Patchwork [v3] mips: Fix store/load gp registers to/from ucontext_t

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Submitter Gordana Cmiljanovic
Date June 13, 2017, 11:51 a.m.
Message ID <655B60FB9854204DB1D72C498A631BB6013C71B585@BADAG02.ba.imgtec.org>
Download mbox | patch
Permalink /patch/20986/
State New
Headers show

Comments

Gordana Cmiljanovic - June 13, 2017, 11:51 a.m.
Modified according to comments:
 - sysdep_routine not needed
 - formatting according to GNU Coding Standards

Regards,
Gordana
Joseph Myers - June 13, 2017, 9:36 p.m.
Thanks, committed.

Patch

General purpose registers in mcontext_t structure
are 8 bytes long for both MIPS32/MIPS64.

get/set/make/swap context implementations for MIPS O32
incorrectly assume that general purpose registers
in this structure are 4 bytes long.

This patch is fixing that.

Tested for MIPS O32 LE and BE.
Compared objdump of modified functions for mips n32 and mips n64.

2017-06-13  Gordana Cmiljanovic  <gordana.cmiljanovic@imgtec.com>

	[BZ #21548]
	* sysdeps/unix/sysv/linux/mips/getcontext.S: Define MCONTEXT_SZGREG as
	8 and use it when copying general purpose registers.
	* sysdeps/unix/sysv/linux/mips/makecontext.S: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/Makefile: Include new test for
	mips o32.
	* sysdeps/unix/sysv/linux/mips/mips32/bug-getcontext-mips-gp.c: Added
	new test for mips o32.
	* sysdeps/unix/sysv/linux/mips/setcontext.S: Define MCONTEXT_SZGREG as
	8 and use it when copying general purpose registers.
	* sysdeps/unix/sysv/linux/mips/swapcontext.S: Likewise.
diff --git a/sysdeps/unix/sysv/linux/mips/getcontext.S b/sysdeps/unix/sysv/linux/mips/getcontext.S
index 64de2eb..aa6f45e 100644
--- a/sysdeps/unix/sysv/linux/mips/getcontext.S
+++ b/sysdeps/unix/sysv/linux/mips/getcontext.S
@@ -38,6 +38,12 @@  MASK = 0x10000000
 #endif
 FRAMESZ = ((LOCALSZ * SZREG) + ALSZ) & ALMASK
 GPOFF = FRAMESZ - (1 * SZREG)
+MCONTEXT_GREGSZ = 8
+#if _MIPS_SIM == _ABIO32 && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+MCONTEXT_GREGOFF = 4
+#else
+MCONTEXT_GREGOFF = 0
+#endif
 
 NESTED (__getcontext, FRAMESZ, ra)
 	.mask	MASK, 0
@@ -74,23 +80,24 @@  NESTED (__getcontext, FRAMESZ, ra)
 
 	/* Store a magic flag.	*/
 	li	v1, 1
-	REG_S	v1, (0 * SZREG + MCONTEXT_GREGS)(a0)	/* zero */
-
-	REG_S	s0, (16 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s1, (17 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s2, (18 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s3, (19 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s4, (20 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s5, (21 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s6, (22 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s7, (23 * SZREG + MCONTEXT_GREGS)(a0)
+	/* zero */
+	REG_S	v1, (MCONTEXT_GREGOFF + 0 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+
+	REG_S	s0, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s1, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s2, (MCONTEXT_GREGOFF + 18 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s3, (MCONTEXT_GREGOFF + 19 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s4, (MCONTEXT_GREGOFF + 20 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s5, (MCONTEXT_GREGOFF + 21 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s6, (MCONTEXT_GREGOFF + 22 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s7, (MCONTEXT_GREGOFF + 23 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 #if ! defined (__PIC__) || _MIPS_SIM != _ABIO32
-	REG_S	_GP, (28 * SZREG + MCONTEXT_GREGS)(a0)
+	REG_S	_GP, (MCONTEXT_GREGOFF + 28 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 #endif
-	REG_S	_SP, (29 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	fp, (30 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	ra, (31 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	ra, MCONTEXT_PC(a0)
+	REG_S	_SP, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	fp, (MCONTEXT_GREGOFF + 30 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	ra, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	ra, (MCONTEXT_GREGOFF + MCONTEXT_PC)(a0)
 
 #ifdef __mips_hard_float
 # if _MIPS_SIM == _ABI64
diff --git a/sysdeps/unix/sysv/linux/mips/makecontext.S b/sysdeps/unix/sysv/linux/mips/makecontext.S
index 5c3af04..6bbdc26 100644
--- a/sysdeps/unix/sysv/linux/mips/makecontext.S
+++ b/sysdeps/unix/sysv/linux/mips/makecontext.S
@@ -53,6 +53,12 @@  NARGREGS = 8
 A3OFF = FRAMESZ + (3 * SZREG)				/* caller-allocated */
 NARGREGS = 4
 #endif
+MCONTEXT_GREGSZ = 8
+#if _MIPS_SIM == _ABIO32 && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+MCONTEXT_GREGOFF = 4
+#else
+MCONTEXT_GREGOFF = 0
+#endif
 
 NESTED (__makecontext, FRAMESZ, ra)
 	.mask	MASK, -(ARGSZ * SZREG)
@@ -89,7 +95,8 @@  NESTED (__makecontext, FRAMESZ, ra)
 
 	/* Store a magic flag.  */
 	li	v1, 1
-	REG_S	v1, (0 * SZREG + MCONTEXT_GREGS)(a0)	/* zero */
+	/* zero */
+	REG_S	v1, (MCONTEXT_GREGOFF + 0 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 
 	/* Set up the stack.  */
 	PTR_L	t0, STACK_SP(a0)
@@ -100,14 +107,14 @@  NESTED (__makecontext, FRAMESZ, ra)
 	blez	a2, 2f					/* no arguments */
 
 	/* Store register arguments.  */
-	PTR_ADDIU t2, a0, MCONTEXT_GREGS + 4 * SZREG
+	PTR_ADDIU t2, a0, MCONTEXT_GREGS + 4 * MCONTEXT_GREGSZ + MCONTEXT_GREGOFF
 	move	t3, zero
 0:
 	addiu	t3, 1
 	REG_L	v1, (t1)
 	PTR_ADDIU t1, SZREG
 	REG_S	v1, (t2)
-	PTR_ADDIU t2, SZREG
+	PTR_ADDIU t2, MCONTEXT_GREGSZ
 	bgeu	t3, a2, 2f				/* all done */
 	bltu	t3, NARGREGS, 0b			/* next */
 
@@ -138,13 +145,17 @@  NESTED (__makecontext, FRAMESZ, ra)
 #else
 	PTR_LA	t9, 99f
 #endif
-	REG_S	t0, (29 * SZREG + MCONTEXT_GREGS)(a0)	/* sp */
-	REG_S	v1, (16 * SZREG + MCONTEXT_GREGS)(a0)	/* s0 */
+	/* sp */
+	REG_S	t0, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	/* s0 */
+	REG_S	v1, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 #ifdef __PIC__
-	REG_S	gp, (17 * SZREG + MCONTEXT_GREGS)(a0)	/* s1 */
+	/* s1 */
+	REG_S	gp, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 #endif
-	REG_S	t9, (31 * SZREG + MCONTEXT_GREGS)(a0)	/* ra */
-	REG_S	a1, MCONTEXT_PC(a0)
+	/* ra */
+	REG_S	t9, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	a1, (MCONTEXT_GREGOFF + MCONTEXT_PC)(a0)
 
