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fb1cf10811
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.
361 lines
12 KiB
C
361 lines
12 KiB
C
/* Copyright (C) 1992-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995.
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Changed by Kaz Kojima, <kkojima@rr.iij4u.or.jp>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _LINUX_SH_SYSDEP_H
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#define _LINUX_SH_SYSDEP_H 1
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/* There is some commonality. */
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#include <sysdeps/unix/sysv/linux/sysdep.h>
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#include <sysdeps/unix/sh/sysdep.h>
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#include <tls.h>
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/* For Linux we can use the system call table in the header file
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/usr/include/asm/unistd.h
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of the kernel. But these symbols do not follow the SYS_* syntax
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so we have to redefine the `SYS_ify' macro here. */
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#undef SYS_ify
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#define SYS_ify(syscall_name) (__NR_##syscall_name)
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#ifdef __ASSEMBLER__
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/* Linux uses a negative return value to indicate syscall errors,
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unlike most Unices, which use the condition codes' carry flag.
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Since version 2.1 the return value of a system call might be
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negative even if the call succeeded. E.g., the `lseek' system call
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might return a large offset. Therefore we must not anymore test
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for < 0, but test for a real error by making sure the value in R0
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is a real error number. Linus said he will make sure the no syscall
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returns a value in -1 .. -4095 as a valid result so we can savely
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test with -4095. */
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#define _IMM1 #-1
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#define _IMM12 #-12
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#undef PSEUDO
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#define PSEUDO(name, syscall_name, args) \
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.text; \
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ENTRY (name); \
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DO_CALL (syscall_name, args); \
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mov r0,r1; \
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mov _IMM12,r2; \
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shad r2,r1; \
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not r1,r1; \
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tst r1,r1; \
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bf .Lpseudo_end; \
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SYSCALL_ERROR_HANDLER; \
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.Lpseudo_end:
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#undef PSEUDO_END
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#define PSEUDO_END(name) \
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END (name)
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#undef PSEUDO_NOERRNO
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#define PSEUDO_NOERRNO(name, syscall_name, args) \
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.text; \
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ENTRY (name); \
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DO_CALL (syscall_name, args)
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#undef PSEUDO_END_NOERRNO
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#define PSEUDO_END_NOERRNO(name) \
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END (name)
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#define ret_NOERRNO ret
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#define PSEUDO_ERRVAL(name, syscall_name, args) \
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.text; \
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ENTRY (name); \
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DO_CALL (syscall_name, args);
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#undef PSEUDO_END_ERRVAL
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#define PSEUDO_END_ERRVAL(name) \
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END (name)
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#define ret_ERRVAL ret
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#ifndef PIC
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# define SYSCALL_ERROR_HANDLER \
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mov.l 0f,r1; \
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jmp @r1; \
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mov r0,r4; \
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.align 2; \
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0: .long __syscall_error
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#else
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# if RTLD_PRIVATE_ERRNO
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# define SYSCALL_ERROR_HANDLER \
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neg r0,r1; \
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mov r12,r2; \
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cfi_register (r12, r2); \
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mov.l 0f,r12; \
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mova 0f,r0; \
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add r0,r12; \
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mov.l 1f,r0; \
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mov.l r1,@(r0,r12); \
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mov r2,r12; \
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cfi_restore (r12); \
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bra .Lpseudo_end; \
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mov _IMM1,r0; \
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.align 2; \
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0: .long _GLOBAL_OFFSET_TABLE_; \
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1: .long rtld_errno@GOTOFF
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# elif defined _LIBC_REENTRANT
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# if IS_IN (libc)
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# define SYSCALL_ERROR_ERRNO __libc_errno
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# else
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# define SYSCALL_ERROR_ERRNO errno
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# endif
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# define SYSCALL_ERROR_HANDLER \
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neg r0,r1; \
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mov r12,r2; \
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cfi_register (r12, r2); \
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mov.l 0f,r12; \
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mova 0f,r0; \
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add r0,r12; \
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mov.l 1f,r0; \
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stc gbr, r4; \
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mov.l @(r0,r12),r0; \
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mov r2,r12; \
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cfi_restore (r12); \
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add r4,r0; \
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mov.l r1,@r0; \
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bra .Lpseudo_end; \
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mov _IMM1,r0; \
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.align 2; \
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0: .long _GLOBAL_OFFSET_TABLE_; \
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1: .long SYSCALL_ERROR_ERRNO@GOTTPOFF
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# else
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/* Store (-r0) into errno through the GOT. */
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# define SYSCALL_ERROR_HANDLER \
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neg r0,r1; \
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mov r12,r2; \
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cfi_register (r12, r2); \
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mov.l 0f,r12; \
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mova 0f,r0; \
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add r0,r12; \
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mov.l 1f,r0; \
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mov.l @(r0,r12),r0; \
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mov r2,r12; \
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cfi_restore (r12); \
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mov.l r1,@r0; \
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bra .Lpseudo_end; \
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mov _IMM1,r0; \
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.align 2; \
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0: .long _GLOBAL_OFFSET_TABLE_; \
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1: .long errno@GOT
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# endif /* _LIBC_REENTRANT */
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#endif /* PIC */
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# ifdef NEED_SYSCALL_INST_PAD
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# define SYSCALL_INST_PAD \
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or r0,r0; or r0,r0; or r0,r0; or r0,r0; or r0,r0
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# else
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# define SYSCALL_INST_PAD
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# endif
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#define SYSCALL_INST0 trapa #0x10
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#define SYSCALL_INST1 trapa #0x11
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#define SYSCALL_INST2 trapa #0x12
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#define SYSCALL_INST3 trapa #0x13
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#define SYSCALL_INST4 trapa #0x14
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#define SYSCALL_INST5 mov.l @(0,r15),r0; trapa #0x15
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#define SYSCALL_INST6 mov.l @(0,r15),r0; mov.l @(4,r15),r1; trapa #0x16
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#undef DO_CALL
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#define DO_CALL(syscall_name, args) \
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mov.l 1f,r3; \
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SYSCALL_INST##args; \
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SYSCALL_INST_PAD; \
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bra 2f; \
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nop; \
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.align 2; \
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1: .long SYS_ify (syscall_name); \
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2:
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#else /* not __ASSEMBLER__ */
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#define SYSCALL_INST_STR0 "trapa #0x10\n\t"
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#define SYSCALL_INST_STR1 "trapa #0x11\n\t"
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#define SYSCALL_INST_STR2 "trapa #0x12\n\t"
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#define SYSCALL_INST_STR3 "trapa #0x13\n\t"
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#define SYSCALL_INST_STR4 "trapa #0x14\n\t"
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#define SYSCALL_INST_STR5 "trapa #0x15\n\t"
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#define SYSCALL_INST_STR6 "trapa #0x16\n\t"
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# ifdef NEED_SYSCALL_INST_PAD
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# define SYSCALL_INST_PAD "\
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or r0,r0; or r0,r0; or r0,r0; or r0,r0; or r0,r0"
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# else
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# define SYSCALL_INST_PAD
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# endif
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#define ASMFMT_0
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#define ASMFMT_1 \
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, "r" (r4)
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#define ASMFMT_2 \
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, "r" (r4), "r" (r5)
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#define ASMFMT_3 \
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, "r" (r4), "r" (r5), "r" (r6)
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#define ASMFMT_4 \
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, "r" (r4), "r" (r5), "r" (r6), "r" (r7)
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#define ASMFMT_5 \
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, "r" (r4), "r" (r5), "r" (r6), "r" (r7), "0" (r0)
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#define ASMFMT_6 \
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, "r" (r4), "r" (r5), "r" (r6), "r" (r7), "0" (r0), "r" (r1)
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#define ASMFMT_7 \
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, "r" (r4), "r" (r5), "r" (r6), "r" (r7), "0" (r0), "r" (r1), "r" (r2)
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#define SUBSTITUTE_ARGS_0()
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#define SUBSTITUTE_ARGS_1(arg1) \
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long int _arg1 = (long int) (arg1); \
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register long int r4 asm ("%r4") = (long int) (_arg1)
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#define SUBSTITUTE_ARGS_2(arg1, arg2) \
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long int _arg1 = (long int) (arg1); \
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long int _arg2 = (long int) (arg2); \
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register long int r4 asm ("%r4") = (long int) (_arg1); \
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register long int r5 asm ("%r5") = (long int) (_arg2)
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#define SUBSTITUTE_ARGS_3(arg1, arg2, arg3) \
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long int _arg1 = (long int) (arg1); \
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long int _arg2 = (long int) (arg2); \
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long int _arg3 = (long int) (arg3); \
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register long int r4 asm ("%r4") = (long int) (_arg1); \
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register long int r5 asm ("%r5") = (long int) (_arg2); \
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register long int r6 asm ("%r6") = (long int) (_arg3)
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#define SUBSTITUTE_ARGS_4(arg1, arg2, arg3, arg4) \
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long int _arg1 = (long int) (arg1); \
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long int _arg2 = (long int) (arg2); \
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long int _arg3 = (long int) (arg3); \
