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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37174 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l5BvN-0004Ol-TQ for qemu-devel@archiver.kernel.org; Thu, 28 Jan 2021 13:21:45 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51778) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l5Bsx-0002sk-Au for qemu-devel@nongnu.org; Thu, 28 Jan 2021 13:19:16 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:47155) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l5Bsq-00055J-QZ for qemu-devel@nongnu.org; Thu, 28 Jan 2021 13:19:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611857947; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KUi5r1hQyO+E8m5RsW0OGiVLbq8c6BMJ5A2fCKaDgZA=; b=as9wTsHRKYr1KmxcRX+FmgZKPMDw2qCjyvOCRaifPaOwpxULkasLd+zXtc2IdTPukQ0+dX GSPhfr6d3/0kTrWXUOXXVvZTvAYchVOuw85yzRw7CrF737Tg+xfTxJNa63KLIbeGuq27xD gbyKqwcHlhIe5Q2jUa1MMHwczig6qy4= 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-488-FOwZUd6fPEiPLUTEomHBwg-1; Thu, 28 Jan 2021 13:19:05 -0500 X-MC-Unique: FOwZUd6fPEiPLUTEomHBwg-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 789A51800D41 for ; Thu, 28 Jan 2021 18:19:04 +0000 (UTC) Received: from wainer-laptop.localdomain (ovpn-116-207.gru2.redhat.com [10.97.116.207]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5ACA3100239F; Thu, 28 Jan 2021 18:19:00 +0000 (UTC) Subject: Re: [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place() To: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , "Dr. David Alan Gilbert" References: <20210128130625.569900-1-wainersm@redhat.com> <20210128171619.GF2951@work-vm> From: Wainer dos Santos Moschetta Message-ID: <26ed58ff-3399-7cc1-f075-401eb28b0f89@redhat.com> Date: Thu, 28 Jan 2021 15:18:58 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=wainersm@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Received-SPF: pass client-ip=63.128.21.124; envelope-from=wainersm@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.252, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, 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: Thomas Huth , qemu-devel@nongnu.org, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi, On 1/28/21 3:07 PM, Philippe Mathieu-Daudé wrote: > On 1/28/21 6:16 PM, Dr. David Alan Gilbert wrote: >> * Wainer dos Santos Moschetta (wainersm@redhat.com) wrote: >>> Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized >>> as shown here: >>> >>> ../migration/qemu-file.c: In function 'qemu_get_buffer_in_place': >>> ../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized] >>> 604 | *buf = src; >>> | ~~~~~^~~~~ >>> cc1: all warnings being treated as errors >>> >>> Signed-off-by: Wainer dos Santos Moschetta >> Yes, I think I had a discussion with someone about this recently but >> can't find it; > Maybe with Thomas, he reported that 2 years ago when building with -O3: > https://www.mail-archive.com/qemu-devel@nongnu.org/msg599522.html I saw that error when compiling QEMU with -O3 as well. > >> the compiler is technically correct, but the only time >> it's unitialised is the case where it's result doesn't matter. >> >> Still, to shut the compiler up: >> >> >> Reviewed-by: Dr. David Alan Gilbert Thanks David! >> >>> --- >>> Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576 >>> >>> migration/qemu-file.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/migration/qemu-file.c b/migration/qemu-file.c >>> index be21518c57..d6e03dbc0e 100644 >>> --- a/migration/qemu-file.c >>> +++ b/migration/qemu-file.c >>> @@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size) >>> { >>> if (size < IO_BUF_SIZE) { >>> size_t res; >>> - uint8_t *src; >>> + uint8_t *src = NULL; >>> >>> res = qemu_peek_buffer(f, &src, size, 0); >>> >>> -- >>> 2.28.0 >>>