On Tue, Mar 01, 2011 at 03:39:12PM +0100, Jean-Philippe Menil wrote: > so this time the bug is: > > [17882.612303] BUG: unable to handle kernel paging request at > 0000000000002458 > [17882.612342] IP: [<ffffffffa03898a0>] kvm_set_irq+0x30/0x140 [kvm] > > markup_oops give me this: > > root@ayrshire:~# cat bug-0103.txt | perl markup_oops.pl -m > /lib/modules/2.6.37.2-dsiun-110105+/kernel/arch/x86/kvm/kvm.ko > /boot/vmlinuz-2.6.37.2-dsiun-110105+ > vmaoffset = 18446744072102621184 ffffffffa0389871: 48 89 e5 mov > %rsp,%rbp > ffffffffa0389874: 41 57 push %r15 > ffffffffa0389876: 41 89 cf mov %ecx,%r15d | %r15 > => 1 %ecx = 1 > ffffffffa0389879: 41 56 push %r14 | %r14 > => ffffffffa038aad0 > ffffffffa038987b: 41 55 push %r13 > ffffffffa038987d: 49 89 fd mov %rdi,%r13 | %edi > = 0 %r13 => 0 > ffffffffa0389880: 41 54 push %r12 | %r12 => 0 > ffffffffa0389882: 53 push %rbx > ffffffffa0389883: 89 d3 mov %edx,%ebx | %ebx => 1a > ffffffffa0389885: 48 81 ec a8 00 00 00 sub $0xa8,%rsp > ffffffffa038988c: 8b 15 00 00 00 00 mov 0x0(%rip),%edx > # ffffffffa0389892 <kvm_set_irq+0x22> > ffffffffa0389892: 89 b5 3c ff ff ff mov %esi,-0xc4(%rbp) | > %esi = 0 > ffffffffa0389898: 85 d2 test %edx,%edx | %edx => 0 > ffffffffa038989a: 0f 85 d5 00 00 00 jne ffffffffa0389975 > <kvm_set_irq+0x105> > *ffffffffa03898a0: 49 8b 85 58 24 00 00 mov 0x2458(%r13),%rax | > %eax = 0 %r13 = 0 <--- faulting instruction > ffffffffa03898a7: 3b 98 28 01 00 00 cmp 0x128(%rax),%ebx > ffffffffa03898ad: 73 61 jae ffffffffa0389910 > <kvm_set_irq+0xa0> > ffffffffa03898af: 89 db mov %ebx,%ebx > ffffffffa03898b1: 48 8b 84 d8 30 01 00 mov 0x130(%rax,%rbx,8),%rax > ffffffffa03898b8: 00 > ffffffffa03898b9: 48 85 c0 test %rax,%rax > ffffffffa03898bc: 74 52 je ffffffffa0389910 > <kvm_set_irq+0xa0> > ffffffffa03898be: 48 8d 95 40 ff ff ff lea -0xc0(%rbp),%rdx > ffffffffa03898c5: 31 db xor %ebx,%ebx > ffffffffa03898c7: 48 8b 08 mov (%rax),%rcx > ffffffffa03898ca: 83 c3 01 add $0x1,%ebx > ffffffffa03898cd: 0f 18 09 prefetcht0 (%rcx) > ffffffffa03898d0: 48 8b 48 e0 mov -0x20(%rax),%rcx > ffffffffa03898d4: 48 89 0a mov %rcx,(%rdx) > ffffffffa03898d7: 48 8b 48 e8 mov -0x18(%rax),%rcx > ffffffffa03898db: 48 89 4a 08 mov %rcx,0x8(%rdx) > ffffffffa03898df: 48 8b 48 f0 mov -0x10(%rax),%rcx > ffffffffa03898e3: 48 89 4a 10 mov %rcx,0x10(%rdx) > ffffffffa03898e7: 48 8b 48 f8 mov -0x8(%rax),%rcx > ffffffffa03898eb: 48 89 4a 18 mov %rcx,0x18(%rdx) > > wich correspond to offset 68a0 (from objdump): > > kvm_set_irq(): > /usr/src/GIT/linux-2.6-stable/arch/x86/kvm/../../../virt/kvm/irq_comm.c:161 > 68a0: 49 8b 85 58 24 00 00 mov 0x2458(%r13),%rax > /usr/src/GIT/linux-2.6-stable/arch/x86/kvm/../../../virt/kvm/irq_comm.c:162 > 68a7: 3b 98 28 01 00 00 cmp 0x128(%rax),%ebx > > root@ayrshire:~# addr2line -e > /lib/modules/2.6.37.2-dsiun-110105+/kernel/arch/x86/kvm/kvm.ko > 0x68a0 > /usr/src/GIT/linux-2.6-stable/arch/x86/kvm/../../../virt/kvm/irq_comm.c:161 > > So here kvm->irq_routing is null. > > How can it be? > > Regards. Not null, this seems to be invalid. I suspect use after free where the kvm pointer is pointing at some random memory. Use after free? Could you please try enabling a slab debugger, recompile and rerun the test? -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
