From patchwork Fri Jul 29 14:48:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Liebler X-Patchwork-Id: 14150 Received: (qmail 88838 invoked by alias); 29 Jul 2016 14:55:20 -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 88820 invoked by uid 89); 29 Jul 2016 14:55:19 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=1.9 required=5.0 tests=AWL, BAYES_00, KAM_LAZY_DOMAIN_SECURITY, MSWORD_ATTACHED, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD autolearn=no version=3.3.2 spammy=176, strong_alias, sk:__libc_, sk:libc_if X-HELO: plane.gmane.org To: libc-alpha@sourceware.org From: Stefan Liebler Subject: Re: [PATCH 4/8] ppc: Use libc_ifunc macro for time, gettimeofday. Date: Fri, 29 Jul 2016 16:48:58 +0200 Lines: 443 Message-ID: <579B6CDA.9020205@linux.vnet.ibm.com> References: <1466682952-6301-1-git-send-email-stli@linux.vnet.ibm.com> <1466682952-6301-4-git-send-email-stli@linux.vnet.ibm.com> Mime-Version: 1.0 Cc: "Paul E. Murphy" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 In-Reply-To: <1466682952-6301-4-git-send-email-stli@linux.vnet.ibm.com> This is an update due to the comments from Paul. On 06/23/2016 01:55 PM, Stefan Liebler wrote: > This patch uses the libc_ifunc macro to create already existing ifunc functions > time and gettimeofday on power. This way, the libc_hidden_def macro can be used > instead of inline assemblies. > On ppc32, the __GI_* symbols do not target the ifunc symbol and thus the > redirection construct has to be applied here. > > ChangeLog: > > * sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (__gettimeofday): > Use libc_ifunc and libc_hidden_def macro. Redirect ifunced function in > header and create a copy of the prototype for using as ifunc function > for ppc32 and add appropiate aliases to the real symbol names. > * sysdeps/unix/sysv/linux/powerpc/time.c (time): Likewise. > --- > sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 64 ++++++++++++++----------- > sysdeps/unix/sysv/linux/powerpc/time.c | 66 +++++++++++++------------- > 2 files changed, 69 insertions(+), 61 deletions(-) > > diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c > index 25a4e7c..366364c 100644 > --- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c > +++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c > @@ -15,6 +15,9 @@ > License along with the GNU C Library; if not, see > . */ > > +#if defined SHARED && !defined __powerpc64__ > +# define __gettimeofday __redirect___gettimeofday > +#endif > > #include > > @@ -24,30 +27,17 @@ > # include > # include > > -void *gettimeofday_ifunc (void) __asm__ ("__gettimeofday"); > +# ifndef __powerpc64__ > +# undef __gettimeofday > > -static int > -__gettimeofday_syscall (struct timeval *tv, struct timezone *tz) > -{ > - return INLINE_SYSCALL (gettimeofday, 2, tv, tz); > -} > +extern __typeof (__redirect___gettimeofday) __libc___gettimeofday; > +# define __gettimeofday __libc___gettimeofday > > -void * > -gettimeofday_ifunc (void) > +int > +__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz) > { > - PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); > - > - /* If the vDSO is not available we fall back syscall. */ > - void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615); > - return (vdso_gettimeofday ? VDSO_IFUNC_RET (vdso_gettimeofday) > - : (void*)__gettimeofday_syscall); > + return INLINE_VSYSCALL (gettimeofday, 2, tv, tz); > } > -asm (".type __gettimeofday, %gnu_indirect_function"); > - > -/* This is doing "libc_hidden_def (__gettimeofday)" but the compiler won't > - let us do it in C because it doesn't know we're defining __gettimeofday > - here in this file. */ > -asm (".globl __GI___gettimeofday"); > > /* __GI___gettimeofday is defined as hidden and for ppc32 it enables the > compiler make a local call (symbol@local) for internal GLIBC usage. It > @@ -55,16 +45,29 @@ asm (".globl __GI___gettimeofday"); > For ppc64 a call to a function in another translation unit might use a > different toc pointer thus disallowing direct branchess and making internal > ifuncs calls safe. */ > -#ifdef __powerpc64__ > -asm ("__GI___gettimeofday = __gettimeofday"); > -#else > -int > -__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz) > +# undef libc_hidden_def > +# define libc_hidden_def(name) \ > + __hidden_ver1 (__gettimeofday_vsyscall, __GI___gettimeofday, \ > + __gettimeofday_vsyscall); > + > +# endif > + > +static int > +__gettimeofday_syscall (struct timeval *tv, struct timezone *tz) > { > - return INLINE_VSYSCALL (gettimeofday, 2, tv, tz); > + return INLINE_SYSCALL (gettimeofday, 2, tv, tz); > } > -asm ("__GI___gettimeofday = __gettimeofday_vsyscall"); > -#endif > + > +# define INIT_ARCH() \ > + PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); \ > + void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615); > + > +/* If the vDSO is not available