From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Korsgaard Subject: Re: [PATCH] mmc: android-goldfish: fix potential panic due to null pointer Date: Mon, 22 Aug 2016 14:33:01 +0200 Message-ID: <87bn0lrnk2.fsf@dell.be.48ers.dk> References: <1471750476-335-1-git-send-email-shawn.lin@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1471750476-335-1-git-send-email-shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org> (Shawn Lin's message of "Sun, 21 Aug 2016 11:34:36 +0800") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+glpar-linux-rockchip=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Shawn Lin Cc: linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, =Ulf Hansson , linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rockchip.vger.kernel.org >>>>> "Shawn" == Shawn Lin writes: > We should never compare virt_base with zero to indicate whether > we get the right buffer or not from dma_alloc_coherent. It's quite > architecture related. If failing to get the address from CMA or swoitlb > cases, the sub architecture code should decide the return value for it. > So we should never presume that zero always means the failure. > Signed-off-by: Shawn Lin > --- > drivers/mmc/host/android-goldfish.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > diff --git a/drivers/mmc/host/android-goldfish.c b/drivers/mmc/host/android-goldfish.c > index dca5518..6d8bd03 100644 > --- a/drivers/mmc/host/android-goldfish.c > +++ b/drivers/mmc/host/android-goldfish.c > @@ -484,7 +484,7 @@ static int goldfish_mmc_probe(struct platform_device *pdev) host-> virt_base = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE, > &buf_addr, GFP_KERNEL); > - if (host->virt_base == 0) { > + if (!host->virt_base) { Huh, these are equivalent? -- Bye, Peter Korsgaard