On Wed, 2013-04-17 at 16:36 +0800, Wanlong Gao wrote: > Hi Tj, all, > > I can get kernel panic on my machine with kernel 3.9.0-rc7-4-gbb33db7 every time > after booting for several minutes. > > Here attached the panic picture and the config. > I'm sorry that the panic log is not completed. > > But fortunately, the panic was gone when I reverted the below commit from Tj, > > commit 3a366e614d0837d9fc23f78cdb1a1186ebc3387f > Author: Tejun Heo <tj@xxxxxxxxxx> > Date: Fri Jan 11 13:06:33 2013 -0800 > > block: add missing block_bio_complete() tracepoint > > I think this will be helpful for you to resolve this bug, and this may be urgent, > because it's already rc-7 now. Doing a objdump on the code I found this: ffffffff8123d479: 8b 77 48 mov 0x48(%rdi),%esi ffffffff8123d47c: 48 8d 7d c8 lea -0x38(%rbp),%rdi ffffffff8123d480: 48 8b 4d b8 mov -0x48(%rbp),%rcx ffffffff8123d484: ba 28 00 00 00 mov $0x28,%edx ffffffff8123d489: 45 89 e8 mov %r13d,%r8d ffffffff8123d48c: e8 1f d3 ea ff callq ffffffff810ea7b0 <trace_current_buffer_lock_reserve> ffffffff8123d491: 48 85 c0 test %rax,%rax ffffffff8123d494: 49 89 c6 mov %rax,%r14 ffffffff8123d497: 74 5a je ffffffff8123d4f3 <ftrace_raw_event_block_bio_complete+0xb3> ffffffff8123d499: 48 89 c7 mov %rax,%rdi ffffffff8123d49c: e8 5f 4f ea ff callq ffffffff810e2400 <ring_buffer_event_data> ffffffff8123d4a1: 48 8b 4b 10 mov 0x10(%rbx),%rcx ffffffff8123d4a5: 31 d2 xor %edx,%edx ffffffff8123d4a7: 48 85 c9 test %rcx,%rcx ffffffff8123d4aa: 74 02 je ffffffff8123d4ae <ftrace_raw_event_block_bio_complete+0x6e> ffffffff8123d4ac: 8b 11 mov (%rcx),%edx <<<---- BUG IS HERE ffffffff8123d4ae: 89 50 08 mov %edx,0x8(%rax) ffffffff8123d4b1: 48 8b 13 mov (%rbx),%rdx ffffffff8123d4b4: 48 8d 78 20 lea 0x20(%rax),%rdi ffffffff8123d4b8: 48 89 50 10 mov %rdx,0x10(%rax) ffffffff8123d4bc: 8b 53 30 mov 0x30(%rbx),%edx ffffffff8123d4bf: 44 89 78 1c mov %r15d,0x1c(%rax) ffffffff8123d4c3: c1 ea 09 shr $0x9,%edx ffffffff8123d4c6: 89 50 18 mov %edx,0x18(%rax) ffffffff8123d4c9: 8b 53 30 mov 0x30(%rbx),%edx ffffffff8123d4cc: 48 8b 73 20 mov 0x20(%rbx),%rsi According to the picture, that showed where in the code dump, it has the command that died: "<8b> 11 89 50 08". Just before that, rcx was tested for zero, and passed (wasn't zero). But it seems that it wasn't a real address space either. bio is allocated with kmalloc and not kzalloc, so it is possible that if bio->bi_bdev never got initialized and is just garbage. -- Steve > > > Thanks, > Wanlong Gao -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
