From: Andreas Schwab <schwab@suse.de>
To: Arjan van de Ven <arjan@infradead.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: how to determine if the noexec stack is defined by an application
References: <46856F24.5060407@andrei.myip.org>
	<1183153758.2894.1.camel@laptopd505.fenrus.org>
Date: Sat, 30 Jun 2007 00:15:19 +0200
In-Reply-To: <1183153758.2894.1.camel@laptopd505.fenrus.org> (Arjan van de
	Ven's message of "Fri\, 29 Jun 2007 14\:49\:18 -0700")
Message-ID: <jefy4aflvs.fsf@sykes.suse.de>
User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.97 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1045
Lines: 29

Arjan van de Ven <arjan@infradead.org> writes:

> like this:
>
> $ eu-readelf -l /bin/true  | grep STACK
>   GNU_STACK      0x000000 0x00000000 0x00000000 0x000000 0x000000 RW 0x4
>
>
> (replace /bin/true with the binary or library you want to check)
>
> if it says "RW" like here, it'll have non-executable stack. If it says
> "RWX" or if this line is absent entirely, the stack will be executable.

The last part is not true.  Some architectures (especially newer ones)
default to non-exec stack.  The absense of a GNU_STACK header represents
the default.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstra?e 5, 90409 N?rnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/