mapi: Delete execmem support code.

No longer used now that we don't dynamically generate dispatch stubs.

Acked-by: Marek Olšák <marek.olsak@amd.com>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23451>

meson.build

@@ -1870,17 +1870,10 @@ endif
 
 dep_selinux = null_dep
 if get_option('selinux')
-  if get_option('execmem') != true
-    warning('execmem option is disabled, selinux will not be able to use execmem.')
-  endif
   dep_selinux = dependency('libselinux')
   pre_args += '-DMESA_SELINUX'
 endif
 
-if get_option('execmem')
-  pre_args += '-DMESA_EXECMEM'
-endif
-
 _libunwind = get_option('libunwind') \
   .require(not with_platform_android, error_message : 'Android requires the use of the backtrace library, not libunwind')
 if host_machine.system() == 'darwin'

meson_options.txt

@@ -460,18 +460,6 @@ option(
                 'with allow_execmem.'
 )
 
-option(
-  'execmem',
-  type : 'boolean',
-  value : true,
-  description : 'Enable execmem support.  Without execmem, glapi will fail ' +
-                'to generate dynamic glapi stubs when entrypoints unknown ' +
-                'to glapi but known to DRI drivers are requested in ' +
-                'eglGetProcAddress or glXGetProcAddress.  This should be ' +
-                'enabled unless the platform can guarantee glapi and DRI ' +
-                'drivers are always built from the same source tree.'
-)
-
 option(
   'osmesa',
   type : 'boolean',

src/mapi/glapi/meson.build

@@ -57,8 +57,6 @@ endif
 static_glapi_files += files(
   '../u_current.c',
   '../u_current.h',
-  '../u_execmem.c',
-  '../u_execmem.h',
   'glapi_dispatch.c',
   'glapi_entrypoint.c',
   'glapi_getproc.c',

src/mapi/shared-glapi/meson.build

@@ -22,8 +22,6 @@ files_shared_glapi = files(
   '../entry.c',
   '../u_current.c',
   '../u_current.h',
-  '../u_execmem.c',
-  '../u_execmem.h',
   'glapi.c',
   'stub.c',
   'stub.h',

src/mapi/u_execmem.c

@@ -1,158 +0,0 @@
-/*
- * 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 "c11/threads.h"
-#include "util/u_call_once.h"
-#include "u_execmem.h"
-
-
-#define EXEC_MAP_SIZE (4*1024)
-
-static mtx_t 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
-
-   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
-
-static void
-u_execmem_init_once(void)
-{
-   if (!init_map())
-      exec_mem = NULL;
-   mtx_init(&exec_mutex, mtx_plain);
-}
-
-void *
-u_execmem_alloc(unsigned int size)
-{
-#ifndef MESA_EXECMEM
-   (void)size;
-   return NULL;
-#else
-   void *addr = NULL;
-   static util_once_flag once = UTIL_ONCE_FLAG_INIT;
-   util_call_once(&once, u_execmem_init_once);
-   if (exec_mem == NULL)
-      return NULL;
-
-   mtx_lock(&exec_mutex);
-
-   /* 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:
-   mtx_unlock(&exec_mutex);
-
-   return addr;
-#endif /* MESA_EXECMEM */
-}
-
-

src/mapi/u_execmem.h

@@ -1,7 +0,0 @@
-#ifndef _U_EXECMEM_H_
-#define _U_EXECMEM_H_
-
-void *
-u_execmem_alloc(unsigned int size);
-
-#endif /* _U_EXECMEM_H_ */