diff options
| author | Florian Fainelli <florian@openwrt.org> | 2013-01-09 16:17:21 +0100 |
|---|---|---|
| committer | Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> | 2013-01-10 10:56:19 +0100 |
| commit | a8dc90eaaa5e6474beac828558d969b1aafee4af (patch) | |
| tree | ed22c27193dcc91697f6b8782da9a9abd08d42b1 /libc/sysdeps/linux/arm/swapcontext.S | |
| parent | df3a5fcc8d1c3402289375c92df705e978fab58d (diff) | |
libc: add {get,set,swap,make}context user context manipulation functions
Add the obsolescent SUSv3 family of user context manipulating functions
for arm, i386, mips, x86_64.
Signed-off-by: Timon ter Braak <timonterbraak@gmail.com>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Diffstat (limited to 'libc/sysdeps/linux/arm/swapcontext.S')
| -rw-r--r-- | libc/sysdeps/linux/arm/swapcontext.S | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/arm/swapcontext.S b/libc/sysdeps/linux/arm/swapcontext.S new file mode 100644 index 000000000..ba6e31c4d --- /dev/null +++ b/libc/sysdeps/linux/arm/swapcontext.S @@ -0,0 +1,63 @@ +/* Copyright (C) 2012 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> + +#include "ucontext_i.h" + + .syntax unified + .text + +/* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */ + +ENTRY(swapcontext) + + /* Have getcontext() do most of the work then fix up + LR afterwards. Save R3 to keep the stack aligned. */ + push {r0,r1,r3,r14} + cfi_adjust_cfa_offset (16) + cfi_rel_offset (r0,0) + cfi_rel_offset (r1,4) + cfi_rel_offset (r3,8) + cfi_rel_offset (r14,12) + + bl __getcontext + mov r4, r0 + + pop {r0,r1,r3,r14} + cfi_adjust_cfa_offset (-16) + cfi_restore (r0) + cfi_restore (r1) + cfi_restore (r3) + cfi_restore (r14) + + /* Exit if getcontext() failed. */ + cmp r4, #0 + itt ne + movne r0, r4 + RETINSTR(ne, r14) + + /* Fix up LR and the PC. */ + str r13,[r0, #MCONTEXT_ARM_SP] + str r14,[r0, #MCONTEXT_ARM_LR] + str r14,[r0, #MCONTEXT_ARM_PC] + + /* And swap using swapcontext(). */ + mov r0, r1 + b __setcontext + +END(swapcontext) |