* perf: perf_fuzzer triggers vmalloc_fault (then crashes) @ 2016-10-22 3:05 Vince Weaver 2016-10-24 10:18 ` Peter Zijlstra 0 siblings, 1 reply; 6+ messages in thread From: Vince Weaver @ 2016-10-22 3:05 UTC (permalink / raw) To: linux-kernel; +Cc: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo This is on an AMD a10 system. With paranoid=1. Think it's probably unrelated to the (unreseolved) AMD IBS issues. This is 4.9-rc0 just before rc1 (can't get actual rc1 to boot) Machine locks hard after this. [ 8098.085662] BAD LUCK: lost 42 message(s) from NMI context! [ 8098.085663] ------------[ cut here ]------------ [ 8098.085664] WARNING: CPU: 0 PID: 21338 at arch/x86/mm/fault.c:435 vmalloc_fault+0x58/0x1f0 [ 8098.085668] CPU: 0 PID: 21338 Comm: perf_fuzzer Not tainted 4.8.0+ #37 [ 8098.085668] Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 [ 8098.085670] Call Trace: [ 8098.085670] <NMI> [<ffffffff81263c2f>] ? dump_stack+0x46/0x59 [ 8098.085670] [<ffffffff810499c4>] ? __warn+0xd5/0xee [ 8098.085671] [<ffffffff8103b4de>] ? vmalloc_fault+0x58/0x1f0 [ 8098.085671] [<ffffffff8103c193>] ? __do_page_fault+0x6d/0x48e [ 8098.085671] [<ffffffff810eaf5b>] ? perf_log_throttle+0xa4/0xf4 [ 8098.085672] [<ffffffff8145df72>] ? trace_page_fault+0x22/0x30 [ 8098.085672] [<ffffffff8103918d>] ? __unwind_start+0x28/0x42 [ 8098.085672] [<ffffffff81004721>] ? perf_callchain_kernel+0x75/0xac [ 8098.085672] [<ffffffff810efb0a>] ? get_perf_callchain+0x13a/0x1f0 [ 8098.085673] [<ffffffff810efc2a>] ? perf_callchain+0x6a/0x6c [ 8098.085673] [<ffffffff810ecf5d>] ? perf_prepare_sample+0x71/0x2eb [ 8098.085673] [<ffffffff810ed1f1>] ? perf_event_output_forward+0x1a/0x54 [ 8098.085674] [<ffffffff810313bc>] ? __default_send_IPI_shortcut+0x10/0x2d [ 8098.085674] [<ffffffff810eb247>] ? __perf_event_overflow+0xfb/0x167 [ 8098.085674] [<ffffffff81004247>] ? x86_pmu_handle_irq+0x113/0x150 [ 8098.085675] [<ffffffff81003116>] ? native_read_msr+0x6/0x34 [ 8098.085675] [<ffffffff81002dee>] ? perf_event_nmi_handler+0x22/0x39 [ 8098.085675] [<ffffffff81006621>] ? perf_ibs_nmi_handler+0x4a/0x51 [ 8098.085676] [<ffffffff81002dee>] ? perf_event_nmi_handler+0x22/0x39 [ 8098.085676] [<ffffffff81018493>] ? nmi_handle+0x4d/0xf0 [ 8098.085676] [<ffffffff810065d7>] ? perf_ibs_handle_irq+0x3d1/0x3d1 [ 8098.085676] [<ffffffff810186dd>] ? default_do_nmi+0x3c/0xd5 [ 8098.085677] [<ffffffff81018808>] ? do_nmi+0x92/0x102 [ 8098.085677] [<ffffffff8145e2a7>] ? end_repeat_nmi+0x1a/0x1e [ 8098.085677] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a [ 8098.085678] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a [ 8098.085678] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a [ 8098.085678] <EOE> ^A4---[ end trace 632723104d47d31a ]--- [ 8098.085679] BUG: stack guard page was hit at ffffc90008500000 (stack is ffffc900084fc000..ffffc900084fffff) [ 8098.085679] kernel stack overflow (page fault): 0000 [#1] SMP [ 8098.085683] CPU: 0 PID: 21338 Comm: perf_fuzzer Tainted: G W 4.8.0+ #37 [ 8098.085683] Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 [ 8098.085684] task: ffff8802265d2080 task.stack: ffffc900084fc000 [ 8098.085684] RIP: 0010:[<ffffffff8103918d>] ^Ac [<ffffffff8103918d>] __unwind_start+0x28/0x42 [ 8098.085684] RSP: 0018:ffff88022ec05af0 EFLAGS: 00010006 [ 8098.085685] RAX: 00000000ffffffea RBX: ffff88022ec05b08 RCX: ffffc90008500000 [ 8098.085685] RDX: ffff88022ec00000 RSI: 0000000000001000 RDI: 000000000000c4d0 [ 8098.085685] RBP: ffffc90008500000 R08: ffff88022ec08000 R09: 0000000000000000 [ 8098.085686] R10: 0000000000000002 R11: 0000000000000206 R12: