* [PATCH] Move __fortify_fail call out of line in x86 ____longjmp_chk
@ 2011-04-08 12:25 Andreas Schwab
2011-04-08 12:48 ` Ulrich Drepper
0 siblings, 1 reply; 4+ messages in thread
From: Andreas Schwab @ 2011-04-08 12:25 UTC (permalink / raw)
To: libc-hacker
2011-04-08 Andreas Schwab <schwab@redhat.com>
* sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Move call to
__fortify_fail out of line.
* sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Likewise.
---
sysdeps/unix/sysv/linux/i386/____longjmp_chk.S | 45 +++++++++-----------
sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S | 48 ++++++++-------------
2 files changed, 39 insertions(+), 54 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
index a07e6c8..4dc828e 100644
--- a/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001,2004,2005,2006,2009 Free Software Foundation, Inc.
+/* Copyright (C) 2001,2004,2005,2006,2009,2011 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
@@ -20,26 +20,6 @@
#include <jmpbuf-offsets.h>
#include <asm-syntax.h>
-
- .section .rodata.str1.1,"aMS",@progbits,1
- .type longjmp_msg,@object
-longjmp_msg:
- .string "longjmp causes uninitialized stack frame"
- .size longjmp_msg, .-longjmp_msg
-
-
-#ifdef PIC
-# define CALL_FAIL movl %ebx, %ecx; \
- cfi_register(%ebx,%ecx); \
- LOAD_PIC_REG (bx); \
- leal longjmp_msg@GOTOFF(%ebx), %eax; \
- call __GI___fortify_fail@PLT
-#else
-# define CALL_FAIL movl $longjmp_msg, %eax; \
- call __fortify_fail
-#endif
-
-
.text
ENTRY (____longjmp_chk)
movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */
@@ -71,11 +51,10 @@ ENTRY (____longjmp_chk)
addl 8(%esp), %eax
subl %edi, %eax
cmpl 8(%esp), %eax
- jae .Lok2
-
-.Lfail: CALL_FAIL
+ jb .Lfail
.Lok2: addl $12, %esp
+ cfi_remember_state
cfi_adjust_cfa_offset(-12)
movl 4(%esp), %ecx
@@ -103,4 +82,22 @@ ENTRY (____longjmp_chk)
/* Jump to saved PC. */
jmp *%edx
+
+ .section .rodata.str1.1,"aMS",@progbits,1
+.Llongjmp_msg:
+ .string "longjmp causes uninitialized stack frame"
+
+ .text
+.Lfail: cfi_restore_state
+
+#ifdef PIC
+ movl %ebx, %ecx
+ cfi_register (%ebx, %ecx)
+ LOAD_PIC_REG (bx)
+ leal .Llongjmp_msg@GOTOFF(%ebx), %eax
+#else
+ movl $.Llongjmp_msg, %eax
+#endif
+ call HIDDEN_JUMPTARGET(__fortify_fail)
+
END (____longjmp_chk)
diff --git a/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S b/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
index 3881082..63ff282 100644
--- a/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
@@ -20,33 +20,6 @@
#include <jmpbuf-offsets.h>
#include <asm-syntax.h>
- .section .rodata.str1.1,"aMS",@progbits,1
- .type longjmp_msg,@object
-longjmp_msg:
- .string "longjmp causes uninitialized stack frame"
- .size longjmp_msg, .-longjmp_msg
-
-
-//#define __longjmp ____longjmp_chk
-
-#ifdef PIC
-# define CALL_FAIL subq $8, %rsp; \
- cfi_remember_state; \
- cfi_def_cfa_offset(16); \
- leaq longjmp_msg(%rip), %rdi; \
- call __GI___fortify_fail; \
- nop; \
- cfi_restore_state
-#else
-# define CALL_FAIL subq $8, %rsp; \
- cfi_remember_state; \
- cfi_def_cfa_offset(16); \
- movq $longjmp_msg, %rdi; \
- call __fortify_fail; \
- nop; \
- cfi_restore_state
-#endif
-
/* Jump to the position specified by ENV, causing the
setjmp call there to return VAL, or 1 if VAL is 0.
void __longjmp (__jmp_buf env, int val). */
@@ -85,11 +58,10 @@ ENTRY(____longjmp_chk)
addq -8(%rsp), %rax
subq %r8, %rax
cmpq -8(%rsp), %rax
- jae .Lok2
-
-.Lfail: CALL_FAIL
+ jb .Lfail
.Lok2: movq %r10, %rdi
+ cfi_remember_state
cfi_restore (%rdi)
movl %ebx, %esi
cfi_restore (%rsi)
@@ -114,4 +86,20 @@ ENTRY(____longjmp_chk)
movq %r8,%rsp
movq %r9,%rbp
jmpq *%rdx
+
+ .section .rodata.str1.1,"aMS",@progbits,1
+.Llongjmp_msg:
+ .string "longjmp causes uninitialized stack frame"
+
+ .text
+.Lfail: cfi_restore_state
+ subq $8, %rsp
+ cfi_def_cfa_offset (16)
+#ifdef PIC
+ leaq .Llongjmp_msg(%rip), %rdi
+#else
+ movq $.Llongjmp_msg, %rdi
+#endif
+ call HIDDEN_JUMPTARGET(__fortify_fail)
+
END (____longjmp_chk)
--
1.7.4.2
--
Andreas Schwab, schwab@redhat.com
GPG Key fingerprint = D4E8 DBE3 3813 BB5D FA84 5EC7 45C6 250E 6F00 984E
"And now for something completely different."
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2011-04-08 12:25 [PATCH] Move __fortify_fail call out of line in x86 ____longjmp_chk Andreas Schwab
2011-04-08 12:48 ` Ulrich Drepper
2011-04-08 12:57 ` Andreas Schwab
2011-04-08 13:04 ` Ulrich Drepper
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