From: Marco Elver <elver@google.com>
To: George Popescu <georgepope@google.com>
Cc: Kees Cook <keescook@chromium.org>,
maz@kernel.org, Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
kvmarm@lists.cs.columbia.edu, LKML <linux-kernel@vger.kernel.org>,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>,
james.morse@arm.com, julien.thierry.kdev@gmail.com,
suzuki.poulose@arm.com,
Nathan Chancellor <natechancellor@gmail.com>,
Nick Desaulniers <ndesaulniers@google.com>,
David Brazdil <dbrazdil@google.com>,
broonie@kernel.org, Fangrui Song <maskray@google.com>,
Andrew Scull <ascull@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dmitry Vyukov <dvyukov@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH 06/14] Fix CFLAGS for UBSAN_BOUNDS on Clang
Date: Tue, 15 Sep 2020 19:32:28 +0200 [thread overview]
Message-ID: <CANpmjNPpq7LfTHYesz2wTVw6Pqv0FQ2gc-vmSB6Mdov+XWPZiw@mail.gmail.com> (raw)
In-Reply-To: <20200915120105.GA2294884@google.com>
On Tue, 15 Sep 2020 at 14:01, George Popescu <georgepope@google.com> wrote:
>
> On Tue, Sep 15, 2020 at 01:18:11PM +0200, Marco Elver wrote:
> > On Tue, 15 Sep 2020 at 12:25, George Popescu <georgepope@google.com> wrote:
> > > On Mon, Sep 14, 2020 at 03:13:14PM -0700, Kees Cook wrote:
> > > > On Mon, Sep 14, 2020 at 05:27:42PM +0000, George-Aurelian Popescu wrote:
> > > > > From: George Popescu <georgepope@google.com>
> > > > >
> > > > > When the kernel is compiled with Clang, UBSAN_BOUNDS inserts a brk after
> > > > > the handler call, preventing it from printing any information processed
> > > > > inside the buffer.
> > > > > For Clang -fsanitize=bounds expands to -fsanitize=array-bounds and
> > > > > -fsanitize=local-bounds, and the latter adds a brk after the handler
> > > > > call
> > > >
> > > This would mean losing the local-bounds coverage. I tried to test it without
> > > local-bounds and with a locally defined array on the stack and it works fine
> > > (the handler is called and the error reported). For me it feels like
> > > --array-bounds and --local-bounds are triggered for the same type of
> > > undefined_behaviours but they are handling them different.
> >
> > Does -fno-sanitize-trap=bounds help?>
>
> I tried replacing it with:
> ifdef CONFIG_CC_IS_CLANG
> CFLAGS_UBSAN += $(call cc-option, -fno-sanitize-trap=bounds)
> CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
> else
> CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
> endif
>
> The code traps.
What's your config? Do you have CONFIG_UBSAN_TRAP=y? If so, you have 2
options: honor UBSAN_TRAP and crash the kernel, or have a
'CFLAGS_REMOVE_... = -fsanitize-undefined-trap-on-error' for the files
where you can't deal with traps.
Thanks,
-- Marco
next prev parent reply other threads:[~2020-09-15 18:44 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-14 17:27 [PATCH 00/14] UBSan Enablement for hyp/nVHE code George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 01/14] KVM: arm64: Enable UBSan instrumentation in nVHE hyp code George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 02/14] KVM: arm64: Define a macro for storing a value inside a per_cpu variable George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 03/14] KVM: arm64: Add support for creating and checking a logging buffer inside hyp/nVHE George-Aurelian Popescu
2020-10-01 10:07 ` Andrew Scull
2020-09-14 17:27 ` [PATCH 04/14] KVM: arm64: Add support for buffer usage George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 05/14] KVM: arm64: Define a buffer that can pass UBSan data from hyp/nVHE to kernel George-Aurelian Popescu
2020-09-15 13:25 ` George Popescu
2020-10-01 10:51 ` Andrew Scull
2020-09-14 17:27 ` [PATCH 06/14] Fix CFLAGS for UBSAN_BOUNDS on Clang George-Aurelian Popescu
2020-09-14 21:17 ` Nick Desaulniers
2020-09-14 22:13 ` Kees Cook
2020-09-15 10:24 ` George Popescu
2020-09-15 11:18 ` Marco Elver
2020-09-15 12:01 ` George Popescu
2020-09-15 17:32 ` Marco Elver [this message]
2020-09-16 7:40 ` George Popescu
2020-09-16 8:32 ` Marco Elver
[not found] ` <20200916121401.GA3362356@google.com>
2020-09-16 13:40 ` Marco Elver
2020-09-17 6:37 ` Marco Elver
2020-09-17 11:35 ` George Popescu
2020-09-17 22:21 ` Kees Cook
2020-09-17 22:17 ` Kees Cook
2020-09-14 17:27 ` [PATCH 07/14] KVM: arm64: Enable UBSAN_BOUNDS for the both the kernel and hyp/nVHE George-Aurelian Popescu
2020-10-01 10:57 ` Andrew Scull
2020-09-14 17:27 ` [PATCH 08/14] KVM: arm64: Enable UBsan check for unreachable code inside hyp/nVHE code George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 09/14] KVM: arm64: Enable shift out of bounds undefined behaviour check for hyp/nVHE George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 10/14] KVM: arm64: __ubsan_handle_load_invalid_value hyp/nVHE implementation George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 11/14] KVM: arm64: Detect type mismatch undefined behaviour from hyp/nVHE code George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 12/14] KVM: arm64: Detect arithmetic overflow is inside hyp/nVHE George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 13/14] KVM: arm64: Enable the CONFIG_TEST UBSan for PKVM George-Aurelian Popescu
2020-09-14 17:27 ` [PATCH 14/14] DO NOT MERGE: Enable configs to test the patch series George-Aurelian Popescu
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=CANpmjNPpq7LfTHYesz2wTVw6Pqv0FQ2gc-vmSB6Mdov+XWPZiw@mail.gmail.com \
--to=elver@google.com \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=ascull@google.com \
--cc=broonie@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=clang-built-linux@googlegroups.com \
--cc=dbrazdil@google.com \
--cc=dvyukov@google.com \
--cc=georgepope@google.com \
--cc=james.morse@arm.com \
--cc=julien.thierry.kdev@gmail.com \
--cc=keescook@chromium.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=masahiroy@kernel.org \
--cc=maskray@google.com \
--cc=maz@kernel.org \
--cc=michal.lkml@markovi.net \
--cc=natechancellor@gmail.com \
--cc=ndesaulniers@google.com \
--cc=suzuki.poulose@arm.com \
--cc=tglx@linutronix.de \
--cc=will@kernel.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 NNTP newsgroup(s).