linux-hardening - Re: [PATCH] linux/const.h: Explain how __is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 2 Feb 2022 21:13:49 +0100
From:   Miguel Ojeda <miguel.ojeda.sandonis@...il.com>
To:     David Laight <David.Laight@...lab.com>
Cc:     Kees Cook <keescook@...omium.org>,
        Jonathan Corbet <corbet@....net>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Martin Uecker <Martin.Uecker@....uni-goettingen.de>,
        Ingo Molnar <mingo@...nel.org>,
        Rikard Falkeborn <rikard.falkeborn@...il.com>,
        Arnd Bergmann <arnd@...db.de>,
        "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
        Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        "Gustavo A. R. Silva" <gustavoars@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-hardening@...r.kernel.org" <linux-hardening@...r.kernel.org>
Subject: Re: [PATCH] linux/const.h: Explain how __is_constexpr() works

On Wed, Feb 2, 2022 at 5:19 PM David Laight <David.Laight@...lab.com> wrote:
>
> - The conditional operator (?:) requires that both expressions have the
>   the same type (after numeric promotions).

I think you are referring to the arithmetic types case, but that one
does not apply here.

> - If the expressions have distinct non-NULL pointer types then they are both
>   cast to (void *) and the result has type 'void *'.

GCC and Clang give `void *` for this, but something like `float *` and
`int *` do not fit the constrains of the operator.

Cheers,
Miguel