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

Borislav Petkov
2020-05-06T08:15:01Z

On Tue, May 05, 2020 at 03:16:04PM +0200, Thomas Gleixner wrote:
> From: Andy Lutomirski <luto@kernel.org>
>
> 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@infradead.org>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> arch/x86/kernel/hw_breakpoint.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)

Reviewed-by: Borislav Petkov <bp@suse.de>

--
Regards/Gruss,
Boris.