390 this appears to be not enough due to bigger frame size. The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting stack overflow is fs sync on xfs filesystem: #0 [9a0681e8] 704 bytes check_usage at 34b1fc #1 [9a0684a8] 432 bytes check_usage at 34c710 #2 [9a068658] 1048 bytes validate_chain at 35044a #3 [9a068a70] 312 bytes __lock_acquire at 3559fe #4 [9a068ba8] 440 bytes lock_acquire at 3576ee #5 [9a068d60] 104 bytes _raw_spin_lock at 21b44e0 #6 [9a068dc8] 1992 bytes enqueue_entity at 2dbf72 #7 [9a069590] 1496 bytes enqueue_task_fair at 2df5f0 #8 [9a069b68] 64 bytes ttwu_do_activate at 28f438 #9 [9a069ba8] 552 bytes try_to_wake_up at 298c4c torvalds#10 [9a069dd0] 168 bytes wake_up_worker at 23f97c torvalds#11 [9a069e78] 200 bytes insert_work at 23fc2e torvalds#12 [9a069f40] 648 bytes __queue_work at 2487c0 torvalds#13 [9a06a1c8] 200 bytes __queue_delayed_work at 24db28 torvalds#14 [9a06a290] 248 bytes mod_delayed_work_on at 24de84 torvalds#15 [9a06a388] 24 bytes kblockd_mod_delayed_work_on at 153e2a0 torvalds#16 [9a06a3a0] 288 bytes __blk_mq_delay_run_hw_queue at 158168c torvalds#17 [9a06a4c0] 192 bytes blk_mq_run_hw_queue at 1581a3c torvalds#18 [9a06a580] 184 bytes blk_mq_sched_insert_requests at 15a2192 torvalds#19 [9a06a638] 1024 bytes blk_mq_flush_plug_list at 1590f3a torvalds#20 [9a06aa38] 704 bytes blk_flush_plug_list at 1555028 torvalds#21 [9a06acf8] 320 bytes schedule at 219e476 torvalds#22 [9a06ae38] 760 bytes schedule_timeout at 21b0aac torvalds#23 [9a06b130] 408 bytes wait_for_common at 21a1706 torvalds#24 [9a06b2c8] 360 bytes xfs_buf_iowait at fa1540 torvalds#25 [9a06b430] 256 bytes __xfs_buf_submit at fadae6 torvalds#26 [9a06b530] 264 bytes xfs_buf_read_map at fae3f6 torvalds#27 [9a06b638] 656 bytes xfs_trans_read_buf_map at 10ac9a8 torvalds#28 [9a06b8c8] 304 bytes xfs_btree_kill_root at e72426 torvalds#29 [9a06b9f8] 288 bytes xfs_btree_lookup_get_block at e7bc5e torvalds#30 [9a06bb18] 624 bytes xfs_btree_lookup at e7e1a6 torvalds#31 [9a06bd88] 2664 bytes xfs_alloc_ag_vextent_near at dfa070 torvalds#32 [9a06c7f0] 144 bytes xfs_alloc_ag_vextent at dff3ca torvalds#33 [9a06c880] 1128 bytes xfs_alloc_vextent at e05fce torvalds#34 [9a06cce8] 584 bytes xfs_bmap_btalloc at e58342 torvalds#35 [9a06cf30] 1336 bytes xfs_bmapi_write at e618de torvalds#36 [9a06d468] 776 bytes xfs_iomap_write_allocate at ff678e torvalds#37 [9a06d770] 720 bytes xfs_map_blocks at f82af8 torvalds#38 [9a06da40] 928 bytes xfs_writepage_map at f83cd6 torvalds#39 [9a06dde0] 320 bytes xfs_do_writepage at f85872 torvalds#40 [9a06df20] 1320 bytes write_cache_pages at 73dfe8 torvalds#41 [9a06e448] 208 bytes xfs_vm_writepages at f7f892 torvalds#42 [9a06e518] 88 bytes do_writepages at 73fe6a torvalds#43 [9a06e570] 872 bytes __writeback_single_inode at a20cb6 torvalds#44 [9a06e8d8] 664 bytes writeback_sb_inodes at a23be2 torvalds#45 [9a06eb70] 296 bytes __writeback_inodes_wb at a242e0 torvalds#46 [9a06ec98] 928 bytes wb_writeback at a2500e torvalds#47 [9a06f038] 848 bytes wb_do_writeback at a260ae torvalds#48 [9a06f388] 536 bytes wb_workfn at a28228 torvalds#49 [9a06f5a0] 1088 bytes process_one_work at 24a234 torvalds#50 [9a06f9e0] 1120 bytes worker_thread at 24ba26 torvalds#51 [9a06fe40] 104 bytes kthread at 26545a #52 [9a06fea8] kernel_thread_starter at 21b6b62 To be able to increase the stack size to 64k reuse LLILL instruction in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE (65192) value as unsigned. Reported-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
jlelli
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May 19, 2020
Commit 64e90a8 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") added the optiont to disable all call_usermodehelper() calls by setting STATIC_USERMODEHELPER_PATH to an empty string. When this is done, and crashdump is triggered, it will crash on null pointer dereference, since we make assumptions over what call_usermodehelper_exec() did. This has been reported by Sergey when one triggers a a coredump with the following configuration: ``` CONFIG_STATIC_USERMODEHELPER=y CONFIG_STATIC_USERMODEHELPER_PATH="" kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e ``` The way disabling the umh was designed was that call_usermodehelper_exec() would just return early, without an error. But coredump assumes certain variables are set up for us when this happens, and calls ile_start_write(cprm.file) with a NULL file. [ 2.819676] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 2.819859] #PF: supervisor read access in kernel mode [ 2.820035] #PF: error_code(0x0000) - not-present page [ 2.820188] PGD 0 P4D 0 [ 2.820305] Oops: 0000 [#1] SMP PTI [ 2.820436] CPU: 2 PID: 89 Comm: a Not tainted 5.7.0-rc1+ #7 [ 2.820680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014 [ 2.821150] RIP: 0010:do_coredump+0xd80/0x1060 [ 2.821385] Code: e8 95 11 ed ff 48 c7 c6 cc a7 b4 81 48 8d bd 28 ff ff ff 89 c2 e8 70 f1 ff ff 41 89 c2 85 c0 0f 84 72 f7 ff ff e9 b4 fe ff ff <48> 8b 57 20 0f b7 02 66 25 00 f0 66 3d 00 8 0 0f 84 9c 01 00 00 44 [ 2.822014] RSP: 0000:ffffc9000029bcb8 EFLAGS: 00010246 [ 2.822339] RAX: 0000000000000000 RBX: ffff88803f860000 RCX: 000000000000000a [ 2.822746] RDX: 0000000000000009 RSI: 0000000000000282 RDI: 0000000000000000 [ 2.823141] RBP: ffffc9000029bde8 R08: 0000000000000000 R09: ffffc9000029bc00 [ 2.823508] R10: 0000000000000001 R11: ffff88803dec90be R12: ffffffff81c39da0 [ 2.823902] R13: ffff88803de84400 R14: 0000000000000000 R15: 0000000000000000 [ 2.824285] FS: 00007fee08183540(0000) GS:ffff88803e480000(0000) knlGS:0000000000000000 [ 2.824767] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.825111] CR2: 0000000000000020 CR3: 000000003f856005 CR4: 0000000000060ea0 [ 2.825479] Call Trace: [ 2.825790] get_signal+0x11e/0x720 [ 2.826087] do_signal+0x1d/0x670 [ 2.826361] ? force_sig_info_to_task+0xc1/0xf0 [ 2.826691] ? force_sig_fault+0x3c/0x40 [ 2.826996] ? do_trap+0xc9/0x100 [ 2.827179] exit_to_usermode_loop+0x49/0x90 [ 2.827359] prepare_exit_to_usermode+0x77/0xb0 [ 2.827559] ? invalid_op+0xa/0x30 [ 