On Wed, Apr 17 2013, Steven Rostedt wrote: > 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 <t...@kernel.org> > > 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.
A bio is always fully initialized, regardless of which internal allocator it came from. If people are doing private kmallocs, then they better be using bio_init() as well. Wanlong, would it be possible to get a full dmesg on boot see I can see what drivers and file systems are in use? Anything special about your setup. Will get this reverted for 3.9 final, so we have some time to investigate. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
