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30891f35fa
We stopped adding "Contributed by" or similar lines in sources in 2012 in favour of git logs and keeping the Contributors section of the glibc manual up to date. Removing these lines makes the license header a bit more consistent across files and also removes the possibility of error in attribution when license blocks or files are copied across since the contributed-by lines don't actually reflect reality in those cases. Move all "Contributed by" and similar lines (Written by, Test by, etc.) into a new file CONTRIBUTED-BY to retain record of these contributions. These contributors are also mentioned in manual/contrib.texi, so we just maintain this additional record as a courtesy to the earlier developers. The following scripts were used to filter a list of files to edit in place and to clean up the CONTRIBUTED-BY file respectively. These were not added to the glibc sources because they're not expected to be of any use in future given that this is a one time task: https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
307 lines
9.9 KiB
C
307 lines
9.9 KiB
C
/* Copyright (C) 1996-2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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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<https://www.gnu.org/licenses/>. */
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#include <sysdeps/unix/sysv/linux/sysdep.h>
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#include <tls.h>
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/* Defines RTLD_PRIVATE_ERRNO. */
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#include <dl-sysdep.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, unlike
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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 negative
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even if the call succeeded. E.g., the `lseek' system call might return
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a large offset. Therefore we must not anymore test for < 0, but test
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for a real error by making sure the value in %d0 is a real error
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number. Linus said he will make sure the no syscall returns a value
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in -1 .. -4095 as a valid result so we can savely test with -4095. */
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/* We don't want the label for the error handler to be visible in the symbol
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table when we define it here. */
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#undef SYSCALL_ERROR_LABEL
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#ifdef PIC
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#define SYSCALL_ERROR_LABEL .Lsyscall_error
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#else
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#define SYSCALL_ERROR_LABEL __syscall_error
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#endif
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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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cmp.l &-4095, %d0; \
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jcc SYSCALL_ERROR_LABEL
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#undef PSEUDO_END
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#define PSEUDO_END(name) \
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SYSCALL_ERROR_HANDLER; \
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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 rts
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/* The function has to return the error code. */
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#undef PSEUDO_ERRVAL
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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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negl %d0
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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 rts
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#ifdef PIC
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# if RTLD_PRIVATE_ERRNO
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# define SYSCALL_ERROR_HANDLER \
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SYSCALL_ERROR_LABEL: \
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PCREL_OP (lea, rtld_errno, %a0, %a0); \
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neg.l %d0; \
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move.l %d0, (%a0); \
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move.l &-1, %d0; \
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/* Copy return value to %a0 for syscalls that are declared to return \
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a pointer (e.g., mmap). */ \
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move.l %d0, %a0; \
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rts;
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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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SYSCALL_ERROR_LABEL: \
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neg.l %d0; \
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move.l %d0, -(%sp); \
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cfi_adjust_cfa_offset (4); \
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jbsr __m68k_read_tp@PLTPC; \
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SYSCALL_ERROR_LOAD_GOT (%a1); \
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add.l (SYSCALL_ERROR_ERRNO@TLSIE, %a1), %a0; \
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move.l (%sp)+, (%a0); \
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cfi_adjust_cfa_offset (-4); \
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move.l &-1, %d0; \
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/* Copy return value to %a0 for syscalls that are declared to return \
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a pointer (e.g., mmap). */ \
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move.l %d0, %a0; \
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rts;
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# else /* !_LIBC_REENTRANT */
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/* Store (- %d0) into errno through the GOT. */
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# define SYSCALL_ERROR_HANDLER \
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SYSCALL_ERROR_LABEL: \
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move.l (errno@GOTPC, %pc), %a0; \
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neg.l %d0; \
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move.l %d0, (%a0); \
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move.l &-1, %d0; \
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/* Copy return value to %a0 for syscalls that are declared to return \
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a pointer (e.g., mmap). */ \
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move.l %d0, %a0; \
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rts;
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# endif /* _LIBC_REENTRANT */
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#else
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# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
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#endif /* PIC */
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/* Linux takes system call arguments in registers:
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syscall number %d0 call-clobbered
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arg 1 %d1 call-clobbered
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arg 2 %d2 call-saved
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arg 3 %d3 call-saved
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arg 4 %d4 call-saved
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arg 5 %d5 call-saved
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arg 6 %a0 call-clobbered
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The stack layout upon entering the function is:
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24(%sp) Arg# 6
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20(%sp) Arg# 5
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16(%sp) Arg# 4
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12(%sp) Arg# 3
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8(%sp) Arg# 2
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4(%sp) Arg# 1
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(%sp) Return address
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(Of course a function with say 3 arguments does not have entries for
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arguments 4 and 5.)
