Fix pathconf statvfs namespace (bug 18507)

[Joseph Myers <joseph at codesourcery dot com>]

pathconf uses __statvfs64, and fpathconf uses __fstatvfs64.  On
systems using sysdeps/unix/sysv/linux/wordsize-64, __statvfs64 then
brings in the strong symbol statvfs, and __fstatvfs64 brings in the
strong symbol fstatvfs, which are not in all the standards that have
pathconf and fpathconf.  This patch fixes this by making those symbols
into weak aliases.

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

2015-06-09  Joseph Myers  <joseph@codesourcery.com>

	[BZ #18507]
	* sysdeps/unix/sysv/linux/fstatvfs.c (fstatvfs): Rename to
	__fstatvfs and define as weak alias of __fstatvfs.  Use
	libc_hidden_weak.
	* sysdeps/unix/sysv/linux/statvfs.c (statvs): Rename to __statvfs
	and define as weak alias of __statvfs.  Use libc_hidden_weak.
	* sysdeps/unix/sysv/linux/wordsize-64/fstatvfs.c (__fstatvfs64):
	Define as alias of __fstatvfs, not fstatvfs.
	(fstatvfs64): Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/statvfs.c (__statvfs64):
	Define as alias of __statvfs, not statvfs.
	(statvfs64): Likewise.
	* conform/Makefile (test-xfail-POSIX/unistd.h/linknamespace):
	Remove variable.

diff --git a/conform/Makefile b/conform/Makefile
index 943a196..12ccc64 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -361,7 +361,6 @@ test-xfail-POSIX/aio.h/linknamespace = yes
 test-xfail-POSIX/mqueue.h/linknamespace = yes
 test-xfail-POSIX/regex.h/linknamespace = yes
 test-xfail-POSIX/semaphore.h/linknamespace = yes
-test-xfail-POSIX/unistd.h/linknamespace = yes
 test-xfail-UNIX98/fmtmsg.h/linknamespace = yes
 test-xfail-UNIX98/mqueue.h/linknamespace = yes
 test-xfail-UNIX98/netdb.h/linknamespace = yes
diff --git a/sysdeps/unix/sysv/linux/fstatvfs.c b/sysdeps/unix/sysv/linux/fstatvfs.c
index 4638526..1b61330 100644
--- a/sysdeps/unix/sysv/linux/fstatvfs.c
+++ b/sysdeps/unix/sysv/linux/fstatvfs.c
@@ -26,7 +26,7 @@ extern void __internal_statvfs (const char *name, struct statvfs *buf,
 
 
 int
-fstatvfs (int fd, struct statvfs *buf)
+__fstatvfs (int fd, struct statvfs *buf)
 {
   struct statfs fsbuf;
 
@@ -40,4 +40,5 @@ fstatvfs (int fd, struct statvfs *buf)
   /* We signal success if the statfs call succeeded.  */
   return 0;
 }
-libc_hidden_def (fstatvfs)
+weak_alias (__fstatvfs, fstatvfs)
+libc_hidden_weak (fstatvfs)
diff --git a/sysdeps/unix/sysv/linux/statvfs.c b/sysdeps/unix/sysv/linux/statvfs.c
index 7af2fc5..e4ab62a 100644
--- a/sysdeps/unix/sysv/linux/statvfs.c
+++ b/sysdeps/unix/sysv/linux/statvfs.c
@@ -26,7 +26,7 @@ extern void __internal_statvfs (const char *name, struct statvfs *buf,
 
 
 int
-statvfs (const char *file, struct statvfs *buf)
+__statvfs (const char *file, struct statvfs *buf)
 {
   struct statfs fsbuf;
 
@@ -40,4 +40,5 @@ statvfs (const char *file, struct statvfs *buf)
   /* We signal success if the statfs call succeeded.  */
   return 0;
 }
-libc_hidden_def (statvfs)
+weak_alias (__statvfs, statvfs)
+libc_hidden_weak (statvfs)
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/fstatvfs.c b/sysdeps/unix/sysv/linux/wordsize-64/fstatvfs.c
index d04bcd4..5803b6f 100644
--- a/sysdeps/unix/sysv/linux/wordsize-64/fstatvfs.c
+++ b/sysdeps/unix/sysv/linux/wordsize-64/fstatvfs.c
@@ -1,5 +1,5 @@
 #define __fstatvfs64(file, buf) __no_fstatvfs64(file, buf)
 #define fstatvfs64(file, buf) no_fstatvfs64(file, buf)
 #include "../fstatvfs.c"
-strong_alias (fstatvfs, __fstatvfs64)
-weak_alias (fstatvfs, fstatvfs64)
+strong_alias (__fstatvfs, __fstatvfs64)
+weak_alias (__fstatvfs, fstatvfs64)
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/statvfs.c b/sysdeps/unix/sysv/linux/wordsize-64/statvfs.c
index f369976..1e1c963 100644
--- a/sysdeps/unix/sysv/linux/wordsize-64/statvfs.c
+++ b/sysdeps/unix/sysv/linux/wordsize-64/statvfs.c
@@ -1,5 +1,5 @@
 #define __statvfs64(file, buf) __no_statvfs64(file, buf)
 #define statvfs64(file, buf) no_statvfs64(file, buf)
 #include "../statvfs.c"
-strong_alias (statvfs, __statvfs64)
-weak_alias (statvfs, statvfs64)
+strong_alias (__statvfs, __statvfs64)
+weak_alias (__statvfs, statvfs64)

-- 
Joseph S. Myers
joseph@codesourcery.com