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X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Kees Cook , Ard Biesheuvel , Masahiro Yamada , Catalin Marinas , Jann Horn , Nick Desaulniers , LKML , Steven Rostedt , Miguel Ojeda , clang-built-linux , Masami Hiramatsu , Marc Zyngier , Kernel Hardening , Laura Abbott , Dave Martin , linux-arm-kernel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jan 16, 2020 at 10:24 AM Will Deacon wrote: > > .macro irq_stack_entry > > mov x19, sp // preserve the original sp > > +#ifdef CONFIG_SHADOW_CALL_STACK > > + mov x20, x18 // preserve the original shadow stack > > +#endif > > Hmm, not sure about corrupting x20 here. Doesn't it hold the PMR value from > kernel_entry? You're right, and it's used in el1_irq after irq_handler if CONFIG_ARM64_PSEUDO_NMI is enabled. Thanks for pointing this out. Looks like one of x24-x29 should be safe here, and the comment needs to be updated to explain why x20-x23 shouldn't be corrupted. Sami _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel