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From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date: Tue, 23 Jan 2024 12:20:17 +0100
Message-ID: <CANiq72=K2Ux9obd6fP3sMhRxRpRs6_ow_5VbG0kjkw8vpx75_A@mail.gmail.com>
Subject: Re: [PATCH 06/82] overflow: Reintroduce signed and unsigned overflow sanitizers
To: Kees Cook <kees@kernel.org>
Cc: Kees Cook <keescook@chromium.org>, linux-hardening@vger.kernel.org, 
	Justin Stitt <justinstitt@google.com>, Miguel Ojeda <ojeda@kernel.org>, 
	Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, 
	Peter Zijlstra <peterz@infradead.org>, Marco Elver <elver@google.com>, Hao Luo <haoluo@google.com>, 
	Przemek Kitszel <przemyslaw.kitszel@intel.com>, 
	"Gustavo A. R. Silva" <gustavoars@kernel.org>, Bill Wendling <morbo@google.com>, linux-kernel@vger.kernel.org
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On Tue, Jan 23, 2024 at 5:45=E2=80=AFAM Kees Cook <kees@kernel.org> wrote:
>
> Yes. We removed this bad behavior by using -fno-strict-overflow, and we w=
ill want to keep it enabled.

Yeah, I only meant that the wording of the commit seems to say there
is something special about the "overflowing behavior", i.e. I was
expecting just UB with the usual implications, but given the extra
text in the parenthesis, I wondered while reading it if there was
something different/special going on.

> The stack usage is separate. (This may even be fixed in modern Clang; thi=
s comes from the original version of this Kconfig.) The not booting part is=
 separate and has not been tracked down yet.

I see. Thanks! In any case, if the sentence means only 32-bit x86,
users couldn't still see it. But since this was already in the revert
now that I take a look, I guess ignore this :)

> I wondered the same -- they were this way when they were removed, so I ju=
st restored them as they were. :)

Makes sense :)

Cheers,
Miguel