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McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , "Peter Zijlstra (Intel)" Subject: Re: [patch V4 part 1 02/36] x86/hw_breakpoint: Prevent data breakpoints on cpu_entry_area Message-ID: <20200506081454.GA25532@zn.tnic> References: <20200505131602.633487962@linutronix.de> <20200505134058.272448010@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200505134058.272448010@linutronix.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 05, 2020 at 03:16:04PM +0200, Thomas Gleixner wrote: > From: Andy Lutomirski > > 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 > Signed-off-by: Andy Lutomirski > Signed-off-by: Peter Zijlstra (Intel) > Signed-off-by: Thomas Gleixner > --- > arch/x86/kernel/hw_breakpoint.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) Reviewed-by: Borislav Petkov -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette