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Wed, 13 May 2020 22:57:04 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma03ams.nl.ibm.com with ESMTP id 3100ubaecc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 13 May 2020 22:57:03 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 04DMv1dM59244712 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 13 May 2020 22:57:01 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9BC044C04A; Wed, 13 May 2020 22:57:01 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 630B34C044; Wed, 13 May 2020 22:57:01 +0000 (GMT) Received: from bahia.lan (unknown [9.145.63.64]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 13 May 2020 22:57:01 +0000 (GMT) Subject: [PATCH v2 3/6] target/ppc: Don't initialize some local variables in ppc_radix64_xlate() From: Greg Kurz To: David Gibson Date: Thu, 14 May 2020 00:57:00 +0200 Message-ID: <158941062048.240484.9693581559252337111.stgit@bahia.lan> In-Reply-To: <158941060199.240484.5620994992064687533.stgit@bahia.lan> References: <158941060199.240484.5620994992064687533.stgit@bahia.lan> User-Agent: StGit/unknown-version MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.676 definitions=2020-05-13_09:2020-05-13, 2020-05-13 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 mlxscore=0 priorityscore=1501 adultscore=0 clxscore=1034 malwarescore=0 spamscore=0 cotscore=-2147483648 phishscore=0 mlxlogscore=999 suspectscore=0 impostorscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2005130188 Received-SPF: softfail client-ip=148.163.158.5; envelope-from=groug@kaod.org; helo=mx0a-001b2d01.pphosted.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/13 18:57:00 X-ACL-Warn: Detected OS = Linux 3.x [generic] X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, KHOP_DYNAMIC=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_SOFTFAIL=0.665, 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: qemu-ppc@nongnu.org, =?utf-8?q?C=C3=A9dric?= Le Goater , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" 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 Reviewed-by: Cédric Le Goater --- 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 c76879f65b78..07f956c9864f 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;