ffff88022ec05b70 [ 8098.085686] R13: ffff88022ec05ef8 R14: 0000000000000000 R15: 0000000000000001 [ 8098.085687] FS: 00007f06e791c700(0000) GS:ffff88022ec00000(0000) knlGS:0000000000000000 [ 8098.085687] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8098.085687] CR2: ffffc90008500000 CR3: 0000000223c25000 CR4: 00000000000407f0 [ 8098.085688] DR0: 0000000000000000 DR1: 0000000000005fc8 DR2: 0000000000005fc8 [ 8098.085688] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 [ 8098.085689] Call Trace: [ 8098.085690] <NMI> ^Ad [<ffffffff81004721>] ? perf_callchain_kernel+0x75/0xac [ 8098.085690] [<ffffffff8126da5e>] ? vsnprintf+0x380/0x3b4 [ 8098.085690] [<ffffffff8126db7e>] ? sprintf+0x42/0x4a [ 8098.085691] [<ffffffff810a8982>] ? __sprint_symbol+0x9d/0xd1 [ 8098.085691] [<ffffffff8126be12>] ? symbol_string+0x51/0x5d [ 8098.085691] [<ffffffff810a8982>] ? __sprint_symbol+0x9d/0xd1 [ 8098.085692] [<ffffffff8126be12>] ? symbol_string+0x51/0x5d [ 8098.085692] [<ffffffff8126d3ea>] ? pointer+0x85/0x379 [ 8098.085692] [<ffffffff8126d75e>] ? vsnprintf+0x80/0x3b4 [ 8098.085692] [<ffffffff810dbe53>] ? irq_work_queue+0xa/0x66 [ 8098.085693] [<ffffffff81084db5>] ? vprintk_nmi+0x88/0x97 [ 8098.085693] [<ffffffff81084db5>] ? vprintk_nmi+0x88/0x97 [ 8098.085693] [<ffffffff810f19b1>] ? printk+0x43/0x4b [ 8098.085694] [<ffffffff810a4919>] ? __module_text_address+0x9/0x4f [ 8098.085694] [<ffffffff810a8346>] ? is_module_text_address+0x5/0xc [ 8098.085694] [<ffffffff81017eed>] ? show_trace_log_lvl+0x108/0x195 [ 8098.085694] [<ffffffff8103bae3>] ? no_context+0x102/0x36c [ 8098.085695] [<ffffffff8103bae3>] ? no_context+0x102/0x36c [ 8098.085695] [<ffffffff8101784a>] ? show_stack_log_lvl+0x15b/0x172 [ 8098.085695] [<ffffffff810178c5>] ? show_regs+0x64/0x136 [ 8098.085696] [<ffffffff81017dad>] ? __die+0x8c/0xc4 [ 8098.085696] [<ffffffff8101802b>] ? die+0x3d/0x56 [ 8098.085696] [<ffffffff810163ed>] ? handle_stack_overflow+0x47/0x51 [ 8098.085697] [<ffffffff8103bae3>] ? no_context+0x102/0x36c [ 8098.085697] <EOE> ^AdCode: ^A1BUG: unable to handle kernel ^AcNULL pointer dereference^Ac at 0000000000000008 [ 8098.085697] IP:^Ac [<0000000000000008>] 0x8 [ 8098.085698] PGD 2231d5067 PUD 225162067 PMD 0 [ 8098.085698] Oops: 0010 [#2] SMP [ 8098.085702] [ 8098.957250] ---[ end trace 632723104d47d31b ]--- [ 8098.957250] Kernel panic - not syncing: Fatal exception in interrupt [ 8098.957301] Kernel Offset: disabled [ 8098.973814] ---[ end Kernel panic - not syncing: Fatal exception in interrupt [ 8098.981719] ------------[ cut here ]------------ [ 8098.981720] WARNING: CPU: 0 PID: 21338 at arch/x86/kernel/smp.c:127 update_process_times+0x3b/0x45 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: perf: perf_fuzzer triggers vmalloc_fault (then crashes) 2016-10-22 3:05 perf: perf_fuzzer triggers vmalloc_fault (then crashes) Vince Weaver @ 2016-10-24 10:18 ` Peter Zijlstra 2016-10-24 11:14 ` Josh Poimboeuf 0 siblings, 1 reply; 6+ messages in thread From: Peter Zijlstra @ 2016-10-24 10:18 UTC (permalink / raw) To: Vince Weaver Cc: linux-kernel, Ingo Molnar, Arnaldo Carvalho de Melo, Andy Lutomirski, Josh Poimboeuf On Fri, Oct 21, 2016 at 11:05:40PM -0400, Vince Weaver wrote: > > This is on an AMD a10 system. With paranoid=1. Think it's > probably unrelated to the (unreseolved) AMD IBS issues. > This is 4.9-rc0 just before rc1 (can't get actual rc1 to boot) > > Machine locks hard after this. > > [ 8098.085662] BAD LUCK: lost 42 message(s) from NMI context! > [ 8098.085663] ------------[ cut here ]------------ > [ 8098.085664] WARNING: CPU: 0 PID: 21338 at