mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-14 01:00:07 +00:00
58 lines
1.7 KiB
C
58 lines
1.7 KiB
C
/* Allocate a memory region shared across processes.
|
|
Copyright (C) 2017-2023 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 <errno.h>
|
|
#include <stddef.h>
|
|
#include <support/support.h>
|
|
#include <support/xunistd.h>
|
|
#include <sys/mman.h>
|
|
|
|
/* Header for the allocation. It contains the size of the allocation
|
|
for subsequent unmapping. */
|
|
struct header
|
|
{
|
|
size_t total_size;
|
|
char data[] __attribute__ ((aligned (__alignof__ (max_align_t))));
|
|
};
|
|
|
|
void *
|
|
support_shared_allocate (size_t size)
|
|
{
|
|
size_t total_size = size + offsetof (struct header, data);
|
|
if (total_size < size)
|
|
{
|
|
errno = ENOMEM;
|
|
oom_error (__func__, size);
|
|
return NULL;
|
|
}
|
|
else
|
|
{
|
|
struct header *result = xmmap (NULL, total_size, PROT_READ | PROT_WRITE,
|
|
MAP_ANONYMOUS | MAP_SHARED, -1);
|
|
result->total_size = total_size;
|
|
return &result->data;
|
|
}
|
|
}
|
|
|
|
void
|
|
support_shared_free (void *data)
|
|
{
|
|
struct header *header = data - offsetof (struct header, data);
|
|
xmunmap (header, header->total_size);
|
|
}
|