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Wysocki" , xen-devel , Jan Beulich , Roger Pau Monne , Kees Cook , mark.rutland@arm.com Subject: [RFC][PATCH 2/6] x86/power: Inline write_cr[04]() References: <20230112143141.645645775@infradead.org> MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1754828927152631295?= X-GMAIL-MSGID: =?utf-8?q?1754828927152631295?= Since we can't do CALL/RET until GS is restored and CR[04] pinning is of dubious value in this code path, simply write the stored values. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook --- arch/x86/power/cpu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -208,11 +208,11 @@ static void notrace __restore_processor_ #else /* CONFIG X86_64 */ native_wrmsrl(MSR_EFER, ctxt->efer); - native_write_cr4(ctxt->cr4); + asm volatile("mov %0,%%cr4": "+r" (ctxt->cr4) : : "memory"); #endif native_write_cr3(ctxt->cr3); native_write_cr2(ctxt->cr2); - native_write_cr0(ctxt->cr0); + asm volatile("mov %0,%%cr0": "+r" (ctxt->cr0) : : "memory"); /* Restore the IDT. */ native_load_idt(&ctxt->idt);