Fix pathconf basename namespace (bug 18444).

pathconf (sysdeps/unix/sysv/linux/pathconf.c) uses basename.  But
pathconf is in POSIX back to 1990 while basename is only reserved with
external linkage in those standards including XPG functions.  This
patch fixes this namespace issue in the usual way, renaming basename
to __basename and making it into a weak alias.

Tested for x86_64 and x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by the patch).

	[BZ #18444]
	* string/basename.c (basename): Rename to __basename and define as
	weak alias of __basename.  Use libc_hidden_weak.
	* include/string.h (__basename): Declare.  Use libc_hidden_proto.
	* sysdeps/unix/sysv/linux/pathconf.c (distinguish_extX): Call
	__basename instead of basename.
	* conform/Makefile (test-xfail-POSIX2008/unistd.h/linknamespace):
	Remove variable.
	(test-xfail-XOPEN2K8/unistd.h/linknamespace): Likewise.

6 files changed, 20 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 27267b1f22..6a44067db4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2015-05-22  Joseph Myers  <joseph@codesourcery.com>
+
+	[BZ #18444]
+	* string/basename.c (basename): Rename to __basename and define as
+	weak alias of __basename.  Use libc_hidden_weak.
+	* include/string.h (__basename): Declare.  Use libc_hidden_proto.
+	* sysdeps/unix/sysv/linux/pathconf.c (distinguish_extX): Call
+	__basename instead of basename.
+	* conform/Makefile (test-xfail-POSIX2008/unistd.h/linknamespace):
+	Remove variable.
+	(test-xfail-XOPEN2K8/unistd.h/linknamespace): Likewise.
+
 2015-05-18  Florian Weimer  <fweimer@redhat.com>
 
 	* libio/libioP.h (_IO_MEMBER_TYPE, _IO_CAST_FIELD_ACCESS)
diff --git a/NEWS b/NEWS
index 324f437a87..56aa6d7f7e 100644
--- a/NEWS
+++ b/NEWS
@@ -18,7 +18,7 @@ Version 2.22
   18030, 18032, 18036, 18038, 18039, 18042, 18043, 18046, 18047, 18049,
   18068, 18080, 18093, 18100, 18104, 18110, 18111, 18125, 18128, 18138,
   18185, 18196, 18197, 18206, 18210, 18211, 18217, 18220, 18221, 18244,
-  18247, 18287, 18319, 18333, 18346, 18397, 18409, 18418, 18434.
+  18247, 18287, 18319, 18333, 18346, 18397, 18409, 18418, 18434, 18444.
 
 * Cache information can be queried via sysconf() function on s390 e.g. with
   _SC_LEVEL1_ICACHE_SIZE as argument.
diff --git a/conform/Makefile b/conform/Makefile
index bdd7203f9e..a81ed54812 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -395,10 +395,8 @@ test-xfail-XOPEN2K/wordexp.h/linknamespace = yes
 test-xfail-POSIX2008/grp.h/linknamespace = yes
 test-xfail-POSIX2008/netdb.h/linknamespace = yes
 test-xfail-POSIX2008/semaphore.h/linknamespace = yes
-test-xfail-POSIX2008/unistd.h/linknamespace = yes
 test-xfail-XOPEN2K8/fmtmsg.h/linknamespace = yes
 test-xfail-XOPEN2K8/grp.h/linknamespace = yes
 test-xfail-XOPEN2K8/netdb.h/linknamespace = yes
 test-xfail-XOPEN2K8/pwd.h/linknamespace = yes
 test-xfail-XOPEN2K8/syslog.h/linknamespace = yes
-test-xfail-XOPEN2K8/unistd.h/linknamespace = yes
diff --git a/include/string.h b/include/string.h
index 034e2953df..89f00fda4e 100644
--- a/include/string.h
+++ b/include/string.h
@@ -82,6 +82,8 @@ libc_hidden_proto (__strndup)
 libc_hidden_proto (__strerror_r)
 libc_hidden_proto (__strverscmp)
 libc_hidden_proto (basename)
+extern char *__basename (const char *__filename) __THROW __nonnull ((1));
+libc_hidden_proto (__basename)
 libc_hidden_proto (strcoll)
 libc_hidden_proto (__strcoll_l)
 libc_hidden_proto (__strxfrm_l)
diff --git a/string/basename.c b/string/basename.c
index 5052ebf4df..4caabca8f0 100644
--- a/string/basename.c
+++ b/string/basename.c
@@ -19,9 +19,11 @@
 #include <string.h>
 
 char *
-basename (const char *filename)
+__basename (const char *filename)
 {
   char *p = strrchr (filename, '/');
   return p ? p + 1 : (char *) filename;
 }
-libc_hidden_def (basename)
+libc_hidden_def (__basename)
+weak_alias (__basename, basename)
+libc_hidden_weak (basename)
diff --git a/sysdeps/unix/sysv/linux/pathconf.c b/sysdeps/unix/sysv/linux/pathconf.c
index e6fd7b5c61..37f308bad7 100644
--- a/sysdeps/unix/sysv/linux/pathconf.c
+++ b/sysdeps/unix/sysv/linux/pathconf.c
@@ -79,7 +79,7 @@ distinguish_extX (const struct statfs *fsbuf, const char *file, int fd)
   if (n != -1 && n < sizeof (path))
     {
       path[n] = '\0';
-      char *base = strdupa (basename (path));
+      char *base = strdupa (__basename (path));
       __snprintf (path, sizeof (path), "/sys/fs/ext4/%s", base);
 
       return __access (path, F_OK) == 0 ? EXT4_LINK_MAX : EXT2_LINK_MAX;