arch/x86/mm/fault.c:435 vmalloc_fault+0x58/0x1f0 > [ 8098.085668] CPU: 0 PID: 21338 Comm: perf_fuzzer Not tainted 4.8.0+ #37 > [ 8098.085668] Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 > [ 8098.085670] Call Trace: > [ 8098.085670] <NMI> [<ffffffff81263c2f>] ? dump_stack+0x46/0x59 > [ 8098.085670] [<ffffffff810499c4>] ? __warn+0xd5/0xee > [ 8098.085671] [<ffffffff8103b4de>] ? vmalloc_fault+0x58/0x1f0 > [ 8098.085671] [<ffffffff8103c193>] ? __do_page_fault+0x6d/0x48e > [ 8098.085671] [<ffffffff810eaf5b>] ? perf_log_throttle+0xa4/0xf4 > [ 8098.085672] [<ffffffff8145df72>] ? trace_page_fault+0x22/0x30 > [ 8098.085672] [<ffffffff8103918d>] ? __unwind_start+0x28/0x42 > [ 8098.085672] [<ffffffff81004721>] ? perf_callchain_kernel+0x75/0xac > [ 8098.085672] [<ffffffff810efb0a>] ? get_perf_callchain+0x13a/0x1f0 > [ 8098.085673] [<ffffffff810efc2a>] ? perf_callchain+0x6a/0x6c > [ 8098.085673] [<ffffffff810ecf5d>] ? perf_prepare_sample+0x71/0x2eb > [ 8098.085673] [<ffffffff810ed1f1>] ? perf_event_output_forward+0x1a/0x54 > [ 8098.085674] [<ffffffff810313bc>] ? __default_send_IPI_shortcut+0x10/0x2d > [ 8098.085674] [<ffffffff810eb247>] ? __perf_event_overflow+0xfb/0x167 > [ 8098.085674] [<ffffffff81004247>] ? x86_pmu_handle_irq+0x113/0x150 > [ 8098.085675] [<ffffffff81003116>] ? native_read_msr+0x6/0x34 > [ 8098.085675] [<ffffffff81002dee>] ? perf_event_nmi_handler+0x22/0x39 > [ 8098.085675] [<ffffffff81006621>] ? perf_ibs_nmi_handler+0x4a/0x51 > [ 8098.085676] [<ffffffff81002dee>] ? perf_event_nmi_handler+0x22/0x39 > [ 8098.085676] [<ffffffff81018493>] ? nmi_handle+0x4d/0xf0 > [ 8098.085676] [<ffffffff810065d7>] ? perf_ibs_handle_irq+0x3d1/0x3d1 > [ 8098.085676] [<ffffffff810186dd>] ? default_do_nmi+0x3c/0xd5 > [ 8098.085677] [<ffffffff81018808>] ? do_nmi+0x92/0x102 > [ 8098.085677] [<ffffffff8145e2a7>] ? end_repeat_nmi+0x1a/0x1e > [ 8098.085677] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a > [ 8098.085678] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a > [ 8098.085678] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a > [ 8098.085678] <EOE> ^A4---[ end trace 632723104d47d31a ]--- So we get an NMI based stack unwind (without frame pointers) overrun the actual stack, and tickle the new guard page thing: > [ 8098.085679] BUG: stack guard page was hit at ffffc90008500000 (stack is ffffc900084fc000..ffffc900084fffff) > [ 8098.085679] kernel stack overflow (page fault): 0000 [#1] SMP > [ 8098.085683] CPU: 0 PID: 21338 Comm: perf_fuzzer Tainted: G W 4.8.0+ #37 > [ 8098.085683] Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 > [ 8098.085684] task: ffff8802265d2080 task.stack: ffffc900084fc000 > [ 8098.085684] RIP: 0010:[<ffffffff8103918d>] ^Ac [<ffffffff8103918d>] __unwind_start+0x28/0x42 > [ 8098.085684] RSP: 0018:ffff88022ec05af0 EFLAGS: 00010006 > [ 8098.085685] RAX: 00000000ffffffea RBX: ffff88022ec05b08 RCX: ffffc90008500000 > [ 8098.085685] RDX: ffff88022ec00000 RSI: 0000000000001000 RDI: 000000000000c4d0 > [ 8098.085685] RBP: ffffc90008500000 R08: ffff88022ec08000 R09: 0000000000000000 > [ 8098.085686] R10: 0000000000000002 R11: 0000000000000206 R12: ffff88022ec05b70 > [ 8098.085686] R13: ffff88022ec05ef8 R14: 0000000000000000 R15: 0000000000000001 > [ 8098.085687] FS: 00007f06e791c700(0000) GS:ffff88022ec00000(0000) knlGS:0000000000000000 > [ 8098.085687] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 8098.085687] CR2: ffffc90008500000 CR3: 0000000223c25000 CR4: 00000000000407f0 > [ 8098.085688] DR0: 0000000000000000 DR1: 0000000000005fc8 DR2: 0000000000005fc8 > [ 8098.085688] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > [ 