text: /*
   * Copyright © 2012 Intel Corporation
   * Copyright © 2013 Collabora, Ltd.
   *
   * 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 (including the
   * next paragraph) 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.
   */
  
  #include "config.h"
  
  #include <errno.h>
  #include <fcntl.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #include "shared/os-compatibility.h"
  #include "weston-test-client-helper.h"
  
  /* These three functions are copied from shared/os-compatibility.c in order to
   * behave like older clients, and allow ftruncate() to shrink the file’s size,
   * so SIGBUS can still happen.
   *
   * There is no reason not to use os_create_anonymous_file() otherwise. */
  
  #ifndef HAVE_MKOSTEMP
  static int
  set_cloexec_or_close(int fd)
  {
  	if (os_fd_set_cloexec(fd) != 0) {
  		close(fd);
  		return -1;
  	}
  	return fd;
  }
  #endif
  
  static int
  create_tmpfile_cloexec(char *tmpname)
  {
  	int fd;
  
  #ifdef HAVE_MKOSTEMP
  	fd = mkostemp(tmpname, O_CLOEXEC);
  	if (fd >= 0)
  		unlink(tmpname);
  #else
  	fd = mkstemp(tmpname);
  	if (fd >= 0) {
  		fd = set_cloexec_or_close(fd);
  		unlink(tmpname);
  	}
  #endif
  
  	return fd;
  }
  
  static int
  create_anonymous_file_without_seals(off_t size)
  {
  	static const char template[] = "/weston-test-XXXXXX";
  	const char *path;
  	char *name;
  	int fd;
  	int ret;
  
  	path = getenv("XDG_RUNTIME_DIR");
  	if (!path) {
  		errno = ENOENT;
  		return -1;
  	}
  
  	name = malloc(strlen(path) + sizeof(template));
  	if (!name)
  		return -1;
  
  	strcpy(name, path);
  	strcat(name, template);
  
  	fd = create_tmpfile_cloexec(name);
  
  	free(name);
  
  	if (fd < 0)
  		return -1;
  
  #ifdef HAVE_POSIX_FALLOCATE
  	do {
  		ret = posix_fallocate(fd, 0, size);
  	} while (ret == EINTR);
  	if (ret != 0) {
  		close(fd);
  		errno = ret;
  		return -1;
  	}
  #else
  	do {
  		ret = ftruncate(fd, size);
  	} while (ret < 0 && errno == EINTR);
  	if (ret < 0) {
  		close(fd);
  		return -1;
  	}
  #endif
  
  	return fd;
  }
  
  /* tests, that attempt to crash the compositor on purpose */
  
  static struct wl_buffer *
  create_bad_shm_buffer(struct client *client, int width, int height)
  {
  	struct wl_shm *shm = client->wl_shm;
  	int stride = width * 4;
  	int size = stride * height;
  	struct wl_shm_pool *pool;
  	struct wl_buffer *buffer;
  	int fd;
  
  	fd = create_anonymous_file_without_seals(size);
  	assert(fd >= 0);
  
  	pool = wl_shm_create_pool(shm, fd, size);
  	buffer = wl_shm_pool_create_buffer(pool, 0, width, height, stride,
  					   WL_SHM_FORMAT_ARGB8888);
  	wl_shm_pool_destroy(pool);
  
  	/* Truncate the file to a small size, so that the compositor
  	 * will access it out-of-bounds, and hit SIGBUS.
  	 */
  	assert(ftruncate(fd, 12) == 0);
  	close(fd);
  
  	return buffer;
  }
  
  TEST(test_truncated_shm_file)
  {
  	struct client *client;
  	struct wl_buffer *bad_buffer;
  	struct wl_surface *surface;
  	int frame;
  
  	client = create_client_and_test_surface(46, 76, 111, 134);
  	assert(client);
  	surface = client->surface->wl_surface;
  
  	bad_buffer = create_bad_shm_buffer(client, 200, 200);
  
  	wl_surface_attach(surface, bad_buffer, 0, 0);
  	wl_surface_damage(surface, 0, 0, 200, 200);
  	frame_callback_set(surface, &frame);
  	wl_surface_commit(surface);
  	frame_callback_wait_nofail(client, &frame);
  
  	expect_protocol_error(client, &wl_buffer_interface,
  			      WL_SHM_ERROR_INVALID_FD);
  }
  