Re: [PATCH 0/3] Kill off show_stack() NULL-implies-current idiom

From: Josh Poimboeuf
Date: Mon Sep 26 2016 - 16:01:47 EST


On Mon, Sep 26, 2016 at 04:16:16PM +0100, Mark Rutland wrote:
> Today, show_stack() accepts a NULL task parameter, which it takes to mean the
> current task. However, as noted in tip/x86/asm commit:
>
> 81539169f283329f ("x86/dumpstack: Remove NULL task pointer convention")
>
> ... having a NULL task parameter imply current leads to subtle bugs in stack
> walking code (so far seen on both 86 and arm64), makes callsites harder to
> read, and is unnecessary as all callers have access to current.
>
> As a step towards removing the problematic NULL-implies-current idiom entirely,
> these patches ensure that generic code explictly passes current to
> show_stack(), rather than relying on arch code to handle NULL.

This is a good step, though it would be really nice to fix this
tree-wide. Do you have any plans to do so?

Regardless, for the series:

Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

--
Josh