glibc/sysdeps/unix/sysv/linux/microblaze/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

314 lines
15 KiB
C

/* Copyright (C) 2000-2015 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/>. */
#ifndef _LINUX_MICROBLAZE_SYSDEP_H
#define _LINUX_MICROBLAZE_SYSDEP_H 1
#include <sysdeps/unix/sysdep.h>
#include <sysdeps/unix/sysv/linux/sysdep.h>
#include <sysdeps/microblaze/sysdep.h>
/* Defines RTLD_PRIVATE_ERRNO. */
#include <dl-sysdep.h>
/* In order to get __set_errno() definition in INLINE_SYSCALL. */
#ifndef __ASSEMBLER__
# include <errno.h>
#endif
/* 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
#ifdef __ASSEMBLER__
/* In microblaze ABI function call arguments are passed in registers
r5...r10. The return value is stored in r3 (or r3:r4 regiters pair).
Linux syscall uses the same convention with the addition that the
syscall number is passed in r12. To enter the kernel "brki r14,8"
instruction is used.
None of the abovementioned registers are presumed across function call
or syscall.
*/
/* Linux uses a negative return value to indicate syscall errors, unlike
most Unices, which use the condition codes' carry flag.
Since version 2.1 the return value of a system call might be negative
even if the call succeeded. E.g., the `lseek' system call might return
a large offset. Therefore we must not anymore test for < 0, but test
for a real error by making sure the value in %d0 is a real error
number. Linus said he will make sure the no syscall returns a value
in -1 .. -4095 as a valid result so we can savely test with -4095. */
/* We don't want the label for the error handler to be visible in the symbol
table when we define it here. */
# ifdef PIC
# define SYSCALL_ERROR_LABEL 0f
# else
# define SYSCALL_ERROR_LABEL __syscall_error
# endif
# undef PSEUDO
# define PSEUDO(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args); \
addik r12,r0,-4095; \
cmpu r12,r12,r3; \
bgei r12,SYSCALL_ERROR_LABEL;
# undef PSEUDO_END
# define PSEUDO_END(name) \
SYSCALL_ERROR_HANDLER; \
END (name)
# undef PSEUDO_NOERRNO
# define PSEUDO_NOERRNO(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args);
# undef PSEUDO_END_NOERRNO
# define PSEUDO_END_NOERRNO(name) \
END (name)
/* The function has to return the error code. */
# undef PSEUDO_ERRVAL
# define PSEUDO_ERRVAL(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args); \
# undef PSEUDO_END_ERRVAL
# define PSEUDO_END_ERRVAL(name) \
END (name)
# define ret_NOERRNO \
rtsd r15,8; addk r0,r0,r0;
# define ret_ERRVAL \
rtsd r15,8; rsubk r3,r3,r0;
# ifdef PIC
# define SYSCALL_ERROR_LABEL_DCL 0
# if RTLD_PRIVATE_ERRNO
# define SYSCALL_ERROR_HANDLER \
SYSCALL_ERROR_LABEL_DCL: \
mfs r12,rpc; \
addik r12,r12,_GLOBAL_OFFSET_TABLE_+8; \
lwi r12,r12,rtld_errno@GOT; \
rsubk r3,r3,r0; \
swi r3,r12,0; \
rtsd r15,8; \
addik r3,r0,-1;
# else /* !RTLD_PRIVATE_ERRNO. */
/* Store (-r3) into errno through the GOT. */
# if defined _LIBC_REENTRANT
# define SYSCALL_ERROR_HANDLER \
SYSCALL_ERROR_LABEL_DCL: \
addik r1,r1,-16; \
swi r15,r1,0; \
swi r20,r1,8; \
rsubk r3,r3,r0; \
swi r3,r1,12; \
mfs r20,rpc; \
addik r20,r20,_GLOBAL_OFFSET_TABLE_+8; \
brlid r15,__errno_location@PLT; \
nop; \
lwi r4,r1,12; \
swi r4,r3,0; \
lwi r20,r1,8; \
lwi r15,r1,0; \
addik r1,r1,16; \
rtsd r15,8; \
addik r3,r0,-1;
# else /* !_LIBC_REENTRANT. */
# define SYSCALL_ERROR_HANDLER \
SYSCALL_ERROR_LABEL_DCL: \
mfs r12,rpc; \
addik r12,r12,_GLOBAL_OFFSET_TABLE_+8; \
lwi r12,r12,errno@GOT; \
rsubk r3,r3,r0; \
swi r3,r12,0; \
rtsd r15,8; \
addik r3,r0,-1;
# endif /* _LIBC_REENTRANT. */
# endif /* RTLD_PRIVATE_ERRNO. */
# else
# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
# endif /* PIC. */
# define DO_CALL(syscall_name, args) \
addik r12,r0,SYS_ify (syscall_name); \
brki r14,8; \
addk r0,r0,r0;
#else /* not __ASSEMBLER__ */
/* Define a macro which expands into the inline wrapper code for a system
call. */
# undef INLINE_SYSCALL
# define INLINE_SYSCALL(name, nr, args...) \
({ INTERNAL_SYSCALL_DECL(err); \
unsigned long resultvar = INTERNAL_SYSCALL(name, err, nr, args); \
if (INTERNAL_SYSCALL_ERROR_P (resultvar, err)) \
{ \
__set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, err)); \
resultvar = (unsigned long) -1; \
} \
(long) resultvar; \
})
