From patchwork Wed May 27 05:38:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 281863 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=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 24757C433E0 for ; Wed, 27 May 2020 05:41:18 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E482C20787 for ; Wed, 27 May 2020 05:41:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="W9qn7RHq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E482C20787 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37028 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jdooX-00071Q-1L for qemu-devel@archiver.kernel.org; Wed, 27 May 2020 01:41:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46190) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jdoll-0001AZ-VB; Wed, 27 May 2020 01:38:25 -0400 Received: from ozlabs.org ([2401:3900:2:1::2]:47895) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jdoll-0001eS-0N; Wed, 27 May 2020 01:38:25 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 49X03r0Y7Dz9sT0; Wed, 27 May 2020 15:38:15 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1590557896; bh=KhokEOK/GurpUpa/QEkymwIvT39eY7CJwIkBx5sD8gs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W9qn7RHq5SmA99apPajBH/e0SptHCvefoRS3fXNd9g+WlOmCeadub5fBKQUxH2sEv pWT7oTvzzDLpnFd8KaBvIF3fYfNiZ4TqppDoCnWP3CLW9v6vWpBb+IvNenI3EoEQWa EYjfr+el2BHRoLDpEKHJugxSX/DsVVTog3UN6Gzg= From: David Gibson To: peter.maydell@linaro.org Subject: [PULL 08/15] target/ppc: Don't initialize some local variables in ppc_radix64_xlate() Date: Wed, 27 May 2020 15:38:02 +1000 Message-Id: <20200527053809.356168-9-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200527053809.356168-1-david@gibson.dropbear.id.au> References: <20200527053809.356168-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Received-SPF: pass client-ip=2401:3900:2:1::2; envelope-from=dgibson@ozlabs.org; helo=ozlabs.org X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, qemu-devel@nongnu.org, groug@kaod.org, qemu-ppc@nongnu.org, =?utf-8?q?C=C3=A9dric_Le_Goater?= , philmd@redhat.com, David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Greg Kurz It is the job of the ppc_radix64_get_fully_qualified_addr() function which is called at the beginning of ppc_radix64_xlate() to set both lpid *and* pid. It doesn't buy us anything to initialize them first. Worse, a bug in ppc_radix64_get_fully_qualified_addr(), eg. failing to set either lpid or pid, would be undetectable by static analysis tools like coverity. Some recent versions of gcc (eg. gcc-9.3.1-2.fc30) may still think that lpid or pid is used uninitialized though, so this also adds default cases in the switch statements to make it clear this cannot happen. Signed-off-by: Greg Kurz Message-Id: <158941062048.240484.9693581559252337111.stgit@bahia.lan> Reviewed-by: Cédric Le Goater Signed-off-by: David Gibson --- target/ppc/mmu-radix64.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/target/ppc/mmu-radix64.c b/target/ppc/mmu-radix64.c index c76879f65b..07f956c986 100644 --- a/target/ppc/mmu-radix64.c +++ b/target/ppc/mmu-radix64.c @@ -50,6 +50,8 @@ static bool ppc_radix64_get_fully_qualified_addr(const CPUPPCState *env, *lpid = 0; *pid = 0; break; + default: + g_assert_not_reached(); } } else { /* !MSR[HV] -> Guest */ switch (eaddr & R_EADDR_QUADRANT) { @@ -64,6 +66,8 @@ static bool ppc_radix64_get_fully_qualified_addr(const CPUPPCState *env, *lpid = env->spr[SPR_LPIDR]; *pid = 0; /* pid set to 0 -> addresses guest operating system */ break; + default: + g_assert_not_reached(); } } @@ -433,7 +437,7 @@ static int ppc_radix64_xlate(PowerPCCPU *cpu, vaddr eaddr, int rwx, bool cause_excp) { CPUPPCState *env = &cpu->env; - uint64_t lpid = 0, pid = 0; + uint64_t lpid, pid; ppc_v3_pate_t pate; int psize, prot; hwaddr g_raddr;