Mark internal nss symbols with attribute_hidden [BZ #18822]

Mark internal nss symbols with attribute_hidden to allow direct access
within libc.so and libc.a without using GOT nor PLT.

Tested on x86-64 with and without --disable-nscd.

	[BZ #18822]
	* grp/initgroups.c (__nss_group_database): Removed.
	(__nss_initgroups_database): Likewise.
	* nscd/gai.c (__nss_hosts_database): Likewise.
	* nss/XXX-lookup.c (DATABASE_NAME_SYMBOL): Likewise.
	* posix/tst-rfc3484-2.c (__nss_hosts_database): Likewise.
	* posix/tst-rfc3484-3.c (__nss_hosts_database): Likewise.
	* posix/tst-rfc3484.c (__nss_hosts_database): Likewise.
	* sysdeps/posix/getaddrinfo.c (__nss_hosts_database): Likewise.
	* nss/getXXent.c (INTERNAL (REENTRANT_GETNAME)): Add
	attribute_hidden.
	* nss/nsswitch.c (__nss_database_custom): Define only if
	USE_NSCD is defined.
	(__nss_configure_lookup): Use __nss_database_custom only if
	USE_NSCD is defined.
	* nss/nsswitch.h (__nss_database_custom): Declare only if
	USE_NSCD is defined.  Add attribute_hidden.
	(__nss_setent): Add attribute_hidden.
	(__nss_endent): Likewise.
	(__nss_getent_r): Likewise.
	(__nss_getent): Likewise.
	(DEFINE_DATABASE): Declare __nss_##arg##_database.

11 files changed, 45 insertions, 23 deletions

diff --git a/ChangeLog b/ChangeLog
index 170d3ac..680f377 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,28 @@
+2017-08-21  H.J. Lu  <hongjiu.lu@intel.com>
+
+	[BZ #18822]
+	* grp/initgroups.c (__nss_group_database): Removed.
+	(__nss_initgroups_database): Likewise.
+	* nscd/gai.c (__nss_hosts_database): Likewise.
+	* nss/XXX-lookup.c (DATABASE_NAME_SYMBOL): Likewise.
+	* posix/tst-rfc3484-2.c (__nss_hosts_database): Likewise.
+	* posix/tst-rfc3484-3.c (__nss_hosts_database): Likewise.
+	* posix/tst-rfc3484.c (__nss_hosts_database): Likewise.
+	* sysdeps/posix/getaddrinfo.c (__nss_hosts_database): Likewise.
+	* nss/getXXent.c (INTERNAL (REENTRANT_GETNAME)): Add
+	attribute_hidden.
+	* nss/nsswitch.c (__nss_database_custom): Define only if
+	USE_NSCD is defined.
+	(__nss_configure_lookup): Use __nss_database_custom only if
+	USE_NSCD is defined.
+	* nss/nsswitch.h (__nss_database_custom): Declare only if
+	USE_NSCD is defined.  Add attribute_hidden.
+	(__nss_setent): Add attribute_hidden.
+	(__nss_endent): Likewise.
+	(__nss_getent_r): Likewise.
+	(__nss_getent): Likewise.
+	(DEFINE_DATABASE): Declare __nss_##arg##_database.
+
 2017-08-20  H.J. Lu  <hongjiu.lu@intel.com>
 
 	[BZ #18822]
diff --git a/grp/initgroups.c b/grp/initgroups.c
index 0d5b841..3e4a3de 100644
--- a/grp/initgroups.c
+++ b/grp/initgroups.c
@@ -36,8 +36,6 @@ typedef enum nss_status (*initgroups_dyn_function) (const char *, gid_t,
 						    long int *, long int *,
 						    gid_t **, long int, int *);
 
-extern service_user *__nss_group_database attribute_hidden;
-service_user *__nss_initgroups_database;
 static bool use_initgroups_entry;
 
 
diff --git a/nscd/gai.c b/nscd/gai.c
index a1aeada..084a1fe 100644
--- a/nscd/gai.c
+++ b/nscd/gai.c
@@ -43,6 +43,3 @@
 #ifdef HAVE_LIBIDN
 # include <libidn/idn-stub.c>
 #endif
-
-/* Some variables normally defined in libc.  */
-service_user *__nss_hosts_database;
diff --git a/nss/XXX-lookup.c b/nss/XXX-lookup.c
index 4941769..839c96e 100644
--- a/nss/XXX-lookup.c
+++ b/nss/XXX-lookup.c
@@ -52,8 +52,6 @@
 #define DEFAULT_CONFIG NULL
 #endif
 
-service_user *DATABASE_NAME_SYMBOL attribute_hidden;
-
 int
 DB_LOOKUP_FCT (service_user **ni, const char *fct_name, const char *fct2_name,
 	       void **fctp)
diff --git a/nss/getXXent.c b/nss/getXXent.c
index aad3741..31bd24b 100644
--- a/nss/getXXent.c
+++ b/nss/getXXent.c
@@ -56,7 +56,7 @@
 /* Prototype of the reentrant version.  */
 extern int INTERNAL (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer,
 					 size_t buflen, LOOKUP_TYPE **result
-					 H_ERRNO_PARM);
+					 H_ERRNO_PARM) attribute_hidden;
 
 /* We need to protect the dynamic buffer handling.  */
 __libc_lock_define_initialized (static, lock);
diff --git a/nss/nsswitch.c b/nss/nsswitch.c
index 8f31658..834bef6 100644
--- a/nss/nsswitch.c
+++ b/nss/nsswitch.c
@@ -73,8 +73,10 @@ static const struct
 };
 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
 
+#ifdef USE_NSCD
 /* Flags whether custom rules for database is set.  */
 bool __nss_database_custom[NSS_DBSIDX_max];
+#endif
 
