From patchwork Fri Aug 5 06:46:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Liebler X-Patchwork-Id: 14322 Received: (qmail 49019 invoked by alias); 5 Aug 2016 06:46:59 -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 48851 invoked by uid 89); 5 Aug 2016 06:46:57 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=4.1 required=5.0 tests=AWL, BAYES_00, KAM_LAZY_DOMAIN_SECURITY, MSWORD_ATTACHED, RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 spammy=redirection, 1718, 3020 X-HELO: mx0a-001b2d01.pphosted.com X-IBM-Helo: d06dlp02.portsmouth.uk.ibm.com X-IBM-MailFrom: stli@linux.vnet.ibm.com X-IBM-RcptTo: libc-alpha@sourceware.org Subject: Re: [PATCH 3/8] i386, x86: Use libc_ifunc macro for time, gettimeofday. References: <1466682952-6301-1-git-send-email-stli@linux.vnet.ibm.com> <1466682952-6301-3-git-send-email-stli@linux.vnet.ibm.com> To: libc-alpha@sourceware.org From: Stefan Liebler Date: Fri, 5 Aug 2016 08:46:42 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2 MIME-Version: 1.0 In-Reply-To: <1466682952-6301-3-git-send-email-stli@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16080506-0032-0000-0000-000001F68E45 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16080506-0033-0000-0000-00001C46CA12 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-08-05_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608050090 This is an updated version due to changes in the first patch with libc_ifunc fallback if gcc does not support gcc attribute ifunc. From 72ee959cd28ed906cb8f35283ba2bd091995728b Mon Sep 17 00:00:00 2001 From: Stefan Liebler Date: Thu, 4 Aug 2016 18:46:23 +0200 Subject: [PATCH 3/8] i386, x86: Use libc_ifunc macro for time, gettimeofday. This patch uses the libc_ifunc_hidden macro to create already existing ifunc functions time and gettimeofday on intel. This way, the libc_hidden_def macro can be used instead of the libc_ifunc_hidden_def one which was only used here. Thus the macro is removed from libc-symbols.h. On i386, the __GI_* symbols do not target the ifunc symbol and thus the redirection construct has to be applied here. ChangeLog: * sysdeps/unix/sysv/linux/x86/gettimeofday.c (__gettimeofday): Use libc_ifunc_hidden macro. Use libc_hidden_def instead of libc_ifunc_hidden_def. * sysdeps/unix/sysv/linux/x86/time.c (time): Likewise. * sysdeps/unix/sysv/linux/i386/gettimeofday.c (__gettimeofday): Redirect ifunced function in header. (redirection): New define. * sysdeps/unix/sysv/linux/i386/time.c (time): Likewise. * include/libc-symbols.h (libc_ifunc_hidden_def, libc_ifunc_hidden_def1): Delete macro. --- include/libc-symbols.h | 15 --------------- sysdeps/unix/sysv/linux/i386/gettimeofday.c | 14 ++++++++++---- sysdeps/unix/sysv/linux/i386/time.c | 14 +++++++++++--- sysdeps/unix/sysv/linux/x86/gettimeofday.c | 28 ++++++++++++++-------------- sysdeps/unix/sysv/linux/x86/time.c | 26 +++++++++++++------------- 5 files changed, 48 insertions(+), 49 deletions(-) diff --git a/include/libc-symbols.h b/include/libc-symbols.h index db6aba2..4c59404 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -772,21 +772,6 @@ for linking") #define libm_ifunc_init() #define libm_ifunc(name, expr) __ifunc (name, name, expr, void, libm_ifunc_init) -#ifdef HAVE_ASM_SET_DIRECTIVE -# define libc_ifunc_hidden_def1(local, name) \ - __asm__ (".globl " #local "\n\t" \ - ".hidden " #local "\n\t" \ - ".set " #local ", " #name); -#else -# define libc_ifunc_hidden_def1(local, name) \ - __asm__ (".globl " #local "\n\t" \ - ".hidden " #local "\n\t" \ - #local " = " #name); -#endif - -#define libc_ifunc_hidden_def(name) \ - libc_ifunc_hidden_def1 (__GI_##name, name) - /* Add the compiler optimization to inhibit loop transformation to library calls. This is used to avoid recursive calls in memset and memmove default implementations. */ diff --git a/sysdeps/unix/sysv/linux/i386/gettimeofday.c b/sysdeps/unix/sysv/linux/i386/gettimeofday.c index 965bb81..cbf7833 100644 --- a/sysdeps/unix/sysv/linux/i386/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/i386/gettimeofday.c @@ -16,14 +16,20 @@ License along with the GNU C Library; if not, see . */ +#ifdef SHARED +# define __gettimeofday __redirect___gettimeofday +#endif + #include #ifdef SHARED +# undef __gettimeofday +# define redirection __redirect___gettimeofday -# undef libc_ifunc_hidden_def -# define libc_ifunc_hidden_def(name) \ - libc_ifunc_hidden_def1 (__GI_##name, __gettimeofday_syscall) - +# undef libc_hidden_def +# define libc_hidden_def(name) \ + __hidden_ver1 (__gettimeofday_syscall, __GI___gettimeofday, \ + __gettimeofday_syscall); #endif #include diff --git a/sysdeps/unix/sysv/linux/i386/time.c b/sysdeps/unix/sysv/linux/i386/time.c index 62b78b2..c1c0cbd 100644 --- a/sysdeps/unix/sysv/linux/i386/time.c +++ b/sysdeps/unix/sysv/linux/i386/time.c @@ -17,10 +17,18 @@ . */ #ifdef SHARED +# define time __redirect_time +#endif + +#include + +#ifdef SHARED +# undef time +# define redirection __redirect_time -# undef libc_ifunc_hidden_def -# define libc_ifunc_hidden_def(name) \ - libc_ifunc_hidden_def1 (__GI_##name, __time_syscall) +# undef libc_hidden_def +# define libc_hidden_def(name) \ + __hidden_ver1 (__time_syscall, __GI_time, __time_syscall); #endif #include diff --git a/sysdeps/unix/sysv/linux/x86/gettimeofday.c b/sysdeps/unix/sysv/linux/x86/gettimeofday.c index 36f7c26..4e53801 100644 --- a/sysdeps/unix/sysv/linux/x86/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/x86/gettimeofday.c @@ -29,20 +29,20 @@ __gettimeofday_syscall (struct timeval *tv, struct timezone *tz) return INLINE_SYSCALL (gettimeofday, 2, tv, tz); } -void *gettimeofday_ifunc (void) __asm__ ("__gettimeofday"); - -void * -gettimeofday_ifunc (void) -{ - PREPARE_VERSION_KNOWN (linux26, LINUX_2_6); - - /* If the vDSO is not available we fall back to syscall. */ - return (_dl_vdso_vsym ("__vdso_gettimeofday", &linux26) - ?: (void*) (&__gettimeofday_syscall)); -} -asm (".type __gettimeofday, %gnu_indirect_function"); - -libc_ifunc_hidden_def(__gettimeofday) +# ifndef redirection +/* The i386 gettimeofday.c includes this file with a defined redirection. + For x86_64 we have to define it to __gettimeofday as the internal symbol is + the ifunc'ed one. */ +# define redirection __gettimeofday +# endif + +# undef INIT_ARCH +# define INIT_ARCH() PREPARE_VERSION_KNOWN (linux26, LINUX_2_6) +/* If the vDSO is not available we fall back to syscall. */ +libc_ifunc_hidden (redirection, __gettimeofday, + (_dl_vdso_vsym ("__vdso_gettimeofday", &linux26) + ?: &__gettimeofday_syscall)) +libc_hidden_def (__gettimeofday) #else diff --git a/sysdeps/unix/sysv/linux/x86/time.c b/sysdeps/unix/sysv/linux/x86/time.c index f5f7f91..88ee750 100644 --- a/sysdeps/unix/sysv/linux/x86/time.c +++ b/sysdeps/unix/sysv/linux/x86/time.c @@ -30,20 +30,20 @@ __time_syscall (time_t *t) return INTERNAL_SYSCALL (time, err, 1, t); } -void *time_ifunc (void) __asm__ ("time"); - -void * -time_ifunc (void) -{ - PREPARE_VERSION_KNOWN (linux26, LINUX_2_6); - +# ifndef redirection +/* The i386 time.c includes this file with a defined redirection. + For x86_64 we have to define it to time as the internal symbol is the + ifunc'ed one. */ +# define redirection time +# endif + +#undef INIT_ARCH +#define INIT_ARCH() PREPARE_VERSION_KNOWN (linux26, LINUX_2_6); /* If the vDSO is not available we fall back on the syscall. */ - return _dl_vdso_vsym ("__vdso_time", &linux26) - ?: (void*) &__time_syscall; -} -asm (".type time, %gnu_indirect_function"); - -libc_ifunc_hidden_def(time) +libc_ifunc_hidden (redirection, time, + (_dl_vdso_vsym ("__vdso_time", &linux26) + ?: &__time_syscall)) +libc_hidden_def (time) #else -- 2.3.0