From: Alexander Stein <alexander.stein@ew.tq-group.com>
To: kernel test robot <lkp@intel.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Ard Biesheuvel <ardb@kernel.org>
Cc: oe-kbuild-all@lists.linux.dev, linux-kbuild@vger.kernel.org
Subject: Re: [masahiroy-kbuild:kbuild 5/7] kernel/kallsyms.c:181:56: warning: array subscript is outside array bounds
Date: Tue, 23 Apr 2024 14:22:26 +0200 [thread overview]
Message-ID: <1887856.tdWV9SEqCh@steina-w> (raw)
In-Reply-To: <CAMj1kXH+i1mEFsgZnXokbJ5srDbZY50QGGJcf7yr0w2BowJB8g@mail.gmail.com>
Hi,
Am Dienstag, 23. April 2024, 08:57:16 CEST schrieb Ard Biesheuvel:
> On Tue, 23 Apr 2024 at 05:50, kernel test robot <lkp@intel.com> wrote:
> >
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git kbuild
> > head: 8246a1e9b922c0e797ec28d8a602de1384ff8140
> > commit: 0bdad28369fc5e93de39b5046228ed78e982fc71 [5/7] kallsyms: Avoid weak references for kallsyms symbols
> > config: i386-randconfig-001-20240423 (https://download.01.org/0day-ci/archive/20240423/202404231102.r0G0StUJ-lkp@intel.com/config)
> > compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240423/202404231102.r0G0StUJ-lkp@intel.com/reproduce)
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202404231102.r0G0StUJ-lkp@intel.com/
> >
> > Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
> >
> > All warnings (new ones prefixed by >>):
> >
> > kernel/kallsyms.c: In function 'get_symbol_pos':
> > >> kernel/kallsyms.c:181:56: warning: array subscript is outside array bounds [-Warray-bounds]
> > return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
> >
>
> OK, so weak definitions result in compiler warnings. I don't know
> whether C requires weak definitions of array types are always the same
> size.
It's not just compiler warnings. UBSAN is also triggered by this commit.
> UBSAN: array-index-out-of-bounds in ../kernel/kallsyms.c:181:56
> index 64143 is out of range for type 'int [1]'
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.9.0-rc5-next-20240423+ #2422 cee92685fac34b7fb981de78571f7250231badab
[1] might also be affected by this as CONFIG_UBSAN_BOUNDS=y is set.
Best regards,
Alexander
[1] https://lore.kernel.org/linux-kbuild/691143b5-4636-4911-9c93-437b95f46157@amd.com/T/#m3e5e9112bac8a56b8a7dfa6a19cbc03dcb43a480
> We could work around this by
> a) emitting the weak definitions into a separate object file, although
> this may still violate C, and does not hide the issue from LTO
> b) go back to using PROVIDE() in the linker scripts
>
> @Masahiro: any preference?
>
>
--
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/
prev parent reply other threads:[~2024-04-23 12:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-23 3:49 [masahiroy-kbuild:kbuild 5/7] kernel/kallsyms.c:181:56: warning: array subscript is outside array bounds kernel test robot
2024-04-23 6:57 ` Ard Biesheuvel
2024-04-23 10:14 ` Masahiro Yamada
2024-04-23 12:22 ` Alexander Stein [this message]
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1887856.tdWV9SEqCh@steina-w \
--to=alexander.stein@ew.tq-group.com \
--cc=ardb@kernel.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=lkp@intel.com \
--cc=masahiroy@kernel.org \
--cc=oe-kbuild-all@lists.linux.dev \
/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).