 #ifdef __PIC__
 	RESTORE_GP64_STACK
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/Makefile b/sysdeps/unix/sysv/linux/mips/mips32/Makefile
index 9439d29..33b4615 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/Makefile
+++ b/sysdeps/unix/sysv/linux/mips/mips32/Makefile
@@ -2,3 +2,7 @@  ifeq ($(subdir),conform)
 # For bugs 17786 and 21278.
 conformtest-xfail-conds += mips-o32-linux
 endif
+
+ifeq ($(subdir),stdlib)
+tests += bug-getcontext-mips-gp
+endif
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/bug-getcontext-mips-gp.c b/sysdeps/unix/sysv/linux/mips/mips32/bug-getcontext-mips-gp.c
new file mode 100644
index 0000000..9327f17
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/mips32/bug-getcontext-mips-gp.c
@@ -0,0 +1,63 @@ 
+/* Tests register values retreived by getcontext() for mips o32.
+   Copyright (C) 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 <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ucontext.h>
+
+
+#if !defined __mips__ || _MIPS_SIM != _ABIO32
+# error "MIPS O32 specific test."
+#endif
+
+#define SP_REG 29
+
+static int
+do_test (void)
+{
+  ucontext_t ctx;
+  memset (&ctx, 0, sizeof (ctx));
+  int status = getcontext (&ctx);
+  if (status)
+    {
+      printf ("\ngetcontext() failed, errno: %d.\n", errno);
+      return 1;
+    }
+
+  if (ctx.uc_mcontext.gregs[SP_REG] == 0
+      || ctx.uc_mcontext.gregs[SP_REG] > 0xffffffff)
+    {
+      printf ("\nError getcontext(): invalid $sp = 0x%llx.\n",
+              ctx.uc_mcontext.gregs[SP_REG]);
+      return 1;
+    }
+
+  if (ctx.uc_mcontext.pc == 0
+      || ctx.uc_mcontext.pc > 0xffffffff)
+    {
+      printf ("\nError getcontext(): invalid ctx.uc_mcontext.pc = 0x%llx.\n",
+              ctx.uc_mcontext.pc);
+      return 1;
+    }
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/mips/setcontext.S b/sysdeps/unix/sysv/linux/mips/setcontext.S
index 4e363d9..4f52b8d 100644
--- a/sysdeps/unix/sysv/linux/mips/setcontext.S
+++ b/sysdeps/unix/sysv/linux/mips/setcontext.S
@@ -47,6 +47,12 @@  A0OFF = FRAMESZ - (1 * SZREG)				/* callee-allocated */
 #else
 A0OFF = FRAMESZ + (0 * SZREG)				/* caller-allocated */
 #endif
+MCONTEXT_GREGSZ = 8
+#if _MIPS_SIM == _ABIO32 && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+MCONTEXT_GREGOFF = 4
+#else
+MCONTEXT_GREGOFF = 0
+#endif
 
 NESTED (__setcontext, FRAMESZ, ra)
 	.mask	MASK, -(ARGSZ * SZREG)
@@ -73,7 +79,8 @@  NESTED (__setcontext, FRAMESZ, ra)
 
 	/* Check for the magic flag.  */
 	li	v0, 1
-	REG_L	v1, (0 * SZREG + MCONTEXT_GREGS)(a0)	/* zero */
+	/* zero */
+	REG_L	v1, (MCONTEXT_GREGOFF + 0 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 	bne	v0, v1, 98f
 
 	REG_S	a0, A0OFF(sp)
@@ -117,32 +124,32 @@  NESTED (__setcontext, FRAMESZ, ra)
 
 	/* Note the contents of argument registers will be random
 	   unless makecontext() has been called.  */
-	REG_L	a0, (4 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a1, (5 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a2, (6 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a3, (7 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	a0, (MCONTEXT_GREGOFF + 4 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a1, (MCONTEXT_GREGOFF + 5 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a2, (MCONTEXT_GREGOFF + 6 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a3, (MCONTEXT_GREGOFF + 7 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #if _MIPS_SIM != _ABIO32
-	REG_L	a4, (8 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a5, (9 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a6, (10 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a7, (11 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	a4, (MCONTEXT_GREGOFF + 8 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a5, (MCONTEXT_GREGOFF + 9 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a6, (MCONTEXT_GREGOFF + 10 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a7, (MCONTEXT_GREGOFF + 11 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #endif
 
-	REG_L	s0, (16 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s1, (17 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s2, (18 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s3, (19 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s4, (20 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s5, (21 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s6, (22 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s7, (23 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	s0, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s1, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s2, (MCONTEXT_GREGOFF + 18 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s3, (MCONTEXT_GREGOFF + 19 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s4, (MCONTEXT_GREGOFF + 20 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s5, (MCONTEXT_GREGOFF + 21 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s6, (MCONTEXT_GREGOFF + 22 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s7, (MCONTEXT_GREGOFF + 23 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #if ! defined (__PIC__) || _MIPS_SIM != _ABIO32
-	REG_L	gp, (28 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	gp, (MCONTEXT_GREGOFF + 28 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #endif
-	REG_L	sp, (29 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	fp, (30 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	ra, (31 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	t9, MCONTEXT_PC(v0)
+	REG_L	sp, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	fp, (MCONTEXT_GREGOFF + 30 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	ra, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	t9, (MCONTEXT_GREGOFF + MCONTEXT_PC)(v0)
 
 	move	v0, zero
 	jr	t9
diff --git a/sysdeps/unix/sysv/linux/mips/swapcontext.S b/sysdeps/unix/sysv/linux/mips/swapcontext.S
index fde6e5e..ff63b3d 100644
--- a/sysdeps/unix/sysv/linux/mips/swapcontext.S
+++ b/sysdeps/unix/sysv/linux/mips/swapcontext.S
@@ -47,6 +47,12 @@  A1OFF = FRAMESZ - (1 * SZREG)				/* callee-allocated */
 #else
 A1OFF = FRAMESZ + (1 * SZREG)				/* caller-allocated */
 #endif
+MCONTEXT_GREGSZ = 8
+#if _MIPS_SIM == _ABIO32 && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+MCONTEXT_GREGOFF = 4
+#else
+MCONTEXT_GREGOFF = 0
+#endif
 