2.827747] ret_from_intr+0x20/0x20 [ 2.827921] RIP: 0033:0x55e2c76d2129 [ 2.828107] Code: 2d ff ff ff e8 68 ff ff ff 5d c6 05 18 2f 00 00 01 c3 0f 1f 80 00 00 00 00 c3 0f 1f 80 00 00 00 00 e9 7b ff ff ff 55 48 89 e5 <0f> 0b b8 00 00 00 00 5d c3 66 2e 0f 1f 84 0 0 00 00 00 00 0f 1f 40 [ 2.828603] RSP: 002b:00007fffeba5e080 EFLAGS: 00010246 [ 2.828801] RAX: 000055e2c76d2125 RBX: 0000000000000000 RCX: 00007fee0817c718 [ 2.829034] RDX: 00007fffeba5e188 RSI: 00007fffeba5e178 RDI: 0000000000000001 [ 2.829257] RBP: 00007fffeba5e080 R08: 0000000000000000 R09: 00007fee08193c00 [ 2.829482] R10: 0000000000000009 R11: 0000000000000000 R12: 000055e2c76d2040 [ 2.829727] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 2.829964] CR2: 0000000000000020 [ 2.830149] ---[ end trace ceed83d8c68a1bf1 ]--- ``` Cc: <stable@vger.kernel.org> # v4.11+ Fixes: 64e90a8 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199795 Reported-by: Tony Vroon <chainsaw@gentoo.org> Reported-by: Sergey Kvachonok <ravenexp@gmail.com> Tested-by: Sergei Trofimovich <slyfox@gentoo.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20200416162859.26518-1-mcgrof@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jlelli
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Jan 11, 2021
Very sporadically I had test case btrfs/069 from fstests hanging (for years, it is not a recent regression), with the following traces in dmesg/syslog: [162301.160628] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg started [162301.181196] BTRFS info (device sdc): scrub: finished on devid 4 with status: 0 [162301.287162] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg finished [162513.513792] INFO: task btrfs-transacti:1356167 blocked for more than 120 seconds. [162513.514318] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.514522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.514747] task:btrfs-transacti state:D stack: 0 pid:1356167 ppid: 2 flags:0x00004000 [162513.514751] Call Trace: [162513.514761] __schedule+0x5ce/0xd00 [162513.514765] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.514771] schedule+0x46/0xf0 [162513.514844] wait_current_trans+0xde/0x140 [btrfs] [162513.514850] ? finish_wait+0x90/0x90 [162513.514864] start_transaction+0x37c/0x5f0 [btrfs] [162513.514879] transaction_kthread+0xa4/0x170 [btrfs] [162513.514891] ? btrfs_cleanup_transaction+0x660/0x660 [btrfs] [162513.514894] kthread+0x153/0x170 [162513.514897] ? kthread_stop+0x2c0/0x2c0 [162513.514902] ret_from_fork+0x22/0x30 [162513.514916] INFO: task fsstress:1356184 blocked for more than 120 seconds. [162513.515192] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.515431] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.515680] task:fsstress state:D stack: 0 pid:1356184 ppid:1356177 flags:0x00004000 [162513.515682] Call Trace: [162513.515688] __schedule+0x5ce/0xd00 [162513.515691] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.515697] schedule+0x46/0xf0 [162513.515712] wait_current_trans+0xde/0x140 [btrfs] [162513.515716] ? finish_wait+0x90/0x90 [162513.515729] start_transaction+0x37c/0x5f0 [btrfs] [162513.515743] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.515753] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.515758] ? __ia32_sys_fdatasync+0x20/0x20 [162513.515761] iterate_supers+0x87/0xf0 [162513.515765] ksys_sync+0x60/0xb0 [162513.515768] __do_sys_sync+0xa/0x10 [162513.515771] do_syscall_64+0x33/0x80 [162513.515774] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.515781] RIP: 0033:0x7f5238f50bd7 [162513.515782] Code: Bad RIP value. [162513.515784] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.515786] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.515788] RDX: 00000000ffffffff RSI: 000000000daf0e74 RDI: 000000000000003a [162513.515789] RBP: 0000000000000032 R08: 000000000000000a R09: 00007f5239019be0 [162513.515791] R10: fffffffffffff24f R11: 0000000000000206 R12: 000000000000003a [162513.515792] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.515804] INFO: task fsstress:1356185 blocked for more than 120 seconds. [162513.516064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.516329] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.516617] task:fsstress state:D stack: 0 pid:1356185 ppid:1356177 flags:0x00000000 [162513.516620] Call Trace: [162513.516625] __schedule+0x5ce/0xd00 [162513.516628] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.516634] schedule+0x46/0xf0 [162513.516647] wait_current_trans+0xde/0x140 [btrfs] [162513.516650] ? finish_wait+0x90/0x90 [162513.516662] start_transaction+0x4d7/0x5f0 [btrfs] [162513.516679] btrfs_setxattr_trans+0x3c/0x100 [btrfs] [162513.516686] __vfs_setxattr+0x66/0x80 [162513.516691] __vfs_setxattr_noperm+0x70/0x200 [162513.516697] vfs_setxattr+0x6b/0x120 [162513.516703] setxattr+0x125/0x240 [162513.516709] ? lock_acquire+0xb1/0x480 [162513.516712] ? mnt_want_write+0x20/0x50 [162513.516721] ? rcu_read_lock_any_held+0x8e/0xb0 [162513.516723] ? preempt_count_add+0x49/0xa0 [162513.516725] ? __sb_start_write+0x19b/0x290 [162513.516727] ? preempt_count_add+0x49/0xa0 [162513.516732] path_setxattr+0xba/0xd0 [162513.516739] __x64_sys_setxattr+0x27/0x30 [162513.516741] do_syscall_64+0x33/0x80 [162513.516743] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.516745] RIP: 0033:0x7f5238f56d5a [162513.516746] Code: Bad RIP value. [162513.516748] RSP: 002b:00007fff67b97868 EFLAGS: 00000202 ORIG_RAX: 00000000000000bc [162513.516750] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f5238f56d5a [162513.516751] RDX: 000055b1fbb0d5a0 RSI: 00007fff67b978a0 RDI: 000055b1fbb0d470 [162513.516753] RBP: 000055b1fbb0d5a0 R08: 0000000000000001 R09: 00007fff67b97700 [162513.516754] R10: 0000000000000004 R11: 0000000000000202 R12: 0000000000000004 [162513.516756] R13: 0000000000000024 R14: 0000000000000001 R15: 00007fff67b978a0 [162513.516767] INFO: task fsstress:1356196 blocked for more than 120 seconds. [162513.517064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.517365] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.517763] task:fsstress state:D stack: 0 pid:1356196 ppid:1356177 flags:0x00004000 [162513.517780] Call Trace: [162513.517786] __schedule+0x5ce/0xd00 [162513.517789] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.517796] schedule+0x46/0xf0 [162513.517810] wait_current_trans+0xde/0x140 [btrfs] [162513.517814] ? finish_wait+0x90/0x90 [162513.517829] start_transaction+0x37c/0x5f0 [btrfs] [162513.517845] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.517857] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.517862] ? __ia32_sys_fdatasync+0x20/0x20 [162513.517865] iterate_supers+0x87/0xf0 [162513.517869] ksys_sync+0x60/0xb0 [162513.517872] __do_sys_sync+0xa/0x10 [162513.517875] do_syscall_64+0x33/0x80 [162513.517878] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.517881] RIP: 0033:0x7f5238f50bd7 [162513.517883] Code: Bad RIP value. [162513.517885] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.517887] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.517889] RDX: 0000000000000000 RSI: 000000007660add2 RDI: 0000000000000053 [162513.517891] RBP: 0000000000000032 R08: 0000000000000067 R09: 00007f5239019be0 [162513.517893] R10: fffffffffffff24f R11: 0000000000000206 R12: 0000000000000053 [162513.517895] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.517908] INFO: task fsstress:1356197 blocked for more than 120 seconds. [162513.518298] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.518672] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.519157] task:fsstress state:D stack: 0 pid:1356197 ppid:1356177 flags:0x00000000 [162513.519160] Call Trace: [162513.519165] __schedule+0x5ce/0xd00 [162513.519168] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.519174] schedule+0x46/0xf0 [162513.519190] wait_current_trans+0xde/0x140 [btrfs] [162513.519193] ? finish_wait+0x90/0x90 [162513.519206] start_transaction+0x4d7/0x5f0 [btrfs] [162513.519222] btrfs_create+0x57/0x200 [btrfs] [162513.519230] lookup_open+0x522/0x650 [162513.519246] path_openat+0x2b8/0xa50 [162513.519270] do_filp_open+0x91/0x100 [162513.519275] ? find_held_lock+0x32/0x90 [162513.519280] ? lock_acquired+0x33b/0x470 [162513.519285] ? do_raw_spin_unlock+0x4b/0xc0 [162513.519287] ? _raw_spin_unlock+0x29/0x40 [162513.519295] do_sys_openat2+0x20d/0x2d0 [162513.519300] do_sys_open+0x44/0x80 [162513.519304] do_syscall_64+0x33/0x80 [162513.519307] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.519309] RIP: 0033:0x7f5238f4a903 [162513.519310] Code: Bad RIP value. [162513.519312] RSP: 002b:00007fff67b97758 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 [162513.519314] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f5238f4a903 [162513.519316] RDX: 0000000000000000 RSI: 00000000000001b6 RDI: 000055b1fbb0d470 [162513.519317] RBP: 00007fff67b978c0 R08: 0000000000000001 R09: 0000000000000002 [162513.519319] R10: 00007fff67b974f7 R11: 0000000000000246 R12: 0000000000000013 [162513.519320] R13: 00000000000001b6 R14: 00007fff67b97906 R15: 000055b1fad1c620 [162513.519332] INFO: task btrfs:1356211 blocked for more than 120 seconds. [162513.519727] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.520115] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.520508] task:btrfs state:D stack: 0 pid:1356211 ppid:1356178 flags:0x00004002 [162513.520511] Call Trace: [162513.520516] __schedule+0x5ce/0xd00 [162513.520519] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.520525] schedule+0x46/0xf0 [162513.520544] btrfs_scrub_pause+0x11f/0x180 [btrfs] [162513.520548] ? finish_wait+0x90/0x90 [162513.520562] btrfs_commit_transaction+0x45a/0xc30 [btrfs] [162513.520574] ? start_transaction+0xe0/0x5f0 [btrfs] [162513.520596] btrfs_dev_replace_finishing+0x6d8/0x711 [btrfs] [162513.520619] btrfs_dev_replace_by_ioctl.cold+0x1cc/0x1fd [btrfs] [162513.520639] btrfs_ioctl+0x2a25/0x36f0 [btrfs] [162513.520643] ? do_sigaction+0xf3/0x240 [162513.520645] ? find_held_lock+0x32/0x90 [162513.520648] ? do_sigaction+0xf3/0x240 [162513.520651] ? lock_acquired+0x33b/0x470 [162513.520655] ? _raw_spin_unlock_irq+0x24/0x50 [162513.520657] ? lockdep_hardirqs_on+0x7d/0x100 [162513.520660] ? _raw_spin_unlock_irq+0x35/0x50 [162513.520662] ? do_sigaction+0xf3/0x240 [162513.520671] ? __x64_sys_ioctl+0x83/0xb0 [162513.520672] __x64_sys_ioctl+0x83/0xb0 [162513.520677] do_syscall_64+0x33/0x80 [162513.520679] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.520681] RIP: 0033:0x7fc3cd307d87 [162513.520682] Code: Bad RIP value. [162513.520684] RSP: 002b:00007ffe30a56bb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [162513.520686] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fc3cd307d87 [162513.520687] RDX: 00007ffe30a57a30 RSI: 00000000ca289435 RDI: 0000000000000003 [162513.520689] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [162513.520690] R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000003 [162513.520692] R13: 0000557323a212e0 R14: 00007ffe30a5a520 R15: 0000000000000001 [162513.520703] Showing all locks held in the system: [162513.520712] 1 lock held by khungtaskd/54: [162513.520713] #0: ffffffffb40a91a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x15/0x197 [162513.520728] 1 lock held by in:imklog/596: [162513.520729] #0: ffff8f3f0d781400 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x4d/0x60 [162513.520782] 1 lock held by btrfs-transacti/1356167: [162513.520784] #0: ffff8f3d810cc848 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0x4a/0x170 [btrfs] [162513.520798] 1 lock held by btrfs/1356190: [162513.520800] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0x60 [162513.520805] 1 lock held by fsstress/1356184: [162513.520806] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520811] 3 locks held by fsstress/1356185: [162513.520812] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520815] #1: ffff8f3d80a650b8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: vfs_setxattr+0x50/0x120 [162513.520820] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520833] 1 lock held by fsstress/1356196: [162513.520834] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520838] 3 locks held by fsstress/1356197: [162513.520839] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520843] #1: ffff8f3d506465e8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: path_openat+0x2a7/0xa50 [162513.520846] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520858] 2 locks held by btrfs/1356211: [162513.520859] #0: ffff8f3d810cde30 (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.