[egenix-users] SIGBUS from mx/BeeBase/mxBeeBase/btr.c on HP-UX,
Alpha, IRIX, Solaris
mal at egenix.com
Wed Jan 11 22:35:24 CET 2006
Albert Chin wrote:
> On Wed, Jan 11, 2006 at 08:27:17PM +0100, M.-A. Lemburg wrote:
>> Albert Chin wrote:
>>> On Wed, Jan 11, 2006 at 10:20:19AM -0600, Albert Chin wrote:
>>>> On Wed, Jan 11, 2006 at 05:00:25PM +0100, M.-A. Lemburg wrote:
>>>>> Are you compiling this on a 64-bit machine ?
>>>> They are all 64-bit CPUs but we are building 32-bit objects.
>>>>> FWIW: When trying the test.py script on an AMD64 machine it
>>>>> runs through fine.
>>>> Yeah, we tried on RHEL 3/AMD64 and 4/AMD64 with success.
>>>>> It's been ages since I last looked at the code, so it's hard
>>>>> to tell what the problem could be.
>>>> What I don't understand is why this doesn't work:
>>>> *mkey1 = 0;
>>>> *(mkey1 + 1) = 0;
>>>> *(mkey1 + 2) = 0;
>>>> *(mkey1 + 3) = 1;
>>>> val = *mkey2;
>>>> ^^^^^^^^^^^^^ SIGBUS
>>> I think it's a memory-alignment issue. Maybe unsigned longs on the
>>> problematic platforms need to be aligned to an even address, or
>>> something like that. If so, how to fix?
>> The above does hint at that yes.
>> Where exactly in test.py do you get the bus error ?
> #0 0xfee7a410 in bInsertKey (h=0x179088, key=0x188c14, rec=1)
> at mx/BeeBase/mxBeeBase/btr.c:1037
> 1037 rec(mkey) = rec;
> Passing this through the preprocessor:
> *(bRecAddr *)((char *)(mkey) + h->keySize) = rec;
> where bRecAddr is an 'unsigned long'.
Thanks, but I meant the line in test.py.
Still, could you check what the value of mkey is at the
time of the bus error ?
If this is not aligned properly for the ABI of the platform,
it might be causing the problem.
The btr.* code was not written by myself and there's a lot
of pointer voodoo going on in there, so this will be hard
to fix if it's indeed an alignment problem.
>> It's possible that on your platforms, a keysize of 10 (which
>> is used in test.py) is not allowed. Perhaps you could try 16
> Same error at the same place. I tried 32 but got:
> Building integer index without duplicates... done.
> Checking integer index without duplicates... done.
> Building string index without duplicates...
> Traceback (most recent call last):
> File "test.py", line 35, in ?
> idx = BeeStringIndex(testfile, keysize=32, dupkeys=0, filemode=2)
> ValueError: illegal sector size (too small or not 0 mod 4)
The message is a bit misleading. There's another case
where you get this error: if you choose a keysize that's
too large for the sector size.
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