Re: [patch V4 part 1 02/36] x86/hw_breakpoint: Prevent data breakpoints on cpu_entry_area

[Borislav Petkov]

On Tue, May 05, 2020 at 03:16:04PM +0200, Thomas Gleixner wrote:
> From: Andy Lutomirski <luto@xxxxxxxxxx>
> 
> A data breakpoint near the top of an IST stack will cause unresoverable

unrecoverable

> recursion.  A data breakpoint on the GDT, IDT, or TSS is terrifying.

"terrifying" huh? Colorful. :)

> Prevent either of these from happening.
> 
> Co-developed-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
>  arch/x86/kernel/hw_breakpoint.c |   25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)

Reviewed-by: Borislav Petkov <bp@xxxxxxx>

-- 
Regards/Gruss,
    Boris.

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