}-{3:3}, at: btrfs_dev_replace_finishing+0x52/0x711 [btrfs] [162513.520877] #1: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] This was weird because the stack traces show that a transaction commit, triggered by a device replace operation, is blocking trying to pause any running scrubs but there are no stack traces of blocked tasks doing a scrub. After poking around with drgn, I noticed there was a scrub task that was constantly running and blocking for shorts periods of time: >>> t = find_task(prog, 1356190) >>> prog.stack_trace(t) #0 __schedule+0x5ce/0xcfc #1 schedule+0x46/0xe4 #2 schedule_timeout+0x1df/0x475 #3 btrfs_reada_wait+0xda/0x132 #4 scrub_stripe+0x2a8/0x112f #5 scrub_chunk+0xcd/0x134 #6 scrub_enumerate_chunks+0x29e/0x5ee #7 btrfs_scrub_dev+0x2d5/0x91b #8 btrfs_ioctl+0x7f5/0x36e7 #9 __x64_sys_ioctl+0x83/0xb0 torvalds#10 do_syscall_64+0x33/0x77 torvalds#11 entry_SYSCALL_64+0x7c/0x156 Which corresponds to: int btrfs_reada_wait(void *handle) { struct reada_control *rc = handle; struct btrfs_fs_info *fs_info = rc->fs_info; while (atomic_read(&rc->elems)) { if (!atomic_read(&fs_info->reada_works_cnt)) reada_start_machine(fs_info); wait_event_timeout(rc->wait, atomic_read(&rc->elems) == 0, (HZ + 9) / 10); } (...) So the counter "rc->elems" was set to 1 and never decreased to 0, causing the scrub task to loop forever in that function. Then I used the following script for drgn to check the readahead requests: $ cat dump_reada.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) def dump_re(re): nzones = re.nzones.value_() print(f're at {hex(re.value_())}') print(f'\t logical {re.logical.value_()}') print(f'\t refcnt {re.refcnt.value_()}') print(f'\t nzones {nzones}') for i in range(nzones): dev = re.zones[i].device name = dev.name.str.string_() print(f'\t\t dev id {dev.devid.value_()} name {name}') print() for _, e in radix_tree_for_each(fs_info.reada_tree): re = cast('struct reada_extent *', e) dump_re(re) $ drgn dump_reada.py re at 0xffff8f3da9d25ad8 logical 38928384 refcnt 1 nzones 1 dev id 0 name b'/dev/sdd' $ So there was one readahead extent with a single zone corresponding to the source device of that last device replace operation logged in dmesg/syslog. Also the ID of that zone's device was 0 which is a special value set in the source device of a device replace operation when the operation finishes (constant BTRFS_DEV_REPLACE_DEVID set at btrfs_dev_replace_finishing()), confirming again that device /dev/sdd was the source of a device replace operation. Normally there should be as many zones in the readahead extent as there are devices, and I wasn't expecting the extent to be in a block group with a 'single' profile, so I went and confirmed with the following drgn script that there weren't any single profile block groups: $ cat dump_block_groups.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) BTRFS_BLOCK_GROUP_DATA = (1 << 0) BTRFS_BLOCK_GROUP_SYSTEM = (1 << 1) BTRFS_BLOCK_GROUP_METADATA = (1 << 2) BTRFS_BLOCK_GROUP_RAID0 = (1 << 3) BTRFS_BLOCK_GROUP_RAID1 = (1 << 4) BTRFS_BLOCK_GROUP_DUP = (1 << 5) BTRFS_BLOCK_GROUP_RAID10 = (1 << 6) BTRFS_BLOCK_GROUP_RAID5 = (1 << 7) BTRFS_BLOCK_GROUP_RAID6 = (1 << 8) BTRFS_BLOCK_GROUP_RAID1C3 = (1 << 9) BTRFS_BLOCK_GROUP_RAID1C4 = (1 << 10) def bg_flags_string(bg): flags = bg.flags.value_() ret = '' if flags & BTRFS_BLOCK_GROUP_DATA: ret = 'data' if flags & BTRFS_BLOCK_GROUP_METADATA: if len(ret) > 0: ret += '|' ret += 'meta' if flags & BTRFS_BLOCK_GROUP_SYSTEM: if len(ret) > 0: ret += '|' ret += 'system' if flags & BTRFS_BLOCK_GROUP_RAID0: ret += ' raid0' elif flags & BTRFS_BLOCK_GROUP_RAID1: ret += ' raid1' elif flags & BTRFS_BLOCK_GROUP_DUP: ret += ' dup' elif flags & BTRFS_BLOCK_GROUP_RAID10: ret += ' raid10' elif flags & BTRFS_BLOCK_GROUP_RAID5: ret += ' raid5' elif flags & BTRFS_BLOCK_GROUP_RAID6: ret += ' raid6' elif flags & BTRFS_BLOCK_GROUP_RAID1C3: ret += ' raid1c3' elif flags & BTRFS_BLOCK_GROUP_RAID1C4: ret += ' raid1c4' else: ret += ' single' return ret def dump_bg(bg): print() print(f'block group at {hex(bg.value_())}') print(f'\t start {bg.start.value_()} length {bg.length.value_()}') print(f'\t flags {bg.flags.value_()} - {bg_flags_string(bg)}') bg_root = fs_info.block_group_cache_tree.address_of_() for bg in rbtree_inorder_for_each_entry('struct btrfs_block_group', bg_root, 'cache_node'): dump_bg(bg) $ drgn dump_block_groups.py block group at 0xffff8f3d673b0400 start 22020096 length 16777216 flags 258 - system raid6 block group at 0xffff8f3d53ddb400 start 38797312 length 536870912 flags 260 - meta raid6 block group at 0xffff8f3d5f4d9c00 start 575668224 length 2147483648 flags 257 - data raid6 block group at 0xffff8f3d08189000 start 2723151872 length 67108864 flags 258 - system raid6 block group at 0xffff8f3db70ff000 start 2790260736 length 1073741824 flags 260 - meta raid6 block group at 0xffff8f3d5f4dd800 start 3864002560 length 67108864 flags 258 - system raid6 block group at 0xffff8f3d67037000 start 3931111424 length 2147483648 flags 257 - data raid6 $ So there were only 2 reasons left for having a readahead extent with a single zone: reada_find_zone(), called when creating a readahead extent, returned NULL either because we failed to find the corresponding block group or because a memory allocation failed. With some additional and custom tracing I figured out that on every further ocurrence of the problem the block group had just been deleted when we were looping to create the zones for the readahead extent (at reada_find_extent()), so we ended up with only one zone in the readahead extent, corresponding to