8098.085689] Call Trace: > [ 8098.085690] <NMI> ^Ad [<ffffffff81004721>] ? perf_callchain_kernel+0x75/0xac > [ 8098.085690] [<ffffffff8126da5e>] ? vsnprintf+0x380/0x3b4 > [ 8098.085690] [<ffffffff8126db7e>] ? sprintf+0x42/0x4a > [ 8098.085691] [<ffffffff810a8982>] ? __sprint_symbol+0x9d/0xd1 > [ 8098.085691] [<ffffffff8126be12>] ? symbol_string+0x51/0x5d > [ 8098.085691] [<ffffffff810a8982>] ? __sprint_symbol+0x9d/0xd1 > [ 8098.085692] [<ffffffff8126be12>] ? symbol_string+0x51/0x5d > [ 8098.085692] [<ffffffff8126d3ea>] ? pointer+0x85/0x379 > [ 8098.085692] [<ffffffff8126d75e>] ? vsnprintf+0x80/0x3b4 > [ 8098.085692] [<ffffffff810dbe53>] ? irq_work_queue+0xa/0x66 > [ 8098.085693] [<ffffffff81084db5>] ? vprintk_nmi+0x88/0x97 > [ 8098.085693] [<ffffffff81084db5>] ? vprintk_nmi+0x88/0x97 > [ 8098.085693] [<ffffffff810f19b1>] ? printk+0x43/0x4b > [ 8098.085694] [<ffffffff810a4919>] ? __module_text_address+0x9/0x4f > [ 8098.085694] [<ffffffff810a8346>] ? is_module_text_address+0x5/0xc > [ 8098.085694] [<ffffffff81017eed>] ? show_trace_log_lvl+0x108/0x195 > [ 8098.085694] [<ffffffff8103bae3>] ? no_context+0x102/0x36c > [ 8098.085695] [<ffffffff8103bae3>] ? no_context+0x102/0x36c > [ 8098.085695] [<ffffffff8101784a>] ? show_stack_log_lvl+0x15b/0x172 > [ 8098.085695] [<ffffffff810178c5>] ? show_regs+0x64/0x136 > [ 8098.085696] [<ffffffff81017dad>] ? __die+0x8c/0xc4 > [ 8098.085696] [<ffffffff8101802b>] ? die+0x3d/0x56 > [ 8098.085696] [<ffffffff810163ed>] ? handle_stack_overflow+0x47/0x51 > [ 8098.085697] [<ffffffff8103bae3>] ? no_context+0x102/0x36c > [ 8098.085697] <EOE> ^AdCode: ^A1BUG: unable to handle kernel ^AcNULL pointer dereference^Ac at 0000000000000008 > [ 8098.085697] IP:^Ac [<0000000000000008>] 0x8 > [ 8098.085698] PGD 2231d5067 PUD 225162067 PMD 0 > [ 8098.085698] Oops: 0010 [#2] SMP > [ 8098.085702] > [ 8098.957250] ---[ end trace 632723104d47d31b ]--- > [ 8098.957250] Kernel panic - not syncing: Fatal exception in interrupt > [ 8098.957301] Kernel Offset: disabled > [ 8098.973814] ---[ end Kernel panic - not syncing: Fatal exception in interrupt > [ 8098.981719] ------------[ cut here ]------------ > [ 8098.981720] WARNING: CPU: 0 PID: 21338 at arch/x86/kernel/smp.c:127 update_process_times+0x3b/0x45 And then the machine (understandably) goes off the rails entirely.. Josh, Andy, any clue on how I should go about fixing this? ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: perf: perf_fuzzer triggers vmalloc_fault (then crashes) 2016-10-24 10:18 ` Peter Zijlstra @ 2016-10-24 11:14 ` Josh Poimboeuf 2016-10-24 11:16 ` Peter Zijlstra 0 siblings, 1 reply; 6+ messages in thread From: Josh Poimboeuf @ 2016-10-24 11:14 UTC (permalink / raw) To: Peter Zijlstra Cc: Vince Weaver, linux-kernel, Ingo Molnar, Arnaldo Carvalho de Melo, Andy Lutomirski On Mon, Oct 24, 2016 at 12:18:02PM +0200, Peter Zijlstra wrote: > On Fri, Oct 21, 2016 at 11:05:40PM -0400, Vince Weaver wrote: > > > > This is on an AMD a10 system. With paranoid=1. Think it's > > probably unrelated to the (unreseolved) AMD IBS issues. > > This is 4.9-rc0 just before rc1 (can't get actual rc1 to boot) > > > > Machine locks hard after this. > > > > [ 8098.085662] BAD LUCK: lost 42 message(s) from NMI context! > > [ 8098.085663] ------------[ cut here ]------------ > > [ 8098.085664] WARNING: CPU: 0 PID: 21338 at arch/x86/mm/fault.c:435 vmalloc_fault+0x58/0x1f0 > > [ 8098.085668] CPU: 0 PID: 21338 Comm: perf_fuzzer Not tainted 4.8.0+ #37 > > [ 8098.085668] Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 > > [ 8098.085670] Call Trace: > > [ 