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 X-Spam-Level: X-Spam-Status: No, score=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21DCEC433DF for ; Thu, 25 Jun 2020 11:54:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04CC020781 for ; Thu, 25 Jun 2020 11:54:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404579AbgFYLyg (ORCPT ); Thu, 25 Jun 2020 07:54:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404364AbgFYLxh (ORCPT ); Thu, 25 Jun 2020 07:53:37 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9773C0613ED; Thu, 25 Jun 2020 04:53:36 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1joQRh-0005sR-FK; Thu, 25 Jun 2020 13:53:33 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 268D71C047D; Thu, 25 Jun 2020 13:53:33 +0200 (CEST) Date: Thu, 25 Jun 2020 11:53:32 -0000 From: "tip-bot2 for Peter Zijlstra" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/entry] x86/entry: Fixup bad_iret vs noinstr Cc: Marco Elver , "Peter Zijlstra (Intel)" , x86 , LKML In-Reply-To: <20200618144801.760070502@infradead.org> References: <20200618144801.760070502@infradead.org> MIME-Version: 1.0 Message-ID: <159308601294.16989.6717371293673263499.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/entry branch of tip: Commit-ID: e3a9e681adb779b39565a28b3252c3be1033f994 Gitweb: https://git.kernel.org/tip/e3a9e681adb779b39565a28b3252c3be1033f994 Author: Peter Zijlstra AuthorDate: Wed, 17 Jun 2020 18:21:16 +02:00 Committer: Peter Zijlstra CommitterDate: Thu, 25 Jun 2020 13:45:39 +02:00 x86/entry: Fixup bad_iret vs noinstr vmlinux.o: warning: objtool: fixup_bad_iret()+0x8e: call to memcpy() leaves .noinstr.text section Worse, when KASAN there is no telling what memcpy() actually is. Force the use of __memcpy() which is our assmebly implementation. Reported-by: Marco Elver Suggested-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Tested-by: Marco Elver Link: https://lkml.kernel.org/r/20200618144801.760070502@infradead.org --- arch/x86/kernel/traps.c | 6 +++--- arch/x86/lib/memcpy_64.S | 4 ++++ 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index af75109..a7d1570 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -690,13 +690,13 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) (struct bad_iret_stack *)__this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1; /* Copy the IRET target to the temporary storage. */ - memcpy(&tmp.regs.ip, (void *)s->regs.sp, 5*8); + __memcpy(&tmp.regs.ip, (void *)s->regs.sp, 5*8); /* Copy the remainder of the stack from the current stack. */ - memcpy(&tmp, s, offsetof(struct bad_iret_stack, regs.ip)); + __memcpy(&tmp, s, offsetof(struct bad_iret_stack, regs.ip)); /* Update the entry stack */ - memcpy(new_stack, &tmp, sizeof(tmp)); + __memcpy(new_stack, &tmp, sizeof(tmp)); BUG_ON(!user_mode(&new_stack->regs)); return new_stack; diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S index 56b243b..bbcc05b 100644 --- a/arch/x86/lib/memcpy_64.S +++ b/arch/x86/lib/memcpy_64.S @@ -8,6 +8,8 @@ #include #include +.pushsection .noinstr.text, "ax" + /* * We build a jump to memcpy_orig by default which gets NOPped out on * the majority of x86 CPUs which set REP_GOOD. In addition, CPUs which @@ -184,6 +186,8 @@ SYM_FUNC_START_LOCAL(memcpy_orig) retq SYM_FUNC_END(memcpy_orig) +.popsection + #ifndef CONFIG_UML MCSAFE_TEST_CTL