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.

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.

1 files changed, 24 insertions, 3 deletions

diff --git a/sysdeps/s390/s390-32/dl-machine.h b/sysdeps/s390/s390-32/dl-machine.h
index 14bde3b58d..ec0ae4a8a3 100644
--- a/sysdeps/s390/s390-32/dl-machine.h
+++ b/sysdeps/s390/s390-32/dl-machine.h
@@ -89,6 +89,11 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
 {
   extern void _dl_runtime_resolve (Elf32_Word);
   extern void _dl_runtime_profile (Elf32_Word);
+#if defined HAVE_S390_VX_ASM_SUPPORT
+  extern void _dl_runtime_resolve_vx (Elf32_Word);
+  extern void _dl_runtime_profile_vx (Elf32_Word);
+#endif
+
 
   if (l->l_info[DT_JMPREL] && lazy)
     {
@@ -116,7 +121,14 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
 	 end in this function.  */
       if (__glibc_unlikely (profile))
 	{
+#if defined HAVE_S390_VX_ASM_SUPPORT
+	  if (GLRO(dl_hwcap) & HWCAP_S390_VX)
+	    got[2] = (Elf32_Addr) &_dl_runtime_profile_vx;
+	  else
+	    got[2] = (Elf32_Addr) &_dl_runtime_profile;
+#else
 	  got[2] = (Elf32_Addr) &_dl_runtime_profile;
+#endif
 
 	  if (GLRO(dl_profile) != NULL
 	      && _dl_name_match_p (GLRO(dl_profile), l))
@@ -125,9 +137,18 @@ elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
 	    GL(dl_profile_map) = l;
 	}
       else
-	/* This function will get called to fix up the GOT entry indicated by
-	   the offset on the stack, and then jump to the resolved address.  */
-	got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+	{
+	  /* This function will get called to fix up the GOT entry indicated by
+	     the offset on the stack, and then jump to the resolved address.  */
+#if defined HAVE_S390_VX_ASM_SUPPORT
+	  if (GLRO(dl_hwcap) & HWCAP_S390_VX)
+	    got[2] = (Elf32_Addr) &_dl_runtime_resolve_vx;
+	  else
+	    got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+#else
+	  got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+#endif
+	}
     }
 
   return lazy;