From patchwork Mon Sep 18 23:51:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Thibault X-Patchwork-Id: 22929 Received: (qmail 89544 invoked by alias); 18 Sep 2017 23:51:58 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 89526 invoked by uid 89); 18 Sep 2017 23:51:58 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-10.3 required=5.0 tests=BAYES_00, GIT_PATCH_2, GIT_PATCH_3, KAM_ASCII_DIVIDERS, SPF_HELO_PASS, SPF_NEUTRAL autolearn=ham version=3.3.2 spammy=RPC, CONTENTS X-HELO: hera.aquilenet.fr Date: Tue, 19 Sep 2017 01:51:45 +0200 From: Samuel Thibault To: libc-alpha@sourceware.org Subject: [PATCH] Introduce NO_RTLD_HIDDEN, make hurd use it instead of NO_HIDDEN Message-ID: <20170918235145.yeucjedi4ywoqs5m@var.youpi.perso.aquilenet.fr> MIME-Version: 1.0 Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) On the Hurd, the rtld needs to see its own dumb versions of a few functions (defined in sysdeps/mach/hurd/dl-sysdep.c) overridden by libc's versions once loaded. rtld should thus not have hidden attribute for these. To achieve this, the Hurd port used to just define NO_HIDDEN, which disables it completely. For now, this changes that to disabling it for all rtld functions, for simplicity. In reality fewer functions need to be not-hidden, those needed early during the load. See Roland's comment on https://sourceware.org/bugzilla/show_bug.cgi?id=15605#c5 The ld.so numbers thus remain at 8 .rel.plt 000000c8 00000c24 00000c24 00000c24 2**2 CONTENTS, ALLOC, LOAD, READONLY, DATA 9 .plt 000001a0 00000cf0 00000cf0 00000cf0 2**4 CONTENTS, ALLOC, LOAD, READONLY, CODE 10 .plt.got 00000010 00000e90 00000e90 00000e90 2**3 CONTENTS, ALLOC, LOAD, READONLY, CODE 18 .got.plt 00000070 0002d000 0002d000 0002c000 2**2 CONTENTS, ALLOC, LOAD, DATA which is about 3 times as much as on Linux. About half of them are due to these functions which need to be overriden by libc.so anyway. So perhaps it's fine to go this way and not try to specifically mark the functions which need to be not-hidden. The libc.so numbers get divided by 3 (the remainings are mostly RPC stub calls). We could then remove the NO_HIDDEN macro, and only keep the NO_RTLD_HIDDEN macro. * include/libc-symbols.h [NO_RTLD_HIDDEN] (rtld_hidden_proto, rtld_hidden_tls_proto, rtld_hidden_def, rtld_hidden_weak, rtld_hidden_ver, rtld_hidden_data_def, rtld_hidden_data_weak, rtld_hidden_data_ver): Define to empty. * include/stdlib.h [NO_RTLD_HIDDEN] (unsetenv, __strtoul_internal): Do not set hidden attribute. * include/assert.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__assert_fail, __assert_perror_fail): Likewise. * include/dirent.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__closedir, __fdopendir, __readdir, __readdir64, __rewinddir): Likewise. * include/libc-internal.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__profile_frequency): Likewise. * include/signal.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__sigaction, __libc_sigaction): Likewise. * include/string.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__stpcpy, __strdup, __strerror_t, __strsep_g, memchr, memcmp, memcpy, memmove, memset, rawmemchr, stpcpy, strchr, strcmp, strlen, strnlen, strsep): Likewise. * include/sys/stat.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__fxstat, __fxstat64, __lxstat, __lxstat64, __xstat, __xstat64, __fxstatat64): Likewise. * include/sys/utsname.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__uname): Likewise. * include/sysdeps/generic/_itoa.