From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CC7EC54EBE for ; Mon, 16 Jan 2023 14:53:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229638AbjAPOxH (ORCPT ); Mon, 16 Jan 2023 09:53:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230218AbjAPOwN (ORCPT ); Mon, 16 Jan 2023 09:52:13 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 895D72BF1B for ; Mon, 16 Jan 2023 06:38:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=dtG3CCLzMA0i0qOsNCGAACCWIWjzH+RX76nYJr/7nUg=; b=mNSQfQeUAAjFw9ESss496f+Z7Q u0TgyafjRhE1gQwftI2iBVWQ3NaSLG34VdbAWazXouiYsRdKyzqy1wML0X2573JOCsV/N0PK5k2F2 TPov7/LEGoLwGuZcybAwU9tHaa3wffyOD9zxSarAfZ29Q4WErfXs+qrs4jgpQMpEdyO9/ORvp95nX EjaMEymmS+cwIurns0c3wEq3uE17tL2K8Hwq/Ex3y3gpAT4bxe9pp5k86FtmXoW5UtC3/6pfTmVtZ 8qPTNYgKrdqtoTo1pP63NdYMrqwT3UhPTSsaXrAPfezN6rdi70FJ8sxMqiPPuMxRvDSFpPFtdzk0Q gXratnhg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pHQcT-008oZ6-SE; Mon, 16 Jan 2023 14:37:54 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id E016530073F; Mon, 16 Jan 2023 15:37:38 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id B816220B75F29; Mon, 16 Jan 2023 15:37:38 +0100 (CET) Message-ID: <20230116143645.768035056@infradead.org> User-Agent: quilt/0.66 Date: Mon, 16 Jan 2023 15:25:37 +0100 From: Peter Zijlstra To: x86@kernel.org, Joan Bruguera Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, Juergen Gross , "Rafael J. Wysocki" , xen-devel , Jan Beulich , Roger Pau Monne , Kees Cook , mark.rutland@arm.com, Andrew Cooper , =?UTF-8?q?J=C3=B6rg=20R=C3=B6del?= , "H. Peter Anvin" Subject: [PATCH v2 4/7] x86/power: Inline write_cr[04]() References: <20230116142533.905102512@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Fixes: e81dc127ef69 ("x86/callthunks: Add call patching for call depth tracking") Reported-by: Joan Bruguera 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);