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.

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]

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;
 
 

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;

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)

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);

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);
 

nss/nsswitch.h

@@ -96,6 +96,7 @@ typedef struct name_database
 } name_database;
 
 
+#ifdef USE_NSCD
 /* Indices into DATABASES in nsswitch.c and __NSS_DATABASE_CUSTOM.  */
 enum
   {
@@ -106,7 +107,8 @@ enum
   };
 
 /* 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)

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.  */

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.  */

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.  */

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