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Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNZGI-0006Od-2l; Wed, 30 Sep 2020 10:23:02 +0000 Received: from mout.kundenserver.de ([212.227.126.130]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNZGF-0006N6-6E; Wed, 30 Sep 2020 10:23:00 +0000 Received: from mail-qk1-f174.google.com ([209.85.222.174]) by mrelayeu.kundenserver.de (mreue010 [212.227.15.129]) with ESMTPSA (Nemesis) id 1MqbDs-1kjimd3nfM-00mYxR; Wed, 30 Sep 2020 12:22:56 +0200 Received: by mail-qk1-f174.google.com with SMTP id w16so821793qkj.7; Wed, 30 Sep 2020 03:22:54 -0700 (PDT) X-Gm-Message-State: AOAM530r6zmeFyGSooBbwpZOni5XHK7z2ya7jfaFpbDup5ThhrT7Z/rk DR2JxF5zRd+Ul5+6xKRg7DGg0sDYLwohw7fspiE= X-Google-Smtp-Source: ABdhPJzbp1ree7OnLK3wvVArvoiDQadBs0pygzava7j+b3qT05utAOWO3J1rLFwcXA64KjCr9Zap1oKqinCzol0q+MY= X-Received: by 2002:a37:5d8:: with SMTP id 207mr1859009qkf.352.1601461373212; Wed, 30 Sep 2020 03:22:53 -0700 (PDT) MIME-Version: 1.0 References: <20200930090238.GA621698@mwanda> In-Reply-To: <20200930090238.GA621698@mwanda> From: Arnd Bergmann Date: Wed, 30 Sep 2020 12:22:37 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] staging: vchiq: silence an uninitialized variable warning To: Dan Carpenter X-Provags-ID: V03:K1:ESLp3BRmkm9RuS3dhlYPznD2y1gr/jA5rAvYDLkkJLuAVx6R3m9 rGhy/m1kqLCVFXdqamKc+sNcGcsKboZo3g+Td6BVeqMEbUXGFLb0lhbLSodja0MEuxoxfB2 om1V2R3s1VXUS75a+BFID5+d1uTBaLDwHiVX0AgGDAJpYDJwNSiFnaYGHfwAmjh10KxWnic LcJFKnKCi3I4a2UQVDdAQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:OHq/ETpDONY=:GJheTL8ovfwTR6pOhNJgPR 1Szl0k+QgsDOwh7B2ecoNfMzft3BtvhAAESnh6x2l3JxX17mQ6WV7D+ZjI19GguaMSPImpsSR IOHv7UA8En1+IxqjJLUYiCfu39W5b7JzUuxDTgVSgdFVT1q6bmBauJz90TqNAak6hwngePsWp A+Xq3ODqch6QfN14jwiqJ79vJXEXWHe9klDDHOQo5oPcemE3QgczesWfrbNSPSEr7Fiv1Ljz0 8gjjqGRhPi5pnhjbeTwGhoC4yb0+VTRJygNNFRbnsU9I2wQsbkzfoEli5Dehzx4NR5xJvjsjp iMqxEbU/Efhe62o3+nY63/rgSLqm4xT7YlXgnoaMPdXEFgadEI/l1ZPdJLukljnG6nIc3zg+y bFYB1ZAQzi6zoUyK+WLwgT1cOqtf6g1/L8g9yB57o0ofJXxxCE6N1Q/o0bLsSX83s3q8ZZb1L dyOh9b6kDfFMNmXIG3RNSJIgmdQw+6L35yx2U8IRlauA64Fi3SK7vEIV+KLsZmuXm9DNTbYI3 14SJyTNBwoq+x4ke6QxKD/61VvDlSvWU3Zc9bKsFg0ndNB1xlov0YY8JYKS3mknikVkjEih7G 3MLn+gPQtL8DUedGPsyTnkbpdv3TEv6gaXUZpK9oiBs3f5qRvbw7/ACpEbo+vCgUVhMK1N/Fn oz61n1SHzwgLipfICcOl8y1V1XeKANoEMFeY2dV4EWcDJ2P6xyhIoFrzjYwH/XsUKy68afvSo LTELCUFvv9EHwBUrQ8wwDFPO5HmIrmR8W393/ekcw2KU7O8JMMnzMRZpES+X4fFSY+aEZ52/d 16EypBUgPFmfHq3kCVL19aU13KcbMCejSh2cA8oUxV5LAoz7XzRF95i8a8o1W5bXRJ3MRpW X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200930_062259_465304_A2F562C7 X-CRM114-Status: GOOD ( 15.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Linux ARM , driverdevel , Greg Kroah-Hartman , Marcelo Diop-Gonzalez , kernel-janitors@vger.kernel.org, bcm-kernel-feedback-list , "moderated list:BROADCOM BCM2835 ARM ARCHITECTURE" , Jamal Shareef , Nicolas Saenz Julienne Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Sep 30, 2020 at 11:02 AM Dan Carpenter wrote: > > Smatch complains that "userdata" can be passed to vchiq_bulk_transfer() > without being initialized. Smatch is correct, however, in that > situation the "userdata" is not used so it doesn't cause a problem. > Passing an uninitialized variable will trigger a UBSan warning at > runtime so this warning is worth silencing by setting "userdata" to > NULL. > > Fixes: a4367cd2b231 ("staging: vchiq: convert compat bulk transfer") > Signed-off-by: Dan Carpenter The change looks fine, but I wonder if it's actually worse and the uninitialized pointer can end up getting copied back to user space in the completion. In either case, thanks for the fix! Acked-by: Arnd Bergmann _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel