Re: [PATCH -tip] x86: hw-breakpoints: Actually flush threadbreakpoints in flush_thread().

From: K.Prasad
Date: Mon Oct 05 2009 - 06:51:25 EST


On Mon, Oct 05, 2009 at 07:23:06PM +0900, Paul Mundt wrote:
> [ I noticed this whilst hacking up SH support, applies to the current
> tracing/hw-breakpoints topic branch. ]
>
> flush_thread() tries to do a TIF_DEBUG check before calling in to
> flush_thread_hw_breakpoint() (which subsequently clears the thread flag),
> but for some reason, the x86 code is manually clearing TIF_DEBUG
> immediately before the test, so this path will never be taken.
>
> This kills off the erroneous clear_tsk_thread_flag() and lets
> flush_thread_hw_breakpoint() actually get invoked.
>

Yes, this is wrong and we missed it. Thanks for fixing!

> Presumably folks were getting lucky with testing and the
> free_thread_info() -> free_thread_xstate() path was taking care of the
> flush there.
>
> Signed-off-by: Paul Mundt <lethal@xxxxxxxxxxxx>

Acked-by: K.Prasad <prasad@xxxxxxxxxxxxxxxxxx>


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