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

[Christian Borntraeger]

Am 15.03.2011 10:50, schrieb Bruno Haible:
> Martin Schwidefsky wrote:
>> Even with the access-exception-fetch/store-indication facility you'll find
>> on the latest machine it is not possible to distinguish read from write
>> faults in all cases ... On older machines the TEID does not carry an
>> indication if the page translation exception has been for a read or a
>> write.
> 
> Oh well then. Thank you for having considered the question.
> 
> libsigsegv will now offer the page-aligned fault address approximation to
> userland, together with a C macro that warns the programmer that it is
> page-aligned.

Can you give some insights about the other use cases? Userspace page faults can
be handled just fine with the page address (I have done that for the s390x
port of valgrind). Would a "works most of the time but might return the page
address in 10% of the cases" be ok for your other use cases? (e.g. just
for pretty printing this is certainly ok)

Christian