On Tue, 11 Sep 2007 17:15:26 +0200
"Ulrich Windl" <[EMAIL PROTECTED]> wrote:
> On 11 Sep 2007 at 15:01, Eric Dumazet wrote:
>
> [...]
> > > Also note that the i586 (32-bit, non-SMP) kernel does not have that
> > > problem.
> > > Linux version 2.6.16.53-0.8-default ([EMAIL PROTECTED]) (gcc version
> > > 4.1.2 20070115
> > > (prerelease) (SUSE Linux)) #1 Fri Aug 31 13:07:27 UTC 2007
> >
> > Are you sure ?
>
> Not any more ;-)
>
> >
> > segfaulting are sysloged only on 64bits kernel.
> >
> > Maybe your slapd/hscan processes are doing bad things, that make them
> > core dump without notice on a 32bits kernel.
>
> I'm using the senddmail milter library that does the socket communication. So
> any
> bad things should be searched there.
>
> I tend to think that the same program when being compiled as a 32-bit
> executable
> does not cause these segfaults on a 64 bit kernel.
>
> I also tried to use ksymoops to get a disassembly of the corresponding kernel
> code, but the result did not look good to me.
>
> Is there a deeper reason why the kernel does not provide more info (like a
> call
> trace) on segfaults?
>
> Will an strace of the program (multi-threaded, unfortunately, just as slapd
> (most
> likely)) be helpful?
>
> When I tried it for slapd, the (rest of the) strace was:
> 9931 socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3
> 9931 connect(3, {sa_family=AF_INET, sin_port=htons(427),
> sin_addr=inet_addr("12
> 7.0.0.1")}, 16) = 0
> 9931 setsockopt(3, SOL_SOCKET, SO_RCVLOWAT, [18], 4) = 0
> 9931 setsockopt(3, SOL_SOCKET, SO_SNDLOWAT, [18], 4) = -1 ENOPROTOOPT
> (Protocol
> not available)
> 9931 mmap(NULL, 1434435584, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS,
> -1
> , 0) = 0x2aaaaae32000
> 9931 --- SIGSEGV (Segmentation fault) @ 0 (0) ---
Definitly a user mode problem, dereferencing a NULL pointer.
Try to attach gdb on this process instead of stracing it, then a "bt" command
should
tell you some usefull things.
Strange thing here is that this program wants a huge block of memory
(1434435584 bytes),
so maybe some file is corrupted, maybe you should check database integrity
first.
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