Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git pidfd_wait commit 890dec2e168dd245f4940d59610643aeda296089 Author: Christian Brauner <christian(a)brauner.io&gt; AuthorDate: Thu Jun 6 15:40:14 2019 +0200 Commit: Christian Brauner <christian(a)brauner.io&gt; CommitDate: Fri Jun 14 16:37:08 2019 +0200 pidfd: support waiting on processes through pidfds Make it possible to wait on processes through pidfds. The pidfd api already allows to retrieve pidfds at process creation time, sending signals via pidfds, and retrieving pidfds for processes that were created through pid-based syscalls. One of the remaining bits is to make it possible to wait on processes through pidfds. This allows users to only keep track of processes via pidfds without resorting to pids at all. To this end, a new flag WPIDFD is introduced. When this flag is specified in the options argument of the waitpid(), wait4(), or waitid() syscalls the argument used to identify the process will be interpreted as a pidfd instead of a pid. Signed-off-by: Christian Brauner <christian(a)brauner.io&gt; Cc: Arnd Bergmann <arnd(a)arndb.de&gt; Cc: "Eric W. Biederman" <ebiederm(a)xmission.com&gt; Cc: Kees Cook <keescook(a)chromium.org&gt; Cc: Joel Fernandes (Google) <joel(a)joelfernandes.org&gt; Cc: Thomas Gleixner <tglx(a)linutronix.de&gt; Cc: Jann Horn <jannh(a)google.com&gt; Cc: David Howells <dhowells(a)redhat.com&gt; Cc: Andy Lutomirsky <luto(a)kernel.org&gt; Cc: Andrew Morton <akpm(a)linux-foundation.org&gt; Cc: Oleg Nesterov <oleg(a)redhat.com&gt; Cc: Aleksa Sarai <cyphar(a)cyphar.com&gt; Cc: Linus Torvalds <torvalds(a)linux-foundation.org&gt; Cc: Al Viro <viro(a)zeniv.linux.org.uk&gt; Cc: linux-api(a)vger.kernel.org f2c7c76c5d Linux 5.2-rc3 890dec2e16 pidfd: support waiting on processes through pidfds +----------------------------------------------------------------------------------+----------+------------+ | | v5.2-rc3 | 890dec2e16 | +----------------------------------------------------------------------------------+----------+------------+ | boot_successes | 344 | 97 | | boot_failures | 16 | 24 | | BUG:soft_lockup-CPU##stuck_for#s | 7 | 6 | | EIP:__do_softirq | 5 | 5 | | Kernel_panic-not_syncing:softlockup:hung_tasks | 7 | 6 | | EIP:_raw_spin_unlock_irq | 1 | | | EIP:swake_up_one | 1 | | | page_allocation_failure:order:#,mode:#(GFP_KERNEL|__GFP_NORETRY),nodemask=(null) | 1 | | | Mem-Info | 5 | 3 | | invoked_oom-killer:gfp_mask=0x | 2 | | | BUG:kernel_reboot-without-warning_in_test_stage | 4 | 1 | | BUG:unable_to_handle_page_fault_for_address | 0 | 10 | | Oops:#[##] | 0 | 12 | | EIP:fput_many | 0 | 14 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 14 | | EIP:smp_call_function_single | 0 | 1 | +----------------------------------------------------------------------------------+----------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <lkp(a)intel.com&gt; [child5:501] migrate_pages (294) returned ENOSYS, marking as inactive. [child3:499] mq_open (277) returned ENOSYS, marking as inactive. [child0:496] lookup_dcookie (253) returned ENOSYS, marking as inactive. [child6:502] init_module (128) returned ENOSYS, marking as inactive. [child0:496] bpf (357) returned ENOSYS, marking as inactive. [ 63.809244] BUG: unable to handle page fault for address: ffff4155 [ 63.823985] #PF: supervisor write access in kernel mode [ 63.836460] #PF: error_code(0x0002) - not-present page [ 63.848806] *pde = 03290067 *pte = 00000000 01 [ 63.897695] Code: b4 26 00 00 00 00 8b 18 e8 39 f8 ff ff 85 db 89 d8 