On 03/11/2014 04:30 PM, Andrew Morton wrote:
All I can think is that find_vma() went and returned a vma from a
different mm, which would be odd. How about I toss this in there?
--- a/mm/vmacache.c~a
+++ a/mm/vmacache.c
@@ -72,8 +72,10 @@ struct vm_area_struct *vmacache_find(str
for (i = 0; i < VMACACHE_SIZE; i++) {
struct vm_area_struct *vma = current->vmacache[i];
- if (vma && vma->vm_start <= addr && vma->vm_end > addr)
+ if (vma && vma->vm_start <= addr && vma->vm_end > addr) {
+ BUG_ON(vma->vm_mm != mm);
return vma;
+ }
}
return NULL;
Bingo! With the above patch:
[ 243.565794] kernel BUG at mm/vmacache.c:76!
[ 243.566720] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 243.568048] Dumping ftrace buffer:
[ 243.568740] (ftrace buffer empty)
[ 243.569481] Modules linked in:
[ 243.570203] CPU: 10 PID: 10073 Comm: trinity-c332 Tainted: G W 3.14.0-rc5-next-20140307-sasha-00010-g1f812cb-dirty #143
[ 243.571505] task: ffff8800b8698000 ti: ffff8800b8694000 task.ti: ffff8800b8694000
[ 243.571505] RIP: 0010:[<ffffffff81299396>] [<ffffffff81299396>] vmacache_find+0x86/0xb0
[ 243.571505] RSP: 0000:ffff8800b8695da8 EFLAGS: 00010287
[ 243.571505] RAX: ffff88042890e400 RBX: 0000000002d6cb18 RCX: 0000000000000002
[ 243.571505] RDX: 0000000000000002 RSI: 0000000002d6cb18 RDI: ffff8800b86a8000
[ 243.571505] RBP: ffff8800b8695da8 R08: ffff8800b8698000 R09: 0000000000000000
[ 243.571505] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8800b86a8000
[ 243.571505] R13: 00000000000014f1 R14: ffff8800b86a80a8 R15: ffff8800b86a8000
[ 243.582665] FS: 00007f74df081700(0000) GS:ffff880b2b800000(0000) knlGS:0000000000000000
[ 243.582665] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 243.582665] CR2: 0000000002d6cb18 CR3: 00000000b8682000 CR4: 00000000000006a0
[ 243.582665] Stack:
[ 243.582665] ffff8800b8695dd8 ffffffff812a7620 ffffffff844abd82 0000000002d6cb18
[ 243.582665] 0000000002d6cb18 00000000000000a9 ffff8800b8695ef8 ffffffff844abdd6
[ 243.582665] ffff8800b8698000 ffff8800b8698000 0000000000000002 ffff8800b8698000
[ 243.582665] Call Trace:
[ 243.582665] [<ffffffff812a7620>] find_vma+0x20/0x90
[ 243.582665] [<ffffffff844abd82>] ? __do_page_fault+0x302/0x5d0
[ 243.582665] [<ffffffff844abdd6>] __do_page_fault+0x356/0x5d0
[ 243.582665] [<ffffffff8118ab46>] ? vtime_account_user+0x96/0xb0
[ 243.582665] [<ffffffff844ac4d2>] ? preempt_count_sub+0xe2/0x120
[ 243.582665] [<ffffffff81269567>] ? context_tracking_user_exit+0x187/0x1d0
[ 243.582665] [<ffffffff844ac115>] do_page_fault+0x45/0x70
[ 243.582665] [<ffffffff844ab3c6>] do_async_page_fault+0x36/0x100
[ 243.582665] [<ffffffff844a7f58>] async_page_fault+0x28/0x30
[ 243.582665] Code: 00 eb 44 66 90 31 d2 49 89 c0 48 63 ca 49 8b 84 c8 b8 07 00 00 48 85 c0 74 23 48 39 30 77 1e 48 3b 70 08 73 18 48 3b 78 40 74 1c <0f> 0b 0f 1f 84 00 00 00 00 00 eb fe 66 0f 1f 44 00 00 ff c2 83
[ 243.582665] RIP [<ffffffff81299396>] vmacache_find+0x86/0xb0
[ 243.582665] RSP <ffff8800b8695da8>
Thanks,
Sasha
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