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Re: [PATCH] Mark internal functions with attribute_hidden
On Thu, Aug 17, 2017 at 7:01 AM, Joseph Myers <joseph@codesourcery.com> wrote:
> On Thu, 17 Aug 2017, H.J. Lu wrote:
>
>> Yes, this is target independent. It should benefit static PIE build for all
>> targets. On x86, it bypasses GOT/PLT.
>
> Specifically, on x86 I'd consider this (making functions hidden if they
> are not exported from the shared library containing their definitions) to
> be part of the fix for bug 18822.
>
You are right. Here is the same patch with libc.so size comparison on
i686 and x86-64.
OK for trunk?
Thanks.
--
H.J.
From 695abbdf691d7742b17ab4801c4ffa849cc31978 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sun, 13 Aug 2017 07:00:22 -0700
Subject: [PATCH] Mark internal functions with attribute_hidden [BZ #18822]
Mark internal functions with attribute_hidden to allow direct access to
internal functions within libc.so and libc.a without using GOT nor PLT.
Size comparison of libc.so:
On x86-64:
text data bss dec hex
Before: 1728577 20584 17088 1766249 1af369
After : 1728593 20584 17088 1766265 1af379
The only change is __gconv_release_shlib in iconv/gconv_dl.c is inlined
since it is hidden, which increases the code size of gconv_dl.os by 18
bytes.
On i686:
text data bss dec hex
Before: 1869039 11444 11112 1891595 1cdd0b
After : 1868635 11444 11112 1891191 1cdb77
The code size is decreased by avoiding GOT/PLT for hidden functions.
[BZ #18822]
* iconv/gconv_int.h (__gconv_open): Add attribute_hidden.
(__gconv_close): Likewise.
(__gconv): Likewise.
(__gconv_find_transform): Likewise.
(__gconv_lookup_cache): Likewise.
(__gconv_compare_alias_cache): Likewise.
(__gconv_load_cache): Likewise.
(__gconv_get_path): Likewise.
(__gconv_close_transform): Likewise.
(__gconv_release_cache): Likewise.
(__gconv_find_shlib): Likewise.
(__gconv_release_shlib): Likewise.
(__gconv_get_builtin_trans): Likewise.
(__gconv_compare_alias): Likewise.
* include/dlfcn.h (_dlerror_run): Likewise.
* include/stdio.h (__fortify_fail_abort): Likewise.
* include/time.h (__tz_compute): Likewise.
(__strptime_internal): Likewise.
* intl/gettextP.h (_nl_find_domain): Likewise.
(_nl_load_domain): Likewise.
(_nl_find_msg): Likewise.
* intl/plural-exp.h (FREE_EXPRESSION): Likewise.
(EXTRACT_PLURAL_EXPRESSION): Likewise.
* locale/coll-lookup.h (__collidx_table_lookup): Likewise.
* resolv/gai_misc.h (__gai_enqueue_request): Likewise.
(__gai_find_request): Likewise.
(__gai_remove_request): Likewise.
(__gai_notify): Likewise.
(__gai_notify_only): Likewise.
* sysdeps/generic/aio_misc.h (__aio_sigqueue): Likewise.
* sysdeps/generic/ldsodefs.h (_dl_symbol_value): Likewise.
(_dl_fini): Likewise.
(_dl_non_dynamic_init): Likewise.
(_dl_aux_init): Likewise.
* sysdeps/i386/machine-gmon.h (mcount_internal): Likewise.
* sysdeps/unix/sysv/linux/i386/olddirent.h (__old_getdents64):
Likewise.
* wcsmbs/wcsmbsload.h (__wcsmbs_load_conv): Likewise.
(__wcsmbs_clone_conv): Likewise.
(__wcsmbs_named_conv): Likewise.
