From: Lukasz Majewski <lukma@denx.de>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Siddhesh Poyarekar <siddhesh@gotplt.org>,
libc-alpha@sourceware.org, Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
Florian Weimer <fweimer@redhat.com>
Subject: Re: [PATCH v3 09/16] elf: Move vDSO setup to rtld (BZ#24967) - regression found
Date: Tue, 7 Jan 2020 17:13:08 +0100 [thread overview]
Message-ID: <20200107171308.10b95c37@jawa> (raw)
In-Reply-To: <24cb9107-0d17-54c8-f169-fbfdebd0099a@linaro.org>
[-- Attachment #1: Type: text/plain, Size: 8966 bytes --]
Hi Adhemerval, Siddhesh
> 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 <siddhesh@sourceware.org>
>
> >> 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
> >> + <https://www.gnu.org/licenses/>. */
> >> +
> >> +#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
> >> + <https://www.gnu.org/licenses/>. */
> >> +
> >> +/* 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.
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=25352
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
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2020-01-07 16:13 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-17 21:47 [PATCH v2 01/16] linux: Fix vDSO macros build with time64 interfaces Adhemerval Zanella
2019-12-17 21:47 ` [PATCH v2 02/16] x86: Make x32 use x86 time implementation Adhemerval Zanella
2020-01-02 12:07 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 03/16] Remove vDSO support from make-syscall.sh Adhemerval Zanella
2020-01-02 12:07 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 04/16] linux: Update x86 vDSO symbols Adhemerval Zanella
2020-01-02 12:07 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 05/16] linux: Update mips " Adhemerval Zanella
2020-01-02 12:08 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 06/16] linux: Consolidate Linux gettimeofday Adhemerval Zanella
2019-12-18 8:46 ` Andreas Schwab
2019-12-18 14:50 ` Adhemerval Zanella
2020-01-02 12:07 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 07/16] linux: Consolidate time implementation Adhemerval Zanella
2020-01-02 12:51 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH v3 08/16] elf: Enable relro for static build Adhemerval Zanella
2020-01-02 12:07 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH v3 09/16] elf: Move vDSO setup to rtld (BZ#24967) Adhemerval Zanella
2020-01-02 12:55 ` Siddhesh Poyarekar
2020-01-02 13:00 ` Adhemerval Zanella
2020-01-07 16:13 ` Lukasz Majewski [this message]
2020-01-07 19:40 ` [PATCH v3 09/16] elf: Move vDSO setup to rtld (BZ#24967) - regression found Adhemerval Zanella
2019-12-17 21:47 ` [PATCH v2 10/16] linux: Add support for clock_gettime64 vDSO Adhemerval Zanella
2020-01-02 13:03 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 11/16] linux: Optimize fallback 32-bit clock_gettime Adhemerval Zanella
2019-12-18 8:53 ` Andreas Schwab
2019-12-18 14:58 ` Adhemerval Zanella
2020-01-02 13:07 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 12/16] linux: Enable vDSO clock_gettime64 for i386 Adhemerval Zanella
2020-01-02 13:08 ` Siddhesh Poyarekar
2020-01-02 13:08 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 13/16] linux: Enable vDSO clock_gettime64 for arm Adhemerval Zanella
2020-01-02 13:08 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 14/16] linux: Enable vDSO clock_gettime64 for mips Adhemerval Zanella
2019-12-18 15:33 ` Florian Weimer
2020-01-02 13:13 ` Siddhesh Poyarekar
2020-01-02 13:50 ` Adhemerval Zanella
2020-01-02 14:09 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH v2 15/16] linux: Add support for clock_getres64 vDSO Adhemerval Zanella
2020-01-02 13:15 ` Siddhesh Poyarekar
2019-12-17 21:47 ` [PATCH 16/16] linux: Optimize fallback 32-bit clock_getres Adhemerval Zanella
2019-12-18 8:56 ` Andreas Schwab
2019-12-18 14:58 ` Adhemerval Zanella
2019-12-18 15:02 ` Adhemerval Zanella
2020-01-02 13:16 ` Siddhesh Poyarekar
2020-01-02 12:07 ` [PATCH v2 01/16] linux: Fix vDSO macros build with time64 interfaces Siddhesh Poyarekar
2020-01-02 12:55 ` Adhemerval Zanella
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/libc/involved.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200107171308.10b95c37@jawa \
--to=lukma@denx.de \
--cc=Szabolcs.Nagy@arm.com \
--cc=adhemerval.zanella@linaro.org \
--cc=fweimer@redhat.com \
--cc=libc-alpha@sourceware.org \
--cc=siddhesh@gotplt.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).