T_REMOVEDIR and AT_EACCESS have the same value.

Add comments to fcntl.h explaining why AT_REMOVEDIR
and AT_EACCESS can have the same value.

diff --git a/ChangeLog b/ChangeLog
index a175d61..c82ed84 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2013-03-06  Patsy Franklin  <pfrankli@redhat.com>
+
+       * io/fcntl.h: Added a comment about AT_EACCESS and AT_REMOVEDIR.
+
 2013-03-06  Andreas Jaeger  <aj@suse.de>
 
        * sysdeps/unix/sysv/linux/bits/mman-linux.h (MAP_ANONYMOUS): Allow

diff --git a/io/fcntl.h b/io/fcntl.h
index 61834ce..14ccae0 100644 (file)
--- a/io/fcntl.h
+++ b/io/fcntl.h
@@ -129,6 +129,12 @@ typedef __pid_t pid_t;
 # define SEEK_END      2       /* Seek from end of file.  */
 #endif /* XPG */
 
+/* The constants AT_REMOVEDIR and AT_EACCESS have the same value.  AT_EASSESS
+   is meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
+   unlinkat.  The two functions do completely different things and therefore,
+   the flags can be allowed to overlap.  For example, passing AT_REMOVEDIR to
+   faccessat would be undefined behavior and thus treating it equivalent to
+   AT_EACCESS is valid undefined behavior.  */
 #ifdef __USE_ATFILE
 # define AT_FDCWD              -100    /* Special value used to indicate
                                           the *at functions should use the