Re: kernel 2.6.39 (user mode linux) crashes (2.6.38 works fine)
From: richard -rw- weinberger
Date: Fri May 20 2011 - 12:25:02 EST
2011/5/20 Toralf Förster <toralf.foerster@xxxxxx>:
>
> richard -rw- weinberger wrote at 09:56:02
>> 2011/5/20 Toralf Förster <toralf.foerster@xxxxxx>:
>> > ...
>> > Kernel panic - not syncing: Kernel mode fault at addr 0x0, ip 0x80a9f6b
>>
>> Looks like a NULL-pointer bug.
>> What code is at address 80a9f6b?
>> Use "objdump -d -S | less" to find it.
> if (unlikely(ret != 0))
> 80a9f3a: 85 c0 test %eax,%eax
> 80a9f3c: 75 ca jne 80a9f08 <futex_wake+0x18>
> goto out;
>
> hb = hash_futex(&key);
> 80a9f3e: 8d 45 e8 lea -0x18(%ebp),%eax
> 80a9f41: e8 aa f6 ff ff call 80a95f0 <hash_futex>
> 80a9f46: 89 c2 mov %eax,%edx
> spin_lock(&hb->lock);
> head = &hb->chain;
>
> plist_for_each_entry_safe(this, next, head, list) {
> 80a9f48: 8b 48 08 mov 0x8(%eax),%ecx
> 80a9f4b: 83 c2 08 add $0x8,%edx
> 80a9f4e: 8d 41 f4 lea -0xc(%ecx),%eax
> 80a9f51: 39 ca cmp %ecx,%edx
> 80a9f53: 8b 70 0c mov 0xc(%eax),%esi
> 80a9f56: 74 6a je 80a9fc2 <futex_wake+0xd2>
> 80a9f58: 89 d9 mov %ebx,%ecx
> 80a9f5a: 83 ee 0c sub $0xc,%esi
> 80a9f5d: 89 d3 mov %edx,%ebx
> 80a9f5f: 89 fa mov %edi,%edx
> 80a9f61: 89 cf mov %ecx,%edi
> 80a9f63: eb 12 jmp 80a9f77 <futex_wake+0x87>
> 80a9f65: 8d 76 00 lea 0x0(%esi),%esi
> 80a9f68: 8d 46 0c lea 0xc(%esi),%eax
> 80a9f6b: 8b 4e 0c mov 0xc(%esi),%ecx
Here in futex_wake() happens a NULL pointer dereference.
Steve, any ideas?
--
Thanks,
//richard
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