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=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 7D391C43381 for ; Mon, 18 Mar 2019 15:53:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D17920880 for ; Mon, 18 Mar 2019 15:53:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="cbkVUiF7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727774AbfCRPxE (ORCPT ); Mon, 18 Mar 2019 11:53:04 -0400 Received: from merlin.infradead.org ([205.233.59.134]:58718 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727409AbfCRPw6 (ORCPT ); Mon, 18 Mar 2019 11:52:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=OXrTqMuylXpQnqjfLjKiLaVE2XD1S2ZTsJmOXFxtGlg=; b=cbkVUiF74uBUPTkYHN4WnV6w+w BkJ5sgN8qncBnLTubG/LF7aRuyI1X5z4z6CibzEOLqF7uvLcJxWV7MhoyHb0F/R9p7CxIE7iK0ebA VDqr5VsXvKY7Z2BWMq0zmbm9e5KzvdvKgDushMsvuOibUDG2G9A1kl8g8S6h/hesRm25zYYTIYDG1 QAm1lBUi9B9MHuTxHCaE/ou4qFt4a5GAjOCEwmpec1vxGKjAqCbV62vl8zx+TmLTGs+dp7nb0f/bT OI0v6KvG4GLnZOWTPbAYwJFHYe1ihk52QfzGgsbI51Ob/BG/JgEC/ytZycB8i2KwBN+smrwYoz5Uy WuxWQblQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5uZ9-0005V7-4N; Mon, 18 Mar 2019 15:52:43 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id CB62E25E45D7B; Mon, 18 Mar 2019 16:52:38 +0100 (CET) Message-Id: <20190318155141.280380020@infradead.org> User-Agent: quilt/0.65 Date: Mon, 18 Mar 2019 16:38:55 +0100 From: Peter Zijlstra To: torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com, julien.thierry@arm.com, will.deacon@arm.com, luto@amacapital.net, mingo@kernel.org, catalin.marinas@arm.com, james.morse@arm.com, valentin.schneider@arm.com, brgerst@gmail.com, jpoimboe@redhat.com, luto@kernel.org, bp@alien8.de, dvlasenk@redhat.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, dvyukov@google.com, rostedt@goodmis.org Subject: [PATCH 15/25] x86/uaccess,ftrace: Fix ftrace_likely_update() vs SMAP References: <20190318153840.906404905@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For CONFIG_TRACE_BRANCH_PROFILING the likely/unlikely things get overloaded and generate callouts to this code, and thus also when AC=1. Make it safe. Cc: Steven Rostedt Signed-off-by: Peter Zijlstra (Intel) --- kernel/trace/trace_branch.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -205,6 +205,8 @@ void trace_likely_condition(struct ftrac void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect, int is_constant) { + unsigned long flags = user_access_save(); + /* A constant is always correct */ if (is_constant) { f->constant++; @@ -223,6 +225,8 @@ void ftrace_likely_update(struct ftrace_ f->data.correct++; else f->data.incorrect++; + + user_access_restore(flags); } EXPORT_SYMBOL(ftrace_likely_update);