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Re: [PATCH 2/3] Mark internal nss symbols with attribute_hidden [BZ #18822]
On Mon, Aug 21, 2017 at 2:58 AM, Florian Weimer <fweimer@redhat.com> wrote:
> On 08/20/2017 07:18 PM, H.J. Lu wrote:
>> diff --git a/grp/initgroups.c b/grp/initgroups.c
>> index 0d5b841796..0ffb5ceea1 100644
>> --- a/grp/initgroups.c
>> +++ b/grp/initgroups.c
>> @@ -37,7 +37,6 @@ typedef enum nss_status (*initgroups_dyn_function) (const char *, gid_t,
>> gid_t **, long int, int *);
>>
>> extern service_user *__nss_group_database attribute_hidden;
>> -service_user *__nss_initgroups_database;
>
> The declaration of __nss_group_database is no longer necessary, either.
>
> I think these additional declarations can be removed as well"
>
> nscd/gai.c:service_user *__nss_hosts_database;
> posix/tst-rfc3484-2.c:service_user *__nss_hosts_database attribute_hidden;
> posix/tst-rfc3484-3.c:service_user *__nss_hosts_database attribute_hidden;
> posix/tst-rfc3484.c:service_user *__nss_hosts_database attribute_hidden;
> sysdeps/posix/getaddrinfo.c:extern service_user *__nss_hosts_database
> attribute_hidden;
>
Here is the updated patch. Tested on x86-64.
I will check it in shortly.
Thanks.
--
H.J.
From 1b8ecdda717ebe4cf01f9af3d4996e5dec23855c Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 18 Aug 2017 12:27:59 -0700
Subject: [PATCH] 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.
---
grp/initgroups.c | 2 --
nscd/gai.c | 3 ---
nss/XXX-lookup.c | 2 --
nss/getXXent.c | 2 +-
nss/nsswitch.c | 4 ++++
nss/nsswitch.h | 23 +++++++++++++++--------
posix/tst-rfc3484-2.c | 2 --
posix/tst-rfc3484-3.c | 2 --
posix/tst-rfc3484.c | 2 --
sysdeps/posix/getaddrinfo.c | 1 -
10 files changed, 20 insertions(+), 23 deletions(-)
diff --git a/grp/initgroups.c b/grp/initgroups.c
index 0d5b841796..3e4a3de11f 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 a1aeadadc3..084a1fe68a 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 49417691b2..839c96e194 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 aad374197f..31bd24b924 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 8f31658523..834bef6f9c 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 2b86d63ddb..ab0a512d40 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 ee9281394b..f509534ca9 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 c987366e4e..ae44087a10 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 73c4dffcf5..7f191abbbc 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 f02bbbe533..fcc5d79362 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
--
2.13.5