UBSAN: Undefined behaviour in arch/x86/events/intel/p6.c:115:29

[Meelis Roos]

Not sure if this is a genuine warning or a false positive but since some 
UBSAN warnings have been real and google does not find report about this 
specific warning, I'll send it in anyway.

I have seen similar amd pmu warnings from UBSAN but I do not have any 
amd machines from that time frame online for now, so p6 only.

[    0.150000] Performance Events: p6 PMU driver.
[    0.150000] ================================================================================
[    0.150000] UBSAN: Undefined behaviour in arch/x86/events/intel/p6.c:115:29
[    0.150000] index 8 is out of range for type 'u64 [8]'
[    0.150000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0 #21
[    0.150000] Hardware name: Dell Computer Corporation PowerEdge 1550/933              , BIOS A09 12/10/2004
[    0.150000]  00000000 c13a4bcc 00000046 f605de88 00000008 c13d5188 c17ddfd4 c13d5725
[    0.150000]  c176ae8c f605de8c c17ddfec 00000202 00000038 00752101 00000002 00000000
[    0.150000]  00000000 00000297 000000c2 c17d2b60 00000000 c102b14f 00000008 00000000
[    0.150000] Call Trace:
[    0.150000]  [<c13a4bcc>] ? dump_stack+0x45/0x69
[    0.150000]  [<c13d5188>] ? ubsan_epilogue+0x8/0x30
[    0.150000]  [<c13d5725>] ? __ubsan_handle_out_of_bounds+0x55/0x60
[    0.150000]  [<c102b14f>] ? __register_nmi_handler+0xbf/0x300
[    0.150000]  [<c10183d0>] ? p4_pmu_schedule_events+0x740/0x740
[    0.150000]  [<c101840d>] ? p6_pmu_event_map+0x3d/0x50
[    0.150000]  [<c10183d0>] ? p4_pmu_schedule_events+0x740/0x740
[    0.150000]  [<c1af0c78>] ? init_hw_perf_events+0x493/0x688
[    0.150000]  [<c1af07e5>] ? merge_attr+0x1d5/0x1d5
[    0.150000]  [<c1000412>] ? do_one_initcall+0x82/0x230
[    0.150000]  [<c10e27ef>] ? vprintk_default+0xf/0x20
[    0.150000]  [<c116de67>] ? printk+0x11/0x12
[    0.150000]  [<c103bf46>] ? print_cpu_info+0x86/0x130
[    0.150000]  [<c1b00754>] ? native_smp_prepare_cpus+0x40e/0x453
[    0.150000]  [<c1aefd87>] ? kernel_init_freeable+0x117/0x2fd
[    0.150000]  [<c16a10e6>] ? kernel_init+0x6/0x100
[    0.150000]  [<c16a9949>] ? ret_from_kernel_thread+0x21/0x38
[    0.150000]  [<c16a10e0>] ? rest_init+0x60/0x60
[    0.150000] ================================================================================
[    0.150000] ================================================================================
[    0.150000] UBSAN: Undefined behaviour in arch/x86/events/intel/p6.c:115:9
[    0.150000] load of address c16adf20 with insufficient space
[    0.150000] for an object of type 'const u64'
[    0.150000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0 #21
[    0.150000] Hardware name: Dell Computer Corporation PowerEdge 1550/933              , BIOS A09 12/10/2004
[    0.150000]  00000000 c13a4bcc 00000046 f605deb4 c16adf20 c13d5188 c17ddfac c13d5229
[    0.150000]  c176a901 c17ddfc8 c176aca4 c176a95e c16adf20 00000202 00000008 00000000
[    0.150000]  c101841d 00000008 c10183d0 00000008 c1af0c78 c17d2c00 f605df08 00000001
[    0.150000] Call Trace:
[    0.150000]  [<c13a4bcc>] ? dump_stack+0x45/0x69
[    0.150000]  [<c13d5188>] ? ubsan_epilogue+0x8/0x30
[    0.150000]  [<c13d5229>] ? __ubsan_handle_type_mismatch+0x79/0x150
[    0.150000]  [<c101841d>] ? p6_pmu_event_map+0x4d/0x50
[    0.150000]  [<c10183d0>] ? p4_pmu_schedule_events+0x740/0x740
[    0.150000]  [<c1af0c78>] ? init_hw_perf_events+0x493/0x688
[    0.150000]  [<c1af07e5>] ? merge_attr+0x1d5/0x1d5
[    0.150000]  [<c1000412>] ? do_one_initcall+0x82/0x230
[    0.150000]  [<c10e27ef>] ? vprintk_default+0xf/0x20
[    0.150000]  [<c116de67>] ? printk+0x11/0x12
[    0.150000]  [<c103bf46>] ? print_cpu_info+0x86/0x130
[    0.150000]  [<c1b00754>] ? native_smp_prepare_cpus+0x40e/0x453
[    0.150000]  [<c1aefd87>] ? kernel_init_freeable+0x117/0x2fd
[    0.150000]  [<c16a10e6>] ? kernel_init+0x6/0x100
[    0.150000]  [<c16a9949>] ? ret_from_kernel_thread+0x21/0x38
[    0.150000]  [<c16a10e0>] ? rest_init+0x60/0x60
[    0.150000] ================================================================================
[    0.150000] ... version:                0
[    0.150000] ... bit width:              32
[    0.150000] ... generic registers:      2
[    0.150000] ... value mask:             00000000ffffffff
[    0.150000] ... max period:             000000007fffffff
[    0.150000] ... fixed-purpose events:   0
[    0.150000] ... event mask:             0000000000000003



-- 
Meelis Roos (mroos@xxxxxxxx)