aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv
diff options
context:
space:
mode:
authorRoland McGrath <roland@hack.frob.com>2014-05-14 09:44:39 -0700
committerRoland McGrath <roland@hack.frob.com>2014-05-14 09:44:39 -0700
commite27871374eda477318f5a694d26cc02fd1cf019e (patch)
tree9f3a2a0d27cc8700a4ee0d92940ab572ed3f39ef /sysdeps/unix/sysv
parent5675da1e845e4b651eb649639137310fd9b6b380 (diff)
downloadglibc-e27871374eda477318f5a694d26cc02fd1cf019e.tar
glibc-e27871374eda477318f5a694d26cc02fd1cf019e.tar.gz
glibc-e27871374eda477318f5a694d26cc02fd1cf019e.tar.bz2
glibc-e27871374eda477318f5a694d26cc02fd1cf019e.zip
x86: Consolidate NPTL/non versions of vfork
Diffstat (limited to 'sysdeps/unix/sysv')
-rw-r--r--sysdeps/unix/sysv/linux/i386/vfork.S26
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/vfork.S25
2 files changed, 39 insertions, 12 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/vfork.S b/sysdeps/unix/sysv/linux/i386/vfork.S
index d6e0ecfcad..2c3d4a3ee7 100644
--- a/sysdeps/unix/sysv/linux/i386/vfork.S
+++ b/sysdeps/unix/sysv/linux/i386/vfork.S
@@ -20,6 +20,8 @@
#define _ERRNO_H 1
#include <bits/errno.h>
#include <kernel-features.h>
+#include <tcb-offsets.h>
+
/* Clone the calling process, but without copying the whole address space.
The calling process is suspended until the new process exits or is
@@ -33,9 +35,16 @@ ENTRY (__vfork)
cfi_adjust_cfa_offset (-4)
cfi_register (%eip, %ecx)
-#ifdef SAVE_PID
- SAVE_PID
-#endif
+ /* Save the TCB-cached PID away in %edx, and then negate the TCB
+ field. But if it's zero, set it to 0x80000000 instead. See
+ raise.c for the logic that relies on this value. */
+ movl %gs:PID, %edx
+ movl %edx, %eax
+ negl %eax
+ jne 1f
+ movl $0x80000000, %eax
+1: movl %eax, %gs:PID
+
/* Stuff the syscall number in EAX and enter into the kernel. */
movl $SYS_ify (vfork), %eax
@@ -47,9 +56,13 @@ ENTRY (__vfork)
pushl %ecx
cfi_adjust_cfa_offset (4)
-#ifdef RESTORE_PID
- RESTORE_PID
-#endif
+ /* Restore the original value of the TCB cache of the PID, if we're
+ the parent. But in the child (syscall return value equals zero),
+ leave things as they are. */
+ testl %eax, %eax
+ je 1f
+ movl %edx, %gs:PID
+1:
cmpl $-4095, %eax
/* Branch forward if it failed. */
@@ -61,3 +74,4 @@ PSEUDO_END (__vfork)
libc_hidden_def (__vfork)
weak_alias (__vfork, vfork)
+strong_alias (__vfork, __libc_vfork)
diff --git a/sysdeps/unix/sysv/linux/x86_64/vfork.S b/sysdeps/unix/sysv/linux/x86_64/vfork.S
index d3b450a48d..15ea281899 100644
--- a/sysdeps/unix/sysv/linux/x86_64/vfork.S
+++ b/sysdeps/unix/sysv/linux/x86_64/vfork.S
@@ -18,6 +18,8 @@
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
+#include <tcb-offsets.h>
+
/* Clone the calling process, but without copying the whole address space.
The calling process is suspended until the new process exits or is
@@ -32,9 +34,15 @@ ENTRY (__vfork)
cfi_adjust_cfa_offset(-8)
cfi_register(%rip, %rdi)
-#ifdef SAVE_PID
- SAVE_PID
-#endif
+ /* Save the TCB-cached PID away in %esi, and then negate the TCB
+ field. But if it's zero, set it to 0x80000000 instead. See
+ raise.c for the logic that relies on this value. */
+ movl %fs:PID, %esi
+ movl $0x80000000, %ecx
+ movl %esi, %edx
+ negl %edx
+ cmove %ecx, %edx
+ movl %edx, %fs:PID
/* Stuff the syscall number in RAX and enter into the kernel. */
movl $SYS_ify (vfork), %eax
@@ -44,9 +52,13 @@ ENTRY (__vfork)
pushq %rdi
cfi_adjust_cfa_offset(8)
-#ifdef RESTORE_PID
- RESTORE_PID
-#endif
+ /* Restore the original value of the TCB cache of the PID, if we're
+ the parent. But in the child (syscall return value equals zero),
+ leave things as they are. */
+ testq %rax, %rax
+ je 1f
+ movl %esi, %fs:PID
+1:
cmpl $-4095, %eax
jae SYSCALL_ERROR_LABEL /* Branch forward if it failed. */
@@ -58,3 +70,4 @@ PSEUDO_END (__vfork)
libc_hidden_def (__vfork)
weak_alias (__vfork, vfork)
+strong_alias (__vfork, __libc_vfork)