---
iconv/gconv_int.h | 31 ++++++++++++++++---------------
include/dlfcn.h | 2 +-
include/stdio.h | 2 +-
include/time.h | 4 ++--
intl/gettextP.h | 8 ++++----
intl/plural-exp.h | 4 ++--
locale/coll-lookup.h | 4 ++--
resolv/gai_misc.h | 10 +++++-----
sysdeps/generic/aio_misc.h | 2 +-
sysdeps/generic/ldsodefs.h | 10 ++++++----
sysdeps/i386/machine-gmon.h | 2 +-
sysdeps/unix/sysv/linux/i386/olddirent.h | 2 +-
wcsmbs/wcsmbsload.h | 6 +++---
13 files changed, 45 insertions(+), 42 deletions(-)
diff --git a/iconv/gconv_int.h b/iconv/gconv_int.h
index 85a67ad31b..52b8aad020 100644
--- a/iconv/gconv_int.h
+++ b/iconv/gconv_int.h
@@ -157,11 +157,11 @@ __libc_lock_define (extern, __gconv_lock attribute_hidden)
/* Return in *HANDLE decriptor for transformation from FROMSET to TOSET. */
extern int __gconv_open (const char *toset, const char *fromset,
__gconv_t *handle, int flags)
- internal_function;
+ internal_function attribute_hidden;
/* Free resources associated with transformation descriptor CD. */
extern int __gconv_close (__gconv_t cd)
- internal_function;
+ internal_function attribute_hidden;
/* Transform at most *INBYTESLEFT bytes from buffer starting at *INBUF
according to rules described by CD and place up to *OUTBYTESLEFT
@@ -170,36 +170,37 @@ extern int __gconv_close (__gconv_t cd)
extern int __gconv (__gconv_t cd, const unsigned char **inbuf,
const unsigned char *inbufend, unsigned char **outbuf,
unsigned char *outbufend, size_t *irreversible)
- internal_function;
+ internal_function attribute_hidden;
/* Return in *HANDLE a pointer to an array with *NSTEPS elements describing
the single steps necessary for transformation from FROMSET to TOSET. */
extern int __gconv_find_transform (const char *toset, const char *fromset,
struct __gconv_step **handle,
size_t *nsteps, int flags)
- internal_function;
+ internal_function attribute_hidden;
/* Search for transformation in cache data. */
extern int __gconv_lookup_cache (const char *toset, const char *fromset,
struct __gconv_step **handle, size_t *nsteps,
int flags)
- internal_function;
+ internal_function attribute_hidden;
/* Compare the two name for whether they are after alias expansion the
same. This function uses the cache and fails if none is
loaded. */
extern int __gconv_compare_alias_cache (const char *name1, const char *name2,
- int *result) internal_function;
+ int *result)
+ internal_function attribute_hidden;
/* Free data associated with a step's structure. */
extern void __gconv_release_step (struct __gconv_step *step)
- internal_function;
+ internal_function attribute_hidden;
/* Read all the configuration data and cache it. */
extern void __gconv_read_conf (void) attribute_hidden;
/* Try to read module cache file. */
-extern int __gconv_load_cache (void) internal_function;
+extern int __gconv_load_cache (void) internal_function attribute_hidden;
/* Retrieve pointer to internal cache. */
extern void *__gconv_get_cache (void);
@@ -211,7 +212,7 @@ extern struct gconv_module *__gconv_get_modules_db (void);
extern void *__gconv_get_alias_db (void);
/* Determine the directories we are looking in. */
-extern void __gconv_get_path (void) internal_function;
+extern void __gconv_get_path (void) internal_function attribute_hidden;
/* Comparison function to search alias. */
extern int __gconv_alias_compare (const void *p1, const void *p2)
@@ -221,33 +222,33 @@ extern int __gconv_alias_compare (const void *p1, const void *p2)
cause the code to be unloaded. */
extern int __gconv_close_transform (struct __gconv_step *steps,
size_t nsteps)
- internal_function;
+ internal_function attribute_hidden;
/* Free all resources allocated for the transformation record when
using the cache. */
extern void __gconv_release_cache (struct __gconv_step *steps, size_t nsteps)
- internal_function;
+ internal_function attribute_hidden;
/* Load shared object named by NAME. If already loaded increment reference
count. */
extern struct __gconv_loaded_object *__gconv_find_shlib (const char *name)
- internal_function;
+ internal_function attribute_hidden;
/* Release shared object. If no further reference is available unload
the object. */
extern void __gconv_release_shlib (struct __gconv_loaded_object *handle)
- internal_function;
+ internal_function attribute_hidden;
/* Fill STEP with information about builtin module with NAME. */
extern void __gconv_get_builtin_trans (const char *name,
struct __gconv_step *step)
- internal_function;
+ internal_function attribute_hidden;
libc_hidden_proto (__gconv_transliterate)
/* If NAME is an codeset alias expand it. */
extern int __gconv_compare_alias (const char *name1, const char *name2)
- internal_function;
+ internal_function attribute_hidden;
/* Builtin transformations. */
diff --git a/include/dlfcn.h b/include/dlfcn.h
index 51cc1dfde8..6aad074e8e 100644
--- a/include/dlfcn.h
+++ b/include/dlfcn.h
@@ -75,7 +75,7 @@ extern void *_dl_vsym (void *handle, const char *name, const char *version,
arranges for `dlerror' to return the error details.
ARGS is passed as argument to OPERATE. */
extern int _dlerror_run (void (*operate) (void *), void *args)
- internal_function;
+ internal_function attribute_hidden;
#ifdef SHARED
# define DL_CALLER_DECL /* Nothing */
diff --git a/include/stdio.h b/include/stdio.h
index 509447c528..5c0ef8ed24 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -100,7 +100,7 @@ extern void __libc_message (enum __libc_message_action action,
const char *__fnt, ...);
extern void __fortify_fail (const char *msg) __attribute__ ((__noreturn__));
extern void __fortify_fail_abort (_Bool, const char *msg)
- __attribute__ ((__noreturn__));
+ __attribute__ ((__noreturn__)) attribute_hidden;
libc_hidden_proto (__fortify_fail)
libc_hidden_proto (__fortify_fail_abort)
diff --git a/include/time.h b/include/time.h
index 9956b82eb8..958cb8600d 100644
--- a/include/time.h
+++ b/include/time.h
@@ -46,7 +46,7 @@ extern void __tzfile_default (const char *std, const char *dst,
long int stdoff, long int dstoff);
extern void __tzset_parse_tz (const char *tz);
extern void __tz_compute (time_t timer, struct tm *tm, int use_localtime)
- __THROW internal_function;
+ __THROW internal_function attribute_hidden;
/* Subroutine of `mktime'. Return the `time_t' representation of TP and
normalize TP, given that a `struct tm *' maps to a `time_t' as performed
@@ -93,7 +93,7 @@ extern int __getclktck (void);
extern char * __strptime_internal (const char *rp, const char *fmt,
struct tm *tm, void *statep,
locale_t locparam)
- internal_function;
+ internal_function attribute_hidden;
extern double __difftime (time_t time1, time_t time0);
diff --git a/intl/gettextP.h b/intl/gettextP.h
index eeb8970852..f88cd782ab 100644
--- a/intl/gettextP.h
+++ b/intl/gettextP.h
@@ -256,22 +256,22 @@ extern const char *_nl_locale_name_default (void);
struct loaded_l10nfile *_nl_find_domain (const char *__dirname, char *__locale,
const char *__domainname,
struct binding *__domainbinding)
- internal_function;
+ internal_function attribute_hidden;
