Re: perf: perf_fuzzer quickly locks up on 4.15-rc7

[Vince Weaver]

On Thu, 11 Jan 2018, Peter Zijlstra wrote:

> It makes my IVB very ill, starts spewing RCU stall warnings, but is
> otherwise very unresponsive.
> 
> Awesome... I'll prod at it when my brain works again.
> 

Not sure if it's related, but I hit this on the core2 machine fuzzing 
overnight with "pti=off"

Jan 11 19:03:03 core2 kernel: [12816.125397] WARNING: CPU: 0 PID: 3144 at kernel/events/core.c:5097 perf_mmap_close+0x129/0x216
Jan 11 19:03:03 core2 kernel: [12816.126204] WARNING: CPU: 1 PID: 3197 at kernel/events/ring_buffer.c:569 __rb_free_aux+0x1a/0xb6
Jan 11 19:03:03 core2 kernel: [12816.126219] CPU: 1 PID: 3197 Comm: perf_fuzzer Not tainted 4.15.0-rc7+ #211
Jan 11 19:03:03 core2 kernel: [12816.126220] Hardware name: AOpen   DE7000/nMCP7ALPx-DE R1.06 Oct.19.2012, BIOS 080015  10/19/2012
Jan 11 19:03:03 core2 kernel: [12816.126222] RIP: 0010:__rb_free_aux+0x1a/0xb6
Jan 11 19:03:03 core2 kernel: [12816.126223] RSP: 0000:ffffc90007417c08 EFLAGS: 00010006
Jan 11 19:03:03 core2 kernel: [12816.126224] RAX: 0000000080110000 RBX: ffff8801197aee00 RCX: 0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.126225] RDX: 0000000000040400 RSI: 00000000000400f6 RDI: ffff8801197aee00
Jan 11 19:03:03 core2 kernel: [12816.126225] RBP: ffff88011fc91000 R08: 0000000000000020 R09: 0000000000000030
Jan 11 19:03:03 core2 kernel: [12816.126226] R10: ffffc90007417c28 R11: 0000000000000246 R12: 0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.126227] R13: 0000000000000001 R14: ffff88011901a800 R15: 0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.126228] FS:  00007f1957682700(0000) GS:ffff88011fc80000(0000) knlGS:0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.126229] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jan 11 19:03:03 core2 kernel: [12816.126230] CR2: 00000000026be684 CR3: 000000011a79a000 CR4: 00000000000407e0
Jan 11 19:03:03 core2 kernel: [12816.126231] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.126231] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Jan 11 19:03:03 core2 kernel: [12816.126232] Call Trace:
Jan 11 19:03:03 core2 kernel: [12816.126236]  perf_aux_output_end+0xf4/0x100
Jan 11 19:03:03 core2 kernel: [12816.126239]  intel_bts_interrupt+0x9e/0xf5
Jan 11 19:03:03 core2 kernel: [12816.126241]  intel_pmu_handle_irq+0x72/0x3dd
Jan 11 19:03:03 core2 kernel: [12816.126245]  ? flush_tlb_mm_range+0xb0/0xca
Jan 11 19:03:03 core2 kernel: [12816.126248]  ? radix_tree_next_chunk+0x73/0x26b
Jan 11 19:03:03 core2 kernel: [12816.126249]  ? get_page+0x5/0xa
Jan 11 19:03:03 core2 kernel: [12816.126251]  ? mm_counter_file+0x5/0x14
Jan 11 19:03:03 core2 kernel: [12816.126254]  ? alloc_set_pte+0x1b9/0x1cf
Jan 11 19:03:03 core2 kernel: [12816.126255]  ? unlock_page+0xa/0x20
Jan 11 19:03:03 core2 kernel: [12816.126256]  ? filemap_map_pages+0x182/0x1f4
Jan 11 19:03:03 core2 kernel: [12816.126258]  ? reuse_swap_page+0x7a/0x115
Jan 11 19:03:03 core2 kernel: [12816.126259]  ? wp_page_reuse+0x31/0x3a
Jan 11 19:03:03 core2 kernel: [12816.126260]  ? do_wp_page+0x16d/0x242
Jan 11 19:03:03 core2 kernel: [12816.126262]  ? __handle_mm_fault+0x67c/0x6f1
Jan 11 19:03:03 core2 kernel: [12816.126264]  ? perf_event_nmi_handler+0x27/0x3e
Jan 11 19:03:03 core2 kernel: [12816.126266]  ? perf_event_nmi_handler+0x1b/0x3e
Jan 11 19:03:03 core2 kernel: [12816.126267]  perf_event_nmi_handler+0x27/0x3e
Jan 11 19:03:03 core2 kernel: [12816.126269]  nmi_handle+0x52/0xf5
Jan 11 19:03:03 core2 kernel: [12816.126271]  default_do_nmi+0x41/0xda
