linux-kernel - Re: [RFC PATCH v2 -tip 0/4] x86: signal handler improvement

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: <48DBD96F.6090309@zytor.com>
Date:	Thu, 25 Sep 2008 11:33:19 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Hiroshi Shimamoto <h-shimamoto@...jp.nec.com>
CC:	Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH v2 -tip 0/4] x86: signal handler improvement

Hiroshi Shimamoto wrote:
>>>
>> This is a gcc failure, and should be reported to the gcc people.
> 
> Does this gcc failure mean unnecessary storing into stack?
> 

Yes, it should be able to process this in a register, instead of storing 
to the stack and then merging later.

It's possible it's trying to do that to hide latency, but that's clearly 
a lose in this case.

I'd hate to obfuscate the code, and I'd *really* hate to obfuscate the 
code to work around gcc brokenness, and then not even bothering to tell 
the gcc folks.

	-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/