From patchwork Wed Mar 30 15:10:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zubair Lutfullah Kakakhel X-Patchwork-Id: 11563 Received: (qmail 23310 invoked by alias); 30 Mar 2016 15:11:05 -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 23285 invoked by uid 89); 30 Mar 2016 15:11:04 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 spammy=SHARED, $25, rebased, gic X-HELO: mailapp01.imgtec.com From: Zubair Lutfullah Kakakhel To: CC: Subject: [RFC] [PATCH] MIPS: Add VDSO support Date: Wed, 30 Mar 2016 16:10:11 +0100 Message-ID: <1459350611-6100-1-git-send-email-Zubair.Kakakhel@imgtec.com> MIME-Version: 1.0 From: Alex Smith This patch adds support for using the implementations of gettimeofday() and clock_gettime() provided by the kernel in the VDSO. The VDSO will always provide clock_gettime() as CLOCK_{REALTIME,MONOTONIC}_COARSE can be implemented regardless of platform. CLOCK_{REALTIME,MONOTONIC}, along with gettimeofday(), are only implemented on platforms which make use of either the CP0 count or GIC as their clocksource. On other platforms, the VDSO does not provide the __vdso_gettimeofday symbol, as it is never useful. The VDSO functions return ENOSYS when they encounter an unsupported request, in which case glibc should fall back to the standard syscall. * sysdeps/unix/sysv/linux/mips/Makefile (sysdep_routines): Include dl-vdso. * sysdeps/unix/sysv/linux/mips/Versions: Add __vdso_clock_gettime. * sysdeps/unix/sysv/linux/mips/init-first.c: New file. * sysdeps/unix/sysv/linux/mips/libc-vdso.h: New file. * sysdeps/unix/sysv/linux/mips/mips32/sysdep.h: (INTERNAL_VSYSCALL_CALL): Define to be compatible with MIPS definitions of INTERNAL_SYSCALL_{ERROR_P,ERRNO}. (HAVE_CLOCK_GETTIME_VSYSCALL): Define. (HAVE_GETTIMEOFDAY_VSYSCALL): Define. * sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h: Likewise. --- Hi, The kernel patches for vdso support are already upstream. I'm picking up this patch to upstream vdso support for MIPS in glibc. Rebased this patch on glibc-2.23 Tested with upstream kernel 4.5 and QEMU emulating Malta. ./vdsotest gettimeofday bench gettimeofday: syscall: 1021 nsec/call gettimeofday: libc: 262 nsec/call gettimeofday: vdso: 174 nsec/call Regards, ZubairLK --- sysdeps/unix/sysv/linux/mips/Makefile | 2 ++ sysdeps/unix/sysv/linux/mips/Versions | 4 +++ sysdeps/unix/sysv/linux/mips/init-first.c | 44 ++++++++++++++++++++++++ sysdeps/unix/sysv/linux/mips/libc-vdso.h | 33 ++++++++++++++++++ sysdeps/unix/sysv/linux/mips/mips32/sysdep.h | 16 +++++++++ sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h | 17 +++++++++ sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h | 17 +++++++++ 7 files changed, 133 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/mips/init-first.c create mode 100644 sysdeps/unix/sysv/linux/mips/libc-vdso.h diff --git a/sysdeps/unix/sysv/linux/mips/Makefile b/sysdeps/unix/sysv/linux/mips/Makefile index 8127025..c6729c1 100644 --- a/sysdeps/unix/sysv/linux/mips/Makefile +++ b/sysdeps/unix/sysv/linux/mips/Makefile @@ -96,6 +96,8 @@ ifeq ($(subdir),elf) ifeq ($(build-shared),yes) # This is needed for DSO loading from static binaries. sysdep-dl-routines += dl-static + +sysdep_routines += dl-vdso endif endif diff --git a/sysdeps/unix/sysv/linux/mips/Versions b/sysdeps/unix/sysv/linux/mips/Versions index a56322a..453f276 100644 --- a/sysdeps/unix/sysv/linux/mips/Versions +++ b/sysdeps/unix/sysv/linux/mips/Versions @@ -37,4 +37,8 @@ libc { GLIBC_2.11 { fallocate64; } + GLIBC_PRIVATE { + # nptl/pthread_cond_timedwait.c uses INTERNAL_VSYSCALL(clock_gettime). + __vdso_clock_gettime; + } } diff --git a/sysdeps/unix/sysv/linux/mips/init-first.c b/sysdeps/unix/sysv/linux/mips/init-first.c new file mode 100644 index 0000000..46dba69 --- /dev/null +++ b/sysdeps/unix/sysv/linux/mips/init-first.c @@ -0,0 +1,44 @@ +/* Initialization code run first thing by the ELF startup code. + Copyright (C) 2015 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifdef SHARED +# include +# include + +int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *) attribute_hidden; +int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *); + +static inline void +_libc_vdso_platform_setup (void) +{ + PREPARE_VERSION_KNOWN (linux26, LINUX_2_6); + + void *p = _dl_vdso_vsym ("__vdso_gettimeofday", &linux26); + PTR_MANGLE (p); + VDSO_SYMBOL (gettimeofday) = p; + + p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26); + PTR_MANGLE (p); + VDSO_SYMBOL (clock_gettime) = p; +} + +# define VDSO_SETUP _libc_vdso_platform_setup +#endif + +#include diff --git a/sysdeps/unix/sysv/linux/mips/libc-vdso.h b/sysdeps/unix/sysv/linux/mips/libc-vdso.h new file mode 100644 index 0000000..1580de8 --- /dev/null +++ b/sysdeps/unix/sysv/linux/mips/libc-vdso.h @@ -0,0 +1,33 @@ +/* VDSO function pointer declarations. + Copyright (C) 2015 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + . */ + +#ifndef _LIBC_VDSO_H +#define _LIBC_VDSO_H + +#ifdef SHARED + +# include + +extern int (*VDSO_SYMBOL(gettimeofday)) (struct timeval *, void *) + attribute_hidden; +extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *); + +#endif + +#endif /* _LIBC_VDSO_H */ diff --git a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h index 2160df7..2335409 100644 --- a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h +++ b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h @@ -371,6 +371,22 @@ #define __SYSCALL_CLOBBERS "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", \ "$14", "$15", "$24", "$25", "hi", "lo", "memory" +/* Standard MIPS syscalls have an error flag, and return a positive errno + when the error flag is set. Emulate this behaviour for vsyscalls so that + the INTERNAL_SYSCALL_{ERROR_P,ERRNO} macros work correctly. */ +#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \ + ({ \ + long _ret = funcptr (args); \ + err = ((unsigned long) (_ret) >= (unsigned long) -4095L); \ + if (err) \ + _ret = -_ret; \ + _ret; \ + }) + +/* List of system calls which are supported as vsyscalls. */ +#define HAVE_CLOCK_GETTIME_VSYSCALL 1 +#define HAVE_GETTIMEOFDAY_VSYSCALL 1 + #endif /* __ASSEMBLER__ */ /* Pointer mangling is not yet supported for MIPS. */ diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h index 466dcde..661b3dc 100644 --- a/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h @@ -295,6 +295,23 @@ #define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \ "$14", "$15", "$24", "$25", "hi", "lo", "memory" + +/* Standard MIPS syscalls have an error flag, and return a positive errno + when the error flag is set. Emulate this behaviour for vsyscalls so that + the INTERNAL_SYSCALL_{ERROR_P,ERRNO} macros work correctly. */ +#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \ + ({ \ + long _ret = funcptr (args); \ + err = ((unsigned long) (_ret) >= (unsigned long) -4095L); \ + if (err) \ + _ret = -_ret; \ + _ret; \ + }) + +/* List of system calls which are supported as vsyscalls. */ +#define HAVE_CLOCK_GETTIME_VSYSCALL 1 +#define HAVE_GETTIMEOFDAY_VSYSCALL 1 + #endif /* __ASSEMBLER__ */ /* Pointer mangling is not yet supported for MIPS. */ diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h index db8b237..476eca3 100644 --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h @@ -291,6 +291,23 @@ #define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \ "$14", "$15", "$24", "$25", "hi", "lo", "memory" + +/* Standard MIPS syscalls have an error flag, and return a positive errno + when the error flag is set. Emulate this behaviour for vsyscalls so that + the INTERNAL_SYSCALL_{ERROR_P,ERRNO} macros work correctly. */ +#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \ + ({ \ + long _ret = funcptr (args); \ + err = ((unsigned long) (_ret) >= (unsigned long) -4095L); \ + if (err) \ + _ret = -_ret; \ + _ret; \ + }) + +/* List of system calls which are supported as vsyscalls. */ +#define HAVE_CLOCK_GETTIME_VSYSCALL 1 +#define HAVE_GETTIMEOFDAY_VSYSCALL 1 + #endif /* __ASSEMBLER__ */ /* Pointer mangling is not yet supported for MIPS. */