glibc/sysdeps/unix/sysv/linux/alpha/sysdep.h
H.J. Lu fb1cf10811 Add INLINE_SYSCALL_ERROR_RETURN_VALUE
For ia32 PIC, the first thing of many syscalls does is to call
__x86.get_pc_thunk.reg to load PC into reg in case there is an error,
which is required for setting errno.  In most cases, there are no
errors.  But we still call __x86.get_pc_thunk.reg.  This patch adds
INLINE_SYSCALL_ERROR_RETURN_VALUE so that i386 can optimize setting
errno by branching to the internal __syscall_error without PLT.

With i386 INLINE_SYSCALL_ERROR_RETURN_VALUE and i386 syscall inlining
optimization for GCC 5, for sysdeps/unix/sysv/linux/fchmodat.c with
-O2 -march=i686 -mtune=generic, GCC 5.2 now generates:

<fchmodat>:
   0:	push   %ebx
   1:	mov    0x14(%esp),%eax
   5:	mov    0x8(%esp),%ebx
   9:	mov    0xc(%esp),%ecx
   d:	mov    0x10(%esp),%edx
  11:	test   $0xfffffeff,%eax
  16:	jne    38 <fchmodat+0x38>
  18:	test   $0x1,%ah
  1b:	jne    48 <fchmodat+0x48>
  1d:	mov    $0x132,%eax
  22:	call   *%gs:0x10
  29:	cmp    $0xfffff000,%eax
  2e:	ja     58 <fchmodat+0x58>
  30:	pop    %ebx
  31:	ret
  32:	lea    0x0(%esi),%esi
  38:	pop    %ebx
  39:	mov    $0xffffffea,%eax
  3e:	jmp    3f <fchmodat+0x3f>	3f: R_386_PC32	__syscall_error
  43:	nop
  44:	lea    0x0(%esi,%eiz,1),%esi
  48:	pop    %ebx
  49:	mov    $0xffffffa1,%eax
  4e:	jmp    4f <fchmodat+0x4f>	4f: R_386_PC32	__syscall_error
  53:	nop
  54:	lea    0x0(%esi,%eiz,1),%esi
  58:	pop    %ebx
  59:	jmp    5a <fchmodat+0x5a>	5a: R_386_PC32	__syscall_error

instead of

<fchmodat>:
   0:	sub    $0x8,%esp
   3:	mov    0x18(%esp),%eax
   7:	mov    %ebx,(%esp)
   a:	call   b <fchmodat+0xb>	b: R_386_PC32	__x86.get_pc_thunk.bx
   f:	add    $0x2,%ebx	11: R_386_GOTPC	_GLOBAL_OFFSET_TABLE_
  15:	mov    %edi,0x4(%esp)
  19:	test   $0xfffffeff,%eax
  1e:	jne    70 <fchmodat+0x70>
  20:	test   $0x1,%ah
  23:	jne    88 <fchmodat+0x88>
  25:	mov    0x14(%esp),%edx
  29:	mov    0x10(%esp),%ecx
  2d:	mov    0xc(%esp),%edi
  31:	xchg   %ebx,%edi
  33:	mov    $0x132,%eax
  38:	call   *%gs:0x10
  3f:	xchg   %edi,%ebx
  41:	cmp    $0xfffff000,%eax
  46:	ja     58 <fchmodat+0x58>
  48:	mov    (%esp),%ebx
  4b:	mov    0x4(%esp),%edi
  4f:	add    $0x8,%esp
  52:	ret
  53:	nop
  54:	lea    0x0(%esi,%eiz,1),%esi
  58:	mov    0x0(%ebx),%edx	5a: R_386_TLS_GOTIE	__libc_errno
  5e:	neg    %eax
  60:	mov    %eax,%gs:(%edx)
  63:	mov    $0xffffffff,%eax
  68:	jmp    48 <fchmodat+0x48>
  6a:	lea    0x0(%esi),%esi
  70:	mov    0x0(%ebx),%eax	72: R_386_TLS_GOTIE	__libc_errno
  76:	movl   $0x16,%gs:(%eax)
  7d:	mov    $0xffffffff,%eax
  82:	jmp    48 <fchmodat+0x48>
  84:	lea    0x0(%esi,%eiz,1),%esi
  88:	mov    0x0(%ebx),%eax	8a: R_386_TLS_GOTIE	__libc_errno
  8e:	movl   $0x5f,%gs:(%eax)
  95:	mov    $0xffffffff,%eax
  9a:	jmp    48 <fchmodat+0x48>