a device that ends up getting replaced. So after figuring that out it became obvious why the hang happens: 1) Task A starts a scrub on any device of the filesystem, except for device /dev/sdd; 2) Task B starts a device replace with /dev/sdd as the source device; 3) Task A calls btrfs_reada_add() from scrub_stripe() and it is currently starting to scrub a stripe from block group X. This call to btrfs_reada_add() is the one for the extent tree. When btrfs_reada_add() calls reada_add_block(), it passes the logical address of the extent tree's root node as its 'logical' argument - a value of 38928384; 4) Task A then enters reada_find_extent(), called from reada_add_block(). It finds there isn't any existing readahead extent for the logical address 38928384, so it proceeds to the path of creating a new one. It calls btrfs_map_block() to find out which stripes exist for the block group X. On the first iteration of the for loop that iterates over the stripes, it finds the stripe for device /dev/sdd, so it creates one zone for that device and adds it to the readahead extent. Before getting into the second iteration of the loop, the cleanup kthread deletes block group X because it was empty. So in the iterations for the remaining stripes it does not add more zones to the readahead extent, because the calls to reada_find_zone() returned NULL because they couldn't find block group X anymore. As a result the new readahead extent has a single zone, corresponding to the device /dev/sdd; 4) Before task A returns to btrfs_reada_add() and queues the readahead job for the readahead work queue, task B finishes the device replace and at btrfs_dev_replace_finishing() swaps the device /dev/sdd with the new device /dev/sdg; 5) Task A returns to reada_add_block(), which increments the counter "->elems" of the reada_control structure allocated at btrfs_reada_add(). Then it returns back to btrfs_reada_add() and calls reada_start_machine(). This queues a job in the readahead work queue to run the function reada_start_machine_worker(), which calls __reada_start_machine(). At __reada_start_machine() we take the device list mutex and for each device found in the current device list, we call reada_start_machine_dev() to start the readahead work. However at this point the device /dev/sdd was already freed and is not in the device list anymore. This means the corresponding readahead for the extent at 38928384 is never started, and therefore the "->elems" counter of the reada_control structure allocated at btrfs_reada_add() never goes down to 0, causing the call to btrfs_reada_wait(), done by the scrub task, to wait forever. Note that the readahead request can be made either after the device replace started or before it started, however in pratice it is very unlikely that a device replace is able to start after a readahead request is made and is able to complete before the readahead request completes - maybe only on a very small and nearly empty filesystem. This hang however is not the only problem we can have with readahead and device removals. When the readahead extent has other zones other than the one corresponding to the device that is being removed (either by a device replace or a device remove operation), we risk having a use-after-free on the device when dropping the last reference of the readahead extent. For example if we create a readahead extent with two zones, one for the device /dev/sdd and one for the device /dev/sde: 1) Before the readahead worker starts, the device /dev/sdd is removed, and the corresponding btrfs_device structure is freed. However the readahead extent still has the zone pointing to the device structure; 2) When the readahead worker starts, it only finds device /dev/sde in the current device list of the filesystem; 3) It starts the readahead work, at reada_start_machine_dev(), using the device /dev/sde; 4) Then when it finishes reading the extent from device /dev/sde, it calls __readahead_hook() which ends up dropping the last reference on the readahead extent through the last call to reada_extent_put(); 5) At reada_extent_put() it iterates over each zone of the readahead extent and attempts to delete an element from the device's 'reada_extents' radix tree, resulting in a use-after-free, as the device pointer of the zone for /dev/sdd is now stale. We can also access the device after dropping the last reference of a zone, through reada_zone_release(), also called by reada_extent_put(). And a device remove suffers the same problem, however since it shrinks the device size down to zero before removing the device, it is very unlikely to still have readahead requests not completed by the time we free the device, the only possibility is if the device has a very little space allocated. While the hang problem is exclusive to scrub, since it is currently the only user of btrfs_reada_add() and btrfs_reada_wait(), the use-after-free problem affects any path that triggers readhead, which includes btree_readahead_hook() and __readahead_hook() (a readahead worker can trigger readahed for the children of a node) for example - any path that ends up calling reada_add_block() can trigger the use-after-free after a device is removed. So fix this by waiting for any readahead requests for a device to complete before removing a device, ensuring that while waiting for existing ones no new ones can be made. This problem has been around for a very long time - the readahead code was added in 2011, device remove exists since 2008 and device replace was introduced in 2013, hard to pick a specific commit for a git Fixes tag. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
jlelli
pushed a commit
that referenced
this issue
Jan 11, 2021
This fix is for a failure that occurred in the DWARF unwind perf test.
Stack unwinders may probe memory when looking for frames.
Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.
This can lead to false memory sanitizer failures for the use of an
uninitialized value.
Avoid this problem by removing the poison on the copied stack.
