On Thu, Mar 03, 2011 at 04:26:11PM +0100, Jean-Philippe Menil wrote: > Le 03/03/2011 15:47, Michael S. Tsirkin a écrit : > >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? > > > Hi, > > I'm not sure to activate the right thing. > Is that what you want? > > CONFIG_SLAB=y > CONFIG_SLABINFO=y > CONFIG_DEBUG_SLAB=y > CONFIG_DEBUG_SLAB_LEAK=y > > Regards. Yes, maybe disable SLAB_LEAK. > -- > Jean-Philippe Menil - Pôle réseau Service IRTS > DSI Université de Nantes > jean-philippe.menil@xxxxxxxxxxxxxx > Tel : 02.53.48.49.27 - Fax : 02.53.48.49.09 -- 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
