[Crash-utility] [PATCH] ARM: corrupted pages tables vs unwind

[Mika Westerberg]

On Sat, Jan 28, 2012 at 03:36:28PM +0530, Rabin Vincent wrote:
> I have access to a system whose crashdump extraction mechanism
> unfortunately trashes the first few hundred kilobytes of physical
> memory,  which includes the page tables at swapper_pg_dir.
> 
> crash does chug along and remains quite useful without these page tables
> since much of the interesting information is in the direct mapped
> region, but it disables the use of the unwind tables because it
> fails to read the module unwind tables, which are placed at a
> non-direct-mapped address.
> 
> The patch below allows unwind tables to be used only for core kernel
> addresses if the module tables are inaccessible.
> 
> Alternatively, we could perhaps not attempt to read the
> module unwind tables when --no_modules is specified.

IMHO crash should at least try to allow user to perform analysis even if it
cannot do V<->P translations via page tables. The patch looks good and makes
ARM port of crash a bit more tolerant so,

Acked-by: Mika Westerberg <mika.westerberg at iki.fi>

Thanks!