glibc/sysdeps/unix/sysv/linux/sysdep.h
Adhemerval Zanella 720480934a linux: Consolidate brk implementation
It removes all the arch-specific assembly implementation.  The
outliers are alpha, where its kernel ABI explict return -ENOMEM
in case of failure; and i686, where it can't use
"call *%gs:SYSINFO_OFFSET" during statup in static PIE.

Also some ABIs exports an additional ___brk_addr symbol and to
handle it an internal HAVE_INTERNAL_BRK_ADDR_SYMBOL is added.

Checked on x86_64-linux-gnu, i686-linux-gnu, adn with builsd for
the affected ABIs.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-12-10 17:42:37 -03:00

107 lines
3.5 KiB
C

/* Copyright (C) 2015-2020 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
<https://www.gnu.org/licenses/>. */
#ifndef _SYSDEP_LINUX_H
#define _SYSDEP_LINUX_H
#include <bits/wordsize.h>
#include <kernel-features.h>
#include <endian.h>
#include <errno.h>
#undef INTERNAL_SYSCALL_ERROR_P
#define INTERNAL_SYSCALL_ERROR_P(val) \
((unsigned long int) (val) > -4096UL)
#ifndef SYSCALL_ERROR_LABEL
# define SYSCALL_ERROR_LABEL(sc_err) \
({ \
__set_errno (sc_err); \
-1L; \
})
#endif
/* Define a macro which expands into the inline wrapper code for a system
call. It sets the errno and returns -1 on a failure, or the syscall
return value otherwise. */
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ \
long int sc_ret = INTERNAL_SYSCALL (name, nr, args); \
__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (sc_ret)) \
? SYSCALL_ERROR_LABEL (INTERNAL_SYSCALL_ERRNO (sc_ret)) \
: sc_ret; \
})
#undef INTERNAL_SYSCALL_ERRNO
#define INTERNAL_SYSCALL_ERRNO(val) (-(val))
/* Set error number and return -1. A target may choose to return the
internal function, __syscall_error, which sets errno and returns -1.
We use -1l, instead of -1, so that it can be casted to (void *). */
#define INLINE_SYSCALL_ERROR_RETURN_VALUE(err) \
({ \
__set_errno (err); \
-1l; \
})
/* Provide a dummy argument that can be used to force register
alignment for register pairs if required by the syscall ABI. */
#ifdef __ASSUME_ALIGNED_REGISTER_PAIRS
#define __ALIGNMENT_ARG 0,
#define __ALIGNMENT_COUNT(a,b) b
#else
#define __ALIGNMENT_ARG
#define __ALIGNMENT_COUNT(a,b) a
#endif
/* Provide a common macro to pass 64-bit value on syscalls. */
#if __WORDSIZE == 64 || defined __ASSUME_WORDSIZE64_ILP32
# define SYSCALL_LL(val) (val)
# define SYSCALL_LL64(val) (val)
#else
#define SYSCALL_LL(val) \
__LONG_LONG_PAIR ((val) >> 31, (val))
#define SYSCALL_LL64(val) \
__LONG_LONG_PAIR ((long) ((val) >> 32), (long) ((val) & 0xffffffff))
#endif
/* Provide a common macro to pass 64-bit value on pread and pwrite
syscalls. */
#ifdef __ASSUME_PRW_DUMMY_ARG
# define SYSCALL_LL_PRW(val) 0, SYSCALL_LL (val)
# define SYSCALL_LL64_PRW(val) 0, SYSCALL_LL64 (val)
#else
# define SYSCALL_LL_PRW(val) __ALIGNMENT_ARG SYSCALL_LL (val)
# define SYSCALL_LL64_PRW(val) __ALIGNMENT_ARG SYSCALL_LL64 (val)
#endif
/* Provide a macro to pass the off{64}_t argument on p{readv,writev}{64}. */
#define LO_HI_LONG(val) \
(long) (val), \
(long) (((uint64_t) (val)) >> 32)
/* Exports the __send symbol on send.c linux implementation (some ABI have
it missing due the usage of a old generic version without it). */
#define HAVE_INTERNAL_SEND_SYMBOL 1
/* Export the ___brk_addr symbol on brk.c implementation (some ABIs export
it due and old crtstuff.c code). */
#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 0
#endif /* _SYSDEP_LINUX_H */