From: "Bhardwaj, Rajneesh" <rajneesh.bhardwaj@amd.com> To: Steven Rostedt <rostedt@goodmis.org> Cc: LKML <linux-kernel@vger.kernel.org>, "Linus Torvalds" <torvalds@linux-foundation.org>, "Felix Kuehling" <Felix.Kuehling@amd.com>, "Christian König" <christian.koenig@amd.com>, dri-devel@lists.freedesktop.org Subject: Re: [BUG] BUG: kernel NULL pointer dereference at ttm_device_init+0xb4 Date: Mon, 22 Jan 2024 19:40:14 -0500 [thread overview] Message-ID: <713eaa19-33b9-40fe-a3a5-69e45d671399@amd.com> (raw) In-Reply-To: <20240122193453.6096d45f@gandalf.local.home> On 1/22/2024 7:34 PM, Steven Rostedt wrote: > On Mon, 22 Jan 2024 19:29:41 -0500 > "Bhardwaj, Rajneesh" <rajneesh.bhardwaj@amd.com> wrote: > >> In one of my previous revisions of this patch when I was experimenting, >> I used something like below. Wonder if that could work in your case >> and/or in general. >> >> >> diff --git a/drivers/gpu/drm/ttm/ttm_device.c >> b/drivers/gpu/drm/ttm/ttm_device.c >> >> index 43e27ab77f95..4c3902b94be4 100644 >> >> --- a/drivers/gpu/drm/ttm/ttm_device.c >> >> +++ b/drivers/gpu/drm/ttm/ttm_device.c >> >> @@ -195,6 +195,7 @@ int ttm_device_init(struct ttm_device *bdev, struct >> ttm_device_funcs *funcs, >> >> bool use_dma_alloc, bool use_dma32){ >> >> struct ttm_global *glob = &ttm_glob; >> >> +bool node_has_cpu = false; >> >> int ret; >> >> if (WARN_ON(vma_manager == NULL)) >> >> @@ -213,7 +214,12 @@ int ttm_device_init(struct ttm_device *bdev, struct >> ttm_device_funcs *funcs, >> >> bdev->funcs = funcs; >> >> ttm_sys_man_init(bdev); >> >> -ttm_pool_init(&bdev->pool, dev, NUMA_NO_NODE, use_dma_alloc, use_dma32); >> >> + >> >> +node_has_cpu = node_state(dev->numa_node, N_CPU); > Considering that qxl_ttm_init() passes in dev = NULL, the above would blow > up just the same. I agree, I think we need something like you suggested i.e. + ttm_pool_init(&bdev->pool, dev, dev ? dev_to_node(dev) : NUMA_NO_NODE, + use_dma_alloc, use_dma32); I am not quite sure if the above node_has_cpu change will be a better solution in general, along with the NULL pointer check as you suggested. If you prefer that, then I can send a fix otherwise, your fix looks good to me. > > -- Steve > > >> +if (node_has_cpu) >> >> +ttm_pool_init(&bdev->pool, dev, dev->numa_node, use_dma_alloc, use_dma32); >> >> +else >> >> +ttm_pool_init(&bdev->pool, dev, NUMA_NO_NODE, use_dma_alloc, >> >> +use_dma32); >> >> bdev->vma_manager = vma_manager; >> >> spin_lock_init(&bdev->lru_lock); >> >> >>> -- Steve
WARNING: multiple messages have this Message-ID (diff)
From: "Bhardwaj, Rajneesh" <rajneesh.bhardwaj@amd.com> To: Steven Rostedt <rostedt@goodmis.org> Cc: "Felix Kuehling" <Felix.Kuehling@amd.com>, "Linus Torvalds" <torvalds@linux-foundation.org>, LKML <linux-kernel@vger.kernel.org>, dri-devel@lists.freedesktop.org, "Christian König" <christian.koenig@amd.com> Subject: Re: [BUG] BUG: kernel NULL pointer dereference at ttm_device_init+0xb4 Date: Mon, 22 Jan 2024 19:40:14 -0500 [thread overview] Message-ID: <713eaa19-33b9-40fe-a3a5-69e45d671399@amd.com> (raw) In-Reply-To: <20240122193453.6096d45f@gandalf.local.home> On 1/22/2024 7:34 PM, Steven