From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id D44E11F463 for ; Thu, 2 Jan 2020 13:01:03 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=pqaekMjYvz0dfkFY 7luBzhELg5jotGfU8uHPs6hW9CS4/4Dw7bhzQurpkdGauwktPWFgeqM0aZtwAK6F ec5bWiXi7Brz7ZEC0p2G/D3/Wu9CL/y5IZwH3keYd1X4jaVZokkCwuSVNK41MRMg 5dd0HrUL8Znd5Udf51LO2D7+xIw= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=aBb+jJdAr5F8PbyHUHHIg9 vdeJ4=; b=CwiK6QLQ0sQXhHFe29e8j+a9AxGHA2HoE1yiojBqA67K1bj+pYYwMG ejy1774wxgG27tiBeohJDLDCpQiUqQKlVRQGRLYOK0dezQIko7nlJDW8QiIQznaA gKwD102tnGvUtCdbsKiCw3GNP6Rh6nFCGI8V0YqGSBqUVNfYILJws= Received: (qmail 99835 invoked by alias); 2 Jan 2020 13:00:55 -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 Received: (qmail 99811 invoked by uid 89); 2 Jan 2020 13:00:54 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-pl1-f193.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=FwygJdEwDxFpiDsrJSrGYgrsyuVvhT1B9wSEkooCp4k=; b=TAmAOfsW+0XiV1qLNCGiwbAKyrsHgN2JnlSCGwNA569Qv9pTOOOrOdxq2CjEs/+hIQ 67HvfJtig7sp9ynU1uwQ0mwnObr2s+La+maBtnPWQ0MpXgdzO8L8aqNyp7nSJ9h/wMR8 NXgLK/jWDOISSN5Pxp/QAZQYQBJMicy3GuLnEtSgfueYmfLS9OWxh8RntkltKr/SkOrA NEgt3UId+fW6Xul3DpCbJIhI9lasAe9OtDAENWYBXA18XDEDFViHMb+bR21B8x+pB1cD rmT6848FLZNfNCDSX0pIcJ2TSLBlTP5PYxNo3mgTRrWJTx35Ulj9UzncEdEIG0VAR0BK noXA== Subject: Re: [PATCH v3 09/16] elf: Move vDSO setup to rtld (BZ#24967) To: Siddhesh Poyarekar , libc-alpha@sourceware.org References: <20191217214728.2886-1-adhemerval.zanella@linaro.org> <20191217214728.2886-9-adhemerval.zanella@linaro.org> From: Adhemerval Zanella Message-ID: <24cb9107-0d17-54c8-f169-fbfdebd0099a@linaro.org> Date: Thu, 2 Jan 2020 10:00:45 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 02/01/2020 09:55, Siddhesh Poyarekar wrote: > On 18/12/19 3:17 am, Adhemerval Zanella wrote: >> Changes from previous version: >> >> - Do not GLRO access on ifunc resolver, ut rather call the vDSO >> resolve function instead (dl_vdso_vsym). >> >> -- >> >> This patch moves the vDSO setup from libc to loader code, just after >> the vDSO link_map setup. For static case the initialization >> is moved to _dl_non_dynamic_init instead. >> >> Instead of using the mangled pointer, the vDSO data is set as >> attribute_relro (on _rtld_global_ro for shared or _dl_vdso_* for >> static). It is read-only even with partial relro. >> >> It fixes BZ#24967 now that the vDSO pointer is setup earlier than >> malloc interposition is called. >> >> Also, vDSO calls should not be a problem for static dlopen as >> indicated by BZ#20802. The vDSO pointer would be zero-initialized >> and the syscall will be issued instead. >> >> Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, >> arm-linux-gnueabihf, powerpc64le-linux-gnu, powerpc64-linux-gnu, >> powerpc-linux-gnu, s390x-linux-gnu, sparc64-linux-gnu, and >> sparcv9-linux-gnu. I also run some tests on mips. >> --- >> csu/init-first.c | 4 - >> elf/dl-support.c | 7 ++ >> elf/rtld.c | 7 +- >> malloc/tst-interpose-aux.c | 5 ++ >> sysdeps/generic/dl-vdso-setup.c | 1 + >> sysdeps/generic/dl-vdso-setup.h | 28 ++++++ >> sysdeps/generic/dl-vdso.h | 30 +++++++ >> sysdeps/generic/ldsodefs.h | 6 ++ >> sysdeps/powerpc/powerpc32/backtrace.c | 16 ++-- >> sysdeps/powerpc/powerpc64/backtrace.c | 8 +- >> sysdeps/unix/sysv/linux/aarch64/Makefile | 1 - >> sysdeps/unix/sysv/linux/arm/Makefile | 1 - >> sysdeps/unix/sysv/linux/dl-vdso-setup.c | 81 +++++++++++++++++ >> sysdeps/unix/sysv/linux/dl-vdso-setup.h | 55 ++++++++++++ >> sysdeps/unix/sysv/linux/dl-vdso.c | 48 ---------- >> sysdeps/unix/sysv/linux/dl-vdso.h | 30 ++++--- >> sysdeps/unix/sysv/linux/gettimeofday.c | 3 +- >> sysdeps/unix/sysv/linux/init-first.c | 90 ------------------- >> sysdeps/unix/sysv/linux/libc-vdso.h | 30 +------ >> sysdeps/unix/sysv/linux/mips/Makefile | 2 - >> sysdeps/unix/sysv/linux/powerpc/Makefile | 1 - >> .../sysv/linux/powerpc/get_timebase_freq.c | 5 +- >> sysdeps/unix/sysv/linux/powerpc/init-first.c | 50 ----------- >> sysdeps/unix/sysv/linux/powerpc/libc-vdso.h | 10 --- >> sysdeps/unix/sysv/linux/riscv/Makefile | 4 - >> sysdeps/unix/sysv/linux/riscv/flush-icache.c | 2 +- >> sysdeps/unix/sysv/linux/s390/Makefile | 4 - >> sysdeps/unix/sysv/linux/sparc/Makefile | 4 - >> sysdeps/unix/sysv/linux/sysdep-vdso.h | 6 +- >> sysdeps/unix/sysv/linux/time.c | 3 +- >> sysdeps/unix/sysv/linux/x86/Makefile | 4 - >> 31 files changed, 257 insertions(+), 289 deletions(-) >> create mode 100644 sysdeps/generic/dl-vdso-setup.c >> create mode 100644 sysdeps/generic/dl-vdso-setup.h >> create mode 100644 sysdeps/generic/dl-vdso.h >> create mode 100644 sysdeps/unix/sysv/linux/dl-vdso-setup.c >> create mode 100644 sysdeps/unix/sysv/linux/dl-vdso-setup.h >> delete mode 100644 sysdeps/unix/sysv/linux/dl-vdso.c >> delete mode 100644 sysdeps/unix/sysv/linux/init-first.c >> delete mode 100644 sysdeps/unix/sysv/linux/powerpc/init-first.c >> > > OK with some minor nits fixed, see below. > > Reviewed-by: Siddhesh Poyarekar >> diff --git a/sysdeps/generic/dl-vdso-setup.h b/sysdeps/generic/dl-vdso-setup.h >> new file mode 100644 >> index 0000000000..3d79bae317 >> --- /dev/null >> +++ b/sysdeps/generic/dl-vdso-setup.h >> @@ -0,0 +1,28 @@ >> +/* ELF symbol initialization functions for VDSO objects. >> + Copyright (C) 2019 Free Software Foundation, Inc. > > Update copyright year. Ack. > >> + 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 _DL_VDSO_INIT_H >> +#define _DL_VDSO_INIT_H >> + >> +/* Initialize the VDSO functions pointers. */ >> +static inline void __attribute__ ((always_inline)) >> +setup_vdso_pointers (void) >> +{ >> +} >> + >> +#endif >> diff --git a/sysdeps/generic/dl-vdso.h b/sysdeps/generic/dl-vdso.h >> new file mode 100644 >> index 0000000000..5651f49a1a >> --- /dev/null >> +++ b/sysdeps/generic/dl-vdso.h >> @@ -0,0 +1,30 @@ >> +/* ELF symbol resolve functions for VDSO objects. >> + Copyright (C) 2019 Free Software Foundation, Inc. > > Update copyright year. Ack. >> diff --git a/sysdeps/unix/sysv/linux/dl-vdso-setup.c b/sysdeps/unix/sysv/linux/dl-vdso-setup.c >> new file mode 100644 >> index 0000000000..1069879f1a >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/dl-vdso-setup.c >> @@ -0,0 +1,81 @@ >> +/* Data for vDSO support. Linux version. >> + Copyright (C) 2019 Free Software Foundation, Inc. > > Update copyright year. Ack. > >> + 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 >> + . */ >> + >> +/* This file is included in three different modes for both static (libc.a) >> + and shared (rtld) modes: >> + >> + 1. PROCINFO_DECL is defined, meaning we are only interested in >> + declarations. For static it requires use the extern keywork along with >> + the attribute_relro while for shared it will be embedded in the >> + rtld_global_ro. >> + >> + 2. PROCINFO_DECL and SHARED are not defined. Nothing to do, the default >> + zero initializion is suffice. >> + >> + 3. PROCINFO_DECL is not defined while SHARED is. Similar to 2., the zero >> + initialization of rtld_global_ro is suffice. */ >> + >> +#ifndef PROCINFO_CLASS >> +# define PROCINFO_CLASS >> +#endif >> + >> +#ifndef SHARED >> +# define RELRO attribute_relro >> +#else >> +# define RELRO >> +#endif >> + >> +#if defined PROCINFO_DECL || !defined SHARED >> +# ifdef HAVE_CLOCK_GETTIME_VSYSCALL >> +PROCINFO_CLASS int (*_dl_vdso_clock_gettime) (clockid_t, >> + struct timespec *) RELRO; >> +#endif > > Fix indentation. Ack. > >> +# ifdef HAVE_GETTIMEOFDAY_VSYSCALL >> +PROCINFO_CLASS int (*_dl_vdso_gettimeofday) (struct timeval *, void *) RELRO; >> +#endif > > Fix indentation. Ack.