75 f3 5b c3 90 3e 8d 74 26 00 83 ec 0c 89 5c 24 04 89 c3 89 74 24 08 89 d6 <f0> 29 73 44 75 44 64 a1 d4 67 b1 82 64 8b 15 cc 67 b1 82 81 e2 00 [ 63.957903] ESI: 00000001 EDI: 77466000 EBP: 02000000 ESP: 9e7fbed8 [ 63.972866] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010296 [ 63.991447] CR0: 80050033 CR2: ffff4155 CR3: 1e7c5000 CR4: 000006d0 [ 64.007220] Call Trace: [ 64.013478] ? kernel_wait4+0x134/0x1d0 [ 6400 .022080 73] 00? __li00s t_de00l _entr00y+0x20/ 0x20 [ 64.034214] ? sys_wait4+0x3e/0xa0 [ 64.039847] ? do_fast_syscall_32+0xa7/0x230 [ 64.040876] init: tty5 main process (454) terminated with status 1 [ 64.046779] ? entry_SYSENTER_32+0x69/0xc2 [ 64.046785] CR2: 00000000ffff4155 [ 64.046810] ---[ end trace 4a93eb27c845069c ]--- [ 64.046816] EIP: fput_many+0x14/0xa0 # HH:MM RESULT GOOD BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD git bisect start 535bd8f046338a136e8f51ece74c5600a10af1d9 d1fdb6d8f6a4109a4263176c84b899076a5f8008 -- git bisect bad 63411690fd3d9602662d93ddeae63bd5f49fb163 # 10:10 B 1 1 0 0 Merge 'tip/timers/core' into devel-hourly-2019061605 git bisect bad b60b3bded74920c4d53eabda0b2e35232e581569 # 10:26 B 12 3 1 2 Merge 'monstr-microblaze/xnext/tap' into devel-hourly-2019061605 git bisect bad 5f3f85387602e71cbd051a45b71aae47f28cad92 # 10:39 B 14 1 2 3 Merge 'linux-review/Nathan-Huckleberry/usb-host-xhci-tegra-Fix-Wunused-const-variable/20190614-141018' into devel-hourly-2019061605 git bisect bad 357692c7c8c1b658db981153bc072e619ffccd00 # 10:58 B 0 1 18 2 Merge 'linux-review/Shobhit-Kukreti/staging-fbtft-Fix-checkpatch-ERROR-space-prohibited-before-that-close-parenthesis/20190616-013220' into devel-hourly-2019061605 git bisect bad e4808c3acd1c2b213d0e341e7e486353cdfeaabe # 11:49 B 10 1 2 3 Merge 'ipmi/for-next' into devel-hourly-2019061605 git bisect bad f938d0c2588a44d5c8198c58c9d2fb426eb4dc38 # 12:09 B 21 3 3 3 Merge 'nsekhar-davinci/fixes' into devel-hourly-2019061605 git bisect good fe9369eacfa6809a1655beb52a26598cc968b731 # 12:36 G 119 0 2 2 Merge 'matthias-bgg/v5.2-next/dts64' into devel-hourly-2019061605 git bisect good 920f2382a27afac20b92511d6e6a5d69bfec3bc1 # 13:01 G 117 0 7 7 Merge 'linux-review/Lijun-Ou/RDMA-hns-reset-function-when-removing-module/20190615-162311' into devel-hourly-2019061605 git bisect bad 4f9568c6d3003edea6093b3ec718d668194caa32 # 13:14 B 2 3 0 0 Merge 'brauner/pidfd_wait' into devel-hourly-2019061605 git bisect bad 890dec2e168dd245f4940d59610643aeda296089 # 13:26 B 2 1 0 0 pidfd: support waiting on processes through pidfds # first bad commit: [890dec2e168dd245f4940d59610643aeda296089] pidfd: support waiting on processes through pidfds git bisect good f2c7c76c5d0a443053e94adb9f0918fa2fb85c3a # 13:56 G 351 0 16 20 Linux 5.2-rc3 # extra tests with debug options git bisect bad 890dec2e168dd245f4940d59610643aeda296089 # 14:11 B 17 1 1 6 pidfd: support waiting on processes through pidfds # extra tests on HEAD of linux-devel/devel-hourly-2019061605 git bisect bad 535bd8f046338a136e8f51ece74c5600a10af1d9 # 14:11 B 7 7 0 0 0day head guard for 'devel-hourly-2019061605' # extra tests on tree/branch brauner/pidfd_wait git bisect bad 890dec2e168dd245f4940d59610643aeda296089 # 14:14 B 92 12 0 17 pidfd: support waiting on processes through pidfds # extra tests with first bad commit reverted git bisect good cba64822fa711f73caef03ef615e05f2ddf5c888 # 14:39 G 118 0 6 6 Revert "pidfd: support waiting on processes through pidfds" --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/lkp Intel Corporation