void _nl_load_domain (struct loaded_l10nfile *__domain,
struct binding *__domainbinding)
- internal_function;
+ internal_function attribute_hidden;
#ifdef IN_LIBGLOCALE
char *_nl_find_msg (struct loaded_l10nfile *domain_file,
struct binding *domainbinding, const char *encoding,
const char *msgid,
size_t *lengthp)
- internal_function;
+ internal_function attribute_hidden;
#else
char *_nl_find_msg (struct loaded_l10nfile *domain_file,
struct binding *domainbinding, const char *msgid,
int convert, size_t *lengthp)
- internal_function;
+ internal_function attribute_hidden;
#endif
/* The internal variables in the standalone libintl.a must have different
diff --git a/intl/plural-exp.h b/intl/plural-exp.h
index 144aa1ed4b..af6c9b9c49 100644
--- a/intl/plural-exp.h
+++ b/intl/plural-exp.h
@@ -106,13 +106,13 @@ struct parse_args
#endif
extern void FREE_EXPRESSION (struct expression *exp)
- internal_function;
+ internal_function attribute_hidden;
extern int PLURAL_PARSE (struct parse_args *arg);
extern const struct expression GERMANIC_PLURAL attribute_hidden;
extern void EXTRACT_PLURAL_EXPRESSION (const char *nullentry,
const struct expression **pluralp,
unsigned long int *npluralsp)
- internal_function;
+ internal_function attribute_hidden;
#if !defined (_LIBC) && !defined (IN_LIBINTL) && !defined (IN_LIBGLOCALE)
extern unsigned long int plural_eval (const struct expression *pexp,
diff --git a/locale/coll-lookup.h b/locale/coll-lookup.h
index d95408ad68..55a0b59236 100644
--- a/locale/coll-lookup.h
+++ b/locale/coll-lookup.h
@@ -20,8 +20,8 @@
/* Lookup in a table of int32_t, with default value 0. */
extern int32_t __collidx_table_lookup (const char *table, uint32_t wc)
- internal_function;
+ internal_function attribute_hidden;
/* Lookup in a table of uint32_t, with default value 0xffffffff. */
extern uint32_t __collseq_table_lookup (const char *table, uint32_t wc)
- internal_function;
+ internal_function attribute_hidden;
diff --git a/resolv/gai_misc.h b/resolv/gai_misc.h
index 6679d2b7d5..01b2f89738 100644
--- a/resolv/gai_misc.h
+++ b/resolv/gai_misc.h
@@ -76,23 +76,23 @@ extern pthread_mutex_t __gai_requests_mutex;
/* Enqueue request. */
extern struct requestlist *__gai_enqueue_request (struct gaicb *gaicbp)
- internal_function;
+ internal_function attribute_hidden;
/* Find request on wait list. */
extern struct requestlist *__gai_find_request (const struct gaicb *gaicbp)
- internal_function;
+ internal_function attribute_hidden;
/* Remove request from waitlist. */
extern int __gai_remove_request (struct gaicb *gaicbp)
- internal_function;
+ internal_function attribute_hidden;
/* Notify initiator of request and tell this everybody listening. */
extern void __gai_notify (struct requestlist *req)
- internal_function;
+ internal_function attribute_hidden;
/* Notify initiator of request. */
extern int __gai_notify_only (struct sigevent *sigev, pid_t caller_pid)
- internal_function;
+ internal_function attribute_hidden;
/* Send the signal. */
extern int __gai_sigqueue (int sig, const union sigval val, pid_t caller_pid)
diff --git a/sysdeps/generic/aio_misc.h b/sysdeps/generic/aio_misc.h
index a941a68aaa..e2264ba2d4 100644
--- a/sysdeps/generic/aio_misc.h
+++ b/sysdeps/generic/aio_misc.h
@@ -41,7 +41,7 @@ typedef union
/* Send the signal. */
extern int __aio_sigqueue (int sig, const union sigval val, pid_t caller_pid)
- internal_function;
+ internal_function attribute_hidden;
#endif /* aio_misc.h */
