Re: [PATCH] lib/Kconfig.debug: disable FRAME_WARN for kasan and kcsan

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Hamza Mahfooz <hamza.mahfooz@amd.com>
Cc: linux-kernel@vger.kernel.org,
	"Rodrigo Siqueira" <rodrigo.siqueira@amd.com>,
	"Harry Wentland" <harry.wentland@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Arnd Bergmann" <arnd@arndb.de>,
	stable@vger.kernel.org, "Miguel Ojeda" <ojeda@kernel.org>,
	"Alex Gaynor" <alex.gaynor@gmail.com>,
	"Wedson Almeida Filho" <wedsonaf@gmail.com>,
	"Boqun Feng" <boqun.feng@gmail.com>,
	"Gary Guo" <gary@garyguo.net>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Nick Terrell" <terrelln@fb.com>,
	"Nathan Chancellor" <nathan@kernel.org>,
	"Nick Desaulniers" <ndesaulniers@google.com>,
	"Tom Rix" <trix@redhat.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Masami Hiramatsu (Google)" <mhiramat@kernel.org>,
	"Randy Dunlap" <rdunlap@infradead.org>,
	"Kees Cook" <keescook@chromium.org>,
	"Zhaoyang Huang" <zhaoyang.huang@unisoc.com>,
	"Li Hua" <hucool.lihua@huawei.com>,
	"Alexander Potapenko" <glider@google.com>,
	"Geert Uytterhoeven" <geert+renesas@glider.be>,
	"Rae Moar" <rmoar@google.com>,
	rust-for-linux@vger.kernel.org, bpf@vger.kernel.org,
	llvm@lists.linux.dev
Subject: Re: [PATCH] lib/Kconfig.debug: disable FRAME_WARN for kasan and kcsan
Date: Wed, 18 Oct 2023 20:29:07 +0200	[thread overview]
Message-ID: <CAMuHMdXSzMJe1zyJu1HkxWggTKJj_sxkPOejjbdRjg3FeFTVHQ@mail.gmail.com> (raw)
In-Reply-To: <20231018182412.80291-1-hamza.mahfooz@amd.com>

Hi Hamza,

On Wed, Oct 18, 2023 at 8:24 PM Hamza Mahfooz <hamza.mahfooz@amd.com> wrote:
> With every release of LLVM, both of these sanitizers eat up more and
> more of the stack. So, set FRAME_WARN to 0 if either of them is enabled
> for a given build.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>

Thanks for your patch!

> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -429,11 +429,10 @@ endif # DEBUG_INFO
>  config FRAME_WARN
>         int "Warn for stack frames larger than"
>         range 0 8192
> -       default 0 if KMSAN
> +       default 0 if KASAN || KCSAN || KMSAN

Are kernels with KASAN || KCSAN || KMSAN enabled supposed to be bootable?
Stack overflows do cause crashes.

>         default 2048 if GCC_PLUGIN_LATENT_ENTROPY
>         default 2048 if PARISC
>         default 1536 if (!64BIT && XTENSA)
> -       default 1280 if KASAN && !64BIT
>         default 1024 if !64BIT
>         default 2048 if 64BIT
>         help

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds