glibc/sysdeps/unix/sysv/linux/mremap.c
H.J. Lu 6c40cb0e9f linux: Update the mremap C implementation [BZ #31968]
Update the mremap C implementation to support the optional argument for
MREMAP_DONTUNMAP added in Linux 5.7 since it may not always be correct
to implement a variadic function as a non-variadic function on all Linux
targets.  Return MAP_FAILED and set errno to EINVAL for unknown flag bits.
This fixes BZ #31968.

Note: A test must be added when a new flag bit is introduced.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-08-01 05:06:12 -07:00

54 lines
1.5 KiB
C

/* Remap a virtual memory address. Linux specific syscall.
Copyright (C) 2021-2024 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/>. */
#include <sys/mman.h>
#include <sysdep.h>
#include <stdarg.h>
#include <stddef.h>
#include <errno.h>
#define MREMAP_KNOWN_BITS \
(MREMAP_MAYMOVE \
| MREMAP_FIXED \
| MREMAP_DONTUNMAP)
void *
__mremap (void *addr, size_t old_len, size_t new_len, int flags, ...)
{
va_list va;
void *new_addr = NULL;
if (flags & ~(MREMAP_KNOWN_BITS))
{
__set_errno (EINVAL);
return MAP_FAILED;
}
if (flags & (MREMAP_FIXED | MREMAP_DONTUNMAP))
{
va_start (va, flags);
new_addr = va_arg (va, void *);
va_end (va);
}
return (void *) INLINE_SYSCALL_CALL (mremap, addr, old_len, new_len, flags,
new_addr);
}
libc_hidden_def (__mremap)
weak_alias (__mremap, mremap)