	* sysdeps/unix/sysv/linux/sysdep.h: New file.
	* sysdeps/unix/sysv/linux/i386/sysdep.c: Likewise.
	* sysdeps/unix/sysv/linux/alpha/sysdep.h: Include
	<sysdeps/unix/sysv/linux/sysdep.h>.
	* sysdeps/unix/sysv/linux/arm/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/generic/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/hppa/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/ia64/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/m68k/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/sh/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/i386/Makefile [$(subdir) == csu]
	(sysdep-dl-routines): Add sysdep.
	[$(subdir) == nptl] (libpthread-routines): Likewise.
	[$(subdir) == rt] (librt-routines): Likewise.
	* sysdeps/unix/sysv/linux/i386/clone.S (__clone): Don't check
	PIC when branching to SYSCALL_ERROR_LABEL.
	* sysdeps/unix/sysv/linux/i386/sysdep.S: Removed.
	* sysdeps/unix/sysv/linux/i386/sysdep.h: Include
	<sysdeps/unix/sysv/linux/sysdep.h>.
	(SYSCALL_ERROR_LABEL): Changed to __syscall_error.
	(SYSCALL_ERROR_ERRNO): Removed.
	(SYSCALL_ERROR_HANDLER): Changed to empty.
	(SYSCALL_ERROR_HANDLER_TLS_STORE): Likewise.
	(__syscall_error): New prototype.
	[IS_IN (libc)] (INLINE_SYSCALL): New macro.
	(INLINE_SYSCALL_ERROR_RETURN_VALUE): Likewise.
2015-10-13 11:59:15 -07:00

97 lines
3.1 KiB
C

/* Copyright (C) 1992-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995.
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/>. */
#ifndef _LINUX_ALPHA_SYSDEP_H
#define _LINUX_ALPHA_SYSDEP_H 1
#ifdef __ASSEMBLER__
#include <asm/pal.h>
#include <alpha/regdef.h>
#endif
/* There is some commonality. */
#include <sysdeps/unix/sysv/linux/sysdep.h>
#include <sysdeps/unix/alpha/sysdep.h>
#include <tls.h>
/* For Linux we can use the system call table in the header file
/usr/include/asm/unistd.h
of the kernel. But these symbols do not follow the SYS_* syntax
so we have to redefine the `SYS_ify' macro here. */
#undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name
/* Define some aliases to make automatic syscall generation work
properly. The SYS_* variants are for the benefit of the files in
sysdeps/unix. */
#define __NR_getpid __NR_getxpid
#define __NR_getuid __NR_getxuid
#define __NR_getgid __NR_getxgid
#define SYS_getpid __NR_getxpid
#define SYS_getuid __NR_getxuid
#define SYS_getgid __NR_getxgid
/*
* Some syscalls no Linux program should know about:
*/
#define __NR_osf_sigprocmask 48
#define __NR_osf_shmat 209
#define __NR_osf_getsysinfo 256
#define __NR_osf_setsysinfo 257
/* Help old kernel headers where particular syscalls are not available. */
#ifndef __NR_semtimedop
# define __NR_semtimedop 423
#endif
/* This is a kludge to make syscalls.list find these under the names
pread and pwrite, since some kernel headers define those names
and some define the *64 names for the same system calls. */
#if !defined __NR_pread && defined __NR_pread64
# define __NR_pread __NR_pread64
#endif
#if !defined __NR_pwrite && defined __NR_pwrite64
# define __NR_pwrite __NR_pwrite64
#endif
/*
* In order to get the hidden arguments for rt_sigaction set up
* properly, we need to call the assembly version. This shouldn't
* happen except for inside sigaction.c, where we handle this
* specially. Catch other uses and error.
*/
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ \
extern char ChEcK[__NR_##name == __NR_rt_sigaction ? -1 : 1] \
__attribute__((unused)); \
INLINE_SYSCALL1(name, nr, args); \
})
#undef INTERNAL_SYSCALL
#define INTERNAL_SYSCALL(name, err_out, nr, args...) \
({ \
extern char ChEcK[__NR_##name == __NR_rt_sigaction ? -1 : 1] \
__attribute__((unused)); \
INTERNAL_SYSCALL1(name, err_out, nr, args); \
})
#endif /* _LINUX_ALPHA_SYSDEP_H */