From: Marek Polacek <polacek@redhat.com>
To: Martin Jambor <mjambor@suse.cz>
Cc: Eric Botcazou <ebotcazou@adacore.com>,
GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] configure: Implement --enable-host-bind-now
Date: Thu, 29 Jun 2023 12:13:11 -0400 [thread overview]
Message-ID: <ZJ2tl7+zDZeRoFJ5@redhat.com> (raw)
In-Reply-To: <ri6wmzmntup.fsf@suse.cz>
On Thu, Jun 29, 2023 at 05:58:22PM +0200, Martin Jambor wrote:
> Hi,
>
> On Tue, Jun 27 2023, Marek Polacek wrote:
> > On Tue, Jun 27, 2023 at 01:39:16PM +0200, Martin Jambor wrote:
> >> Hello,
> >>
> >> On Tue, May 16 2023, Marek Polacek via Gcc-patches wrote:
> >> > As promised in the --enable-host-pie patch, this patch adds another
> >> > configure option, --enable-host-bind-now, which adds -z now when linking
> >> > the compiler executables in order to extend hardening. BIND_NOW with RELRO
> >> > allows the GOT to be marked RO; this prevents GOT modification attacks.
> >> >
> >> > This option does not affect linking of target libraries; you can use
> >> > LDFLAGS_FOR_TARGET=-Wl,-z,relro,-z,now to enable RELRO/BIND_NOW.
> >> >
> >> > With this patch:
> >> > $ readelf -Wd cc1{,plus} | grep FLAGS
> >> > 0x000000000000001e (FLAGS) BIND_NOW
> >> > 0x000000006ffffffb (FLAGS_1) Flags: NOW PIE
> >> > 0x000000000000001e (FLAGS) BIND_NOW
> >> > 0x000000006ffffffb (FLAGS_1) Flags: NOW PIE
> >> >
> >> > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
> >> >
> >> > c++tools/ChangeLog:
> >> >
> >> > * configure.ac (--enable-host-bind-now): New check.
> >> > * configure: Regenerate.
> >> >
> >> > gcc/ChangeLog:
> >> >
> >> > * configure.ac (--enable-host-bind-now): New check. Add
> >> > -Wl,-z,now to LD_PICFLAG if --enable-host-bind-now.
> >> > * configure: Regenerate.
> >> > * doc/install.texi: Document --enable-host-bind-now.
> >> >
> >> > lto-plugin/ChangeLog:
> >> >
> >> > * configure.ac (--enable-host-bind-now): New check. Link with
> >> > -z,now.
> >> > * configure: Regenerate.
> >>
> >> Our reconfiguration checking script complains about a missing hunk in
> >> lto-plugin/Makefile.in:
> >>
> >> diff --git a/lto-plugin/Makefile.in b/lto-plugin/Makefile.in
> >> index cb568e1e09f..f6f5b020ff5 100644
> >> --- a/lto-plugin/Makefile.in
> >> +++ b/lto-plugin/Makefile.in
> >> @@ -298,6 +298,7 @@ datadir = @datadir@
> >> datarootdir = @datarootdir@
> >> docdir = @docdir@
> >> dvidir = @dvidir@
> >> +enable_host_bind_now = @enable_host_bind_now@
> >> exec_prefix = @exec_prefix@
> >> gcc_build_dir = @gcc_build_dir@
> >> get_gcc_base_ver = @get_gcc_base_ver@
> >>
> >>
> >> I am somewhat puzzled why the line is not missing in any of the other
> >> Makefile.in files. Can you please check whether that is the only thing
> >> that is missing (assuming it is actually missing)?
> >
> > Arg, once again, I'm sorry. I don't know how this happened. It would
> > be trivial to fix it but since
> >
> > commit 4a48a38fa99f067b8f3a3d1a5dc7a1e602db351f
> > Author: Eric Botcazou <ebotcazou@adacore.com>
> > Date: Wed Jun 21 18:19:36 2023 +0200
> >
> > ada: Fix build of GNAT tools
> >
> > the build with Ada included fails with --enable-host-pie. So that needs
> > to be fixed first.
> >
> > Eric, I'm not asking you to fix that, but I'm curious, what did the
> > commit above fix? The patch looks correct; I'm just puzzled why I
> > hadn't seen any build failures.
> >
> > The --enable-host-pie patch has been a nightmare :(.
> >
>
> No worries, I can see how these things can easily get difficult.
>
> Unfortunately I won't have time to actually look at this in the next 2-3
> weeks, so I am inclined to just trust the verification script (which
> essentially runs autoconf/automake everywhere and then expects no diff)
> and commit the one-line change. What do you think, does that make sense
> (even without looking at why other Makefile.in files did not change)?
Yes please, go ahead with the one line change meanwhile. Thanks!
I've opened PR110467 for the build problem.
Marek
next prev parent reply other threads:[~2023-06-29 16:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-16 15:37 Marek Polacek
2023-05-19 21:29 ` Jeff Law
2023-06-27 11:39 ` Martin Jambor
2023-06-27 15:31 ` Marek Polacek
2023-06-27 15:50 ` Iain Sandoe
2023-06-27 17:06 ` Eric Botcazou
2023-06-29 15:58 ` Martin Jambor
2023-06-29 16:13 ` Marek Polacek [this message]
2023-06-30 11:33 ` [committed] Regenrate lto-plugin/Makefile.in Martin Jambor
-- strict thread matches above, loose matches on Subject: below --
2022-11-11 2:53 [PATCH] configure: Implement --enable-host-bind-now Marek Polacek
2022-11-20 15:09 ` Jeff Law
2022-02-10 16:50 Marek Polacek
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