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. -- 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 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
