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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 EA322C43464 for ; Fri, 18 Sep 2020 21:43:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DA1920848 for ; Fri, 18 Sep 2020 21:43:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DhtBHG1j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726218AbgIRVn2 (ORCPT ); Fri, 18 Sep 2020 17:43:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53652 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726139AbgIRVn1 (ORCPT ); Fri, 18 Sep 2020 17:43:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600465406; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ibBVe9XWamlvD+LShn+aQH8WeaCxGv/MaF5KwAhNyIk=; b=DhtBHG1jdGFxvFlrH/9//kbjfgxaPAW85Gk51e6iaPvfevwuZz/F9bP65uKmd8B70N+bE2 yZ1y+GgziJO3mf5vFgJRfLVJf086B8W+HjX41yawMO2ZPn38KSu3jfEfelLY2TCj+gn1Zn XmYYNCQBLh3QuyaeIRzfNqLwIBX/Op8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-431-MOPrzJKDOrW9DmZulLAmhQ-1; Fri, 18 Sep 2020 17:43:22 -0400 X-MC-Unique: MOPrzJKDOrW9DmZulLAmhQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 51DE41882FB5; Fri, 18 Sep 2020 21:43:21 +0000 (UTC) Received: from treble (ovpn-112-141.rdu2.redhat.com [10.10.112.141]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9842E10016DA; Fri, 18 Sep 2020 21:43:20 +0000 (UTC) Date: Fri, 18 Sep 2020 16:43:18 -0500 From: Josh Poimboeuf To: Julien Thierry Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mbenes@suse.cz, raphael.gault@arm.com, benh@kernel.crashing.org Subject: Re: [PATCH 3/3] objtool: check: Make SP memory operation match PUSH/POP semantics Message-ID: <20200918214318.2d7msla53ysxkbaz@treble> References: <20200915081204.9204-1-jthierry@redhat.com> <20200915081204.9204-4-jthierry@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200915081204.9204-4-jthierry@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 15, 2020 at 09:12:04AM +0100, Julien Thierry wrote: > Architectures without PUSH/POP instructions will always access the stack > though memory operations (SRC/DEST_INDIRECT). Make those operations have > the same effect on the CFA as PUSH/POP, with no stack pointer > modification. > > Signed-off-by: Julien Thierry > --- > tools/objtool/check.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/tools/objtool/check.c b/tools/objtool/check.c > index f45991c2db41..7ff87fa3caec 100644 > --- a/tools/objtool/check.c > +++ b/tools/objtool/check.c > @@ -2005,6 +2005,13 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, > break; > > case OP_SRC_REG_INDIRECT: > + if (!cfi->drap && op->dest.reg == cfa->base) { && op->dest.reg == CFI_BP ? > + > + /* mov disp(%rsp), %rbp */ > + cfa->base = CFI_SP; > + cfa->offset = cfi->stack_size; > + } > + > if (cfi->drap && op->src.reg == CFI_BP && > op->src.offset == cfi->drap_offset) { > > @@ -2026,6 +2033,11 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, > /* mov disp(%rbp), %reg */ > /* mov disp(%rsp), %reg */ > restore_reg(cfi, op->dest.reg); > + } else if (op->src.reg == CFI_SP && An empty line above the else would help readability. > + op->src.offset == regs[op->dest.reg].offset + cfi->stack_size) { > + > + /* mov disp(%rsp), %reg */ > + restore_reg(cfi, op->dest.reg); > } > > break; > @@ -2103,6 +2115,11 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi, > /* mov reg, disp(%rsp) */ > save_reg(cfi, op->src.reg, CFI_CFA, > op->dest.offset - cfi->cfa.offset); > + } else if (op->dest.reg == CFI_SP) { Same here. > + > + /* mov reg, disp(%rsp) */ > + save_reg(cfi, op->src.reg, CFI_CFA, > + op->dest.offset - cfi->stack_size); > } > > break; > -- > 2.21.3 > -- Josh