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]
Date:	Sat, 26 Feb 2011 08:47:36 +0000
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Saravana Kannan <skannan@...eaurora.org>
Cc:	Will Deacon <will.deacon@....com>, linux-arm-msm@...r.kernel.org,
	David Brown <davidb@...eaurora.org>,
	Stephen Boyd <sboyd@...eaurora.org>,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 2/4] msm: scm: Fix improper register assignment

On Fri, Feb 25, 2011 at 09:09:05PM -0800, Saravana Kannan wrote:
> Yeah, Stephen and I spent quite a bit of time discussing this and  
> experimenting to figure out what the heck GCC was doing. But it kept  
> optimizing the fake code we put in trying to force GCC to use a specific  
> register.

One way to look at it is that if you specify a value for r0, assign it,
and then call a function, how do you expect the r0 value to be preserved?
r0 will be corrupted by the called function as its used to pass arg0 and
the return value.

I'm surprised the compiler didn't spit out an error.
--
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/

Powered by blists - more mailing lists