Fix qsort_r namespace (bug 17571)

[Joseph Myers <joseph at codesourcery dot com>]

qsort_r is defined in the same file as qsort, but is not an ISO C
function, so should be a weak alias for __qsort_r.  The uses in
getaddrinfo should also call __qsort_r, since getaddrinfo is a POSIX
function and qsort_r isn't.  This patch implements this, fixing one of
the bugs shown in the sample output of my proposed tests for such
namespace issues
<https://sourceware.org/ml/libc-alpha/2014-11/msg00157.html>.  Because
nscd uses the getaddrinfo sources outside libc, as do the tst-rfc3484
tests, a #define of __qsort_r to qsort_r is added there alongside the
similar defines for other libc-internal symbols used in getaddrinfo.

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

2014-11-10  Joseph Myers  <joseph@codesourcery.com>

	[BZ #17571]
	* stdlib/msort.c (qsort_r): Rename to __qsort_r and define as weak
	alias of __qsort_r.
	(qsort): Call __qsort_r instead of qsort_r.
	* include/stdlib.h (qsort_r): Do not call libc_hidden_proto.
	(__qsort_r): Declare.  Call libc_hidden_proto.
	* sysdeps/posix/getaddrinfo.c (getaddrinfo): Call __qsort_r
	instead of qsort_r.
	* nscd/gai.c (__qsort_r): Define to qsort_r.
	* posix/tst-rfc3484.c (__qsort_r): Likewise.
	* posix/tst-rfc3484-2.c (__qsort_r): Likewise.
	* posix/tst-rfc3484-3.c (__qsort_r): Likewise.

diff --git a/include/stdlib.h b/include/stdlib.h
index 8d8c753..b8efbd7 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -37,7 +37,8 @@ extern __typeof (secure_getenv) __libc_secure_getenv;
 libc_hidden_proto (__libc_secure_getenv)
 libc_hidden_proto (bsearch)
 libc_hidden_proto (qsort)
-libc_hidden_proto (qsort_r)
+extern __typeof (qsort_r) __qsort_r;
+libc_hidden_proto (__qsort_r)
 libc_hidden_proto (lrand48_r)
 libc_hidden_proto (wctomb)
 
diff --git a/nscd/gai.c b/nscd/gai.c
index 95373e4..c159c0b 100644
--- a/nscd/gai.c
+++ b/nscd/gai.c
@@ -28,6 +28,7 @@
 #define __sendto sendto
 #define __strchrnul strchrnul
 #define __getline getline
+#define __qsort_r qsort_r
 /* nscd uses 1MB or 2MB thread stacks.  */
 #define __libc_use_alloca(size) (size <= __MAX_ALLOCA_CUTOFF)
 
diff --git a/posix/tst-rfc3484-2.c b/posix/tst-rfc3484-2.c
index fcf8a8c..ee92813 100644
--- a/posix/tst-rfc3484-2.c
+++ b/posix/tst-rfc3484-2.c
@@ -10,6 +10,7 @@
 #define __inet_aton inet_aton
 #define __gethostbyaddr_r gethostbyaddr_r
 #define __gethostbyname2_r gethostbyname2_r
+#define __qsort_r qsort_r
 
 void
 attribute_hidden
diff --git a/posix/tst-rfc3484-3.c b/posix/tst-rfc3484-3.c
index 86d59be..c987366 100644
--- a/posix/tst-rfc3484-3.c
+++ b/posix/tst-rfc3484-3.c
@@ -10,6 +10,7 @@
 #define __inet_aton inet_aton
 #define __gethostbyaddr_r gethostbyaddr_r
 #define __gethostbyname2_r gethostbyname2_r
+#define __qsort_r qsort_r
 
 void
 attribute_hidden
diff --git a/posix/tst-rfc3484.c b/posix/tst-rfc3484.c
index 2726fa0..73c4dff 100644
--- a/posix/tst-rfc3484.c
+++ b/posix/tst-rfc3484.c
@@ -10,6 +10,7 @@
 #define __inet_aton inet_aton
 #define __gethostbyaddr_r gethostbyaddr_r
 #define __gethostbyname2_r gethostbyname2_r
+#define __qsort_r qsort_r
 
 void
 attribute_hidden
diff --git a/stdlib/msort.c b/stdlib/msort.c
index 02ef28b..5ac5df7 100644
--- a/stdlib/msort.c
+++ b/stdlib/msort.c
@@ -162,7 +162,7 @@ msort_with_tmp (const struct msort_param *p, void *b, size_t n)
 
 
 void
-qsort_r (void *b, size_t n, size_t s, __compar_d_fn_t cmp, void *arg)
+__qsort_r (void *b, size_t n, size_t s, __compar_d_fn_t cmp, void *arg)
 {
   size_t size = n * s;
   char *tmp = NULL;
@@ -298,12 +298,13 @@ qsort_r (void *b, size_t n, size_t s, __compar_d_fn_t cmp, void *arg)
     }
   free (tmp);
 }
-libc_hidden_def (qsort_r)
+libc_hidden_def (__qsort_r)
+weak_alias (__qsort_r, qsort_r)
 
 
 void
 qsort (void *b, size_t n, size_t s, __compar_fn_t cmp)
 {
-  return qsort_r (b, n, s, (__compar_d_fn_t) cmp, NULL);
+  return __qsort_r (b, n, s, (__compar_d_fn_t) cmp, NULL);
 }
 libc_hidden_def (qsort)
diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c
index 8f392b9..31bb7e6 100644
--- a/sysdeps/posix/getaddrinfo.c
+++ b/sysdeps/posix/getaddrinfo.c
@@ -2626,11 +2626,11 @@ getaddrinfo (const char *name, const char *service,
 	  __libc_lock_lock (lock);
 	  if (__libc_once_get (old_once) && gaiconf_reload_flag)
 	    gaiconf_reload ();
-	  qsort_r (order, nresults, sizeof (order[0]), rfc3484_sort, &src);
+	  __qsort_r (order, nresults, sizeof (order[0]), rfc3484_sort, &src);
 	  __libc_lock_unlock (lock);
 	}
       else
-	qsort_r (order, nresults, sizeof (order[0]), rfc3484_sort, &src);
+	__qsort_r (order, nresults, sizeof (order[0]), rfc3484_sort, &src);
 
       /* Queue the results up as they come out of sorting.  */
       q = p = results[order[0]].dest_addr;

-- 
Joseph S. Myers
joseph@codesourcery.com