Fix __get_nprocs fgets_unlocked namespace (bug 17582).

__get_nprocs is called from malloc code, but calls fgets_unlocked,
which is not an ISO C or POSIX function.  This patch fixes it to call
a new __fgets_unlocked name instead.

Note: there are various other uses of fgets_unlocked in glibc's
libraries, and I haven't yet investigated which others might also be
problematic (called directly or indirectly from standard functions)
and so need to change to use __fgets_unlocked.

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

	[BZ #17582]
	* libio/iofgets.c [weak_alias && !_IO_MTSAFE_IO]
	(__fgets_unlocked): Add alias of _IO_fgets.  Use libc_hidden_def.
	* libio/iofgets_u.c (fgets_unlocked): Rename to __fgets_unlocked
	and define as weak alias of __fgets_unlocked.  Use
	libc_hidden_weak.
	(__fgets_unlocked): Use libc_hidden_def.
	* include/stdio.h (__fgets_unlocked): Declare.  Use
	libc_hidden_proto.
	* sysdeps/unix/sysv/linux/getsysstats.c (phys_pages_info): Use
	__fgets_unlocked instead of fgets_unlocked.
	* sysdeps/unix/sysv/linux/alpha/getsysstats.c
	(GET_NPROCS_CONF_PARSER): Likewise.
	* sysdeps/unix/sysv/linux/sparc/getsysstats.c
	(GET_NPROCS_CONF_PARSER): Likewise.

ChangeLog

@@ -1,5 +1,21 @@
 2014-11-12  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #17582]
+	* libio/iofgets.c [weak_alias && !_IO_MTSAFE_IO]
+	(__fgets_unlocked): Add alias of _IO_fgets.  Use libc_hidden_def.
+	* libio/iofgets_u.c (fgets_unlocked): Rename to __fgets_unlocked
+	and define as weak alias of __fgets_unlocked.  Use
+	libc_hidden_weak.
+	(__fgets_unlocked): Use libc_hidden_def.
+	* include/stdio.h (__fgets_unlocked): Declare.  Use
+	libc_hidden_proto.
+	* sysdeps/unix/sysv/linux/getsysstats.c (phys_pages_info): Use
+	__fgets_unlocked instead of fgets_unlocked.
+	* sysdeps/unix/sysv/linux/alpha/getsysstats.c
+	(GET_NPROCS_CONF_PARSER): Likewise.
+	* sysdeps/unix/sysv/linux/sparc/getsysstats.c
+	(GET_NPROCS_CONF_PARSER): Likewise.
+
 	[BZ #17574]
 	* wcsmbs/wmemset.c (wmemset): Rename to __wmemset and define as
 	weak alias of __wmemset.  Use libc_hidden_weak.

NEWS

@@ -11,7 +11,7 @@ Version 2.21
 
   6652, 12926, 14132, 14138, 14171, 15215, 15884, 17266, 17344, 17363,
   17370, 17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508, 17522,
-  17555, 17570, 17571, 17572, 17573, 17574, 17583, 17584.
+  17555, 17570, 17571, 17572, 17573, 17574, 17582, 17583, 17584.
 
 * New locales: tu_IN, bh_IN.
 

include/stdio.h

@@ -155,6 +155,8 @@ extern __typeof (fread_unlocked) __fread_unlocked;
 libc_hidden_proto (__fread_unlocked)
 libc_hidden_proto (fwrite_unlocked)
 libc_hidden_proto (fgets_unlocked)
+extern __typeof (fgets_unlocked) __fgets_unlocked;
+libc_hidden_proto (__fgets_unlocked)
 libc_hidden_proto (fputs_unlocked)
 libc_hidden_proto (fmemopen)
 libc_hidden_proto (open_memstream)

libio/iofgets.c

@@ -73,6 +73,8 @@ _IO_fgets (buf, n, fp)
 weak_alias (_IO_fgets, fgets)
 
 # ifndef _IO_MTSAFE_IO
+strong_alias (_IO_fgets, __fgets_unlocked)
+libc_hidden_def (__fgets_unlocked)
 weak_alias (_IO_fgets, fgets_unlocked)
 libc_hidden_weak (fgets_unlocked)
 # endif

libio/iofgets_u.c

@@ -28,7 +28,7 @@
 #include <stdio.h>
 
 char *
-fgets_unlocked (buf, n, fp)
+__fgets_unlocked (buf, n, fp)
      char *buf;
      int n;
      _IO_FILE *fp;
@@ -66,4 +66,6 @@ fgets_unlocked (buf, n, fp)
   fp->_IO_file_flags |= old_error;
   return result;
 }
-libc_hidden_def (fgets_unlocked)
+libc_hidden_def (__fgets_unlocked)
+weak_alias (__fgets_unlocked, fgets_unlocked)
+libc_hidden_weak (fgets_unlocked)

sysdeps/unix/sysv/linux/alpha/getsysstats.c

@@ -47,7 +47,7 @@
 	 the kernel will not generate them.  8192 bytes are really enough. \
 	 If there is no "CPUs ..." line then we are on a UP system.  */	   \
       (RESULT) = 1;							   \
-      while (fgets_unlocked ((BUFFER), sizeof (BUFFER), (FP)) != NULL)	   \
+      while (__fgets_unlocked ((BUFFER), sizeof (BUFFER), (FP)) != NULL)   \
 	if ((sscanf (buffer, "cpus detected : %d", &(RESULT)) == 1)	   \
 	    || (sscanf (buffer, "CPUs probed %d", &(RESULT)) == 1))	   \
 	  break;							   \

sysdeps/unix/sysv/linux/getsysstats.c

@@ -299,7 +299,7 @@ phys_pages_info (const char *format)
 	 string "processor".  We don't have to fear extremely long
 	 lines since the kernel will not generate them.  8192
 	 bytes are really enough.  */
-      while (fgets_unlocked (buffer, sizeof buffer, fp) != NULL)
+      while (__fgets_unlocked (buffer, sizeof buffer, fp) != NULL)
 	if (sscanf (buffer, format, &result) == 1)
 	  {
 	    result /= (__getpagesize () / 1024);

sysdeps/unix/sysv/linux/sparc/getsysstats.c

@@ -46,7 +46,7 @@
 	 probed cpus.  We don't have to fear extremely long lines since	 \
 	 the kernel will not generate them.  8192 bytes are really	 \
 	 enough.  */							 \
-      while (fgets_unlocked ((BUFFER), sizeof (BUFFER), (FP)) != NULL)	 \
+      while (__fgets_unlocked ((BUFFER), sizeof (BUFFER), (FP)) != NULL) \
 	if (sscanf (buffer, "ncpus probed : %d", &(RESULT)) == 1)	 \
 	  break;							 \
     }									 \