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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 26472C1975A for ; Thu, 12 Mar 2020 13:52:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E71D72072F for ; Thu, 12 Mar 2020 13:52:01 +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="C1/I6q/O" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727513AbgCLNvn (ORCPT ); Thu, 12 Mar 2020 09:51:43 -0400 Received: from merlin.infradead.org ([205.233.59.134]:46822 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727435AbgCLNvl (ORCPT ); Thu, 12 Mar 2020 09:51:41 -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:In-Reply-To; bh=piGWWulTk/Ov0pTiMRYfA+U7bMQU7zVTS0znoAEkY9M=; b=C1/I6q/ODL3KWeoyiZrHLkX910 7A+NHYoWvcKw9S/CPZE/6oIs/HdMoTraUzZIx7ZT+zgrnSHzQ/abV+zajN1QegBH1XDtBAHf/td25 83a7I7nQqKT9FSIyEDDqDMd7MEhtg3X2+4Ax+ja3g8QIMDUw489do8TKLaJ03YRv8BIvNiLvSlxl2 2rL+GTcxz99KpbYtYWw6JQfFuaW87Cz7pX2+LZxd2F0yrh8++bXo8/TzeEeWGHTLC7a+r1TDMBLbE AoUsY+V6faDIqErhJ21aMkxg/siDaxXpVL+gj5kYV9SuLFCYScOPqVr0WswafM/bQP30byIcQv6Y+ NhAErP+A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCOFM-0003AP-O1; Thu, 12 Mar 2020 13:51:37 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 3182F305C92; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 08EB72B7403A7; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Message-Id: <20200312135041.465550716@infradead.org> User-Agent: quilt/0.65 Date: Thu, 12 Mar 2020 14:41:08 +0100 From: Peter Zijlstra To: tglx@linutronix.de, jpoimboe@redhat.com Cc: linux-kernel@vger.kernel.org, x86@kernel.org, peterz@infradead.org Subject: [RFC][PATCH 01/16] objtool: Introduce validate_return() References: <20200312134107.700205216@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 Trivial 'cleanup' to save one indentation level and match validate_call(). Signed-off-by: Peter Zijlstra (Intel) --- tools/objtool/check.c | 64 ++++++++++++++++++++++++++++---------------------- 1 file changed, 36 insertions(+), 28 deletions(-) --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1935,6 +1935,41 @@ static int validate_sibling_call(struct return validate_call(insn, state); } +static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state) +{ + if (state->uaccess && !func_uaccess_safe(func)) { + WARN_FUNC("return with UACCESS enabled", + insn->sec, insn->offset); + return 1; + } + + if (!state->uaccess && func_uaccess_safe(func)) { + WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function", + insn->sec, insn->offset); + return 1; + } + + if (state->df) { + WARN_FUNC("return with DF set", + insn->sec, insn->offset); + return 1; + } + + if (func && has_modified_stack_frame(state)) { + WARN_FUNC("return with modified stack frame", + insn->sec, insn->offset); + return 1; + } + + if (state->bp_scratch) { + WARN("%s uses BP as a scratch register", + func->name); + return 1; + } + + return 0; +} + /* * Follow the branch starting at the given instruction, and recursively follow * any other branches (jumps). Meanwhile, track the frame pointer state at @@ -2050,34 +2085,7 @@ static int validate_branch(struct objtoo switch (insn->type) { case INSN_RETURN: - if (state.uaccess && !func_uaccess_safe(func)) { - WARN_FUNC("return with UACCESS enabled", sec, insn->offset); - return 1; - } - - if (!state.uaccess && func_uaccess_safe(func)) { - WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function", sec, insn->offset); - return 1; - } - - if (state.df) { - WARN_FUNC("return with DF set", sec, insn->offset); - return 1; - } - - if (func && has_modified_stack_frame(&state)) { - WARN_FUNC("return with modified stack frame", - sec, insn->offset); - return 1; - } - - if (state.bp_scratch) { - WARN("%s uses BP as a scratch register", - func->name); - return 1; - } - - return 0; + return validate_return(func, insn, &state); case INSN_CALL: case INSN_CALL_DYNAMIC: