Dear Linux folks,
Enabling the undefined behavior sanitizer and building GNU/Linux
4.18-rc5+ (with some unrelated commits) with GCC 8.1.0 from Debian
Sid/unstable, the warning below is shown.
[ 2.111913]
================================================================================
[ 2.111917] UBSAN: Undefined behaviour in arch/x86/events/amd/ibs.c:582:24
[ 2.111919] member access within null pointer of type 'struct perf_event'
[ 2.111926] CPU: 0 PID: 144 Comm: udevadm Not tainted
4.18.0-rc5-00316-g4864b68cedf2 #104
[ 2.111928] Hardware name: ASROCK E350M1/E350M1, BIOS TIMELESS 01/01/1970
[ 2.111930] Call Trace:
[ 2.111943] dump_stack+0x55/0x89
[ 2.111949] ubsan_epilogue+0xb/0x33
[ 2.111953] handle_null_ptr_deref+0x7f/0x90
[ 2.111958] __ubsan_handle_type_mismatch_v1+0x55/0x60
[ 2.111964] perf_ibs_handle_irq+0x596/0x620
[ 2.111968] ? perf_output_sample+0x771/0xa90
[ 2.111971] ? perf_prepare_sample+0x48a/0x8b0
[ 2.111976] ? sched_clock_cpu+0x13/0x200
[ 2.111978] ? perf_prepare_sample+0x8b0/0x8b0
[ 2.111982] ? perf_output_end+0xd/0x10
[ 2.111985] ? perf_event_output_forward+0x4e/0x70
[ 2.111990] ? __perf_event_overflow+0x7b/0x1a0
[ 2.111993] ? perf_event_overflow+0x15/0x20
[ 2.111996] ? x86_pmu_handle_irq+0x180/0x230
[ 2.112001] ? x86_pmu_enable_all+0x6c/0x1b0
[ 2.112005] ? x86_pmu_commit_txn+0xc1/0x190
[ 2.112012] ? native_sched_clock+0x32/0x120
[ 2.112017] perf_ibs_nmi_handler+0x2b/0x65
[ 2.112020] nmi_handle+0x8f/0x240
[ 2.112025] default_do_nmi+0x4e/0x2e0
[ 2.112028] do_nmi+0xb7/0x100
[ 2.112032] nmi+0x51/0x6c
[ 2.112036] EIP: x86_pmu_enable_all+0x6c/0x1b0
[ 2.112037] Code: 10 01 00 00 8b 45 e8 8b 75 e4 81 ca 00 00 40 00 f7 d0 21 d0 8b 93 14 01 00 00 f7 d6 8b 9b 20 01 00 00 21 d6 89 d9 89 f2 0f 30 <0f> 1f 44 00 00 47 39 3d 08 cd 40 d6 0f 8e a1 00 00 00 83 ff 3f 0f
[ 2.112079] EAX: 00530076 EBX: c0010000 ECX: c0010000 EDX: 00000000
[ 2.112081] ESI: 00000000 EDI: 00000000 EBP: f2cffaf0 ESP: f2cffacc
[ 2.112083] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00000046
[ 2.112089] x86_pmu_enable+0x162/0x480
[ 2.112094] perf_pmu_enable.part.39+0x14/0x30
[ 2.112097] ctx_resched+0xa4/0x130
[ 2.112101] __perf_event_enable+0x1d0/0x390
[ 2.112104] ? ctx_resched+0x130/0x130
[ 2.112107] event_function+0xb2/0x1b0
[ 2.112111] ? task_function_call+0x80/0x80
[ 2.112113] remote_function+0x45/0x60
[ 2.112118] flush_smp_call_function_queue+0x6c/0x1e0
[ 2.112123] generic_smp_call_function_single_interrupt+0x12/0x2a
[ 2.112126] smp_call_function_single_interrupt+0x3c/0x1c0
[ 2.112129] call_function_single_interrupt+0x3c/0x44
[ 2.112134] EIP: kmem_cache_alloc+0x65/0x3e0
[ 2.112135] Code: 45 e4 89 da e8 1c d8 f9 ff 85 c0 0f 85 eb 01 00 00 e9 ef 00 00 00 8b 45 e4 89 45 e8 8b 75 e8 85 f6 0f 84 d5 01 00 00 8b 45 e8 <8b> 30 64 8b 4e 04 64 03 35 28 71 51 d6 85 f6 0f 84 e9 02 00 00 8b
[ 2.112172] EAX: f4c60300 EBX: 00000000 ECX: 00000001 EDX: 00611ac0
[ 2.112174] ESI: f4c60300 EDI: f4c60300 EBP: f2cffc5c ESP: f2cffc28
[ 2.112177] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00000286
[ 2.112183] ? create_object+0x3a/0x3a0
[ 2.112186] create_object+0x3a/0x3a0
[ 2.112190] ? create_object+0x270/0x3a0
[ 2.112194] kmemleak_alloc+0x9b/0xb0
[ 2.112199] __kmalloc_track_caller+0x18c/0x420
[ 2.112203] ? __alloc_skb+0x6c/0x2b0
[ 2.112208] __kmalloc_reserve.isra.16+0x28/0x80
[ 2.112211] __alloc_skb+0x6c/0x2b0
[ 2.112215] alloc_uevent_skb+0x4a/0x160
[ 2.112218] ? add_uevent_var+0x57/0x130
[ 2.112222] kobject_uevent_env+0x599/0xa10
[ 2.112228] ? device_get_devnode+0x1a0/0x1a0
[ 2.112231] kobject_synth_uevent+0x36e/0x515
[ 2.112234] ? mntput+0x2f/0x60
[ 2.112239] uevent_store+0x2b/0x70
[ 2.112241] ? __check_heap_object+0x4c/0x190
[ 2.112244] ? dev_err+0x50/0x50
[ 2.112247] dev_attr_store+0x33/0x60
[ 2.112249] ? dev_uevent_name+0x40/0x40
[ 2.112254] sysfs_kf_write+0x5e/0x100
[ 2.112257] ? mutex_lock+0x2a/0x80
[ 2.112260] ? sysfs_kf_bin_read+0x170/0x170
[ 2.112263] kernfs_fop_write+0x132/0x250
[ 2.112266] ? kernfs_fop_open+0x660/0x660
[ 2.112270] __vfs_write+0x52/0x2d0
[ 2.112273] ? kmemleak_free+0x6d/0x90
[ 2.112277] ? kmem_cache_free+0xc6/0x440
[ 2.112281] vfs_write+0xb0/0x2b0
[ 2.112284] ? do_sys_open+0x174/0x2a0
[ 2.112287] ksys_write+0x51/0xc0
[ 2.112291] sys_write+0x16/0x20
[ 2.112294] do_fast_syscall_32+0xce/0x3e0
[ 2.112298] entry_SYSENTER_32+0x4e/0x7c
[ 2.112301] EIP: 0xb7f0fbb5
[ 2.112302] Code: 89 e5 8b 55 08 85 d2 8b 80 5c cd ff ff 74 02 89 02 5d c3 8b 04 24 c3 8b 1c 24 c3 8b 3c 24 c3 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d 76 00 58 b8 77 00 00 00 cd 80 90 8d 76
[ 2.112339] EAX: ffffffda EBX: 00000003 ECX: bfadbf54 EDX: 00000003
[ 2.112341] ESI: 01f0a640 EDI: 00000003 EBP: bfadaf0c ESP: bfadae80
[ 2.112344] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000246
[ 2.112347]
================================================================================
Kind regards,
Paul
