On 3/24/2020 2:00 AM, kernel test robot wrote: > FYI, we noticed the following commit (built with gcc-7): > > commit: 92b1f046a283a7dafd30067d93444fb6402b42d7 ("[PATCH] perf/core: Fix endless multiplex timer") > url: https://github.com/0day-ci/linux/commits/kan-liang-linux-intel-com/perf-core-Fix-endless-multiplex-timer/20200304-050638 > The patch has been dropped. It is replaced by Peter's patch. https://lkml.kernel.org/r/20200305123851.GX2596@hirez.programming.kicks-ass.net We don't need to worry about the bug anymore. Thanks, Kan > > in testcase: kernel-selftests > with following parameters: > > group: kselftests-00 > > test-description: The kernel contains a set of "self tests" under the tools/testing/selftests/ directory. These are intended to be small unit tests to exercise individual code paths in the kernel. > test-url: https://www.kernel.org/doc/Documentation/kselftest.txt > > > on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G > > caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): > > > +---------------------------------------------+------------+------------+ > | | fdb6482244 | 92b1f046a2 | > +---------------------------------------------+------------+------------+ > | boot_successes | 3 | 0 | > | boot_failures | 21 | 9 | > | BUG:kernel_in_stage | 21 | 9 | > | BUG:kernel_NULL_pointer_dereference,address | 0 | 6 | > | Oops:#[##] | 0 | 6 | > | RIP:__perf_event_disable | 0 | 6 | > | Kernel_panic-not_syncing:Fatal_exception | 0 | 6 | > | Mem-Info | 0 | 1 | > +---------------------------------------------+------------+------------+ > > > If you fix the issue, kindly add following tag > Reported-by: kernel test robot > > > [ 54.787532] BUG: kernel NULL pointer dereference, address: 0000000000000094 > [ 54.788968] #PF: supervisor read access in kernel mode > [ 54.790070] #PF: error_code(0x0000) - not-present page > [ 54.791164] PGD 0 P4D 0 > [ 54.792019] Oops: 0000 [#1] SMP PTI > [ 54.792956] CPU: 0 PID: 9996 Comm: breakpoint_test Not tainted 5.6.0-rc1-00017-g92b1f046a283a7 #1 > [ 54.794419] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 > [ 54.795898] RIP: 0010:__perf_event_disable+0x26/0x1a0 > [ 54.797012] Code: 0f 1f 40 00 8b 87 a8 00 00 00 85 c0 0f 88 66 01 00 00 41 55 41 54 49 89 d4 55 53 48 89 f5 f6 82 98 00 00 00 04 48 89 fb 75 7c <8b> 85 94 00 00 00 39 85 90 00 00 00 74 09 83 f8 01 0f 84 39 01 00 > [ 54.801211] RSP: 0018:ffffa93d05073d30 EFLAGS: 00010046 > [ 54.803308] RAX: 0000000000000000 RBX: ffff9c35692e7000 RCX: 0000000000000000 > [ 54.813087] RDX: ffff9c34f6499500 RSI: 0000000000000000 RDI: ffff9c35692e7000 > [ 54.815527] RBP: 0000000000000000 R08: ffffa93d05073eac R09: 0000000000000000 > [ 54.818026] R10: ffffa93d05073d18 R11: ffffffff9b663150 R12: ffff9c34f6499500 > [ 54.820629] R13: 0000000000000000 R14: ffff9c34f6499508 R15: 0000000000000000 > [ 54.823122] FS: 00007fa354f06540(0000) GS:ffff9c357fc00000(0000) knlGS:0000000000000000 > [ 54.825834] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 54.828126] CR2: 0000000000000094 CR3: 000000019fb0e000 CR4: 00000000000406f0 > [ 54.830677] DR0: 0000556d8bb0a10b DR1: 0000000000000000 DR2: 0000000000000000 > [ 54.833152] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > [ 54.835683] Call Trace: > [ 54.837844] ? __perf_event_enable+0x1f0/0x1f0 > [ 54.839834] event_function_call+0xd0/0x130 > [ 54.841771] ? __perf_event_enable+0x1f0/0x1f0 > [ 54.843696] ? _cond_resched+0x19/0x30 > [ 54.853765] perf_event_disable+0x15/0x30 > [ 54.855597] modify_user_hw_breakpoint+0x43/0x80 > [ 54.857481] ptrace_modify_breakpoint+0x120/0x150 > [ 54.859393] ptrace_set_debugreg+0xc8/0x1a0 > [ 54.861232] arch_ptrace+0x2f4/0x440 > [ 54.862927] __x64_sys_ptrace+0xc9/0x140 > [ 54.864687] do_syscall_64+0x5b/0x1f0 > [ 54.866422] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [ 54.868130] RIP: 0033:0x7fa354e378ff > [ 54.869124] Code: c7 44 24 10 08 00 00 00 48 89 44 24 18 48 8d 44 24 30 8b 70 08 48 8b 50 10 4c 0f 43 50 18 48 89 44 24 20 b8 65 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 48 85 c0 78 06 41 83 f8 02 76 1e 48 8b 4c > [ 54.872340] RSP: 002b:00007fffe648e1a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000065 > [ 54.873760] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa354e378ff > [ 54.875136] RDX: 0000000000000388 RSI: 000000000000270d RDI: 0000000000000006 > [ 54.876526] RBP: 00007fffe648e250 R08: 0000000000000005 R09: 0000000000000000 > [ 54.877903] R10: 0000000000000000 R11: 0000000000000202 R12: 0000556d8bb09950 > [ 54.879286] R13: 00007fffe648e7b0 R14: 0000000000000000 R15: 0000000000000000 > [ 54.880682] Modules linked in: binfmt_misc intel_rapl_msr intel_rapl_common sr_mod cdrom crct10dif_pclmul sg crc32_pclmul ppdev crc32c_intel ghash_clmulni_intel bochs_drm drm_vram_helper drm_ttm_helper snd_pcm ttm snd_timer snd aesni_intel soundcore crypto_simd joydev ata_generic drm_kms_helper pata_acpi cryptd glue_helper pcspkr serio_raw syscopyarea sysfillrect sysimgblt fb_sys_fops parport_pc floppy drm parport ata_piix i2c_piix4 libata ip_tables > [ 54.887273] CR2: 0000000000000094 > [ 54.888345] ---[ end trace 3c65e40013a20268 ]--- > > > To reproduce: > > # build kernel > cd linux > cp config-5.6.0-rc1-00017-g92b1f046a283a7 .config > make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage > > git clone https://github.com/intel/lkp-tests.git > cd lkp-tests > bin/lkp qemu -k job-script # job-script is attached in this email > > > > Thanks, > Rong Chen >