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 49e673dd24..e4004eee78 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -912,7 +912,7 @@ extern lookup_t _dl_lookup_symbol_x (const char *undef,
/* Look up symbol NAME in MAP's scope and return its run-time address. */
extern ElfW(Addr) _dl_symbol_value (struct link_map *map, const char *name)
- internal_function;
+ internal_function attribute_hidden;
/* Add the new link_map NEW to the end of the namespace list. */
extern void _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
@@ -968,7 +968,7 @@ extern void _dl_init (struct link_map *main_map, int argc, char **argv,
/* Call the finalizer functions of all shared objects whose
initializer functions have completed. */
-extern void _dl_fini (void);
+extern void _dl_fini (void) attribute_hidden;
/* Sort array MAPS according to dependencies of the contained objects. */
extern void _dl_sort_fini (struct link_map **maps, size_t nmaps, char *used,
@@ -1147,10 +1147,12 @@ extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr);
rtld_hidden_proto (_dl_find_dso_for_object)
/* Initialization which is normally done by the dynamic linker. */
-extern void _dl_non_dynamic_init (void) internal_function;
+extern void _dl_non_dynamic_init (void)
+ internal_function attribute_hidden;
/* Used by static binaries to check the auxiliary vector. */
-extern void _dl_aux_init (ElfW(auxv_t) *av) internal_function;
+extern void _dl_aux_init (ElfW(auxv_t) *av)
+ internal_function attribute_hidden;
__END_DECLS
diff --git a/sysdeps/i386/machine-gmon.h b/sysdeps/i386/machine-gmon.h
index 3e90b8c0c7..81e168e4e6 100644
--- a/sysdeps/i386/machine-gmon.h
+++ b/sysdeps/i386/machine-gmon.h
@@ -30,7 +30,7 @@
#define mcount_internal __mcount_internal
extern void mcount_internal (u_long frompc, u_long selfpc)
- __attribute__ ((regparm (2)));
+ __attribute__ ((regparm (2))) attribute_hidden;
#define _MCOUNT_DECL(frompc, selfpc) \
__attribute__ ((regparm (2))) \
diff --git a/sysdeps/unix/sysv/linux/i386/olddirent.h b/sysdeps/unix/sysv/linux/i386/olddirent.h
index 413f78d108..4875a1f2fa 100644
--- a/sysdeps/unix/sysv/linux/i386/olddirent.h
+++ b/sysdeps/unix/sysv/linux/i386/olddirent.h
@@ -34,7 +34,7 @@ extern struct __old_dirent64 *__old_readdir64 (DIR *__dirp);
extern int __old_readdir64_r (DIR *__dirp, struct __old_dirent64 *__entry,
struct __old_dirent64 **__result);
extern __ssize_t __old_getdents64 (int __fd, char *__buf, size_t __nbytes)
- internal_function;
+ internal_function attribute_hidden;
int __old_scandir64 (const char * __dir,
struct __old_dirent64 *** __namelist,
int (*__selector) (const struct __old_dirent64 *),
diff --git a/wcsmbs/wcsmbsload.h b/wcsmbs/wcsmbsload.h
index 3e254a877e..eb2a2bea33 100644
--- a/wcsmbs/wcsmbsload.h
+++ b/wcsmbs/wcsmbsload.h
@@ -38,15 +38,15 @@ extern const struct gconv_fcts __wcsmbs_gconv_fcts_c attribute_hidden;
/* Load conversion functions for the currently selected locale. */
extern void __wcsmbs_load_conv (struct __locale_data *new_category)
- internal_function;
+ internal_function attribute_hidden;
/* Clone the current `__wcsmbs_load_conv' value. */
extern void __wcsmbs_clone_conv (struct gconv_fcts *copy)
- internal_function;
+ internal_function attribute_hidden;
/* Find the conversion functions for converting to and from NAME. */
extern int __wcsmbs_named_conv (struct gconv_fcts *copy, const char *name)
- internal_function;
+ internal_function attribute_hidden;
/* Function used for the `private.cleanup' hook. */
extern void _nl_cleanup_ctype (struct __locale_data *)
--
2.13.5