[PATCH 1/2] S390: Save and restore fprs/vrs while resolving symbols.

[Stefan Liebler]

On 04/06/2016 01:56 PM, Florian Weimer wrote:
> On 03/22/2016 12:25 PM, Stefan Liebler wrote:
>> On s390, no fpr/vrs were saved while resolving a symbol
>> via _dl_runtime_resolve/_dl_runtime_profile.
>>
>> According to the abi, the fpr-arguments are defined as call clobbered.
>> In leaf-functions, gcc 4.9 and newer can use fprs for saving/restoring gprs
>> instead of saving them to the stack.
>> If gcc do this in one of the resolver-functions, then the floating point
>> arguments of a library-function are invalid for the first library-function-call.
>> Thus, this patch saves/restores the fprs around the resolving code.
>
> I think this bug is end-user-visible because it is due to an incorrect
> implementation of the original ABI.  Can you file a bug to track this
> and add the number to the ChangeLog retroactively?
>
> (The other patch, “Extend structs La_s390_regs / La_s390_retval” seems
> different in this regard; I believe applications would have to check
> that glibc supports the new ABI before they use the new features.)
>
> Thanks,
> Florian
>
Okay. Done. Here is the bugzilla 19916:
https://sourceware.org/bugzilla/show_bug.cgi?id=19916