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| author | Roland McGrath <roland@hack.frob.com> | 2014-05-14 09:44:39 -0700 |
|---|---|---|
| committer | Roland McGrath <roland@hack.frob.com> | 2014-05-14 09:44:39 -0700 |
| commit | e27871374eda477318f5a694d26cc02fd1cf019e (patch) | |
| tree | 9f3a2a0d27cc8700a4ee0d92940ab572ed3f39ef /sysdeps/unix/sysv/linux/i386 | |
| parent | 5675da1e845e4b651eb649639137310fd9b6b380 (diff) | |
| download | glibc-e27871374eda477318f5a694d26cc02fd1cf019e.tar.gz | |
x86: Consolidate NPTL/non versions of vfork
Diffstat (limited to 'sysdeps/unix/sysv/linux/i386')
| -rw-r--r-- | sysdeps/unix/sysv/linux/i386/vfork.S | 26 |
1 files changed, 20 insertions, 6 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) |