From 637dd3b5ca9e0d38b046f04e97a1d2f7523e7e25 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20K=C3=B6nig?= Date: Thu, 3 Mar 2016 14:24:57 +0100 Subject: [PATCH] drm/amdgpu: prevent get_user_pages recursion MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Remember the tasks which are inside get_user_pages() and ignore MMU callbacks from there. Signed-off-by: Christian König Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 48 +++++++++++++++++++------ 1 file changed, 38 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index e52fc641edfb..53e627970798 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -494,13 +494,20 @@ static void amdgpu_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_mem_re /* * TTM backend functions. */ +struct amdgpu_ttm_gup_task_list { + struct list_head list; + struct task_struct *task; +}; + struct amdgpu_ttm_tt { - struct ttm_dma_tt ttm; - struct amdgpu_device *adev; - u64 offset; - uint64_t userptr; - struct mm_struct *usermm; - uint32_t userflags; + struct ttm_dma_tt ttm; + struct amdgpu_device *adev; + u64 offset; + uint64_t userptr; + struct mm_struct *usermm; + uint32_t userflags; + spinlock_t guptasklock; + struct list_head guptasks; }; /* prepare the sg table with the user pages */ @@ -530,9 +537,20 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm) unsigned num_pages = ttm->num_pages - pinned; uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE; struct page **pages = ttm->pages + pinned; + struct amdgpu_ttm_gup_task_list guptask; + + guptask.task = current; + spin_lock(>t->guptasklock); + list_add(&guptask.list, >t->guptasks); + spin_unlock(>t->guptasklock); r = get_user_pages(current, current->mm, userptr, num_pages, write, 0, pages, NULL); + + spin_lock(>t->guptasklock); + list_del(&guptask.list); + spin_unlock(>t->guptasklock); + if (r < 0) goto release_pages; @@ -783,6 +801,9 @@ int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr, gtt->userptr = addr; gtt->usermm = current->mm; gtt->userflags = flags; + spin_lock_init(>t->guptasklock); + INIT_LIST_HEAD(>t->guptasks); + return 0; } @@ -800,18 +821,25 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start, unsigned long end) { struct amdgpu_ttm_tt *gtt = (void *)ttm; + struct amdgpu_ttm_gup_task_list *entry; unsigned long size; - if (gtt == NULL) - return false; - - if (gtt->ttm.ttm.state != tt_bound || !gtt->userptr) + if (gtt == NULL || !gtt->userptr) return false; size = (unsigned long)gtt->ttm.ttm.num_pages * PAGE_SIZE; if (gtt->userptr > end || gtt->userptr + size <= start) return false; + spin_lock(>t->guptasklock); + list_for_each_entry(entry, >t->guptasks, list) { + if (entry->task == current) { + spin_unlock(>t->guptasklock); + return false; + } + } + spin_unlock(>t->guptasklock); + return true; } -- GitLab