Fix getpass fflush_unlocked namespace (bug 18540).

The getpass function (XPG3 / XPG4 / UNIX98) calls fflush_unlocked (not
in any of those standards).  This patch fixes this by making
fflush_unlocked into a weak alias for __fflush_unlocked and calling
__fflush_unlocked from getpass.

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

	[BZ #18540]
	* libio/iofflush.c [!_IO_MTSAFE_IO] (__fflush_unlocked): Define as
	strong alias of _IO_fflush.  Use libc_hidden_def.
	* libio/iofflush_u.c (fflush_unlocked): Rename to
	__fflush_unlocked and define as weak alias of __fflush_unlocked.
	Use libc_hidden_weak.
	* include/stdio.h (__fflush_unlocked): Declare.  Use
	libc_hidden_proto.
	* misc/getpass.c (getpass): Call __fflush_unlocked instead of
	fflush_unlocked.
	* conform/Makefile (test-xfail-UNIX98/unistd.h/linknamespace):
	Remove variable.

ChangeLog

@@ -1,5 +1,18 @@
 2015-06-17  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #18540]
+	* libio/iofflush.c [!_IO_MTSAFE_IO] (__fflush_unlocked): Define as
+	strong alias of _IO_fflush.  Use libc_hidden_def.
+	* libio/iofflush_u.c (fflush_unlocked): Rename to
+	__fflush_unlocked and define as weak alias of __fflush_unlocked.
+	Use libc_hidden_weak.
+	* include/stdio.h (__fflush_unlocked): Declare.  Use
+	libc_hidden_proto.
+	* misc/getpass.c (getpass): Call __fflush_unlocked instead of
+	fflush_unlocked.
+	* conform/Makefile (test-xfail-UNIX98/unistd.h/linknamespace):
+	Remove variable.
+
 	[BZ #18539]
 	* stdlib/fmtmsg.c (addseverity): Rename to __addseverity and
 	define as weak alias of __addseverity.

NEWS

@@ -22,7 +22,7 @@ Version 2.22
   18324, 18333, 18346, 18397, 18409, 18410, 18412, 18418, 18422, 18434,
   18444, 18468, 18469, 18470, 18479, 18483, 18495, 18496, 18497, 18498,
   18507, 18512, 18519, 18520, 18522, 18527, 18528, 18529, 18530, 18532,
-  18533, 18534, 18536, 18539.
+  18533, 18534, 18536, 18539, 18540.
 
 * Cache information can be queried via sysconf() function on s390 e.g. with
   _SC_LEVEL1_ICACHE_SIZE as argument.

conform/Makefile

@@ -348,5 +348,4 @@ test-xfail-XPG3/unistd.h/linknamespace = yes
 test-xfail-XPG4/unistd.h/linknamespace = yes
 test-xfail-POSIX/mqueue.h/linknamespace = yes
 test-xfail-UNIX98/mqueue.h/linknamespace = yes
-test-xfail-UNIX98/unistd.h/linknamespace = yes
 test-xfail-UNIX98/wchar.h/linknamespace = yes

include/stdio.h

@@ -155,6 +155,8 @@ extern __typeof (ftello) __ftello;
 libc_hidden_proto (__ftello)
 libc_hidden_proto (fflush)
 libc_hidden_proto (fflush_unlocked)
+extern __typeof (fflush_unlocked) __fflush_unlocked;
+libc_hidden_proto (__fflush_unlocked)
 extern __typeof (fread_unlocked) __fread_unlocked;
 libc_hidden_proto (__fread_unlocked)
 libc_hidden_proto (fwrite_unlocked)

libio/iofflush.c

@@ -50,6 +50,8 @@ weak_alias (_IO_fflush, fflush)
 libc_hidden_weak (fflush)
 
 #ifndef _IO_MTSAFE_IO
+strong_alias (_IO_fflush, __fflush_unlocked)
+libc_hidden_def (__fflush_unlocked)
 weak_alias (_IO_fflush, fflush_unlocked)
 libc_hidden_weak (fflush_unlocked)
 #endif

libio/iofflush_u.c

@@ -28,7 +28,7 @@
 #include <stdio.h>
 
 int
-fflush_unlocked (fp)
+__fflush_unlocked (fp)
      _IO_FILE *fp;
 {
   if (fp == NULL)
@@ -39,4 +39,6 @@ fflush_unlocked (fp)
       return _IO_SYNC (fp) ? EOF : 0;
     }
 }
-libc_hidden_def (fflush_unlocked)
+libc_hidden_def (__fflush_unlocked)
+weak_alias (__fflush_unlocked, fflush_unlocked)
+libc_hidden_weak (fflush_unlocked)

misc/getpass.c

@@ -91,7 +91,7 @@ getpass (prompt)
 
   /* Write the prompt.  */
   __fxprintf (out, "%s", prompt);
-  fflush_unlocked (out);
+  __fflush_unlocked (out);
 
   /* Read the password.  */
   nread = __getline (&buf, &bufsize, in);