 NESTED (__swapcontext, FRAMESZ, ra)
 	.mask	MASK, -(ARGSZ * SZREG)
@@ -83,23 +89,24 @@  NESTED (__swapcontext, FRAMESZ, ra)
 
 	/* Store a magic flag.	*/
 	li	v1, 1
-	REG_S	v1, (0 * SZREG + MCONTEXT_GREGS)(a0)	/* zero */
-
-	REG_S	s0, (16 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s1, (17 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s2, (18 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s3, (19 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s4, (20 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s5, (21 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s6, (22 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	s7, (23 * SZREG + MCONTEXT_GREGS)(a0)
+	/* zero */
+	REG_S	v1, (MCONTEXT_GREGOFF + 0 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+
+	REG_S	s0, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s1, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s2, (MCONTEXT_GREGOFF + 18 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s3, (MCONTEXT_GREGOFF + 19 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s4, (MCONTEXT_GREGOFF + 20 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s5, (MCONTEXT_GREGOFF + 21 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s6, (MCONTEXT_GREGOFF + 22 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	s7, (MCONTEXT_GREGOFF + 23 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 #if ! defined (__PIC__) || _MIPS_SIM != _ABIO32
-	REG_S	_GP, (28 * SZREG + MCONTEXT_GREGS)(a0)
+	REG_S	_GP, (MCONTEXT_GREGOFF + 28 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
 #endif
-	REG_S	_SP, (29 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	fp, (30 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	ra, (31 * SZREG + MCONTEXT_GREGS)(a0)
-	REG_S	ra, MCONTEXT_PC(a0)
+	REG_S	_SP, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	fp, (MCONTEXT_GREGOFF + 30 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	ra, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
+	REG_S	ra, (MCONTEXT_GREGOFF + MCONTEXT_PC)(a0)
 
 #ifdef __mips_hard_float
 # if _MIPS_SIM == _ABI64
@@ -167,32 +174,32 @@  NESTED (__swapcontext, FRAMESZ, ra)
 
 	/* Note the contents of argument registers will be random
 	   unless makecontext() has been called.  */
-	REG_L	a0, (4 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a1, (5 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a2, (6 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a3, (7 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	a0, (MCONTEXT_GREGOFF + 4 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a1, (MCONTEXT_GREGOFF + 5 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a2, (MCONTEXT_GREGOFF + 6 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a3, (MCONTEXT_GREGOFF + 7 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #if _MIPS_SIM != _ABIO32
-	REG_L	a4, (8 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a5, (9 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a6, (10 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	a7, (11 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	a4, (MCONTEXT_GREGOFF + 8 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a5, (MCONTEXT_GREGOFF + 9 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a6, (MCONTEXT_GREGOFF + 10 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	a7, (MCONTEXT_GREGOFF + 11 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #endif
 
-	REG_L	s0, (16 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s1, (17 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s2, (18 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s3, (19 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s4, (20 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s5, (21 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s6, (22 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	s7, (23 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	s0, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s1, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s2, (MCONTEXT_GREGOFF + 18 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s3, (MCONTEXT_GREGOFF + 19 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s4, (MCONTEXT_GREGOFF + 20 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s5, (MCONTEXT_GREGOFF + 21 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s6, (MCONTEXT_GREGOFF + 22 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	s7, (MCONTEXT_GREGOFF + 23 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #if ! defined (__PIC__) || _MIPS_SIM != _ABIO32
-	REG_L	gp, (28 * SZREG + MCONTEXT_GREGS)(v0)
+	REG_L	gp, (MCONTEXT_GREGOFF + 28 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 #endif
-	REG_L	sp, (29 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	fp, (30 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	ra, (31 * SZREG + MCONTEXT_GREGS)(v0)
-	REG_L	t9, MCONTEXT_PC(v0)
+	REG_L	sp, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	fp, (MCONTEXT_GREGOFF + 30 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	ra, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
+	REG_L	t9, (MCONTEXT_GREGOFF + MCONTEXT_PC)(v0)
 
 	move	v0, zero
 	jr	t9