[COMMITED 2.23] S390: Save and restore fprs/vrs while resolving symbols.

[Stefan Liebler]

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

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.

The same could occur for vector registers. Furthermore an ifunc-resolver
could also clobber the vector/floating point argument registers.
Thus this patch provides the further variants _dl_runtime_resolve_vx/
_dl_runtime_profile_vx, which are used if the kernel claims, that
we run on a machine with vector registers.

Furthermore, if _dl_runtime_profile calls _dl_call_pltexit,
the pointers to inregs-/outregs-structs were setup invalid.
Now they point to the correct location in the stack-frame.
Before branching back to the caller, the return values are now
restored instead of containing the return values of the
_dl_call_pltexit() call.
On s390-32, an endless loop occurs if _dl_call_pltexit() should be called.
Now, this code-path branches to this function instead of just after the
preceding basr-instruction.

(Picked from upstream commits 4603c51ef7989d7eb800cdd6f42aab206f891077
and d8a012c5c9e4bfc1b8db2bc6deacb85b44a2e1eb)

ChangeLog:

	* sysdeps/s390/s390-32/dl-trampoline.S: Include dl-trampoline.h twice
	to create a non-vector/vector version for _dl_runtime_resolve and
	_dl_runtime_profile. Move implementation to ...
	* sysdeps/s390/s390-32/dl-trampoline.h: ... here.
	(_dl_runtime_resolve) Save and restore fpr/vrs.
	(_dl_runtime_profile) Save and restore vrs and fix some issues
	if _dl_call_pltexit is called.
	* sysdeps/s390/s390-32/dl-machine.h (elf_machine_runtime_setup):
	Choose the correct resolver function if running on a machine with vx.
	* sysdeps/s390/s390-64/dl-trampoline.S: Include dl-trampoline.h twice
	to create a non-vector/vector version for _dl_runtime_resolve and
	_dl_runtime_profile. Move implementation to ...
	* sysdeps/s390/s390-64/dl-trampoline.h: ... here.
	(_dl_runtime_resolve) Save and restore fpr/vrs.
	(_dl_runtime_profile) Save and restore vrs and fix some issues
	* sysdeps/s390/s390-64/dl-machine.h: (elf_machine_runtime_setup):
	Choose the correct resolver function if running on a machine with vx.


[PATCH 2/2] S390: Extend structs La_s390_regs / La_s390_retval with
  vector-registers.

Starting with z13, vector registers can also occur as argument registers.
Thus the passed input/output register structs for
la_s390_[32|64]_gnu_plt[enter|exit] functions should reflect those new
registers. This patch extends these structs La_s390_regs and La_s390_retval
and adjusts _dl_runtime_profile() to handle those fields in case of
running on a z13 machine.

(picked form upstream commit 5cdd1989d1d2f135d02e66250f37ba8e767f9772)

ChangeLog:

	* sysdeps/s390/bits/link.h: (La_s390_vr) New typedef.
	(La_s390_32_regs): Append vector register lr_v24-lr_v31.
	(La_s390_64_regs): Likewise.
	(La_s390_32_retval): Append vector register lrv_v24.
	(La_s390_64_retval): Likeweise.
	* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_profile):
	Handle extended structs La_s390_32_regs and La_s390_32_retval.
	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_profile):
	Handle extended structs La_s390_64_regs and La_s390_64_retval.
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