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long int _arg4 = (long int) (arg4); \
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register long int r4 asm ("%r4") = (long int) (_arg1); \
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register long int r5 asm ("%r5") = (long int) (_arg2); \
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register long int r6 asm ("%r6") = (long int) (_arg3); \
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register long int r7 asm ("%r7") = (long int) (_arg4)
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#define SUBSTITUTE_ARGS_5(arg1, arg2, arg3, arg4, arg5) \
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long int _arg1 = (long int) (arg1); \
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long int _arg2 = (long int) (arg2); \
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long int _arg3 = (long int) (arg3); \
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long int _arg4 = (long int) (arg4); \
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long int _arg5 = (long int) (arg5); \
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register long int r4 asm ("%r4") = (long int) (_arg1); \
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register long int r5 asm ("%r5") = (long int) (_arg2); \
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register long int r6 asm ("%r6") = (long int) (_arg3); \
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register long int r7 asm ("%r7") = (long int) (_arg4); \
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register long int r0 asm ("%r0") = (long int) (_arg5)
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#define SUBSTITUTE_ARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
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long int _arg1 = (long int) (arg1); \
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long int _arg2 = (long int) (arg2); \
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long int _arg3 = (long int) (arg3); \
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long int _arg4 = (long int) (arg4); \
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long int _arg5 = (long int) (arg5); \
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long int _arg6 = (long int) (arg6); \
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register long int r4 asm ("%r4") = (long int)(_arg1); \
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register long int r5 asm ("%r5") = (long int) (_arg2); \
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register long int r6 asm ("%r6") = (long int) (_arg3); \
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register long int r7 asm ("%r7") = (long int) (_arg4); \
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register long int r0 asm ("%r0") = (long int) (_arg5); \
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register long int r1 asm ("%r1") = (long int) (_arg6)
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#define SUBSTITUTE_ARGS_7(arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
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long int _arg1 = (long int) (arg1); \
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long int _arg2 = (long int) (arg2); \
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long int _arg3 = (long int) (arg3); \
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long int _arg4 = (long int) (arg4); \
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long int _arg5 = (long int) (arg5); \
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long int _arg6 = (long int) (arg6); \
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long int _arg7 = (long int) (arg7); \
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register long int r4 asm ("%r4") = (long int) (_arg1); \
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register long int r5 asm ("%r5") = (long int) (_arg2); \
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register long int r6 asm ("%r6") = (long int) (_arg3); \
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register long int r7 asm ("%r7") = (long int) (_arg4); \
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register long int r0 asm ("%r0") = (long int) (_arg5); \
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register long int r1 asm ("%r1") = (long int) (_arg6); \
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register long int r2 asm ("%r2") = (long int) (_arg7)
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#undef INLINE_SYSCALL
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#define INLINE_SYSCALL(name, nr, args...) \
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({ \
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unsigned int resultvar = INTERNAL_SYSCALL (name, , nr, args); \
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if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (resultvar, ), 0)) \
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{ \
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__set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, )); \
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resultvar = 0xffffffff; \
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} \
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(int) resultvar; })
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#undef INTERNAL_SYSCALL
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#define INTERNAL_SYSCALL(name, err, nr, args...) \
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({ \
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unsigned long int resultvar; \
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register long int r3 asm ("%r3") = SYS_ify (name); \
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SUBSTITUTE_ARGS_##nr(args); \
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\
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asm volatile (SYSCALL_INST_STR##nr SYSCALL_INST_PAD \
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: "=z" (resultvar) \
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: "r" (r3) ASMFMT_##nr \
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: "memory", "t"); \
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\
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(int) resultvar; })
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/* The _NCS variant allows non-constant syscall numbers. */
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#define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
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({ \
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unsigned long int resultvar; \
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register long int r3 asm ("%r3") = (name); \
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SUBSTITUTE_ARGS_##nr(args); \
|
|
\
|
|
asm volatile (SYSCALL_INST_STR##nr SYSCALL_INST_PAD \
|
|
: "=z" (resultvar) \
|
|
: "r" (r3) ASMFMT_##nr \
|
|
: "memory", "t"); \
|
|
\
|
|
(int) resultvar; })
|
|
|
|
#undef INTERNAL_SYSCALL_DECL
|
|
#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
|
|
|
|
#undef INTERNAL_SYSCALL_ERROR_P
|
|
#define INTERNAL_SYSCALL_ERROR_P(val, err) \
|
|
((unsigned int) (val) >= 0xfffff001u)
|
|
|
|
#undef INTERNAL_SYSCALL_ERRNO
|
|
#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
|
|
|
|
#endif /* __ASSEMBLER__ */
|
|
|
|
/* Pointer mangling support. */
|
|
#if IS_IN (rtld)
|
|
/* We cannot use the thread descriptor because in ld.so we use setjmp
|
|
earlier than the descriptor is initialized. Using a global variable
|
|
is too complicated here since we have no PC-relative addressing mode. */
|
|
#else
|
|
# ifdef __ASSEMBLER__
|
|
# define PTR_MANGLE(reg, tmp) \
|
|
stc gbr,tmp; mov.l @(POINTER_GUARD,tmp),tmp; xor tmp,reg
|
|
# define PTR_MANGLE2(reg, tmp) xor tmp,reg
|
|
# define PTR_DEMANGLE(reg, tmp) PTR_MANGLE (reg, tmp)
|
|
# define PTR_DEMANGLE2(reg, tmp) PTR_MANGLE2 (reg, tmp)
|
|
# else
|
|
# define PTR_MANGLE(var) \
|
|
(var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
|
|
# define PTR_DEMANGLE(var) PTR_MANGLE (var)
|
|
# endif
|
|
#endif
|
|
|
|
#endif /* linux/sh/sysdep.h */
|