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (_itoa_upper_digits, _itoa_lower_digits): Likewise. * sysdeps/i386/dl-tlsdesc.S [NO_RTLD_HIDDEN] (_dl_tlsdesc_dynamic): Call JUMPTARGET (___tls_get_addr) instead of HIDDEN_JUMPTARGET (___tls_get_addr). * sysdeps/mach/hurd/configure.ac (NO_HIDDEN): Do not set. (NO_RTLD_HIDDEN): Set. * sysdeps/mach/hurd/configure: Refresh. * config.h.in (NO_RTLD_HIDDEN): Add undefined macro. Index: glibc-2.26/include/libc-symbols.h =================================================================== --- glibc-2.26.orig/include/libc-symbols.h +++ glibc-2.26/include/libc-symbols.h @@ -544,7 +544,7 @@ for linking") # define libc_hidden_data_ver(local, name) #endif -#if IS_IN (rtld) +#if IS_IN (rtld) && !defined NO_RTLD_HIDDEN # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) # define rtld_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs) # define rtld_hidden_def(name) hidden_def (name) Index: glibc-2.26/include/stdlib.h =================================================================== --- glibc-2.26.orig/include/stdlib.h +++ glibc-2.26/include/stdlib.h @@ -287,7 +287,7 @@ struct abort_msg_s extern struct abort_msg_s *__abort_msg; libc_hidden_proto (__abort_msg) -# if IS_IN (rtld) +# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (unsetenv) unsetenv attribute_hidden; extern __typeof (__strtoul_internal) __strtoul_internal attribute_hidden; # endif Index: glibc-2.26/sysdeps/mach/hurd/configure.ac =================================================================== --- glibc-2.26.orig/sysdeps/mach/hurd/configure.ac +++ glibc-2.26/sysdeps/mach/hurd/configure.ac @@ -3,7 +3,7 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the dnl We need this setting because of the need for PLT calls in ld.so. dnl See Roland's comment in dnl https://sourceware.org/bugzilla/show_bug.cgi?id=15605 -AC_DEFINE([NO_HIDDEN]) +AC_DEFINE([NO_RTLD_HIDDEN]) if test -n "$sysheaders"; then OLD_CPPFLAGS=$CPPFLAGS Index: glibc-2.26/sysdeps/mach/hurd/configure =================================================================== --- glibc-2.26.orig/sysdeps/mach/hurd/configure +++ glibc-2.26/sysdeps/mach/hurd/configure @@ -1,6 +1,6 @@ # This file is generated from configure.ac by Autoconf. DO NOT EDIT! -$as_echo "#define NO_HIDDEN 1" >>confdefs.h +$as_echo "#define NO_RTLD_HIDDEN 1" >>confdefs.h if test -n "$sysheaders"; then Index: glibc-2.26/include/assert.h =================================================================== --- glibc-2.26.orig/include/assert.h +++ glibc-2.26/include/assert.h @@ -20,7 +20,7 @@ extern void __assert_fail_base (const ch const char *function) __THROW __attribute__ ((__noreturn__)); -# if IS_IN (libc) || IS_IN (rtld) +# if IS_IN (libc) || (IS_IN (rtld) && !defined NO_RTLD_HIDDEN) hidden_proto (__assert_fail) hidden_proto (__assert_perror_fail) # endif Index: glibc-2.26/include/dirent.h =================================================================== --- glibc-2.26.orig/include/dirent.h +++ glibc-2.26/include/dirent.h @@ -76,7 +76,7 @@ extern __typeof (scandirat) __scandirat; libc_hidden_proto (__scandirat) libc_hidden_proto (scandirat64) -# if IS_IN (rtld) +# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (__closedir) __closedir attribute_hidden; extern __typeof (__fdopendir) __fdopendir attribute_hidden; extern __typeof (__readdir) __readdir attribute_hidden; Index: glibc-2.26/include/libc-internal.h =================================================================== --- glibc-2.26.orig/include/libc-internal.h +++ glibc-2.26/include/libc-internal.h @@ -49,7 +49,7 @@ extern void __libc_thread_freeres (void) /* Define and initialize `__progname' et. al. */ extern void __init_misc (int, char **, char **); -# if IS_IN (rtld) +# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (__profile_frequency) __profile_frequency attribute_hidden; # endif Index: