From: Jeff Law <jeffreyalaw@gmail.com>
To: Marek Polacek <polacek@redhat.com>,
GCC Patches <gcc-patches@gcc.gnu.org>
Cc: oliva@adacore.com, Joseph Myers <joseph@codesourcery.com>
Subject: Re: [PATCH] configure: Implement --enable-host-bind-now
Date: Sun, 20 Nov 2022 08:09:22 -0700 [thread overview]
Message-ID: <204aa39e-d85f-8639-08ed-57c8ccf7fdc9@gmail.com> (raw)
In-Reply-To: <20221111025309.188226-1-polacek@redhat.com>
On 11/10/22 19:53, Marek Polacek via Gcc-patches wrote:
> This is a rebased version of the patch I posted in February:
> <https://gcc.gnu.org/pipermail/gcc-patches/2022-February/590201.html>.
>
> Fortunately it is much simpler than the patch implementing --enable-host-pie.
> I've converted the install.texi part into configuration.rst, otherwise
> there are no changes to the original version.
>
> With --enable-host-bind-now --enable-host-pie:
> $ readelf -Wd ./gcc/cc1 ./gcc/cc1plus | 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?
>
> -- >8 --
>
> 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.
>
> 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/configuration.rst: Document --enable-host-bind-now.
>
> lto-plugin/ChangeLog:
>
> * configure.ac (--enable-host-bind-now): New check. Link with
> -z,now.
> * configure: Regenerate.
> ---
OK. Glad to see this finally get to resolution. While I'm largely in
agreement with Jakub that PIE doesn't provide a major security benefit
for the compiler, it seems better to not have the compiler be special
WRT security options.
Jeff
next prev parent reply other threads:[~2022-11-20 15:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-11 2:53 Marek Polacek
2022-11-20 15:09 ` Jeff Law [this message]
-- strict thread matches above, loose matches on Subject: below --
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
2022-02-10 16:50 Marek Polacek
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