Comment 6 for bug 1875941

Revision history for this message
Colin Ian King (colin-king) wrote : Re: using perf as root locks up focal kernel

Appears to be a stack overflow:

Top of stack dump (attached) shows it's a stack overflow

[ 22.163398] BUG: stack guard page was hit at (____ptrval____) (stack is (____ptrval____)..(____ptrval____))
[ 22.165204] kernel stack overflow (double-fault): 0000 [#1] SMP PTI
[ 22.166729] CPU: 3 PID: 935 Comm: perf Not tainted 5.4.0-28-generic #32-Ubuntu
[ 22.168813] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1 04/01/2014
[ 22.171263] RIP: 0010:perf_trace_x86_exceptions+0x44/0xf0
[ 22.172769] Code: 83 ec 18 48 8b 5f 78 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 65 48 03 1d 00 0c f9 68 48 8b 87 80 00 00 00 48 85 c0 75 08 <48> 8b 03 48 85 c0 74 74 bf 24 00 00 00 48 8d 55 c4 48 8d 75 c8 e8
[ 22.176573] RSP: 0018:ffff978f00838020 EFLAGS: 00010046
[ 22.177569] RAX: 0000000000000000 RBX: ffffb78effdcab70 RCX: 0000000000000000
[ 22.178800] RDX: ffff978f008380b8 RSI: ffffb78effdcab70 RDI: ffffffff9863e620
[ 22.179993] RBP: ffff978f00838060 R08: 0000000000000000 R09: 0000000000000000
[ 22.181188] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9863e620
[ 22.182698] R13: 0000000000000000 R14: ffffb78effdcab70 R15: ffff978f008380b8
[ 22.184019] FS: 00007ff4818af780(0000) GS:ffff892b7db80000(0000) knlGS:0000000000000000
[ 22.185592] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 22.186732] CR2: ffff978f00837ff8 CR3: 000000007d5d8000 CR4: 00000000000006e0
[ 22.188100] Call Trace:
[ 22.188689] do_page_fault+0xca/0xe0
[ 22.189493] do_async_page_fault+0x39/0x70
[ 22.190388] async_page_fault+0x34/0x40
[ 22.191233] RIP: 0010:perf_trace_x86_exceptions+0x44/0xf0