glibc/sysdeps/s390/s390-64/dl-trampoline.S

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2013-02-18 09:29:40 +00:00
/* PLT trampolines. s390x version.
Copyright (C) 2005-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
.text
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.
2016-03-31 15:37:16 +00:00
/* Create variant of _dl_runtime_resolve/profile for machines before z13.
No vector registers are saved/restored. */
#include <dl-trampoline.h>
#if defined HAVE_S390_VX_ASM_SUPPORT
/* Create variant of _dl_runtime_resolve/profile for z13 and newer.
The vector registers are saved/restored, too.*/
# define _dl_runtime_resolve _dl_runtime_resolve_vx
# define _dl_runtime_profile _dl_runtime_profile_vx
# define RESTORE_VRS
# include <dl-trampoline.h>
#endif