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| author | Ulrich Drepper <drepper@redhat.com> | 2002-11-28 08:32:24 +0000 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2002-11-28 08:32:24 +0000 |
| commit | acd42b789378ab70046966872003347c0ef067db (patch) | |
| tree | b8c0b7bdc9c5c312581e8550b02e98aa077b58d8 /sysdeps | |
| parent | d08bef807b655576c07e5dffe8365d0713b218c4 (diff) | |
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Update.
2002-11-28 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/sysv/linux/x86_64/vfork.S: Don't trash the CPU's
branch prediction buffers by using unpaired call/ret.
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/vfork.S | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/vfork.S b/sysdeps/unix/sysv/linux/x86_64/vfork.S index 79f3260efc..3315df7253 100644 --- a/sysdeps/unix/sysv/linux/x86_64/vfork.S +++ b/sysdeps/unix/sysv/linux/x86_64/vfork.S @@ -29,22 +29,19 @@ ENTRY (__vfork) /* Pop the return PC value into RDI. We need a register that is preserved by the syscall and that we're allowed to destroy. */ - popq %rdi + popq %rdi /* Stuff the syscall number in RAX and enter into the kernel. */ movl $SYS_ify (vfork), %eax syscall - cmpl $-4095, %eax - jae .Lerror /* Branch forward if it failed. */ - - /* Jump to the return PC. */ - jmp *%rdi -.Lerror: /* Push back the return PC. */ pushq %rdi - jmp SYSCALL_ERROR_LABEL + cmpl $-4095, %eax + jae SYSCALL_ERROR_LABEL /* Branch forward if it failed. */ + + /* Normal return. */ .Lpseudo_end: ret |