Re: [PATCH] Kprobes i386 fix for mark ro data

From: Ian McDonald
Date: Sun Jun 10 2007 - 02:24:31 EST


On 6/7/07, S. P. Prasanna <prasanna@xxxxxxxxxx> wrote:
> >It faulted when it tried to write the breakpoint instruction into the
> >running kernel's executable code. Apparently the kernel code is now marked
> >read-only?
> >
> >
> Yes it would appear to be the case as user has CONFIG_DEBUG_RODATA
> set. Patrick - can you turn this off and retest? It's under Kernel
> Hacking, Write protect kernel read only data structures.
>

Ian,

Please find the fix as suggested by Andi Kleen
for the above stated problem.

Thanks
Prasanna


I went to test the fix and first of all went to replicate the problem.
My build has CONFIG_DEBUG_RODATA set but the problem does not occur
without the patch. Should I be concerned about this and raise a bug
for that as I would think that means there is a problem that the read
only protection isn't working (this is off Linus' tree synced
tonight).

Patrick - can you test whether this patch fixes your problem? You said
disabling CONFIG_DEBUG_RODATA fixed your problem but can you try
re-enabling and testing this patch?

Ian
--
Web: http://wand.net.nz/~iam4/
Blog: http://iansblog.jandi.co.nz
WAND Network Research Group
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/