sysdeps/posix/dl-fileid.h

   1 /* File identity for the dynamic linker.  Generic POSIX.1 version.
   2    Copyright (C) 2015-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdbool.h>
  20 #include <sys/stat.h>
  21
  22 /* For POSIX.1 systems, the pair of st_dev and st_ino constitute
  23    a unique identifier for a file.  */
  24 struct r_file_id
  25   {
  26     dev_t dev;
  27     ino64_t ino;
  28   };
  29
  30 /* Sample FD to fill in *ID.  Returns true on success.
  31    On error, returns false, with errno set.  */
  32 static inline bool
  33 _dl_get_file_id (int fd, struct r_file_id *id)
  34 {
  35   struct __stat64_t64 st;
  36
  37   if (__glibc_unlikely (__fstat64_time64 (fd, &st) < 0))
  38     return false;
  39
  40   id->dev = st.st_dev;
  41   id->ino = st.st_ino;
  42   return true;
  43 }
  44
  45 /* Compare two results from _dl_get_file_id for equality.  */
  46 static inline bool
  47 _dl_file_id_match_p (const struct r_file_id *a, const struct r_file_id *b)
  48 {
  49   return a->dev == b->dev && a->ino == b->ino;
  50 }