glibc-2.26/include/setjmp.h =================================================================== --- glibc-2.26.orig/include/setjmp.h +++ glibc-2.26/include/setjmp.h @@ -25,7 +25,7 @@ libc_hidden_proto (__libc_longjmp) libc_hidden_proto (_setjmp) libc_hidden_proto (__sigsetjmp) -# if IS_IN (rtld) +# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (__sigsetjmp) __sigsetjmp attribute_hidden; # endif #endif Index: glibc-2.26/include/signal.h =================================================================== --- glibc-2.26.orig/include/signal.h +++ glibc-2.26/include/signal.h @@ -53,7 +53,7 @@ extern int __xpg_sigpause (int sig); /* Allocate real-time signal with highest/lowest available priority. */ extern int __libc_allocate_rtsig (int __high); -# if IS_IN (rtld) +# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (__sigaction) __sigaction attribute_hidden; extern __typeof (__libc_sigaction) __libc_sigaction attribute_hidden; # endif Index: glibc-2.26/include/string.h =================================================================== --- glibc-2.26.orig/include/string.h +++ glibc-2.26/include/string.h @@ -142,7 +142,7 @@ libc_hidden_builtin_proto (strspn) libc_hidden_builtin_proto (strstr) libc_hidden_builtin_proto (ffs) -#if IS_IN (rtld) +#if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (__stpcpy) __stpcpy attribute_hidden; extern __typeof (__strdup) __strdup attribute_hidden; extern __typeof (__strerror_r) __strerror_r attribute_hidden; Index: glibc-2.26/include/sys/stat.h =================================================================== --- glibc-2.26.orig/include/sys/stat.h +++ glibc-2.26/include/sys/stat.h @@ -12,7 +12,7 @@ extern __mode_t __umask (__mode_t __mask extern int __mkdir (const char *__path, __mode_t __mode); extern int __mknod (const char *__path, __mode_t __mode, __dev_t __dev); -#if IS_IN (libc) || IS_IN (rtld) +#if IS_IN (libc) || (IS_IN (rtld) && !defined NO_RTLD_HIDDEN) hidden_proto (__fxstat) hidden_proto (__fxstat64) hidden_proto (__lxstat) @@ -35,7 +35,7 @@ libc_hidden_proto (__xmknodat) libc_hidden_proto (__fxstatat) libc_hidden_proto (__fxstatat64) -# if IS_IN (rtld) +# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (__fxstatat64) __fxstatat64 attribute_hidden; # endif Index: glibc-2.26/include/sys/utsname.h =================================================================== --- glibc-2.26.orig/include/sys/utsname.h +++ glibc-2.26/include/sys/utsname.h @@ -7,7 +7,7 @@ extern int __uname (struct utsname *__na libc_hidden_proto (uname) libc_hidden_proto (__uname) -# if IS_IN (rtld) +# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN extern __typeof (__uname) __uname attribute_hidden; # endif #endif Index: glibc-2.26/sysdeps/generic/_itoa.h =================================================================== --- glibc-2.26.orig/sysdeps/generic/_itoa.h +++ glibc-2.26/sysdeps/generic/_itoa.h @@ -46,7 +46,7 @@ extern char *_itoa (unsigned long long i extern const char _itoa_upper_digits[]; extern const char _itoa_lower_digits[]; -#if IS_IN (libc) || IS_IN (rtld) +#if IS_IN (libc) || (IS_IN (rtld) && !defined NO_RTLD_HIDDEN) hidden_proto (_itoa_upper_digits) hidden_proto (_itoa_lower_digits) #endif Index: glibc-2.26/config.h.in =================================================================== --- glibc-2.26.orig/config.h.in +++ glibc-2.26/config.h.in @@ -93,6 +93,10 @@ include/libc-symbols.h that avoid PLT slots in the shared objects. */ #undef NO_HIDDEN +/* Define this to disable in rtld the 'hidden_proto' et al macros in + include/libc-symbols.h that avoid PLT slots in the shared objects. */ +#undef NO_RTLD_HIDDEN + /* Define this to disable lazy relocations in DSOs. */ #undef BIND_NOW