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 C7E6C1F463 for ; Tue, 7 Jan 2020 16:13:25 +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:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-type; q=dns; s=default; b=OcO0K Cz/AOVDeLuwu5nMzr/0HV46nnTtnrh3Mw5MJB/7JbfmJrEI1UOMrAoyGDr6kye6m qo8a7LH0qtBg0yq+hUn1GaiGKJamu9aV83+q3AXYQpABkdb/trB86f+WFS5ZXDwh JfXhnE6ciAUNwPJI7gune+2DH4DN/W18KBWKlI= 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:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-type; s=default; bh=4qUloOvaq9I dwN6l3Z75BT4Xmqk=; b=IkedAGpeNiL4jn2ej+HYH0ZbGBqBbrUooYHS+q42eGP Fe211NAKEso/wQsDTs1tjmTT+/Co3sXClb9zhABZq8yYZ3OuqQVEED/7QosPmpj4 dwb+TQ3LV9bgyHfvZSkzhRXUfAke2dTXD8fq++D+tQOLNhyp52MDui2fhP7SLQgQ = Received: (qmail 116954 invoked by alias); 7 Jan 2020 16:13:23 -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 116939 invoked by uid 89); 7 Jan 2020 16:13:23 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-out.m-online.net Date: Tue, 7 Jan 2020 17:13:08 +0100 From: Lukasz Majewski To: Adhemerval Zanella Cc: Siddhesh Poyarekar , libc-alpha@sourceware.org, Szabolcs Nagy , Florian Weimer Subject: Re: [PATCH v3 09/16] elf: Move vDSO setup to rtld (BZ#24967) - regression found Message-ID: <20200107171308.10b95c37@jawa> In-Reply-To: <24cb9107-0d17-54c8-f169-fbfdebd0099a@linaro.org> References: <20191217214728.2886-1-adhemerval.zanella@linaro.org> <20191217214728.2886-9-adhemerval.zanella@linaro.org> <24cb9107-0d17-54c8-f169-fbfdebd0099a@linaro.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; boundary="Sig_/e445dim0FIUnfv/8vN2EGOR"; protocol="application/pgp-signature" --Sig_/e445dim0FIUnfv/8vN2EGOR Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hi Adhemerval, Siddhesh > On 02/01/2020 09:55, Siddhesh Poyarekar wrote: > > On 18/12/19 3:17 am, Adhemerval Zanella wrote: =20 > >> 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 > >> =20 > >=20 > > OK with some minor nits fixed, see below. > >=20 > > Reviewed-by: Siddhesh Poyarekar =20 >=20 > >> 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. =20 > >=20 > > Update copyright year. =20 >=20 > Ack. >=20 > > =20 > >> + 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. =20 > >=20 > > Update copyright year. =20 >=20 > Ack. >=20 > >> 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. =20 > >=20 > > Update copyright year. =20 >=20 > Ack. >=20 > > =20 > >> + 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 =20 > >=20 > > Fix indentation. =20 >=20 > Ack. >=20 > > =20 > >> +# ifdef HAVE_GETTIMEOFDAY_VSYSCALL > >> +PROCINFO_CLASS int (*_dl_vdso_gettimeofday) (struct timeval *, > >> void *) RELRO; +#endif =20 > >=20 > > Fix indentation. =20 >=20 > Ack. Unfortunately this patch caused regression on my ARMv7 32 bit setup. Please find filled in bugzilla entry: https://sourceware.org/bugzilla/show_bug.cgi?id=3D25352 Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de --Sig_/e445dim0FIUnfv/8vN2EGOR Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEgAyFJ+N6uu6+XupJAR8vZIA0zr0FAl4UrhQACgkQAR8vZIA0 zr0tAggAx6sGsdKlCCq1M89a8z8/RRp4WWRskRHjOASJUP43ljvlK4HcmQtiH0e3 j2Ovcd/nMPmTiA9doxEG9dNYRa7plzBDD4XTfrhxFWE1xjLSgBynqcSY3EGNO6qC fB3ZbFNhWMYKu2sB+EwZvegzToOqkXEeF4NVReiULcWuFCFxZejvnV9hB30NFsRY 3Wc8Xfse2Qs0W5x/JO0/f8Gy+aIY+maSRX1Inf1ZmvjA835I4V/lYhOnlbdPPxXJ zYwlfVl8DaPx4m08yqxn62uRKCb7lVw18bB6ObcTRhUxUR5nugXU4MDZG9GWsF/E sHzJe/Jt2BUjfH5uRiKWLChABpUqBw== =8MBI -----END PGP SIGNATURE----- --Sig_/e445dim0FIUnfv/8vN2EGOR--