Rostedt wrote: > On Mon, 22 Jan 2024 19:29:41 -0500 > "Bhardwaj, Rajneesh" <rajneesh.bhardwaj@amd.com> wrote: > >> In one of my previous revisions of this patch when I was experimenting, >> I used something like below. Wonder if that could work in your case >> and/or in general. >> >> >> diff --git a/drivers/gpu/drm/ttm/ttm_device.c >> b/drivers/gpu/drm/ttm/ttm_device.c >> >> index 43e27ab77f95..4c3902b94be4 100644 >> >> --- a/drivers/gpu/drm/ttm/ttm_device.c >> >> +++ b/drivers/gpu/drm/ttm/ttm_device.c >> >> @@ -195,6 +195,7 @@ int ttm_device_init(struct ttm_device *bdev, struct >> ttm_device_funcs *funcs, >> >> bool use_dma_alloc, bool use_dma32){ >> >> struct ttm_global *glob = &ttm_glob; >> >> +bool node_has_cpu = false; >> >> int ret; >> >> if (WARN_ON(vma_manager == NULL)) >> >> @@ -213,7 +214,12 @@ int ttm_device_init(struct ttm_device *bdev, struct >> ttm_device_funcs *funcs, >> >> bdev->funcs = funcs; >> >> ttm_sys_man_init(bdev); >> >> -ttm_pool_init(&bdev->pool, dev, NUMA_NO_NODE, use_dma_alloc, use_dma32); >> >> + >> >> +node_has_cpu = node_state(dev->numa_node, N_CPU); > Considering that qxl_ttm_init() passes in dev = NULL, the above would blow > up just the same. I agree, I think we need something like you suggested i.e. + ttm_pool_init(&bdev->pool, dev, dev ? dev_to_node(dev) : NUMA_NO_NODE, + use_dma_alloc, use_dma32); I am not quite sure if the above node_has_cpu change will be a better solution in general, along with the NULL pointer check as you suggested. If you prefer that, then I can send a fix otherwise, your fix looks good to me. > > -- Steve > > >> +if (node_has_cpu) >> >> +ttm_pool_init(&bdev->pool, dev, dev->numa_node, use_dma_alloc, use_dma32); >> >> +else >> >> +ttm_pool_init(&bdev->pool, dev, NUMA_NO_NODE, use_dma_alloc, >> >> +use_dma32); >> >> bdev->vma_manager = vma_manager; >> >> spin_lock_init(&bdev->lru_lock); >> >> >>> -- Steve
next prev parent reply other threads:[~2024-01-23 0:40 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-01-22 23:06 [BUG] BUG: kernel NULL pointer dereference at ttm_device_init+0xb4 Steven Rostedt 2024-01-22 23:06 ` Steven Rostedt 2024-01-22 23:15 ` Steven Rostedt 2024-01-22 23:15 ` Steven Rostedt 2024-01-22 23:19 ` Steven Rostedt 2024-01-22 23:19 ` Steven Rostedt 2024-01-23 0:43 ` Linus Torvalds 2024-01-23 0:43 ` Linus Torvalds 2024-01-23 0:56 ` Bhardwaj, Rajneesh 2024-01-23 1:25 ` Linus Torvalds 2024-01-23 1:25 ` Linus Torvalds 2024-01-23 1:35 ` Steven Rostedt 2024-01-23 1:35 ` Steven Rostedt 2024-01-23 2:21 ` Dave Airlie 2024-01-23 2:21 ` Dave Airlie 2024-01-23 2:32 ` Dave Airlie 2024-01-23 2:32 ` Dave Airlie 2024-01-23 2:52 ` Steven Rostedt 2024-01-23 2:52 ` Steven Rostedt 2024-01-23 9:43 ` Christian König 2024-01-23 9:43 ` Christian König 2024-01-23 14:35 ` Steven Rostedt 2024-01-23 14:35 ` Steven Rostedt 2024-01-23 1:06 ` Bhardwaj, Rajneesh 2024-01-23 1:06 ` Bhardwaj, Rajneesh 2024-01-23 0:29 ` Bhardwaj, Rajneesh 2024-01-23 0:34 ` Steven Rostedt 2024-01-23 0:34 ` Steven Rostedt 2024-01-23 0:40 ` Bhardwaj, Rajneesh [this message] 2024-01-23 0:40 ` Bhardwaj, Rajneesh
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