 
 __libc_lock_define_initialized (static, lock)
@@ -304,7 +306,9 @@ __nss_configure_lookup (const char *dbname, const char *service_line)
 
   /* Install new rules.  */
   *databases[cnt].dbp = new_db;
+#ifdef USE_NSCD
   __nss_database_custom[cnt] = true;
+#endif
 
   __libc_lock_unlock (lock);
 
diff --git a/nss/nsswitch.h b/nss/nsswitch.h
index 2b86d63..ab0a512 100644
--- a/nss/nsswitch.h
+++ b/nss/nsswitch.h
@@ -96,17 +96,19 @@ typedef struct name_database
 } name_database;
 
 
+#ifdef USE_NSCD
 /* Indices into DATABASES in nsswitch.c and __NSS_DATABASE_CUSTOM.  */
 enum
   {
-#define DEFINE_DATABASE(arg) NSS_DBSIDX_##arg,
-#include "databases.def"
-#undef DEFINE_DATABASE
+# define DEFINE_DATABASE(arg) NSS_DBSIDX_##arg,
+# include "databases.def"
+# undef DEFINE_DATABASE
     NSS_DBSIDX_max
   };
 
 /* Flags whether custom rules for database is set.  */
-extern bool __nss_database_custom[NSS_DBSIDX_max];
+extern bool __nss_database_custom[NSS_DBSIDX_max] attribute_hidden;
+#endif
 
 /* Warning for NSS functions, which don't require dlopen if glibc
    was built with --enable-static-nss.  */
@@ -180,11 +182,13 @@ extern void __nss_setent (const char *func_name,
 			  db_lookup_function lookup_fct,
 			  service_user **nip, service_user **startp,
 			  service_user **last_nip, int stayon,
-			  int *stayon_tmp, int res);
+			  int *stayon_tmp, int res)
+     attribute_hidden;
 extern void __nss_endent (const char *func_name,
 			  db_lookup_function lookup_fct,
 			  service_user **nip, service_user **startp,
-			  service_user **last_nip, int res);
+			  service_user **last_nip, int res)
+     attribute_hidden;
 extern int __nss_getent_r (const char *getent_func_name,
 			   const char *setent_func_name,
 			   db_lookup_function lookup_fct,
@@ -192,10 +196,12 @@ extern int __nss_getent_r (const char *getent_func_name,
 			   service_user **last_nip, int *stayon_tmp,
 			   int res,
 			   void *resbuf, char *buffer, size_t buflen,
-			   void **result, int *h_errnop);
+			   void **result, int *h_errnop)
+     attribute_hidden;
 extern void *__nss_getent (getent_r_function func,
 			   void **resbuf, char **buffer, size_t buflen,
-			   size_t *buffer_size, int *h_errnop);
+			   size_t *buffer_size, int *h_errnop)
+     attribute_hidden;
 struct resolv_context;
 struct hostent;
 extern int __nss_hostname_digits_dots_context (struct resolv_context *,
@@ -221,6 +227,7 @@ libc_hidden_proto (__nss_hostname_digits_dots)
 
 /* Prototypes for __nss_*_lookup2 functions.  */
 #define DEFINE_DATABASE(arg)				    \
+  service_user *__nss_##arg##_database attribute_hidden;    \
   int __nss_##arg##_lookup2 (service_user **, const char *, \
 			     const char *, void **);	    \
   libc_hidden_proto (__nss_##arg##_lookup2)
diff --git a/posix/tst-rfc3484-2.c b/posix/tst-rfc3484-2.c
index ee92813..f509534 100644
--- a/posix/tst-rfc3484-2.c
+++ b/posix/tst-rfc3484-2.c
@@ -58,8 +58,6 @@ _res_hconf_init (void)
 #undef	USE_NSCD
 #include "../sysdeps/posix/getaddrinfo.c"
 
-service_user *__nss_hosts_database attribute_hidden;
-
 
 /* This is the beginning of the real test code.  The above defines
    (among other things) the function rfc3484_sort.  */
diff --git a/posix/tst-rfc3484-3.c b/posix/tst-rfc3484-3.c
index c987366..ae44087 100644
--- a/posix/tst-rfc3484-3.c
+++ b/posix/tst-rfc3484-3.c
@@ -58,8 +58,6 @@ _res_hconf_init (void)
 #undef	USE_NSCD
 #include "../sysdeps/posix/getaddrinfo.c"
 
-service_user *__nss_hosts_database attribute_hidden;
-
 
 /* This is the beginning of the real test code.  The above defines
    (among other things) the function rfc3484_sort.  */
diff --git a/posix/tst-rfc3484.c b/posix/tst-rfc3484.c
index 73c4dff..7f191ab 100644
--- a/posix/tst-rfc3484.c
+++ b/posix/tst-rfc3484.c
@@ -58,8 +58,6 @@ _res_hconf_init (void)
 #undef	USE_NSCD
 #include "../sysdeps/posix/getaddrinfo.c"
 
-service_user *__nss_hosts_database attribute_hidden;
-
 
 /* This is the beginning of the real test code.  The above defines
    (among other things) the function rfc3484_sort.  */
diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c
index f02bbbe..fcc5d79 100644
--- a/sysdeps/posix/getaddrinfo.c
+++ b/sysdeps/posix/getaddrinfo.c
@@ -318,7 +318,6 @@ typedef enum nss_status (*nss_gethostbyname3_r)
 typedef enum nss_status (*nss_getcanonname_r)
   (const char *name, char *buffer, size_t buflen, char **result,
    int *errnop, int *h_errnop);
-extern service_user *__nss_hosts_database attribute_hidden;
 
 /* This function is called if a canonical name is requested, but if
    the service function did not provide it.  It tries to obtain the