From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Christian_K=c3=b6nig?= Subject: Re: [PATCH] drm: fix call_kern.cocci warnings (fwd) Date: Thu, 25 Oct 2018 08:53:21 +0200 Message-ID: <823eb7cc-ba7e-b816-1821-c73dfd4c70bf@googlemail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: "Zhou, David(ChunMing)" , Julia Lawall Cc: "kbuild-all@01.org" , "intel-gfx@lists.freedesktop.org" , "dri-devel@lists.freedesktop.org" , Gustavo Padovan , Maarten Lankhorst , Sean Paul , David Airlie , "linux-kernel@vger.kernel.org" List-Id: intel-gfx@lists.freedesktop.org Am 25.10.18 um 03:28 schrieb Zhou, David(ChunMing): > Reviewed-by: Chunming Zhou NAK, GFP_ATOMIC should be avoided. The correct solution is to move the allocation out of the spinlock or drop the lock and reacquire. Christian. > >> -----Original Message----- >> From: Julia Lawall >> Sent: Thursday, October 25, 2018 2:57 AM >> To: Zhou, David(ChunMing) >> Cc: kbuild-all@01.org; intel-gfx@lists.freedesktop.org; dri- >> devel@lists.freedesktop.org; Christian König >> ; Gustavo Padovan >> ; Maarten Lankhorst >> ; Sean Paul ; David >> Airlie ; dri-devel@lists.freedesktop.org; linux- >> kernel@vger.kernel.org >> Subject: [PATCH] drm: fix call_kern.cocci warnings (fwd) >> >> The containing function is called with a spin_lock held, so GFP_KERNEL can't >> be used. >> >> julia >> >> ---------- Forwarded message ---------- >> Date: Tue, 23 Oct 2018 17:14:25 +0800 >> From: kbuild test robot >> To: kbuild@01.org >> Cc: Julia Lawall >> Subject: [PATCH] drm: fix call_kern.cocci warnings >> >> CC: kbuild-all@01.org >> CC: intel-gfx@lists.freedesktop.org >> CC: dri-devel@lists.freedesktop.org >> TO: Chunming Zhou >> CC: "Christian König" >> CC: Gustavo Padovan >> CC: Maarten Lankhorst >> CC: Sean Paul >> CC: David Airlie >> CC: dri-devel@lists.freedesktop.org >> CC: linux-kernel@vger.kernel.org >> >> From: kbuild test robot >> >> drivers/gpu/drm/drm_syncobj.c:202:4-14: ERROR: function >> drm_syncobj_find_signal_pt_for_point called on line 390 inside lock on line >> 389 but uses GFP_KERNEL >> >> Find functions that refer to GFP_KERNEL but are called with locks held. >> >> Semantic patch information: >> The proposed change of converting the GFP_KERNEL is not necessarily the >> correct one. It may be desired to unlock the lock, or to not call the function >> under the lock in the first place. >> >> Generated by: scripts/coccinelle/locks/call_kern.cocci >> >> Fixes: 48197bc564c7 ("drm: add syncobj timeline support v9") >> CC: Chunming Zhou >> Signed-off-by: kbuild test robot >> --- >> >> tree: git://anongit.freedesktop.org/drm/drm-tip drm-tip >> head: 8d7ffd2298c607c3e1a16f94d51450d7940fd6a7 >> commit: 48197bc564c7a1888c86024a1ba4f956e0ec2300 [1968/2033] drm: add >> syncobj timeline support v9 >> :::::: branch date: 4 hours ago >> :::::: commit date: 5 days ago >> >> Please take the patch only if it's a positive warning. Thanks! >> >> drm_syncobj.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> --- a/drivers/gpu/drm/drm_syncobj.c >> +++ b/drivers/gpu/drm/drm_syncobj.c >> @@ -199,7 +199,7 @@ static struct dma_fence >> (point <= syncobj->timeline)) { >> struct drm_syncobj_stub_fence *fence = >> kzalloc(sizeof(struct drm_syncobj_stub_fence), >> - GFP_KERNEL); >> + GFP_ATOMIC); >> >> if (!fence) >> return NULL;