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/*
* Mesa 3-D graphics library
* Version: 6.5
*
* Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* \file glapi_execmem.c
*
* Function for allocating executable memory for dispatch stubs.
*
* Copied from main/execmem.c and simplified for dispatch stubs.
*/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#include "glapi/mesa.h"
#else
#include "main/compiler.h"
#endif
#include "glapi/glthread.h"
#if defined(__linux__) || defined(__OpenBSD__) || defined(_NetBSD__) || defined(__sun)
#include <unistd.h>
#include <sys/mman.h>
#ifdef MESA_SELINUX
#include <selinux/selinux.h>
#endif
#ifndef MAP_ANONYMOUS
#define MAP_ANONYMOUS MAP_ANON
#endif
#define EXEC_MAP_SIZE (4*1024)
_glthread_DECLARE_STATIC_MUTEX(exec_mutex);
static unsigned int head = 0;
static unsigned char *exec_mem = NULL;
/*
* Dispatch stubs are of fixed size and never freed. Thus, we do not need to
* overlay a heap, we just mmap a page and manage through an index.
*/
static int
init_map(void)
{
#ifdef MESA_SELINUX
if (is_selinux_enabled()) {
if (!security_get_boolean_active("allow_execmem") ||
!security_get_boolean_pending("allow_execmem"))
return 0;
}
#endif
if (!exec_mem)
exec_mem = mmap(NULL, EXEC_MAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
return (exec_mem != MAP_FAILED);
}
void *
_glapi_exec_malloc(unsigned int size)
{
void *addr = NULL;
_glthread_LOCK_MUTEX(exec_mutex);
if (!init_map())
goto bail;
/* free space check, assumes no integer overflow */
if (head + size > EXEC_MAP_SIZE)
goto bail;
/* allocation, assumes proper addr and size alignement */
addr = exec_mem + head;
head += size;
bail:
_glthread_UNLOCK_MUTEX(exec_mutex);
return addr;
}
#else
void *
_glapi_exec_malloc(unsigned int size)
{
return malloc(size);
}
#endif
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