[bug-libsigsegv] Re: sigsegv on s390 only giving start address of page in segv handler

[Christian Borntraeger]

Am 14.03.2011 12:56, schrieb Heiko Carstens:
> On Mon, Mar 14, 2011 at 11:50:37AM +0100, Bruno Haible wrote:
>> Heiko Carstens wrote:
>>> You would have to perform instruction decoding to figure out what was the
>>> exact failing address. Not really a thankful job.
>>
>> This is done in libsigsegv and Boehm GC for m68k, PowerPC, and Alpha processors
>> (see [1][2][3][4]) already. Why not also for s390 and s390x?
> 
> You can certainly do that. Even if some parts might be a bit ugly (thinking of
> e.g. the EXECUTE instruction).
> But most of that should have been done in the s390 Valgrind port anyway (cc'ing
> Christian).

I changed valgrind to accept faults with the lower 12bits set to zero. After all
thats what the hardware gives us. (the lower bits are used for something else).
I even think that this cannot be fully solved by looking at the instruction, 
e.g. you cannot tell which access triggered the fault for instruction with
two memory accesses (mvc) in the same page.

Christian