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From: Rusty Russell <rusty@rustcorp.com.au>
To: Andrew Morton <akpm@osdl.org>
Cc: Ashutosh Naik <ashutosh.naik@gmail.com>,
	jesper.juhl@gmail.com, anandhkrishnan@yahoo.co.in,
	linux-kernel@vger.kernel.org, rth@redhat.com, greg@kroah.com,
	alan@lxorguk.ukuu.org.uk, kaos@ocs.com.au
Subject: Re: [RFC][PATCH] Prevent overriding of Symbols in the Kernel, avoiding Undefined behaviour
Date: Thu, 15 Dec 2005 16:15:04 +1100	[thread overview]
Message-ID: <1134623704.7773.34.camel@localhost.localdomain> (raw)
In-Reply-To: <20051214204032.57c4c6ae.akpm@osdl.org>

On Wed, 2005-12-14 at 20:40 -0800, Andrew Morton wrote:
> Ashutosh Naik <ashutosh.naik@gmail.com> wrote:
> >
> > This patch ensures that an exported symbol  does not already exist in
> >  the kernel or in some other module's exported symbol table. This is
> >  done by checking the symbol tables for the exported symbol at the time
> >  of loading the module. Currently this is done after the relocation of
> >  the symbol.
> 
> This patch causes weird things to happen on ppc64.

And probably in general:

+       for (i = 0; i < mod->num_syms; i++)
+               if (!__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
+                       name = mod->syms[i].name;
+                       ret = -ENOEXEC;
+                       goto dup;

__find_symbol returns the value, or 0 on failure.  This test is
backwards, as is the one below it.

Rusty.
-- 
 ccontrol: http://ozlabs.org/~rusty/ccontrol


  reply	other threads:[~2005-12-15  5:15 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-12-12 12:39 [RFC][PATCH] Prevent overriding of Symbols in the Kernel, avoiding Undefined behaviour Ashutosh Naik
2005-12-12 12:44 ` Ashutosh Naik
2005-12-12 22:25   ` Jesper Juhl
2005-12-13  8:23     ` Anand H. Krishnan
2005-12-12 19:13 ` Andrew Morton
2005-12-12 19:27   ` Richard Henderson
2005-12-12 20:20     ` Greg KH
2005-12-12 20:30       ` Jesper Juhl
2005-12-12 22:48   ` Alan Cox
2005-12-13  8:03     ` Arjan van de Ven
2005-12-13 14:32     ` Ashutosh Naik
2005-12-12 22:01 ` Rusty Russell
2005-12-13 14:26   ` Ashutosh Naik
2005-12-13 15:28     ` Ashutosh Naik
2005-12-13 16:49     ` [RFC][PATCH] " Jesper Juhl
2005-12-14  2:03       ` Rusty Russell
2005-12-14  4:10         ` Ashutosh Naik
2005-12-14  5:02           ` Ashutosh Naik
2005-12-15  4:40             ` Andrew Morton
2005-12-15  5:15               ` Rusty Russell [this message]
2005-12-15  5:45                 ` Ashutosh Naik
2005-12-14  5:46         ` Ashutosh Naik
2005-12-14 23:02           ` Rusty Russell

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