# undef INTERNAL_SYSCALL_DECL
# define INTERNAL_SYSCALL_DECL(err) do { } while (0)
/* Define a macro which expands inline into the wrapper code for a system
call. This use is for internal calls that do not need to handle errors
normally. It will never touch errno. This returns just what the kernel
gave back. */
# undef INTERNAL_SYSCALL
# define INTERNAL_SYSCALL(name, err, nr, args...) \
inline_syscall##nr(SYS_ify(name), args)
# undef INTERNAL_SYSCALL_NCS
# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
inline_syscall##nr(name, args)
# undef INTERNAL_SYSCALL_ERROR_P
# define INTERNAL_SYSCALL_ERROR_P(val, err) \
((unsigned int) (val) >= -4095U)
# undef INTERNAL_SYSCALL_ERRNO
# define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
# define SYSCALL_CLOBBERS_6 "r11", "r4", "memory"
# define SYSCALL_CLOBBERS_5 "r10", SYSCALL_CLOBBERS_6
# define SYSCALL_CLOBBERS_4 "r9", SYSCALL_CLOBBERS_5
# define SYSCALL_CLOBBERS_3 "r8", SYSCALL_CLOBBERS_4
# define SYSCALL_CLOBBERS_2 "r7", SYSCALL_CLOBBERS_3
# define SYSCALL_CLOBBERS_1 "r6", SYSCALL_CLOBBERS_2
# define SYSCALL_CLOBBERS_0 "r5", SYSCALL_CLOBBERS_1
# define inline_syscall0(name,dummy) \
({ \
register long ret __asm__("r3"); \
register long __r12 __asm__("r12") = name; \
__asm__ __volatile__( "brki r14,8; nop;" \
: "=r"(ret) \
: "r"(__r12) \
: SYSCALL_CLOBBERS_0 ); ret; \
})
# define inline_syscall1(name,arg1) \
({ \
register long ret __asm__("r3"); \
register long __r12 __asm__("r12") = name; \
register long __r5 __asm__("r5") = (long)(arg1); \
__asm__ __volatile__( "brki r14,8; nop;" \
: "=r"(ret) \
: "r"(__r5), "r"(__r12) \
: SYSCALL_CLOBBERS_1 ); ret; \
})
# define inline_syscall2(name,arg1,arg2) \
({ \
register long ret __asm__("r3"); \
register long __r12 __asm__("r12") = name; \
register long __r5 __asm__("r5") = (long)(arg1); \
register long __r6 __asm__("r6") = (long)(arg2); \
__asm__ __volatile__( "brki r14,8; nop;" \
: "=r"(ret) \
: "r"(__r5), "r"(__r6), "r"(__r12) \
: SYSCALL_CLOBBERS_2 ); ret; \
})
# define inline_syscall3(name,arg1,arg2,arg3) \
({ \
register long ret __asm__("r3"); \
register long __r12 __asm__("r12") = name; \
register long __r5 __asm__("r5") = (long)(arg1); \
register long __r6 __asm__("r6") = (long)(arg2); \
register long __r7 __asm__("r7") = (long)(arg3); \
__asm__ __volatile__( "brki r14,8; nop;" \
: "=r"(ret) \
: "r"(__r5), "r"(__r6), "r"(__r7), "r"(__r12) \
: SYSCALL_CLOBBERS_3 ); ret; \
})
# define inline_syscall4(name,arg1,arg2,arg3,arg4) \
({ \
register long ret __asm__("r3"); \
register long __r12 __asm__("r12") = name; \
register long __r5 __asm__("r5") = (long)(arg1); \
register long __r6 __asm__("r6") = (long)(arg2); \
register long __r7 __asm__("r7") = (long)(arg3); \
register long __r8 __asm__("r8") = (long)(arg4); \
__asm__ __volatile__( "brki r14,8; nop;" \
: "=r"(ret) \
: "r"(__r5), "r"(__r6), "r"(__r7), "r"(__r8),"r"(__r12) \
: SYSCALL_CLOBBERS_4 ); ret; \
})
# define inline_syscall5(name,arg1,arg2,arg3,arg4,arg5) \
({ \
register long ret __asm__("r3"); \
register long __r12 __asm__("r12") = name; \
register long __r5 __asm__("r5") = (long)(arg1); \
register long __r6 __asm__("r6") = (long)(arg2); \
register long __r7 __asm__("r7") = (long)(arg3); \
register long __r8 __asm__("r8") = (long)(arg4); \
register long __r9 __asm__("r9") = (long)(arg5); \
__asm__ __volatile__( "brki r14,8; nop;" \
: "=r"(ret) \
: "r"(__r5), "r"(__r6), "r"(__r7), "r"(__r8),"r"(__r9), "r"(__r12) \
: SYSCALL_CLOBBERS_5 ); ret; \
})
# define inline_syscall6(name,arg1,arg2,arg3,arg4,arg5,arg6) \
({ \
register long ret __asm__("r3"); \
register long __r12 __asm__("r12") = name; \
register long __r5 __asm__("r5") = (long)(arg1); \
register long __r6 __asm__("r6") = (long)(arg2); \
register long __r7 __asm__("r7") = (long)(arg3); \
register long __r8 __asm__("r8") = (long)(arg4); \
register long __r9 __asm__("r9") = (long)(arg5); \
register long __r10 __asm__("r10") = (long)(arg6); \
__asm__ __volatile__( "brki r14,8; nop;" \
: "=r"(ret) \
: "r"(__r5), "r"(__r6), "r"(__r7), "r"(__r8),"r"(__r9), "r"(__r10), \
"r"(__r12) \
: SYSCALL_CLOBBERS_6 ); ret; \
})
/* Pointer mangling is not yet supported for Microblaze. */
# define PTR_MANGLE(var) (void) (var)
# define PTR_DEMANGLE(var) (void) (var)
#endif /* not __ASSEMBLER__ */
#endif /* _LINUX_MICROBLAZE_SYSDEP_H */