The full msan failure with track origins looks like:
==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
#1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
#8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
#9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
torvalds#10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
torvalds#11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
torvalds#12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
torvalds#13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
torvalds#14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
torvalds#15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
torvalds#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
torvalds#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
torvalds#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
torvalds#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
torvalds#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
torvalds#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
torvalds#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
torvalds#23 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
#1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
#2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
#9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
torvalds#10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
torvalds#11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
torvalds#12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
torvalds#13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
torvalds#14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
torvalds#15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
torvalds#16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
torvalds#17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
torvalds#18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
torvalds#19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
torvalds#20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
torvalds#21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
torvalds#22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
torvalds#23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
torvalds#24 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
#1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
#8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
#9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
torvalds#10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
torvalds#11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
torvalds#12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
torvalds#13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
torvalds#14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
torvalds#15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
torvalds#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
torvalds#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
torvalds#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
torvalds#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
torvalds#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
torvalds#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
torvalds#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
torvalds#23 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
#1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
#2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
#3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
torvalds#10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
torvalds#11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
torvalds#12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
torvalds#13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
torvalds#14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
torvalds#15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
torvalds#16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
torvalds#17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
torvalds#18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
torvalds#19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
torvalds#20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
torvalds#21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
torvalds#22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
torvalds#23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
torvalds#24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
torvalds#25 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
#1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
#2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
#3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
#4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
#5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
#6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
#7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
#8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
#9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
torvalds#10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
torvalds#11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
torvalds#12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
torvalds#13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
torvalds#14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
torvalds#15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
torvalds#16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
torvalds#17 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
#0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445
SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
jlelli
pushed a commit
that referenced
this issue
Jan 11, 2021
Actually, burst size is equal to '1 << desc->rqcfg.brst_size'. we should use burst size, not desc->rqcfg.brst_size. dma memcpy performance on Rockchip RV1126 @ 1512MHz A7, 1056MHz LPDDR3, 200MHz DMA: dmatest: /# echo dma0chan0 > /sys/module/dmatest/parameters/channel /# echo 4194304 > /sys/module/dmatest/parameters/test_buf_size /# echo 8 > /sys/module/dmatest/parameters/iterations /# echo y > /sys/module/dmatest/parameters/norandom /# echo y > /sys/module/dmatest/parameters/verbose /# echo 1 > /sys/module/dmatest/parameters/run dmatest: dma0chan0-copy0: result #1: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #2: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #3: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #4: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #5: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #6: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #7: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 dmatest: dma0chan0-copy0: result #8: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000 Before: dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 48 iops 200338 KB/s (0) After this patch: dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 179 iops 734873 KB/s (0) After this patch and increase dma clk to 400MHz: dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 259 iops 1062929 KB/s (0) Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com> Link: https://lore.kernel.org/r/1605326106-55681-1-git-send-email-sugar.zhang@rock-chips.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
jlelli
pushed a commit
that referenced
this issue
Aug 2, 2021
ASan reported a memory leak caused by info_linear not being deallocated.
The info_linear was allocated during in perf_event__synthesize_one_bpf_prog().
This patch adds the corresponding free() when bpf_prog_info_node
is freed in perf_env__purge_bpf().
$ sudo ./perf record -- sleep 5
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]
=================================================================
==297735==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 7688 byte(s) in 19 object(s) allocated from:
#0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f)
#1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16
#2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16
#3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9
#4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8
#5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8
#6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8
#7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
#8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
#9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2
torvalds#10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3
torvalds#11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: http://lore.kernel.org/lkml/20210602224024.300485-1-rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
jlelli
pushed a commit
that referenced
this issue
May 8, 2023
In thread__comm_len(),strlen() is called outside of the
thread->comm_lock critical section,which may cause a UAF
problems if comm__free() is called by the process_thread
concurrently.
backtrace of the core file is as follows:
(gdb) bt
#0 __strlen_evex () at ../sysdeps/x86_64/multiarch/strlen-evex.S:77
#1 0x000055ad15d31de5 in thread__comm_len (thread=0x7f627d20e300) at util/thread.c:320
#2 0x000055ad15d4fade in hists__calc_col_len (h=0x7f627d295940, hists=0x55ad1772bfe0)
at util/hist.c:103
#3 hists__calc_col_len (hists=0x55ad1772bfe0, h=0x7f627d295940) at util/hist.c:79
#4 0x000055ad15d52c8c in output_resort (hists=hists@entry=0x55ad1772bfe0, prog=0x0,
use_callchain=false, cb=cb@entry=0x0, cb_arg=0x0) at util/hist.c:1926
#5 0x000055ad15d530a4 in evsel__output_resort_cb (evsel=evsel@entry=0x55ad1772bde0,
prog=prog@entry=0x0, cb=cb@entry=0x0, cb_arg=cb_arg@entry=0x0) at util/hist.c:1945
#6 0x000055ad15d53110 in evsel__output_resort (evsel=evsel@entry=0x55ad1772bde0,
prog=prog@entry=0x0) at util/hist.c:1950
#7 0x000055ad15c6ae9a in perf_top__resort_hists (t=t@entry=0x7ffcd9cbf4f0) at builtin-top.c:311
#8 0x000055ad15c6cc6d in perf_top__print_sym_table (top=0x7ffcd9cbf4f0) at builtin-top.c:346
#9 display_thread (arg=0x7ffcd9cbf4f0) at builtin-top.c:700
torvalds#10 0x00007f6282fab4fa in start_thread (arg=<optimized out>) at pthread_create.c:443
torvalds#11 0x00007f628302e200 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
The reason is that strlen() get a pointer to a memory that has been freed.
The string pointer is stored in the structure comm_str, which corresponds
to a rb_tree node,when the node is erased, the memory of the string is also freed.
In thread__comm_len(),it gets the pointer within the thread->comm_lock critical section,
but passed to strlen() outside of the thread->comm_lock critical section, and the perf
process_thread may called comm__free() concurrently, cause this segfault problem.
The process is as follows:
display_thread process_thread
-------------- --------------
thread__comm_len
-> thread__comm_str
# held the comm read lock
-> __thread__comm_str(thread)
# release the comm read lock
thread__delete
# held the comm write lock
-> comm__free
-> comm_str__put(comm->comm_str)
-> zfree(&cs->str)
# release the comm write lock
# The memory of the string pointed
to by comm has been free.
-> thread->comm_len = strlen(comm);
This patch expand the critical section range of thread->comm_lock in thread__comm_len(),
to make strlen() called safe.
