glibc/sysdeps/unix/sysv/linux/mmap_internal.h
Florian Weimer c1b68685d4 Linux: Define MMAP_CALL_INTERNAL
Unlike MMAP_CALL, this avoids a TCB dependency for an errno update
on failure.

<mmap_internal.h> cannot be included as is on several architectures
due to the definition of page_unit, so introduce a separate header
file for the definition of MMAP_CALL and MMAP_CALL_INTERNAL,
<mmap_call.h>.

Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
2022-05-04 15:37:21 +02:00

48 lines
1.6 KiB
C

/* Common mmap definition for Linux implementation.
Copyright (C) 2017-2022 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 MMAP_INTERNAL_LINUX_H
#define MMAP_INTERNAL_LINUX_H 1
#include <stdint.h>
/* This is the minimum mmap2 unit size accept by the kernel. An architecture
with multiple minimum page sizes (such as m68k) might define it as -1 and
thus it will queried at runtime. */
#ifndef MMAP2_PAGE_UNIT
# define MMAP2_PAGE_UNIT 4096ULL
#endif
#if MMAP2_PAGE_UNIT == -1
static uint64_t page_unit;
# define MMAP_CHECK_PAGE_UNIT() \
if (page_unit == 0) \
page_unit = __getpagesize ();
# undef MMAP2_PAGE_UNIT
# define MMAP2_PAGE_UNIT page_unit
#else
# define MMAP_CHECK_PAGE_UNIT()
#endif
/* Do not accept offset not multiple of page size. */
#define MMAP_OFF_LOW_MASK (MMAP2_PAGE_UNIT - 1)
#include <mmap_call.h>
#endif /* MMAP_INTERNAL_LINUX_H */