aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--sysdeps/unix/sysv/linux/i386/vfork.S29
1 files changed, 20 insertions, 9 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/vfork.S b/sysdeps/unix/sysv/linux/i386/vfork.S
index 6f7477e89d..59657e49c0 100644
--- a/sysdeps/unix/sysv/linux/i386/vfork.S
+++ b/sysdeps/unix/sysv/linux/i386/vfork.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Schwab <schwab@gnu.org>.
@@ -20,6 +20,7 @@
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
+#include <kernel-features.h>
/* Clone the calling process, but without copying the whole address space.
The calling process is suspended until the new process exits or is
@@ -36,22 +37,32 @@ ENTRY (__vfork)
/* Stuff the syscall number in EAX and enter into the kernel. */
movl $SYS_ify (vfork), %eax
int $0x80
+
+ /* Jump to the return PC. Don't jump directly since this
+ disturbs the branch target cache. Instead push the return
+ address back on the stack. */
+ pushl %ecx
+
cmpl $-4095, %eax
- jae .Lerror /* Branch forward if it failed. */
+ /* Branch forward if it failed. */
+# ifdef __ASSUME_VFORK_SYSCALL
+ jae SYSCALL_ERROR_LABEL
+.Lpseudo_end:
+# else
+ jae .Lerror
+# endif
- /* Jump to the return PC. */
- jmp *%ecx
+ ret
+# ifndef __ASSUME_VFORK_SYSCALL
.Lerror:
- /* Push back the return PC. */
- pushl %ecx
-
/* Check if vfork syscall is known at all. */
cmpl $-ENOSYS, %eax
jne SYSCALL_ERROR_LABEL
-
+# endif
#endif
+#ifndef __ASSUME_VFORK_SYSCALL
/* If we don't have vfork, fork is close enough. */
movl $SYS_ify (fork), %eax
@@ -60,7 +71,7 @@ ENTRY (__vfork)
jae SYSCALL_ERROR_LABEL
.Lpseudo_end:
ret
-
+#endif
PSEUDO_END (__vfork)
weak_alias (__vfork, vfork)