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Separate move's are faster than movem, but need more space. Since
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speed is more important, we don't use movem. Since %a0 and %a1 are
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scratch registers, we can use them for saving as well. */
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#define DO_CALL(syscall_name, args) \
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move.l &SYS_ify(syscall_name), %d0; \
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DOARGS_##args \
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trap &0; \
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UNDOARGS_##args
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#define DOARGS_0 /* No arguments to frob. */
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#define UNDOARGS_0 /* No arguments to unfrob. */
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#define _DOARGS_0(n) /* No arguments to frob. */
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#define DOARGS_1 _DOARGS_1 (4)
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#define _DOARGS_1(n) move.l n(%sp), %d1; _DOARGS_0 (n)
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#define UNDOARGS_1 UNDOARGS_0
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#define DOARGS_2 _DOARGS_2 (8)
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#define _DOARGS_2(n) move.l %d2, %a0; cfi_register (%d2, %a0); \
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move.l n(%sp), %d2; _DOARGS_1 (n-4)
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#define UNDOARGS_2 UNDOARGS_1; move.l %a0, %d2; cfi_restore (%d2)
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#define DOARGS_3 _DOARGS_3 (12)
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#define _DOARGS_3(n) move.l %d3, %a1; cfi_register (%d3, %a1); \
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move.l n(%sp), %d3; _DOARGS_2 (n-4)
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#define UNDOARGS_3 UNDOARGS_2; move.l %a1, %d3; cfi_restore (%d3)
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#define DOARGS_4 _DOARGS_4 (16)
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#define _DOARGS_4(n) move.l %d4, -(%sp); \
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cfi_adjust_cfa_offset (4); cfi_rel_offset (%d4, 0); \
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move.l n+4(%sp), %d4; _DOARGS_3 (n)
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#define UNDOARGS_4 UNDOARGS_3; move.l (%sp)+, %d4; \
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cfi_adjust_cfa_offset (-4); cfi_restore (%d4)
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#define DOARGS_5 _DOARGS_5 (20)
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#define _DOARGS_5(n) move.l %d5, -(%sp); \
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cfi_adjust_cfa_offset (4); cfi_rel_offset (%d5, 0); \
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move.l n+4(%sp), %d5; _DOARGS_4 (n)
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#define UNDOARGS_5 UNDOARGS_4; move.l (%sp)+, %d5; \
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cfi_adjust_cfa_offset (-4); cfi_restore (%d5)
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#define DOARGS_6 _DOARGS_6 (24)
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#define _DOARGS_6(n) _DOARGS_5 (n-4); move.l %a0, -(%sp); \
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cfi_adjust_cfa_offset (4); \
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move.l n+12(%sp), %a0;
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#define UNDOARGS_6 move.l (%sp)+, %a0; cfi_adjust_cfa_offset (-4); \
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UNDOARGS_5
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#define ret rts
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#if 0 /* Not used by Linux */
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#define r0 %d0
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#define r1 %d1
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#define MOVE(x,y) movel x , y
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#endif
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#else /* not __ASSEMBLER__ */
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/* Define a macro which expands inline into the wrapper code for a system
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call. This use is for internal calls that do not need to handle errors
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normally. It will never touch errno. This returns just what the kernel
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gave back. */
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#undef INTERNAL_SYSCALL
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#define INTERNAL_SYSCALL_NCS(name, nr, args...) \
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({ unsigned int _sys_result; \
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{ \
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/* Load argument values in temporary variables
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to perform side effects like function calls
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before the call used registers are set. */ \
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LOAD_ARGS_##nr (args) \
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LOAD_REGS_##nr \
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register int _d0 asm ("%d0") = name; \
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asm volatile ("trap #0" \
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: "=d" (_d0) \
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: "0" (_d0) ASM_ARGS_##nr \
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: "memory"); \
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_sys_result = _d0; \
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} \
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(int) _sys_result; })
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#define INTERNAL_SYSCALL(name, nr, args...) \
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INTERNAL_SYSCALL_NCS (__NR_##name, nr, ##args)
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#define LOAD_ARGS_0()
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#define LOAD_REGS_0
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#define ASM_ARGS_0
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#define LOAD_ARGS_1(a1) \
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LOAD_ARGS_0 () \
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int __arg1 = (int) (a1);
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#define LOAD_REGS_1 \
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register int _d1 asm ("d1") = __arg1; \
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LOAD_REGS_0
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#define ASM_ARGS_1 ASM_ARGS_0, "d" (_d1)
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#define LOAD_ARGS_2(a1, a2) \
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LOAD_ARGS_1 (a1) \
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int __arg2 = (int) (a2);
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#define LOAD_REGS_2 \
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register int _d2 asm ("d2") = __arg2; \
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LOAD_REGS_1
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#define ASM_ARGS_2 ASM_ARGS_1, "d" (_d2)
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#define LOAD_ARGS_3(a1, a2, a3) \
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LOAD_ARGS_2 (a1, a2) \
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int __arg3 = (int) (a3);
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#define LOAD_REGS_3 \
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register int _d3 asm ("d3") = __arg3; \
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LOAD_REGS_2
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#define ASM_ARGS_3 ASM_ARGS_2, "d" (_d3)
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#define LOAD_ARGS_4(a1, a2, a3, a4) \
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LOAD_ARGS_3 (a1, a2, a3) \
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int __arg4 = (int) (a4);
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#define LOAD_REGS_4 \
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register int _d4 asm ("d4") = __arg4; \
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LOAD_REGS_3
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#define ASM_ARGS_4 ASM_ARGS_3, "d" (_d4)
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#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \
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LOAD_ARGS_4 (a1, a2, a3, a4) \
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int __arg5 = (int) (a5);
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#define LOAD_REGS_5 \
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register int _d5 asm ("d5") = __arg5; \
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LOAD_REGS_4
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#define ASM_ARGS_5 ASM_ARGS_4, "d" (_d5)
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#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \
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LOAD_ARGS_5 (a1, a2, a3, a4, a5) \
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int __arg6 = (int) (a6);
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#define LOAD_REGS_6 \
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register int _a0 asm ("a0") = __arg6; \
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LOAD_REGS_5
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#define ASM_ARGS_6 ASM_ARGS_5, "a" (_a0)
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#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
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#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
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#endif /* not __ASSEMBLER__ */
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/* Pointer mangling is not yet supported for M68K. */
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#define PTR_MANGLE(var) (void) (var)
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#define PTR_DEMANGLE(var) (void) (var)
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#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
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/* M68K needs system-supplied DSO to access TLS helpers
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even when statically linked. */
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# define NEED_STATIC_SYSINFO_DSO 1
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#endif
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