kc3-lang/libxkbcommon/src/utils.c

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• Hash : 763e2b7e
  Author :
  Date : 2016-03-13T20:24:44
  

  src/utils: check if fileno() failed in map_file
  
  fileno() can fail, if called on e.g. fmemopen() FILEs which are not
  backed by a file descriptor. This functions uses mmap to map the entire
  file to memory, so using such FILEs will not work.
  
  (There is actually no change of behavior here, since the following fstat
  would have already failed with EBADF. But lets make it clear.)
  
  Another possibility is to fall back to the !HAVE_MMAP case; but it
  sounds like a better idea to leave it to the programmer to use the
  new_from_string/new_from_buffer functions instead, instead of doing
  double allocation behind their back.
  
  Signed-off-by: Ran Benita <ran234@gmail.com>
  

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• src/utils.c

• /*
   * Copyright © 2013 Ran Benita <ran234@gmail.com>
   *
   * 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 "utils.h"
  
  #ifdef HAVE_MMAP
  
  #include <fcntl.h>
  #include <unistd.h>
  #include <sys/mman.h>
  #include <sys/stat.h>
  #include <sys/types.h>
  
  bool
  map_file(FILE *file, char **string_out, size_t *size_out)
  {
      struct stat stat_buf;
      int fd;
      char *string;
  
      /* Make sure to keep the errno on failure! */
      fd = fileno(file);
      if (fd < 0)
          return false;
  
      if (fstat(fd, &stat_buf) != 0)
          return false;
  
      string = mmap(NULL, stat_buf.st_size, PROT_READ, MAP_SHARED, fd, 0);
      if (string == MAP_FAILED)
          return false;
  
      *string_out = string;
      *size_out = stat_buf.st_size;
      return true;
  }
  
  void
  unmap_file(char *str, size_t size)
  {
      munmap(str, size);
  }
  
  #else
  
  bool
  map_file(FILE *file, char **string_out, size_t *size_out)
  {
      long ret;
      size_t ret_s;
      char *string;
      size_t size;
  
      /* Make sure to keep the errno on failure! */
  
      ret = fseek(file, 0, SEEK_END);
      if (ret != 0)
          return false;
  
      ret = ftell(file);
      if (ret < 0)
          return false;
      size = (size_t) ret;
  
      ret = fseek(file, 0, SEEK_SET);
      if (ret < 0)
          return false;
  
      string = malloc(size);
      if (!string)
          return false;
  
      ret_s = fread(string, 1, size, file);
      if (ret_s < size) {
          free(string);
          return false;
      }
  
      *string_out = string;
      *size_out = size;
      return true;
  }
  
  void
  unmap_file(char *str, size_t size)
  {
      free(str);
  }
  
  #endif
  

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