| 0,0 → 1,145 |
|---|
| /* |
| * Mesa 3-D graphics library |
| * |
| * 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 |
| * THE AUTHORS OR COPYRIGHT HOLDERS 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. |
| */ |
| |
| |
| #include "u_compiler.h" |
| #include "u_thread.h" |
| #include "u_execmem.h" |
| |
| |
| #define EXEC_MAP_SIZE (4*1024) |
| |
| u_mutex_declare_static(exec_mutex); |
| |
| static unsigned int head = 0; |
| |
| static unsigned char *exec_mem = (unsigned char *)0; |
| |
| |
| #if defined(__linux__) || defined(__OpenBSD__) || defined(_NetBSD__) || defined(__sun) || defined(__HAIKU__) |
| |
| #include <unistd.h> |
| #include <sys/mman.h> |
| |
| #ifdef MESA_SELINUX |
| #include <selinux/selinux.h> |
| #endif |
| |
| |
| #ifndef MAP_ANONYMOUS |
| #define MAP_ANONYMOUS MAP_ANON |
| #endif |
| |
| |
| /* |
| * 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); |
| } |
| |
| |
| #elif defined(_WIN32) |
| |
| #include <windows.h> |
| |
| |
| /* |
| * Avoid Data Execution Prevention. |
| */ |
| |
| static int |
| init_map(void) |
| { |
| exec_mem = VirtualAlloc(NULL, EXEC_MAP_SIZE, MEM_COMMIT, PAGE_EXECUTE_READWRITE); |
| |
| return (exec_mem != NULL); |
| } |
| |
| |
| #else |
| |
| #include <stdlib.h> |
| |
| static int |
| init_map(void) |
| { |
| exec_mem = malloc(EXEC_MAP_SIZE); |
| |
| return (exec_mem != NULL); |
| } |
| |
| |
| #endif |
| |
| void * |
| u_execmem_alloc(unsigned int size) |
| { |
| void *addr = NULL; |
| |
| u_mutex_lock(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: |
| u_mutex_unlock(exec_mutex); |
| |
| return addr; |
| } |
| |
| |