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 27F66C001DD for ; Sun, 9 Jul 2023 11:33:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230051AbjGILds (ORCPT ); Sun, 9 Jul 2023 07:33:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229777AbjGILdo (ORCPT ); Sun, 9 Jul 2023 07:33:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A931118F for ; Sun, 9 Jul 2023 04:33:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3EF1C60BC0 for ; Sun, 9 Jul 2023 11:33:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 501B2C433C7; Sun, 9 Jul 2023 11:33:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1688902422; bh=B32SVhQMe+FpiMbO6keH5Pk5eWOnQv6AS1MyQdnAyUk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UUkM6SbyHt8FZE0Hb6VF5QGNDxw+JPoH0lYkO8e2jndRvqXtVlWvDpd6pRuqJQFLb kwhTag8YXWMwgRHPwTIu8efbUf47SyDeU9Hjg0xLcgKqQcPyq18eJEyUYAuJ6w68qO swIPwJ2CYRrV4vq8UUKwGR7W7PwPZd2v2/GkIqP8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christophe Leroy , Michael Ellerman , Sasha Levin Subject: [PATCH 6.3 371/431] powerpc/signal32: Force inlining of __unsafe_save_user_regs() and save_tm_user_regs_unsafe() Date: Sun, 9 Jul 2023 13:15:19 +0200 Message-ID: <20230709111459.860958592@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230709111451.101012554@linuxfoundation.org> References: <20230709111451.101012554@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Christophe Leroy [ Upstream commit a03b1a0b19398a47489fdcef02ec19c2ba05a15d ] Looking at generated code for handle_signal32() shows calls to a function called __unsafe_save_user_regs.constprop.0 while user access is open. And that __unsafe_save_user_regs.constprop.0 function has two nops at the begining, allowing it to be traced, which is unexpected during user access open window. The solution could be to mark __unsafe_save_user_regs() no trace, but to be on the safe side the most efficient is to flag it __always_inline as already done for function __unsafe_restore_general_regs(). The function is relatively small and only called twice, so the size increase will remain in the noise. Do the same with save_tm_user_regs_unsafe() as it may suffer the same issue. Fixes: ef75e7318294 ("powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/7e469c8f01860a69c1ada3ca6a5e2aa65f0f74b2.1685955220.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin --- arch/powerpc/kernel/signal_32.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index c114c7f25645c..7a718ed32b277 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -264,8 +264,9 @@ static void prepare_save_user_regs(int ctx_has_vsx_region) #endif } -static int __unsafe_save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, - struct mcontext __user *tm_frame, int ctx_has_vsx_region) +static __always_inline int +__unsafe_save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, int ctx_has_vsx_region) { unsigned long msr = regs->msr; @@ -364,8 +365,9 @@ static void prepare_save_tm_user_regs(void) current->thread.ckvrsave = mfspr(SPRN_VRSAVE); } -static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, - struct mcontext __user *tm_frame, unsigned long msr) +static __always_inline int +save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, unsigned long msr) { /* Save both sets of general registers */ unsafe_save_general_regs(¤t->thread.ckpt_regs, frame, failed); @@ -444,8 +446,9 @@ static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user #else static void prepare_save_tm_user_regs(void) { } -static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, - struct mcontext __user *tm_frame, unsigned long msr) +static __always_inline int +save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, unsigned long msr) { return 0; } -- 2.39.2