[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAG_fn=XcJ=rZEJN+L1zZwk=qA90KShhZK1MA6fdW0oh7BqSJKw@mail.gmail.com>
Date: Thu, 19 Oct 2023 12:04:23 +0200
From: Alexander Potapenko <glider@...gle.com>
To: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Hamza Mahfooz <hamza.mahfooz@....com>,
linux-kernel@...r.kernel.org,
Rodrigo Siqueira <rodrigo.siqueira@....com>,
Harry Wentland <harry.wentland@....com>,
Alex Deucher <alexander.deucher@....com>,
Arnd Bergmann <arnd@...db.de>, stable@...r.kernel.org,
Miguel Ojeda <ojeda@...nel.org>,
Alex Gaynor <alex.gaynor@...il.com>,
Wedson Almeida Filho <wedsonaf@...il.com>,
Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>,
Björn Roy Baron <bjorn3_gh@...tonmail.com>,
Nick Terrell <terrelln@...com>,
Nathan Chancellor <nathan@...nel.org>,
Nick Desaulniers <ndesaulniers@...gle.com>,
Tom Rix <trix@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>,
"Masami Hiramatsu (Google)" <mhiramat@...nel.org>,
Randy Dunlap <rdunlap@...radead.org>,
Kees Cook <keescook@...omium.org>,
Zhaoyang Huang <zhaoyang.huang@...soc.com>,
Li Hua <hucool.lihua@...wei.com>, Rae Moar <rmoar@...gle.com>,
rust-for-linux@...r.kernel.org, bpf@...r.kernel.org,
llvm@...ts.linux.dev
Subject: Re: [PATCH] lib/Kconfig.debug: disable FRAME_WARN for kasan and kcsan
> > > Are kernels with KASAN || KCSAN || KMSAN enabled supposed to be bootable?
> >
> > They are all intended to be used for runtime debugging, so I'd imagine so.
>
> Then I strongly suggest putting a nonzero value here. As you write
> that "with every release of LLVM, both of these sanitizers eat up more and more
> of the stack", don't you want to have at least some canary to detect
> when "more and more" is guaranteed to run into problems?
FRAME_WARN is a poor canary. First, it does not necessarily indicate
that a build is faulty (a single bloated stack frame won't crash the
system).
Second, devs are unlikely to fix a function because its stack frame is
too big under some exotic tool+compiler combination.
So the remaining option would be to just increase the frame size every
time a new function surpasses the limit.
Powered by blists - more mailing lists