linux-kernel - Re: [PATCH] Protect prefetch macro arguments.

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 linux-cve-announce 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]

Message-ID: <alpine.LFD.2.00.1003261402170.3721@i5.linux-foundation.org>
Date:	Fri, 26 Mar 2010 14:04:08 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	David Daney <ddaney@...iumnetworks.com>
cc:	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	linux-arch@...r.kernel.org
Subject: Re: [PATCH] Protect prefetch macro arguments.



On Fri, 26 Mar 2010, David Daney wrote:
>
> The GCC built-in __builtin_prefetch() is a vargs function.  If we
> don't wrap the macro parameter in parentheses, a comma operator in the
> actual argument list might cause unintended parameters to be passed to
> __builtin_prefetch().

This seems totally pointless and actively wrong.

You cannot have a comma operator in the actual argument list to the 
#define, because if you did, then you'd get a

	macro "prefetch()" passed 2 arguments, but takes just 1

so the only way I see to pass a comma operator is to _already_ have the 
macro parameter in parenthesis.

		Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/