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authorFlorian Fainelli <florian@openwrt.org>2013-01-09 16:17:21 +0100
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2013-01-10 10:56:19 +0100
commita8dc90eaaa5e6474beac828558d969b1aafee4af (patch)
treeed22c27193dcc91697f6b8782da9a9abd08d42b1 /libc/sysdeps/linux/mips/makecontext.S
parentdf3a5fcc8d1c3402289375c92df705e978fab58d (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/mips/makecontext.S')
-rw-r--r--libc/sysdeps/linux/mips/makecontext.S188
1 files changed, 188 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/mips/makecontext.S b/libc/sysdeps/linux/mips/makecontext.S
new file mode 100644
index 000000000..6427339a6
--- /dev/null
+++ b/libc/sysdeps/linux/mips/makecontext.S
@@ -0,0 +1,188 @@
+/* Modify saved context.
+ Copyright (C) 2009 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Maciej W. Rozycki <macro@codesourcery.com>.
+
+ 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 <sys/asm.h>
+#include <sys/fpregdef.h>
+#include <sys/regdef.h>
+
+#include "ucontext_i.h"
+
+/* int makecontext (ucontext_t *ucp, (void *func) (), int argc, ...) */
+
+ .text
+LOCALSZ = 0
+ARGSZ = 0
+MASK = 0x00000000
+#ifdef __PIC__
+LOCALSZ = 1 /* save gp */
+#endif
+#if _MIPS_SIM != _ABIO32
+ARGSZ = 5 /* save a3-a7 */
+# ifdef __PIC__
+MASK = 0x10000000
+# endif
+#endif
+FRAMESZ = (((ARGSZ + LOCALSZ) * SZREG) + ALSZ) & ALMASK
+GPOFF = FRAMESZ - ((ARGSZ + 1) * SZREG)
+#if _MIPS_SIM != _ABIO32
+A3OFF = FRAMESZ - (5 * SZREG) /* callee-allocated */
+A4OFF = FRAMESZ - (4 * SZREG)
+A5OFF = FRAMESZ - (3 * SZREG)
+A6OFF = FRAMESZ - (2 * SZREG)
+A7OFF = FRAMESZ - (1 * SZREG)
+NARGREGS = 8
+#else
+A3OFF = FRAMESZ + (3 * SZREG) /* caller-allocated */
+NARGREGS = 4
+#endif
+
+NESTED (__makecontext, FRAMESZ, ra)
+ .mask MASK, -(ARGSZ * SZREG)
+ .fmask 0x00000000, 0
+
+98:
+#ifdef __PIC__
+ SETUP_GP
+#endif
+
+ PTR_ADDIU sp, -FRAMESZ
+
+#ifdef __PIC__
+ SETUP_GP64 (GPOFF, __makecontext)
+ SAVE_GP (GPOFF)
+#endif
+
+#ifdef PROF
+ .set noat
+ move AT, ra
+ jal _mcount
+ .set at
+#endif
+
+ /* Store args to be passed. */
+ REG_S a3, A3OFF(sp)
+#if _MIPS_SIM != _ABIO32
+ REG_S a4, A4OFF(sp)
+ REG_S a5, A5OFF(sp)
+ REG_S a6, A6OFF(sp)
+ REG_S a7, A7OFF(sp)
+#endif
+
+ /* Store a magic flag. */
+ li v1, 1
+ REG_S v1, (0 * SZREG + MCONTEXT_GREGS)(a0) /* zero */
+
+ /* Set up the stack. */
+ PTR_L t0, STACK_SP(a0)
+ PTR_L t2, STACK_SIZE(a0)
+ PTR_ADDIU t1, sp, A3OFF
+ PTR_ADDU t0, t2
+ and t0, ALMASK
+ blez a2, 2f /* no arguments */
+
+ /* Store register arguments. */
+ PTR_ADDIU t2, a0, MCONTEXT_GREGS + 4 * SZREG
+ move t3, zero
+0:
+ addiu t3, 1
+ REG_L v1, (t1)
+ PTR_ADDIU t1, SZREG
+ REG_S v1, (t2)
+ PTR_ADDIU t2, SZREG
+ bgeu t3, a2, 2f /* all done */
+ bltu t3, NARGREGS, 0b /* next */
+
+ /* Make room for stack arguments. */
+ PTR_SUBU t2, a2, t3
+ PTR_SLL t2, 3
+ PTR_SUBU t0, t2
+ and t0, ALMASK
+
+ /* Store stack arguments. */
+ move t2, t0
+1:
+ addiu t3, 1
+ REG_L v1, (t1)
+ PTR_ADDIU t1, SZREG
+ REG_S v1, (t2)
+ PTR_ADDIU t2, SZREG
+ bltu t3, a2, 1b /* next */
+
+2:
+#if _MIPS_SIM == _ABIO32
+ /* Make room for a0-a3 storage. */
+ PTR_ADDIU t0, -(NARGSAVE * SZREG)
+#endif
+ PTR_L v1, UCONTEXT_LINK(a0)
+#ifdef __PIC__
+ PTR_ADDIU t9, 99f - 98b
+#else
+ PTR_LA t9, 99f
+#endif
+ REG_S t0, (29 * SZREG + MCONTEXT_GREGS)(a0) /* sp */
+ REG_S v1, (16 * SZREG + MCONTEXT_GREGS)(a0) /* s0 */
+#ifdef __PIC__
+ REG_S gp, (17 * SZREG + MCONTEXT_GREGS)(a0) /* s1 */
+#endif
+ REG_S t9, (31 * SZREG + MCONTEXT_GREGS)(a0) /* ra */
+ REG_S a1, MCONTEXT_PC(a0)
+
+#ifdef __PIC__
+ RESTORE_GP64
+ PTR_ADDIU sp, FRAMESZ
+#endif
+ jr ra
+
+99:
+#ifdef __PIC__
+ move gp, s1
+#endif
+ move a0, zero
+ beqz s0, 0f
+
+ /* setcontext (ucp) */
+ move a0, s0
+#ifdef __PIC__
+ PTR_LA t9, JUMPTARGET (__setcontext)
+ jalr t9
+# if _MIPS_SIM == _ABIO32
+ move gp, s1
+# endif
+#else
+ jal JUMPTARGET (__setcontext)
+#endif
+ move a0, v0
+
+0:
+ /* exit (a0) */
+#ifdef __PIC__
+ PTR_LA t9, HIDDEN_JUMPTARGET (exit)
+ jalr t9
+#else
+ jal HIDDEN_JUMPTARGET (exit)
+#endif
+
+ /* You don't exist, you won't feel anything. */
+1:
+ lb zero, (zero)
+ b 1b
+PSEUDO_END (__makecontext)
+
+weak_alias (__makecontext, makecontext)