[2/2,roland/nptl] x86: Consolidate NPTL/non versions of vfork
diff mbox

Message ID 20140513222221.CAF4E2C39DB@topped-with-meat.com
State New
Headers show

Commit Message

Roland McGrath May 13, 2014, 10:22 p.m. UTC
This requires the 1/1 (ARM) patch be in place first, for the libpthread
vfork compatibility code that is machine-independent.

Tested x86_64-linux-gnu and i686-linux-gnu.

If nobody objects, I'll commit this after Joseph approves the ARM change.


Thanks,
Roland


	* sysdeps/unix/sysv/linux/i386/vfork.S: Include <tcb-offsets.h>.
	(__vfork): Incorporate save/restore of PID from nptl/vfork.S here.
	(__libc_vfork): New strong alias.
	* nptl/sysdeps/unix/sysv/linux/i386/vfork.S: File removed.
	* nptl/sysdeps/unix/sysv/linux/i386/pt-vfork.S: File removed.

	* sysdeps/unix/sysv/linux/x86_64/vfork.S: Include <tcb-offsets.h>.
	(__vfork): Incorporate save/restore of PID from nptl/vfork.S here.
	(__libc_vfork): New strong alias.
	* nptl/sysdeps/unix/sysv/linux/x86_64/vfork.S: File removed.
	* nptl/sysdeps/unix/sysv/linux/x86_64/pt-vfork.S: File removed.

Patch
diff mbox

--- a/nptl/sysdeps/unix/sysv/linux/i386/pt-vfork.S
+++ /dev/null
@@ -1,66 +0,0 @@ 
-/* Copyright (C) 1999-2014 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Andreas Schwab <schwab@gnu.org>.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#define _ERRNO_H	1
-#include <bits/errno.h>
-#include <kernel-features.h>
-#include <tcb-offsets.h>
-
-/* Save the PID value.  */
-#define SAVE_PID \
-	movl	%gs:PID, %edx; 						      \
-	movl	%edx, %eax;						      \
-	negl	%eax;							      \
-	movl	%eax, %gs:PID
-
-/* Restore the old PID value in the parent.  */
-#define RESTORE_PID \
-	testl	%eax, %eax;						      \
-	je	1f;							      \
-	movl	%edx, %gs:PID;						      \
-1:
-
-/* Clone the calling process, but without copying the whole address space.
-   The calling process is suspended until the new process exits or is
-   replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
-   and the process ID of the new process to the old process.  */
-
-ENTRY (__vfork)
-	/* Pop the return PC value into ECX.  */
-	popl	%ecx
-
-	SAVE_PID
-
-	/* Stuff the syscall number in EAX and enter into the kernel.  */
-	movl	$SYS_ify (vfork), %eax
-	int	$0x80
-
-	RESTORE_PID
-
-	/* 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	SYSCALL_ERROR_LABEL	/* Branch forward if it failed.  */
-	ret
-PSEUDO_END (__vfork)
-
-weak_alias (__vfork, vfork)
--- a/nptl/sysdeps/unix/sysv/linux/i386/vfork.S
+++ /dev/null
@@ -1,44 +0,0 @@ 
-/* Copyright (C) 1999-2014 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
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-/* We want an #include_next, but we are the main source file.
-   So, #include ourselves and in that incarnation we can use #include_next.  */
-#ifndef INCLUDED_SELF
-# define INCLUDED_SELF
-# include <vfork.S>
-#else
-
-# include <tcb-offsets.h>
-
-/* Save the PID value.  */
-# define SAVE_PID \
-	movl	%gs:PID, %edx; 						      \
-	movl	%edx, %eax;						      \
-	negl	%eax;							      \
-	jne	1f;							      \
-	movl	$0x80000000, %eax;					      \
-1:	movl	%eax, %gs:PID
-
-/* Restore the old PID value in the parent.  */
-# define RESTORE_PID \
-	testl	%eax, %eax;						      \
-	je	1f;							      \
-	movl	%edx, %gs:PID;						      \
-1:
-
-# include_next <vfork.S>
-#endif
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/pt-vfork.S
+++ /dev/null
@@ -1,32 +0,0 @@ 
-/* Copyright (C) 2004-2014 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
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <tcb-offsets.h>
-
-#define SAVE_PID \
-	movl	%fs:PID, %esi;						      \
-	movl	%esi, %edx;						      \
-	negl	%edx;							      \
-	movl	%edx, %fs:PID
-
-#define RESTORE_PID \
-	testq	%rax, %rax;						      \
-	je	1f;							      \
-	movl	%esi, %fs:PID;						      \
-1:
-
-#include <../../../../../../sysdeps/unix/sysv/linux/x86_64/vfork.S>
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/vfork.S
+++ /dev/null
@@ -1,42 +0,0 @@ 
-/* Copyright (C) 2004-2014 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
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-/* We want an #include_next, but we are the main source file.
-   So, #include ourselves and in that incarnation we can use #include_next.  */
-#ifndef INCLUDED_SELF
-# define INCLUDED_SELF
-# include <vfork.S>
-#else
-
-# include <tcb-offsets.h>
-
-# define SAVE_PID \
-	movl	%fs:PID, %esi;						      \
-	movl	$0x80000000, %ecx;					      \
-	movl	%esi, %edx;						      \
-	negl	%edx;							      \
-	cmove	%ecx, %edx;						      \
-	movl	%edx, %fs:PID
-
-# define RESTORE_PID \
-	testq	%rax, %rax;						      \
-	je	1f;							      \
-	movl	%esi, %fs:PID;						      \
-1:
-
-# include_next <vfork.S>
-#endif
--- 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)
--- 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)