Jan 11 19:03:03 core2 kernel: [12816.126273]  do_nmi+0x92/0x102
Jan 11 19:03:03 core2 kernel: [12816.126275]  nmi+0x67/0xb0
Jan 11 19:03:03 core2 kernel: [12816.126277] RIP: 0033:0x40fa77
Jan 11 19:03:03 core2 kernel: [12816.126277] RSP: 002b:00007fff93ea1d48 EFLAGS: 00000202
Jan 11 19:03:03 core2 kernel: [12816.126278] RAX: 0000000000000000 RBX: 000000000000000c RCX: 000000000007887c
Jan 11 19:03:03 core2 kernel: [12816.126279] RDX: 0000000000000000 RSI: 00007f1957470620 RDI: 00007f19574714e0
Jan 11 19:03:03 core2 kernel: [12816.126280] RBP: 00007fff93ea1d60 R08: 0000000000000000 R09: 00007f1957682700
Jan 11 19:03:03 core2 kernel: [12816.126281] R10: 00007f19576829d0 R11: 0000000000000246 R12: 0000000000401950
Jan 11 19:03:03 core2 kernel: [12816.126281] R13: 00007fff93ea4150 R14: 0000000000000000 R15: 0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.126282] Code: 38 48 01 c7 48 c7 47 08 00 00 00 00 e9 4c 98 00 00 66 66 66 66 90 65 8b 05 57 59 f1 7e a9 ff ff ff 7f 41 54 55 53 48 89 fb 74 02 <0f> ff 48 8b bb e0 00 00 00 48 85 ff 74 1c ff 93 c8 00 00 00 48 
Jan 11 19:03:03 core2 kernel: [12816.126299] ---[ end trace d8df98463050a325 ]---
Jan 11 19:03:03 core2 kernel: [12816.445380] CPU: 0 PID: 3144 Comm: perf_fuzzer Tainted: G        W        4.15.0-rc7+ #211
Jan 11 19:03:03 core2 kernel: [12816.453689] Hardware name: AOpen   DE7000/nMCP7ALPx-DE R1.06 Oct.19.2012, BIOS 080015  10/19/2012
Jan 11 19:03:03 core2 kernel: [12816.462611] RIP: 0010:perf_mmap_close+0x129/0x216
Jan 11 19:03:03 core2 kernel: [12816.467360] RSP: 0018:ffffc9000729fe58 EFLAGS: 00010202
Jan 11 19:03:03 core2 kernel: [12816.472630] RAX: 0000000000000001 RBX: ffff8801197aee00 RCX: 0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.479808] RDX: 0000000000000000 RSI: 00000000000008fb RDI: ffff8801197aee00
Jan 11 19:03:03 core2 kernel: [12816.486984] RBP: ffff88011a5b1000 R08: 0000000000000001 R09: ffff880118c94d80
Jan 11 19:03:03 core2 kernel: [12816.494160] R10: ffffc9000729fe30 R11: ffff880118c94d80 R12: ffff88011914b300
Jan 11 19:03:03 core2 kernel: [12816.501336] R13: ffff88011a133a28 R14: ffff88011a5b1270 R15: ffff8801197aebc8
Jan 11 19:03:03 core2 kernel: [12816.508512] FS:  00007f1957682700(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000
Jan 11 19:03:03 core2 kernel: [12816.516652] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jan 11 19:03:03 core2 kernel: [12816.522441] CR2: 0000000000837f80 CR3: 0000000118caa000 CR4: 00000000000407f0
Jan 11 19:03:03 core2 kernel: [12816.529618] DR0: 0000000000000000 DR1: 0000000000000040 DR2: 0000000000000040
Jan 11 19:03:03 core2 kernel: [12816.536796] DR3: 0000000000000040 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Jan 11 19:03:03 core2 kernel: [12816.543971] Call Trace:
Jan 11 19:03:03 core2 kernel: [12816.546467]  remove_vma+0x2d/0x5f
Jan 11 19:03:03 core2 kernel: [12816.549828]  do_munmap+0x2d7/0x2fb
Jan 11 19:03:03 core2 kernel: [12816.553277]  vm_munmap+0x54/0x7a
Jan 11 19:03:03 core2 kernel: [12816.556553]  SyS_munmap+0x1f/0x24
Jan 11 19:03:03 core2 kernel: [12816.559917]  entry_SYSCALL_64_fastpath+0x17/0x70
Jan 11 19:03:03 core2 kernel: [12816.564580] RIP: 0033:0x7f19571af757
Jan 11 19:03:03 core2 kernel: [12816.568200] RSP: 002b:00007fff93ea1ce8 EFLAGS: 00000206
Jan 11 19:03:03 core2 kernel: [12816.568201] Code: 00 f0 49 29 44 24 60 49 8b 45 40 48 8b 93 c0 00 00 00 48 89 df 48 29 90 c8 00 00 00 e8 f0 43 00 00 8b 83 d0 00 00 00 85 c0 74 02 <0f> ff 4c 89 f7 e8 47 68 4b 00 f0 ff 4b 78 48 8d bd 90 02 00 00 
Jan 11 19:03:03 core2 kernel: [12816.592397] ---[ end trace d8df98463050a326 ]---