8098.085670] <NMI> [<ffffffff81263c2f>] ? dump_stack+0x46/0x59 > > [ 8098.085670] [<ffffffff810499c4>] ? __warn+0xd5/0xee > > [ 8098.085671] [<ffffffff8103b4de>] ? vmalloc_fault+0x58/0x1f0 > > [ 8098.085671] [<ffffffff8103c193>] ? __do_page_fault+0x6d/0x48e > > [ 8098.085671] [<ffffffff810eaf5b>] ? perf_log_throttle+0xa4/0xf4 > > [ 8098.085672] [<ffffffff8145df72>] ? trace_page_fault+0x22/0x30 > > [ 8098.085672] [<ffffffff8103918d>] ? __unwind_start+0x28/0x42 > > [ 8098.085672] [<ffffffff81004721>] ? perf_callchain_kernel+0x75/0xac > > [ 8098.085672] [<ffffffff810efb0a>] ? get_perf_callchain+0x13a/0x1f0 > > [ 8098.085673] [<ffffffff810efc2a>] ? perf_callchain+0x6a/0x6c > > [ 8098.085673] [<ffffffff810ecf5d>] ? perf_prepare_sample+0x71/0x2eb > > [ 8098.085673] [<ffffffff810ed1f1>] ? perf_event_output_forward+0x1a/0x54 > > [ 8098.085674] [<ffffffff810313bc>] ? __default_send_IPI_shortcut+0x10/0x2d > > [ 8098.085674] [<ffffffff810eb247>] ? __perf_event_overflow+0xfb/0x167 > > [ 8098.085674] [<ffffffff81004247>] ? x86_pmu_handle_irq+0x113/0x150 > > [ 8098.085675] [<ffffffff81003116>] ? native_read_msr+0x6/0x34 > > [ 8098.085675] [<ffffffff81002dee>] ? perf_event_nmi_handler+0x22/0x39 > > [ 8098.085675] [<ffffffff81006621>] ? perf_ibs_nmi_handler+0x4a/0x51 > > [ 8098.085676] [<ffffffff81002dee>] ? perf_event_nmi_handler+0x22/0x39 > > [ 8098.085676] [<ffffffff81018493>] ? nmi_handle+0x4d/0xf0 > > [ 8098.085676] [<ffffffff810065d7>] ? perf_ibs_handle_irq+0x3d1/0x3d1 > > [ 8098.085676] [<ffffffff810186dd>] ? default_do_nmi+0x3c/0xd5 > > [ 8098.085677] [<ffffffff81018808>] ? do_nmi+0x92/0x102 > > [ 8098.085677] [<ffffffff8145e2a7>] ? end_repeat_nmi+0x1a/0x1e > > [ 8098.085677] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a > > [ 8098.085678] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a > > [ 8098.085678] [<ffffffff8145c2d5>] ? entry_SYSCALL_64_after_swapgs+0x12/0x4a > > [ 8098.085678] <EOE> ^A4---[ end trace 632723104d47d31a ]--- > > So we get an NMI based stack unwind (without frame pointers) overrun the > actual stack, and tickle the new guard page thing: > > > [ 8098.085679] BUG: stack guard page was hit at ffffc90008500000 (stack is ffffc900084fc000..ffffc900084fffff) > > [ 8098.085679] kernel stack overflow (page fault): 0000 [#1] SMP > > [ 8098.085683] CPU: 0 PID: 21338 Comm: perf_fuzzer Tainted: G W 4.8.0+ #37 > > [ 8098.085683] Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 > > [ 8098.085684] task: ffff8802265d2080 task.stack: ffffc900084fc000 > > [ 8098.085684] RIP: 0010:[<ffffffff8103918d>] ^Ac [<ffffffff8103918d>] __unwind_start+0x28/0x42 > > [ 8098.085684] RSP: 0018:ffff88022ec05af0 EFLAGS: 00010006 > > [ 8098.085685] RAX: 00000000ffffffea RBX: ffff88022ec05b08 RCX: ffffc90008500000 > > [ 8098.085685] RDX: ffff88022ec00000 RSI: 0000000000001000 RDI: 000000000000c4d0 > > [ 8098.085685] RBP: ffffc90008500000 R08: ffff88022ec08000 R09: 0000000000000000 > > [ 8098.085686] R10: 0000000000000002 R11: 0000000000000206 R12: ffff88022ec05b70 > > [ 8098.085686] R13: ffff88022ec05ef8 R14: 0000000000000000 R15: 0000000000000001 > > [ 8098.085687] FS: 00007f06e791c700(0000) GS:ffff88022ec00000(0000) knlGS:0000000000000000 > > [ 8098.085687] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 8098.085687] CR2: ffffc90008500000 CR3: 0000000223c25000 CR4: 00000000000407f0 > > [ 8098.085688] DR0: 0000000000000000 DR1: 0000000000005fc8 DR2: 0000000000005fc8 > > [ 8098.085688] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > > [ 8098.085689] Call Trace: > > [ 8098.085690] <NMI> ^Ad [<ffffffff81004721>] ? perf_callchain_kernel+0x75/0xac > > [ 8098.085690] [<ffffffff8126da5e>] ? vsnprintf+0x380/0x3b4 > > [ 8098.085690] [<ffffffff8126db7e>] ? sprintf+0x42/0x4a > > [ 8098.085691] [<ffffffff810a8982>] ? __sprint_symbol+0x9d/0xd1 > > [ 8098.085691] [<ffffffff8126be12>] ? symbol_string+0x51/0x5d > > [ 8098.085691] [<ffffffff810a8982>] ? __sprint_symbol+0x9d/0xd1 > > [ 8098.085692] [<ffffffff8126be12>] ? symbol_string+0x51/0x5d > > [ 8098.085692] [<ffffffff8126d3ea>] ? pointer+0x85/0x379 > > [ 8098.085692] [<ffffffff8126d75e>] ? vsnprintf+0x80/0x3b4 > > [ 8098.085692] [<ffffffff810dbe53>] ? irq_work_queue+0xa/0x66 > > [ 8098.085693] [<ffffffff81084db5>] ? vprintk_nmi+0x88/0x97 > > [ 8098.085693] [<ffffffff81084db5>] ? vprintk_nmi+0x88/0x97 > > [ 8098.085693] [<ffffffff810f19b1>] ? printk+0x43/0x4b > > [ 8098.085694] [<ffffffff810a4919>] ? __module_text_address+0x9/0x4f > > [ 8098.085694] [<ffffffff810a8346>] ? is_module_text_address+0x5/0xc > > [ 8098.085694] [<ffffffff81017eed>] ? show_trace_log_lvl+0x108/0x195 > > [ 8098.085694] [<ffffffff8103bae3>] ? no_context+0x102/0x36c > > [ 8098.085695] [<ffffffff8103bae3>] ? no_context+0x102/0x36c > > [ 8098.085695] [<ffffffff8101784a>] ? show_stack_log_lvl+0x15b/0x172 > > [ 8098.085695] [<ffffffff810178c5>] ? show_regs+0x64/0x136 > > [ 8098.085696] [<ffffffff81017dad>] ? __die+0x8c/0xc4 > > [ 8098.085696] [<ffffffff8101802b>] ? die+0x3d/0x56 > > [ 8098.085696] [<ffffffff810163ed>] ? handle_stack_overflow+0x47/0x51 > > [ 8098.085697] [<ffffffff8103bae3>] ? no_context+0x102/0x36c > > [ 8098.085697] <EOE> ^AdCode: ^A1BUG: unable to handle kernel ^AcNULL pointer dereference^Ac at 0000000000000008 > > [ 8098.085697] IP:^Ac [<0000000000000008>] 0x8 > > [ 8098.085698] PGD 2231d5067 PUD 225162067 PMD 0 > > [ 8098.085698] Oops: 0010 [#2] SMP > > [ 8098.085702] > > [ 8098.957250] ---[ end trace 632723104d47d31b ]--- > > [ 8098.957250] Kernel panic - not syncing: Fatal exception in interrupt > > [ 8098.957301] Kernel Offset: disabled > > [ 8098.973814] ---[ end Kernel panic - not syncing: Fatal exception in interrupt > > [ 8098.981719] ------------[ cut here ]------------ > > [ 8098.981720] WARNING: CPU: 0 PID: 21338 at arch/x86/kernel/smp.c:127 update_process_times+0x3b/0x45 > > And then the machine (understandably) goes off the rails entirely.. > > Josh, Andy, any clue on how I should go about fixing this? This is a bug in the unwinder. The NMI hit in the entry code right after setting up the stack pointer from cpu_current_top_of_stack, so the kernel stack was empty. __unwind_start() tried to dereference the pointer (0xffffc90008500000) at the top of the stack. I'll make a patch. -- Josh ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: perf: perf_fuzzer triggers vmalloc_fault (then crashes) 2016-10-24 11:14 ` Josh Poimboeuf @ 2016-10-24 11:16 ` Peter Zijlstra 2016-10-24 13:31 ` [PATCH] x86/unwind: fix empty stack dereference in guess unwinder Josh Poimboeuf 0 siblings, 1 reply; 6+ messages in thread From: Peter Zijlstra @ 2016-10-24 11:16 UTC (permalink / raw) To: Josh Poimboeuf Cc: Vince Weaver, linux-kernel, Ingo Molnar, Arnaldo Carvalho de Melo, Andy Lutomirski On Mon, Oct 24, 2016 at 06:14:02AM -0500, Josh Poimboeuf wrote: > > Josh, Andy, any clue on how I should go about fixing this? > > This is a bug in the unwinder. The NMI hit in the entry code right > after setting up the stack pointer from cpu_current_top_of_stack, so the > kernel stack was empty. __unwind_start() tried to dereference the > pointer (0xffffc90008500000) at the top of the stack. I'll make a > patch. Great, thanks! ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] x86/unwind: fix empty stack dereference in guess unwinder 2016-10-24 11:16 ` Peter Zijlstra @ 2016-10-24 13:31 ` Josh Poimboeuf 2016-10-25 10:30 ` [tip:x86/urgent] x86/unwind: Fix " tip-bot for Josh Poimboeuf 0 siblings, 1 reply; 6+ messages in thread From: Josh Poimboeuf @ 2016-10-24 13:31 UTC (permalink / raw) To: Peter Zijlstra Cc: Vince Weaver, linux-kernel, Ingo Molnar, Arnaldo Carvalho de Melo, Andy Lutomirski, x86 Vince reported the following bug: WARNING: CPU: 0 PID: 21338 at arch/x86/mm/fault.c:435 vmalloc_fault+0x58/0x1f0 CPU: 0 PID: 21338 Comm: perf_fuzzer Not tainted 4.8.0+ #37 Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 Call Trace: <NMI> ? dump_stack+0x46/0x59 ? __warn+0xd5/0xee ? vmalloc_fault+0x58/0x1f0 ? __do_page_fault+0x6d/0x48e ? perf_log_throttle+0xa4/0xf4 ? trace_page_fault+0x22/0x30 ? __unwind_start+0x28/0x42 ? perf_callchain_kernel+0x75/0xac ? get_perf_callchain+0x13a/0x1f0 ? perf_callchain+0x6a/0x6c ? perf_prepare_sample+0x71/0x2eb ? perf_event_output_forward+0x1a/0x54 ? __default_send_IPI_shortcut+0x10/0x2d ? __perf_event_overflow+0xfb/0x167 ? x86_pmu_handle_irq+0x113/0x150 ? native_read_msr+0x6/0x34 ? perf_event_nmi_handler+0x22/0x39 ? perf_ibs_nmi_handler+0x4a/0x51 ? perf_event_nmi_handler+0x22/0x39 ? nmi_handle+0x4d/0xf0 ? perf_ibs_handle_irq+0x3d1/0x3d1 ? default_do_nmi+0x3c/0xd5 ? do_nmi+0x92/0x102 ? end_repeat_nmi+0x1a/0x1e ? entry_SYSCALL_64_after_swapgs+0x12/0x4a ? entry_SYSCALL_64_after_swapgs+0x12/0x4a ? entry_SYSCALL_64_after_swapgs+0x12/0x4a <EOE> ^A4---[ end trace 632723104d47d31a ]--- BUG: stack guard page was hit at ffffc90008500000 (stack is ffffc900084fc000..ffffc900084fffff) kernel stack overflow (page fault): 0000 [#1] SMP ... The NMI hit in the entry code right after setting up the stack pointer from 'cpu_current_top_of_stack', so the kernel stack was empty. The 'guess' version of __unwind_start() attempted to dereference the "top of stack" pointer, which is not actually *on* the stack. Add a check in the guess unwinder to deal with an empty stack. (The frame pointer unwinder already has such a check.) Fixes: 7c7900f89770 ("x86/unwind: Add new unwind interface and implementations") Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> --- arch/x86/kernel/unwind_guess.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c index 9298993..2d721e5 100644 --- a/arch/x86/kernel/unwind_guess.c +++ b/arch/x86/kernel/unwind_guess.c @@ -47,7 +47,14 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, get_stack_info(first_frame, state->task, &state->stack_info, &state->stack_mask); - if (!__kernel_text_address(*first_frame)) + /* + * The caller can provide the address of the first frame directly + * (first_frame) or indirectly (regs->sp) to indicate which stack frame + * to start unwinding at. Skip ahead until we reach it. + */ + if (!unwind_done(state) && + (!on_stack(&state->stack_info, first_frame, sizeof(long)) || + !__kernel_text_address(*first_frame))) unwind_next_frame(state); } EXPORT_SYMBOL_GPL(__unwind_start); -- 2.7.4 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [tip:x86/urgent] x86/unwind: Fix empty stack dereference in guess unwinder 2016-10-24 13:31 ` [PATCH] x86/unwind: fix empty stack dereference in guess unwinder Josh Poimboeuf @ 2016-10-25 10:30 ` tip-bot for Josh Poimboeuf 0 siblings, 0 replies; 6+ messages in thread From: tip-bot for Josh Poimboeuf @ 2016-10-25 10:30 UTC (permalink / raw) To: linux-tip-commits Cc: torvalds, acme, hpa, tglx, peterz, linux-kernel, vincent.weaver, jpoimboe, luto, mingo Commit-ID: 