linux-kernel - Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 3 Mar 2008 18:48:58 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	"Klaus S. Madsen" <ksm@...rnemadsen.org>
Cc:	Pavel Machek <pavel@....cz>,
	Suspend-devel list <suspend-devel@...ts.sourceforge.net>,
	"H. Peter Anvin" <hpa@...or.com>,
	LKML <linux-kernel@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>,
	Thomas Gleixner <tglx@...utronix.de>,
	Matthew Garrett <mjg59@...f.ucam.org>
Subject: Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending


* Klaus S. Madsen <ksm@...rnemadsen.org> wrote:

> The following patch solves the segfault, by changing the mmap flags of 
> the video memory area, to allow execution. The patch is against 
> libx86-0.99 available from http://www.codon.org.uk/~mjg59/libx86/
> 
> --- libx86-0.99/x86-common.c	2006-09-08 00:44:27.000000000 +0200
> +++ libx86-0.99.new/x86-common.c	2008-03-01 10:08:25.000000000 +0100
> @@ -232,7 +232,7 @@
>  	}
>  
>  	m = mmap((void *)0xa0000, 0x100000 - 0xa0000,
> -	 PROT_READ | PROT_WRITE,
> +	 PROT_READ | PROT_WRITE | PROT_EXEC,

are you sure you ID-ed the right commit that broke things?

while requiring PROT_EXEC is fine, breaking existing user-space apps 
over that is not fine. So are you absolutely sure that by reverting that 
PWT|PCD commit, s2ram again starts to work? That's utmost weird...

perhaps there's some CPU bug that causes NX to _NOT_ work if only PCD is 
used (not PCD|PWT). Seems like a pretty unlikely scenario though.

	Ingo
--
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/