From patchwork Thu Jun 23 11:55:48 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Liebler X-Patchwork-Id: 13317 Received: (qmail 3452 invoked by alias); 23 Jun 2016 11:56:19 -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 3147 invoked by uid 89); 23 Jun 2016 11:56:18 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.9 required=5.0 tests=AWL, BAYES_00, KAM_LAZY_DOMAIN_SECURITY, RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 spammy=assemblies, D*local, ifunc, resolver X-HELO: mx0a-001b2d01.pphosted.com X-IBM-Helo: d06dlp03.portsmouth.uk.ibm.com X-IBM-MailFrom: stli@linux.vnet.ibm.com X-IBM-RcptTo: libc-alpha@sourceware.org From: Stefan Liebler To: libc-alpha@sourceware.org Cc: stli@linux.vnet.ibm.com, joseph@codesourcery.com, carlos@redhat.com, munroesj@linux.vnet.ibm.com Subject: [PATCH 4/8] ppc: Use libc_ifunc macro for time, gettimeofday. Date: Thu, 23 Jun 2016 13:55:48 +0200 In-Reply-To: <1466682952-6301-1-git-send-email-stli@linux.vnet.ibm.com> References: <1466682952-6301-1-git-send-email-stli@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16062311-0040-0000-0000-0000029EE00E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16062311-0041-0000-0000-00001BFDF1F6 Message-Id: <1466682952-6301-4-git-send-email-stli@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-06-23_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-1606230130 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 */