7fbe6ac02485504b964b283aca62b36b4313ca79 Gitweb: http://git.kernel.org/tip/7fbe6ac02485504b964b283aca62b36b4313ca79 Author: Josh Poimboeuf <jpoimboe@redhat.com> AuthorDate: Mon, 24 Oct 2016 08:31:27 -0500 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 25 Oct 2016 11:36:43 +0200 x86/unwind: Fix empty stack dereference in guess unwinder Vince Waver reported the following bug: WARNING: CPU: 0 PID: 21338 at arch/x86/mm/fault.c:435 vmalloc_fault+0x58/0x1f0 CPU: 0 PID: 21338 Comm: perf_fuzzer Not tainted 4.8.0+ #37 Hardware name: Hewlett-Packard HP Compaq Pro 6305 SFF/1850, BIOS K06 v02.57 08/16/2013 Call Trace: <NMI> ? dump_stack+0x46/0x59 ? __warn+0xd5/0xee ? vmalloc_fault+0x58/0x1f0 ? __do_page_fault+0x6d/0x48e ? perf_log_throttle+0xa4/0xf4 ? trace_page_fault+0x22/0x30 ? __unwind_start+0x28/0x42 ? perf_callchain_kernel+0x75/0xac ? get_perf_callchain+0x13a/0x1f0 ? perf_callchain+0x6a/0x6c ? perf_prepare_sample+0x71/0x2eb ? perf_event_output_forward+0x1a/0x54 ? __default_send_IPI_shortcut+0x10/0x2d ? __perf_event_overflow+0xfb/0x167 ? x86_pmu_handle_irq+0x113/0x150 ? native_read_msr+0x6/0x34 ? perf_event_nmi_handler+0x22/0x39 ? perf_ibs_nmi_handler+0x4a/0x51 ? perf_event_nmi_handler+0x22/0x39 ? nmi_handle+0x4d/0xf0 ? perf_ibs_handle_irq+0x3d1/0x3d1 ? default_do_nmi+0x3c/0xd5 ? do_nmi+0x92/0x102 ? end_repeat_nmi+0x1a/0x1e ? entry_SYSCALL_64_after_swapgs+0x12/0x4a ? entry_SYSCALL_64_after_swapgs+0x12/0x4a ? entry_SYSCALL_64_after_swapgs+0x12/0x4a <EOE> ^A4---[ end trace 632723104d47d31a ]--- BUG: stack guard page was hit at ffffc90008500000 (stack is ffffc900084fc000..ffffc900084fffff) kernel stack overflow (page fault): 0000 [#1] SMP ... The NMI hit in the entry code right after setting up the stack pointer from 'cpu_current_top_of_stack', so the kernel stack was empty. The 'guess' version of __unwind_start() attempted to dereference the "top of stack" pointer, which is not actually *on* the stack. Add a check in the guess unwinder to deal with an empty stack. (The frame pointer unwinder already has such a check.) Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 7c7900f89770 ("x86/unwind: Add new unwind interface and implementations") Link: http://lkml.kernel.org/r/20161024133127.e5evgeebdbohnmpb@treble Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/unwind_guess.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c index 9298993..2d721e5 100644 --- a/arch/x86/kernel/unwind_guess.c +++ b/arch/x86/kernel/unwind_guess.c @@ -47,7 +47,14 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, get_stack_info(first_frame, state->task, &state->stack_info, &state->stack_mask); - if (!__kernel_text_address(*first_frame)) + /* + * The caller can provide the address of the first frame directly + * (first_frame) or indirectly (regs->sp) to indicate which stack frame + * to start unwinding at. Skip ahead until we reach it. + */ + if (!unwind_done(state) && + (!on_stack(&state->stack_info, first_frame, sizeof(long)) || + !__kernel_text_address(*first_frame))) unwind_next_frame(state); } EXPORT_SYMBOL_GPL(__unwind_start); ^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-10-25 10:30 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-10-22 3:05 perf: perf_fuzzer triggers vmalloc_fault (then crashes) Vince Weaver 2016-10-24 10:18 ` Peter Zijlstra 2016-10-24 11:14 ` Josh Poimboeuf 2016-10-24 11:16 ` Peter Zijlstra 2016-10-24 13:31 ` [PATCH] x86/unwind: fix empty stack dereference in guess unwinder Josh Poimboeuf 2016-10-25 10:30 ` [tip:x86/urgent] x86/unwind: Fix " tip-bot for Josh Poimboeuf
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