From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] kernel/dma: Fix panic caused by passing cma to command line Date: Thu, 20 Sep 2018 08:54:30 +0200 Message-ID: <20180920065430.GA13761@lst.de> References: <1537154660-296740-1-git-send-email-zhe.he@windriver.com> <20180918092834eucas1p1ebdbc3051a7ca8bbacec26b955689784~VdHnT_5yZ0331203312eucas1p1U@eucas1p1.samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20180918092834eucas1p1ebdbc3051a7ca8bbacec26b955689784~VdHnT_5yZ0331203312eucas1p1U-MHMrYXj8g+pqW5MlFJXMulaTQe2KTcn/@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Marek Szyprowski Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, zhe.he-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org, robin.murphy-5wv7dgnIgG8@public.gmane.org, hch-jcswGhMUV9g@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Tue, Sep 18, 2018 at 11:28:33AM +0200, Marek Szyprowski wrote: > Hi > > On 2018-09-17 05:24, zhe.he-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org wrote: > > From: He Zhe > > > > early_cma does not check input argument before passing it to > > simple_strtoull. The argument would be a NULL pointer if "cma", without > > its value, is set in command line and thus causes the following panic. > > > > PANIC: early exception 0xe3 IP 10:ffffffffa3e9db8d error 0 cr2 0x0 > > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #7 > > [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70 > > ... > > [ 0.000000] Call Trace: > > [ 0.000000] simple_strtoull+0x29/0x70 > > [ 0.000000] memparse+0x26/0x90 > > [ 0.000000] early_cma+0x17/0x6a > > [ 0.000000] do_early_param+0x57/0x8e > > [ 0.000000] parse_args+0x208/0x320 > > [ 0.000000] ? rdinit_setup+0x30/0x30 > > [ 0.000000] parse_early_options+0x29/0x2d > > [ 0.000000] ? rdinit_setup+0x30/0x30 > > [ 0.000000] parse_early_param+0x36/0x4d > > [ 0.000000] setup_arch+0x336/0x99e > > [ 0.000000] start_kernel+0x6f/0x4e6 > > [ 0.000000] x86_64_start_reservations+0x24/0x26 > > [ 0.000000] x86_64_start_kernel+0x6f/0x72 > > [ 0.000000] secondary_startup_64+0xa4/0xb0 > > > > This patch adds a check to prevent the panic. > > > > Signed-off-by: He Zhe > > Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > > Cc: hch-jcswGhMUV9g@public.gmane.org > > Cc: m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org > > Cc: robin.murphy-5wv7dgnIgG8@public.gmane.org > > Thanks for the fix. > > Reviewed-by: Marek Szyprowski Thanks, added to the dma-mapping tree.