From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <1520546351.23648.32.camel@hellion.org.uk>
Subject: Re: [PATCH] kernel.h: Skip single-eval logic on literals in
 min()/max()
From: Ian Campbell <ijc@hellion.org.uk>
Date: Thu, 08 Mar 2018 21:59:11 +0000
In-Reply-To: <20180308214045.GA6787@beast>
References: <20180308214045.GA6787@beast>
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To: Kees Cook <keescook@chromium.org>, Andrew Morton <akpm@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>, Rasmus Villemoes <linux@rasmusvillemoes.dk>, "Gustavo A. R. Silva" <gustavo@embeddedor.com>, "Tobin C. Harding" <me@tobin.cc>, rostedt@goodmis.org, corbet@lwn.net, Chris Mason <clm@fb.com>, Josef Bacik <jbacik@fb.com>, David Sterba <dsterba@suse.com>, "David S. Miller" <davem@davemloft.net>, Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>, Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>, Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Masahiro Yamada <yamada.masahiro@socionext.com>, Borislav Petkov <bp@suse.de>, Randy Dunlap <rdunlap@infradead.org>, Ian Abbott <abbotti@mev.co.uk>, Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>, Petr Mladek <pmladek@suse.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Pantelis Antoniou <pantelis.antoniou@konsulko.com>, linux-btrfs@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com
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On Thu, 2018-03-08 at 13:40 -0800, Kees Cook wrote:
> 
> +#define __min(t1, t2, x, y)						\
> +	__builtin_choose_expr(__builtin_constant_p(x) &&		\
> +			      __builtin_constant_p(y) &&		\
> +			      __builtin_types_compatible_p(t1, t2),	\
> +			      (t1)(x) < (t2)(y) ? (t1)(x) : (t2)(y),	\
> +			      __single_eval_min(t1, t2,			\
> +						__UNIQUE_ID(max1_),	\
> +						__UNIQUE_ID(max2_),	\

min1_ etc?

Ian.

From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <ijc@hellion.org.uk>
Subject: Re: [PATCH] kernel.h: Skip single-eval logic on literals in
 min()/max()
Date: Thu, 08 Mar 2018 21:59:11 +0000
Message-ID: <1520546351.23648.32.camel@hellion.org.uk>
References: <20180308214045.GA6787@beast>
Mime-Version: 1.0
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Cc: Josh Poimboeuf <jpoimboe@redhat.com>, Rasmus Villemoes
 <linux@rasmusvillemoes.dk>, "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
  "Tobin C. Harding" <me@tobin.cc>, rostedt@goodmis.org, corbet@lwn.net,
 Chris Mason <clm@fb.com>,  Josef Bacik <jbacik@fb.com>, David Sterba
 <dsterba@suse.com>, "David S. Miller" <davem@davemloft.net>,  Alexey
 Kuznetsov <kuznet@ms2.inr.ac.ru>, Hideaki YOSHIFUJI
 <yoshfuji@linux-ipv6.org>, Ingo Molnar <mingo@kernel.org>,  Peter Zijlstra
 <peterz@infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Masahiro
 Yamada <yamada.masahiro@socionext.com>, Borislav Petkov <bp@suse.de>, Randy
 Dunlap <rdunlap@infradead.org>, Ian Abbott <abbotti@mev.co.uk>, Sergey
 Senozhatsky <sergey.senozhatsky.work@gmail.com>, Petr Mladek
 <pmladek@suse.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
 Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
 linux-btrf
To: Kees Cook <keescook@chromium.org>, Andrew Morton
 <akpm@linux-foundation.org>
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On Thu, 2018-03-08 at 13:40 -0800, Kees Cook wrote:
> 
> +#define __min(t1, t2, x, y)						\
> +	__builtin_choose_expr(__builtin_constant_p(x) &&		\
> +			      __builtin_constant_p(y) &&		\
> +			      __builtin_types_compatible_p(t1, t2),	\
> +			      (t1)(x) < (t2)(y) ? (t1)(x) : (t2)(y),	\
> +			      __single_eval_min(t1, t2,			\
> +						__UNIQUE_ID(max1_),	\
> +						__UNIQUE_ID(max2_),	\

min1_ etc?

Ian.