Signed-off-by: Wenyu Liu <liuwenyu7@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Feilong Lin <linfeilong@huawei.com>
Cc: Hewenliang <hewenliang4@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Yunfeng Ye <yeyunfeng@huawei.com>
Link: https://lore.kernel.org/r/322bfb49-840b-f3b6-9ef1-f9ec3435b07e@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
jlelli
pushed a commit
that referenced
this issue
May 8, 2023
I got a report of a msan failure like below:
$ sudo perf lock con -ab -- sleep 1
...
==224416==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x5651160d6c96 in lock_contention_read util/bpf_lock_contention.c:290:8
#1 0x565115f90870 in __cmd_contention builtin-lock.c:1919:3
#2 0x565115f90870 in cmd_lock builtin-lock.c:2385:8
#3 0x565115f03a83 in run_builtin perf.c:330:11
#4 0x565115f03756 in handle_internal_command perf.c:384:8
#5 0x565115f02d53 in run_argv perf.c:428:2
#6 0x565115f02d53 in main perf.c:562:3
#7 0x7f43553bc632 in __libc_start_main
#8 0x565115e865a9 in _start
It was because the 'key' variable is not initialized. Actually it'd be set
by bpf_map_get_next_key() but msan didn't seem to understand it. Let's make
msan happy by initializing the variable.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230324001922.937634-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
jlelli
pushed a commit
that referenced
this issue
May 8, 2023
Seen in "perf stat --bpf-counters --for-each-cgroup test" running in a
container:
libbpf: Failed to bump RLIMIT_MEMLOCK (err = -1), you might need to do it explicitly!
libbpf: Error in bpf_object__probe_loading():Operation not permitted(1). Couldn't load trivial BPF program. Make sure your kernel supports BPF (CONFIG_BPF_SYSCALL=y) and/or that RLIMIT_MEMLOCK is set to big enough value.
libbpf: failed to load object 'bperf_cgroup_bpf'
libbpf: failed to load BPF skeleton 'bperf_cgroup_bpf': -1
Failed to load cgroup skeleton
#0 0x55f28a650981 in list_empty tools/include/linux/list.h:189
#1 0x55f28a6593b4 in evsel__exit util/evsel.c:1518
#2 0x55f28a6596af in evsel__delete util/evsel.c:1544
#3 0x55f28a89d166 in bperf_cgrp__destroy util/bpf_counter_cgroup.c:283
#4 0x55f28a899e9a in bpf_counter__destroy util/bpf_counter.c:816
#5 0x55f28a659455 in evsel__exit util/evsel.c:1520
#6 0x55f28a6596af in evsel__delete util/evsel.c:1544
#7 0x55f28a640d4d in evlist__purge util/evlist.c:148
#8 0x55f28a640ea6 in evlist__delete util/evlist.c:169
#9 0x55f28a4efbf2 in cmd_stat tools/perf/builtin-stat.c:2598
torvalds#10 0x55f28a6050c2 in run_builtin tools/perf/perf.c:330
torvalds#11 0x55f28a605633 in handle_internal_command tools/perf/perf.c:384
torvalds#12 0x55f28a6059fb in run_argv tools/perf/perf.c:428
torvalds#13 0x55f28a6061d3 in main tools/perf/perf.c:562
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230410205659.3131608-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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…us union field
If bperf (perf tools that use BPF skels) sets evsel->leader_skel or
evsel->follower_skel then it appears that evsel->bpf_skel is set and can
trigger the following use-after-free:
==13575==ERROR: AddressSanitizer: heap-use-after-free on address 0x60c000014080 at pc 0x55684b939880 bp 0x7ffdfcf30d70 sp 0x7ffdfcf30d68
READ of size 8 at 0x60c000014080 thread T0
#0 0x55684b93987f in sample_filter_bpf__destroy tools/perf/bpf_skel/sample_filter.skel.h:44:11
#1 0x55684b93987f in perf_bpf_filter__destroy tools/perf/util/bpf-filter.c:155:2
#2 0x55684b98f71e in evsel__exit tools/perf/util/evsel.c:1521:2
#3 0x55684b98a352 in evsel__delete tools/perf/util/evsel.c:1547:2
#4 0x55684b981918 in evlist__purge tools/perf/util/evlist.c:148:3
#5 0x55684b981918 in evlist__delete tools/perf/util/evlist.c:169:2
#6 0x55684b887d60 in cmd_stat tools/perf/builtin-stat.c:2598:2
..
0x60c000014080 is located 0 bytes inside of 128-byte region [0x60c000014080,0x60c000014100)
freed by thread T0 here:
#0 0x55684b780e86 in free compiler-rt/lib/asan/asan_malloc_linux.cpp:52:3
#1 0x55684b9462da in bperf_cgroup_bpf__destroy tools/perf/bpf_skel/bperf_cgroup.skel.h:61:2
#2 0x55684b9462da in bperf_cgrp__destroy tools/perf/util/bpf_counter_cgroup.c:282:2
#3 0x55684b944c75 in bpf_counter__destroy tools/perf/util/bpf_counter.c:819:2
#4 0x55684b98f716 in evsel__exit tools/perf/util/evsel.c:1520:2
#5 0x55684b98a352 in evsel__delete tools/perf/util/evsel.c:1547:2
#6 0x55684b981918 in evlist__purge tools/perf/util/evlist.c:148:3
#7 0x55684b981918 in evlist__delete tools/perf/util/evlist.c:169:2
#8 0x55684b887d60 in cmd_stat tools/perf/builtin-stat.c:2598:2
...
previously allocated by thread T0 here:
#0 0x55684b781338 in calloc compiler-rt/lib/asan/asan_malloc_linux.cpp:77:3
#1 0x55684b944e25 in bperf_cgroup_bpf__open_opts tools/perf/bpf_skel/bperf_cgroup.skel.h:73:35
#2 0x55684b944e25 in bperf_cgroup_bpf__open tools/perf/bpf_skel/bperf_cgroup.skel.h:97:9
#3 0x55684b944e25 in bperf_load_program tools/perf/util/bpf_counter_cgroup.c:55:9
#4 0x55684b944e25 in bperf_cgrp__load tools/perf/util/bpf_counter_cgroup.c:178:23
#5 0x55684b889289 in __run_perf_stat tools/perf/builtin-stat.c:713:7
#6 0x55684b889289 in run_perf_stat tools/perf/builtin-stat.c:949:8
#7 0x55684b888029 in cmd_stat tools/perf/builtin-stat.c:2537:12
Resolve by clearing 'evsel->bpf_skel' as part of bpf_counter__destroy().
