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[PATCH] Tweak sparc32 longjmp to not store a dummy frame pointeronto the stack.
- From: David Miller <davem at davemloft dot net>
- To: libc-alpha at sourceware dot org
- Date: Tue, 21 Feb 2012 00:37:16 -0500 (EST)
- Subject: [PATCH] Tweak sparc32 longjmp to not store a dummy frame pointeronto the stack.
I had this sitting around for several months, just never got around
to giving it a good testing. Committed to master.
* sysdeps/sparc/sparc32/__longjmp.S: Unwind in the 'thread' path
using a normal save/restore sequence, rather than allocating a
dummy stack frame just to store a frame pointer and restore.
* sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S: Likewise.
---
ChangeLog | 7 +++++++
sysdeps/sparc/sparc32/__longjmp.S | 10 ++++------
.../sysv/linux/sparc/sparc32/____longjmp_chk.S | 10 ++++------
3 files changed, 15 insertions(+), 12 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index d0352f6..73e51dc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-02-20 David S. Miller <davem@davemloft.net>
+
+ * sysdeps/sparc/sparc32/__longjmp.S: Unwind in the 'thread' path
+ using a normal save/restore sequence, rather than allocating a
+ dummy stack frame just to store a frame pointer and restore.
+ * sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S: Likewise.
+
2012-02-21 Joseph Myers <joseph@codesourcery.com>
* manual/install.texi: Fix stray word in line-wrapped comment.
diff --git a/sysdeps/sparc/sparc32/__longjmp.S b/sysdeps/sparc/sparc32/__longjmp.S
index 7e05c95..e4caf7b 100644
--- a/sysdeps/sparc/sparc32/__longjmp.S
+++ b/sysdeps/sparc/sparc32/__longjmp.S
@@ -21,7 +21,6 @@
#include <jmpbuf-offsets.h>
#define ENV(base,reg) [%base + (reg * 4)]
#define ST_FLUSH_WINDOWS 3
-#define RW_FP [%fp + 0x48]
ENTRY(__longjmp)
/* Store our arguments in global registers so we can still
@@ -54,6 +53,7 @@ LOC(loop):
ld ENV(g1,JB_SP), %o0 /* Delay slot: extract target SP. */
LOC(thread):
+ save %sp, -96, %sp
/*
* Do a "flush register windows trap". The trap handler in the
* kernel writes all the register windows to their stack slots, and
@@ -66,15 +66,13 @@ LOC(thread):
#ifdef PTR_DEMANGLE
ld ENV(g1,JB_PC), %g5 /* Set return PC. */
ld ENV(g1,JB_SP), %g1 /* Set saved SP on restore below. */
- PTR_DEMANGLE2 (%o7, %g5, %g4)
+ PTR_DEMANGLE2 (%i7, %g5, %g4)
PTR_DEMANGLE2 (%fp, %g1, %g4)
#else
- ld ENV(g1,JB_PC), %o7 /* Set return PC. */
+ ld ENV(g1,JB_PC), %i7 /* Set return PC. */
ld ENV(g1,JB_SP), %fp /* Set saved SP on restore below. */
#endif
- sub %fp, 64, %sp /* Allocate a register frame. */
- st %g3, RW_FP /* Set saved FP on restore below. */
- retl
+ jmp %i7 + 8
restore %g2, 0, %o0 /* Restore values from above register frame. */
LOC(found):
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S b/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S
index dfbf761..7246e89 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S
@@ -20,7 +20,6 @@
#define ENV(base,reg) [%base + (reg * 4)]
#define ST_FLUSH_WINDOWS 3
-#define RW_FP [%fp + 0x48]
.section .rodata.str1.1,"aMS",@progbits,1
.type longjmp_msg,@object
@@ -97,6 +96,7 @@ ENTRY (____longjmp_chk)
mov 1, %g2 /* Delay slot only hit if zero: VAL = 1. */
0:
+ save %sp, -96, %sp
/*
* Do a "flush register windows trap". The trap handler in the
* kernel writes all the register windows to their stack slots, and
@@ -108,14 +108,12 @@ ENTRY (____longjmp_chk)
ta ST_FLUSH_WINDOWS
#ifdef PTR_DEMANGLE
ld ENV(g1,JB_PC), %g1 /* Set return PC. */
- PTR_DEMANGLE2 (%o7, %g1, %g4)
+ PTR_DEMANGLE2 (%i7, %g1, %g4)
#else
- ld ENV(g1,JB_PC), %o7 /* Set return PC. */
+ ld ENV(g1,JB_PC), %i7 /* Set return PC. */
#endif
mov %g5, %fp
- sub %fp, 64, %sp /* Allocate a register frame. */
- st %g3, RW_FP /* Set saved FP on restore below. */
- retl
+ jmp %i7 + 8
restore %g2, 0, %o0 /* Restore values from above register frame. */
END(____longjmp_chk)
--
1.7.6.401.g6a319