linux-kernel - Re: [PATCH 1/2] UNREACHABLE() macro

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: <4AAB26FE.7010309@kernel.org>
Date:	Fri, 11 Sep 2009 21:43:42 -0700
From:	"H. Peter Anvin" <hpa@...nel.org>
To:	Arjan van de Ven <arjan@...radead.org>
CC:	Roland McGrath <roland@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	torvalds@...ux-foundation.org, jakub@...hat.com,
	linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
	x86@...nel.org
Subject: Re: [PATCH 1/2] UNREACHABLE() macro

On 09/11/2009 08:49 PM, Arjan van de Ven wrote:
> On Fri, 11 Sep 2009 14:55:25 -0700 (PDT)
> Roland McGrath <roland@...hat.com> wrote:
> 
>>> That's a bit of a mouthful.  Did you consider a runtime probe with
>>> scripts/Kbuild.include's try-run, cc-option, etc?  
>>
>> I did not see any precedent in the sources for using those to test for
>> features by compiling particular test sources (i.e. in autoconf
> 
> look at the stackprotector flags.. they work this way already.
> It gets done once per kernel build...
> 

That works for flags, but not for the presence of builtin functions.
You can't even just try compiling something, since it will turn into an
ordinary function if not present... not obvious until link.

	-hpa
--
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/