[PATCH 2/2] ARM: unwind: enable dumping stacks for SMP && ARM_UNWIND

Laura Abbott lauraa at codeaurora.org
Thu Oct 11 20:52:26 EDT 2012


On 8/26/2012 3:46 PM, Colin Cross wrote:
> Unwinding with CONFIG_ARM_UNWIND is much more complicated than
> unwinding with CONFIG_FRAME_POINTER, but there are only a few points
> that require validation in order to avoid faults or infinite loops.
> Avoiding faults is easy by adding checks to verify that all accesses
> relative to the frame's stack pointer remain inside the stack.
> When CONFIG_FRAME_POINTER is not set it is possible for two frames to
> have the same SP, so there is no way to avoid repeated calls to
> unwind_frame continuing forever.
> Signed-off-by: Colin Cross <ccross at android.com>
> ---

This is a feature we've wanted for a long time. I ran some test with 
repeated catting of stacks with processes dying and the results looked good.

You can add a Tested-by: Laura Abbott <lauraa at codeaurora.org>


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