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20230411051718.267228-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Sai Krishna says: ==================== octeontx2: Miscellaneous fixes This patchset includes following fixes. Patch #1 Fix for the race condition while updating APR table Patch #2 Fix end bit position in NPC scan config Patch #3 Fix depth of CAM, MEM table entries Patch #4 Fix in increase the size of DMAC filter flows Patch #5 Fix driver crash resulting from invalid interface type information retrieved from firmware Patch #6 Fix incorrect mask used while installing filters involving fragmented packets Patch #7 Fixes for NPC field hash extract w.r.t IPV6 hash reduction, IPV6 filed hash configuration. Patch #8 Fix for NPC hardware parser configuration destination address hash, IPV6 endianness issues. Patch #9 Fix for skipping mbox initialization for PFs disabled by firmware. Patch torvalds#10 Fix disabling packet I/O in case of mailbox timeout. Patch torvalds#11 Fix detaching LF resources in case of VF probe fail. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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On the node of an NFS client, some files saved in the mountpoint of the NFS server were copied to another location of the same NFS server. Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference crash with the following syslog: [232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116 [232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116 [232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 [232066.588586] Mem abort info: [232066.588701] ESR = 0x0000000096000007 [232066.588862] EC = 0x25: DABT (current EL), IL = 32 bits [232066.589084] SET = 0, FnV = 0 [232066.589216] EA = 0, S1PTW = 0 [232066.589340] FSC = 0x07: level 3 translation fault [232066.589559] Data abort info: [232066.589683] ISV = 0, ISS = 0x00000007 [232066.589842] CM = 0, WnR = 0 [232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400 [232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000 [232066.590757] Internal error: Oops: 96000007 [#1] SMP [232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2 [232066.591052] vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs [232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1 [232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06 [232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4] [232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4] [232066.598595] sp : ffff8000f568fc70 [232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000 [232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001 [232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050 [232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000 [232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000 [232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6 [232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828 [232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a [232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058 [232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000 [232066.601636] Call trace: [232066.601749] nfs4_reclaim_open_state+0x220/0x800 [nfsv4] [232066.601998] nfs4_do_reclaim+0x1b8/0x28c [nfsv4] [232066.602218] nfs4_state_manager+0x928/0x10f0 [nfsv4] [232066.602455] nfs4_run_state_manager+0x78/0x1b0 [nfsv4] [232066.602690] kthread+0x110/0x114 [232066.602830] ret_from_fork+0x10/0x20 [232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00) [232066.603284] SMP: stopping secondary CPUs [232066.606936] Starting crashdump kernel... [232066.607146] Bye! Analysing the vmcore, we know that nfs4_copy_state listed by destination nfs_server->ss_copies was added by the field copies in handle_async_copy(), and we found a waiting copy process with the stack as: PID: 3511963 TASK: ffff710028b47e00 CPU: 0 COMMAND: "cp" #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4 #1 [ffff8001116ef760] __schedule at ffff800008dd0650 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898 #6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4] #7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4] #8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4] #9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4] The NULL-pointer dereference was due to nfs42_complete_copies() listed the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state. So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and the data accessed through this pointer was also incorrect. Generally, the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state(). When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED and copies are not deleted in nfs_server->ss_copies, the source state may be passed to the nfs42_complete_copies() process earlier, resulting in this crash scene finally. To solve this issue, we add a list_head nfs_server->ss_src_copies for a server-to-server copy specially. Fixes: 0e65a32 ("NFS: handle source server reboot") Signed-off-by: Yanjun Zhang <zhangyanjun@cestc.cn> Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
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…ation When testing the XDP_REDIRECT function on the LS1028A platform, we found a very reproducible issue that the Tx frames can no longer be sent out even if XDP_REDIRECT is turned off. Specifically, if there is a lot of traffic on Rx direction, when XDP_REDIRECT is turned on, the console may display some warnings like "timeout for tx ring #6 clear", and all redirected frames will be dropped, the detailed log is as follows. root@ls1028ardb:~# ./xdp-bench redirect eno0 eno2 Redirecting from eno0 (ifindex 3; driver fsl_enetc) to eno2 (ifindex 4; driver fsl_enetc) [203.849809] fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #5 clear [204.006051] fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #6 clear [204.161944] fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #7 clear eno0->eno2 1420505 rx/s 1420590 err,drop/s 0 xmit/s xmit eno0->eno2 0 xmit/s 1420590 drop/s 0 drv_err/s 15.71 bulk-avg eno0->eno2 1420484 rx/s 1420485 err,drop/s 0 xmit/s xmit eno0->eno2 0 xmit/s 1420485 drop/s 0 drv_err/s 15.71 bulk-avg By analyzing the XDP_REDIRECT implementation of enetc driver, the driver will reconfigure Tx and Rx BD rings when a bpf program is installed or uninstalled, but there is no mechanisms to block the redirected frames when enetc driver reconfigures rings. Similarly, XDP_TX verdicts on received frames can also lead to frames being enqueued in the Tx rings. Because XDP ignores the state set by the netif_tx_wake_queue() API, so introduce the ENETC_TX_DOWN flag to suppress transmission of XDP frames. Fixes: c33bfaf ("net: enetc: set up XDP program under enetc_reconfigure()") Cc: stable@vger.kernel.org Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20241010092056.298128-3-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The Tx BD rings are disabled first in enetc_stop() and the driver waits for them to become empty. This operation is not safe while the ring is actively transmitting frames, and will cause the ring to not be empty and hardware exception. As described in the NETC block guide, software should only disable an active Tx ring after all pending ring entries have been consumed (i.e. when PI = CI). Disabling a transmit ring that is actively processing BDs risks a HW-SW race hazard whereby a hardware resource becomes assigned to work on one or more ring entries only to have those entries be removed due to the ring becoming disabled. When testing XDP_REDIRECT feautre, although all frames were blocked from being put into Tx rings during ring reconfiguration, the similar warning log was still encountered: fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #6 clear fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #7 clear The reason is that when there are still unsent frames in the Tx ring, disabling the Tx ring causes the remaining frames to be unable to be sent out. And the Tx ring cannot be restored, which means that even if the xdp program is uninstalled, the Tx frames cannot be sent out anymore. Therefore, correct the operation order in enect_start() and enect_stop(). Fixes: ff58fda ("net: enetc: prioritize ability to go down over packet processing") Cc: stable@vger.kernel.org Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20241010092056.298128-4-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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As done @
linux/kernel/sched/deadline.c
Line 1522 in af3e79d
we instantaneously remove a task's running and total bandwidth contribution when the task is migrated between CPUs (see also push/pull functions), same also happens when setscheduler/affinity are called (the task in that case is dequeued and enqueued back with different scheduling/affinity parameters).
@lucabe72 shouldn't we wait the 0-lag time?
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