we fall back syscall. */ > +libc_ifunc (__gettimeofday, > + vdso_gettimeofday > + ? VDSO_IFUNC_RET (vdso_gettimeofday) > + : (void *) __gettimeofday_syscall); > +libc_hidden_def (__gettimeofday) > > #else > > @@ -81,3 +84,8 @@ libc_hidden_def (__gettimeofday) > #endif > weak_alias (__gettimeofday, gettimeofday) > libc_hidden_weak (gettimeofday) > + > +#if defined SHARED && !defined __powerpc64__ > +# undef __gettimeofday > +strong_alias (__libc___gettimeofday, __gettimeofday) > +#endif > diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c > index 7973419..200f4a7 100644 > --- a/sysdeps/unix/sysv/linux/powerpc/time.c > +++ b/sysdeps/unix/sysv/linux/powerpc/time.c > @@ -17,6 +17,9 @@ > . */ > > #ifdef SHARED > +# ifndef __powerpc64__ > +# define time __redirect_time > +# endif > > # include > # include > @@ -24,7 +27,27 @@ > # include > # include > > -void *time_ifunc (void) asm ("time"); > +# ifndef __powerpc64__ > +# undef time > +extern __typeof (__redirect_time) time; > + > +time_t > +__time_vsyscall (time_t *t) > +{ > + return INLINE_VSYSCALL (time, 1, t); > +} > + > +/* __GI_time is defined as hidden and for ppc32 it enables the > + compiler make a local call (symbol@local) for internal GLIBC usage. It > + means the PLT won't be used and the ifunc resolver will be called directly. > + For ppc64 a call to a function in another translation unit might use a > + different toc pointer thus disallowing direct branchess and making internal > + ifuncs calls safe. */ > +# undef libc_hidden_def > +# define libc_hidden_def(name) \ > + __hidden_ver1 (__time_vsyscall, __GI_time, __time_vsyscall); > + > +# endif /* !__powerpc64__ */ > > static time_t > time_syscall (time_t *t) > @@ -42,42 +65,19 @@ time_syscall (time_t *t) > return result; > } > > -void * > -time_ifunc (void) > -{ > - PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); > - > - /* If the vDSO is not available we fall back to the syscall. */ > +# define INIT_ARCH() \ > + PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); \ > void *vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615); > - return (vdso_time ? VDSO_IFUNC_RET (vdso_time) > - : (void*)time_syscall); > -} > -asm (".type time, %gnu_indirect_function"); > > -/* This is doing "libc_hidden_def (time)" but the compiler won't > - * let us do it in C because it doesn't know we're defining time > - * here in this file. */ > -asm (".globl __GI_time"); > - > -/* __GI_time is defined as hidden and for ppc32 it enables the > - compiler make a local call (symbol@local) for internal GLIBC usage. It > - means the PLT won't be used and the ifunc resolver will be called directly. > - For ppc64 a call to a function in another translation unit might use a > - different toc pointer thus disallowing direct branchess and making internal > - ifuncs calls safe. */ > -#ifdef __powerpc64__ > -asm ("__GI_time = time"); > -#else > -time_t > -__time_vsyscall (time_t *t) > -{ > - return INLINE_VSYSCALL (time, 1, t); > -} > -asm ("__GI_time = __time_vsyscall"); > -#endif > +/* If the vDSO is not available we fall back to the syscall. */ > +libc_ifunc (time, > + vdso_time > + ? VDSO_IFUNC_RET (vdso_time) > + : (void *) time_syscall); > +libc_hidden_def (time) > > #else > > #include > > -#endif > +#endif /* !SHARED */ > From 1d0febc930b57ad58cce43ea520ab4dba98d155c Mon Sep 17 00:00:00 2001 From: Stefan Liebler Date: Fri, 29 Jul 2016 16:38:57 +0200 Subject: [PATCH 4/8] ppc: Use libc_ifunc macro for time, gettimeofday. This patch uses the libc_ifunc macro to create already existing ifunc functions time and gettimeofday on power. This way, the libc_hidden_def macro can be used instead of inline assemblies. On ppc32, the __GI_* symbols do not target the ifunc symbol and thus the redirection construct has to be applied here. ChangeLog: * sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (__gettimeofday): Use libc_ifunc and libc_hidden_def macro. Redirect ifunced function in header for using it as type for ifunc function because __GI_* symbols for ppc32 do not target the ifunc symbols. * sysdeps/unix/sysv/linux/powerpc/time.c (time): Likewise. --- sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 60 ++++++++++++----------- sysdeps/unix/sysv/linux/powerpc/time.c | 67 +++++++++++++------------- 2 files changed, 65 insertions(+), 62 deletions(-) diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c index 25a4e7c..9cbcaf6 100644 --- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c @@ -15,6 +15,11 @@ License along with the GNU C Library; if not, see . */ +#if defined SHARED && !defined __powerpc64__ +# define __gettimeofday __redirect___gettimeofday +#else +# define __redirect___gettimeofday __gettimeofday +#endif #include @@ -24,30 +29,14 @@ # include # include -void *gettimeofday_ifunc (void) __asm__ ("__gettimeofday"); - -static int -__gettimeofday_syscall (struct timeval *tv, struct timezone *tz) -{ - return INLINE_SYSCALL (gettimeofday, 2, tv, tz); -} +# ifndef __powerpc64__ +# undef __gettimeofday -void * -gettimeofday_ifunc (void) +int +__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz) { - PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); - - /* If the vDSO is not available we fall back syscall. */ - void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615); - return (vdso_gettimeofday ? VDSO_IFUNC_RET (vdso_gettimeofday) - : (void*)__gettimeofday_syscall); + return INLINE_VSYSCALL (gettimeofday, 2, tv, tz); } -asm (".type __gettimeofday, %gnu_indirect_function"); - -/* This is doing "libc_hidden_def (__gettimeofday)" but the compiler won't - let us do it in C because it doesn't know we're defining __gettimeofday - here in this file. */ -asm (".globl __GI___gettimeofday"); /* __GI___gettimeofday is defined as hidden and for ppc32 it enables the compiler make a local call (symbol@local) for internal GLIBC usage. It @@ -55,16 +44,29 @@ asm (".globl __GI___gettimeofday"); For ppc64 a call to a function in another translation unit might use a different toc pointer thus disallowing direct branchess and making internal ifuncs calls safe. */ -#ifdef __powerpc64__ -asm ("__GI___gettimeofday = __gettimeofday"); -#else -int -__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz) +# undef libc_hidden_def +# define libc_hidden_def(name) \ + __hidden_ver1 (__gettimeofday_vsyscall, __GI___gettimeofday, \ + __gettimeofday_vsyscall); + +# endif /* !__powerpc64__ */ + +static int +__gettimeofday_syscall (struct timeval *tv, struct timezone *tz) { - return INLINE_VSYSCALL (gettimeofday, 2, tv, tz); + return INLINE_SYSCALL (gettimeofday, 2, tv, tz); } -asm ("__GI___gettimeofday = __gettimeofday_vsyscall"); -#endif + +# define INIT_ARCH() \ + PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); \ + void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615); + +/* If the vDSO is not available we fall back syscall. */ +libc_ifunc_redirected (__redirect___gettimeofday, __gettimeofday, + vdso_gettimeofday + ? VDSO_IFUNC_RET (vdso_gettimeofday) + : (void *) __gettimeofday_syscall); +libc_hidden_def (__gettimeofday) #else diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c index 7973419..b42827a 100644 --- a/sysdeps/unix/sysv/linux/powerpc/time.c +++ b/sysdeps/unix/sysv/linux/powerpc/time.c @@ -17,6 +17,11 @@ . */ #ifdef SHARED +# ifndef __powerpc64__ +# define time __redirect_time +# else +# define __redirect_time time +# endif # include # include @@ -24,7 +29,26 @@ # include # include -void *time_ifunc (void) asm ("time"); +# ifndef __powerpc64__ +# undef time + +time_t +__time_vsyscall (time_t *t) +{ + return INLINE_VSYSCALL (time, 1, t); +} + +/* __GI_time is defined as hidden and for ppc32 it enables the + compiler make a local call (symbol@local) for internal GLIBC usage. It + means the PLT won't be used and the ifunc resolver will be called directly. + For ppc64 a call to a function in another translation unit might use a + different toc pointer thus disallowing direct branchess and making internal + ifuncs calls safe. */ +# undef libc_hidden_def +# define libc_hidden_def(name) \ + __hidden_ver1 (__time_vsyscall, __GI_time, __time_vsyscall); + +# endif /* !__powerpc64__ */ static time_t time_syscall (time_t *t) @@ -42,42 +66,19 @@ time_syscall (time_t *t) return result; } -void * -time_ifunc (void) -{ - PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); - - /* If the vDSO is not available we fall back to the syscall. */ +# define INIT_ARCH() \ + PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565); \ void *vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615); - return (vdso_time ? VDSO_IFUNC_RET (vdso_time) - : (void*)time_syscall); -} -asm (".type time, %gnu_indirect_function"); -/* This is doing "libc_hidden_def (time)" but the compiler won't - * let us do it in C because it doesn't know we're defining time - * here in this file. */ -asm (".globl __GI_time"); - -/* __GI_time is defined as hidden and for ppc32 it enables the - compiler make a local call (symbol@local) for internal GLIBC usage. It - means the PLT won't be used and the ifunc resolver will be called directly. - For ppc64 a call to a function in another translation unit might use a - different toc pointer thus disallowing direct branchess and making internal - ifuncs calls safe. */ -#ifdef __powerpc64__ -asm ("__GI_time = time"); -#else -time_t -__time_vsyscall (time_t *t) -{ - return INLINE_VSYSCALL (time, 1, t); -} -asm ("__GI_time = __time_vsyscall"); -#endif +/* If the vDSO is not available we fall back to the syscall. */ +libc_ifunc_redirected (__redirect_time, time, + vdso_time + ? VDSO_IFUNC_RET (vdso_time) + : (void *) time_syscall); +libc_hidden_def (time) #else #include -#endif +#endif /* !SHARED */ -- 2.3.0