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Wed, 5 May 2021 07:59:03 +0000 (UTC) Date: Wed, 5 May 2021 03:59:03 -0400 (EDT) From: Miroslav Rezanina To: QEMU Developers Message-ID: <1162368493.17178530.1620201543649.JavaMail.zimbra@redhat.com> In-Reply-To: <603798381.17174916.1620200426349.JavaMail.zimbra@redhat.com> Subject: Prevent compiler warning on block.c MIME-Version: 1.0 X-Originating-IP: [10.40.192.172, 10.4.195.23] Thread-Topic: Prevent compiler warning on block.c Thread-Index: ZQfkvE+NRwyFJWCI41vTjxwszg2NPw== X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mrezanin@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=mrezanin@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.697, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no 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: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Commit 3108a15cf (block: introduce bdrv_drop_filter()) introduced uninitialized variable to_cow_parent in bdrv_replace_node_common function that is used only when detach_subchain is true. It is used in two places. First if block properly initialize the variable and second block use it. However, compiler treats this two blocks as two independent cases so it thinks first block can fail test and second one pass (although both use same condition). This cause warning that variable can be uninitialized in second block. To prevent this warning, initialize the variable with NULL. Signed-off-by: Miroslav Rezanina Reviewed-by: Vladimir Sementsov-Ogievskiy diff --git a/block.c b/block.c index 874c22c43e..3ca27bd2d9 100644 --- a/block.c +++ b/block.c @@ -4851,7 +4851,7 @@ static int bdrv_replace_node_common(BlockDriverState *from, Transaction *tran = tran_new(); g_autoptr(GHashTable) found = NULL; g_autoptr(GSList) refresh_list = NULL; - BlockDriverState *to_cow_parent; + BlockDriverState *to_cow_parent = NULL; int ret; if (detach_subchain) {