diff options
Diffstat (limited to 'mesalib/src/mapi/mapi/u_execmem.c')
-rw-r--r-- | mesalib/src/mapi/mapi/u_execmem.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/mesalib/src/mapi/mapi/u_execmem.c b/mesalib/src/mapi/mapi/u_execmem.c new file mode 100644 index 000000000..e5072e06e --- /dev/null +++ b/mesalib/src/mapi/mapi/u_execmem.c @@ -0,0 +1,145 @@ +/* + * 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. + */ + + +#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) + +#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; +} + + |