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drm/amdgpu: prevent get_user_pages recursion

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Remember the tasks which are inside get_user_pages()
and ignore MMU callbacks from there.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Christian König 2016-03-03 14:24:57 +01:00 committed by Alex Deucher
parent 211dff5518
commit 637dd3b5ca
1 changed files with 38 additions and 10 deletions
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48
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
View file

@ -494,13 +494,20 @@ static void amdgpu_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_mem_re
/* /*
* TTM backend functions. * TTM backend functions.
*/ */
struct amdgpu_ttm_gup_task_list {
struct list_head list;
struct task_struct *task;
};
struct amdgpu_ttm_tt { struct amdgpu_ttm_tt {
struct ttm_dma_tt ttm; struct ttm_dma_tt ttm;
struct amdgpu_device *adev; struct amdgpu_device *adev;
u64 offset; u64 offset;
uint64_t userptr; uint64_t userptr;
struct mm_struct *usermm; struct mm_struct *usermm;
uint32_t userflags; uint32_t userflags;
spinlock_t guptasklock;
struct list_head guptasks;
}; };
/* prepare the sg table with the user pages */ /* 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; unsigned num_pages = ttm->num_pages - pinned;
uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE; uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
struct page **pages = ttm->pages + pinned; struct page **pages = ttm->pages + pinned;
struct amdgpu_ttm_gup_task_list guptask;
guptask.task = current;
spin_lock(&gtt->guptasklock);
list_add(&guptask.list, &gtt->guptasks);
spin_unlock(&gtt->guptasklock);
r = get_user_pages(current, current->mm, userptr, num_pages, r = get_user_pages(current, current->mm, userptr, num_pages,
write, 0, pages, NULL); write, 0, pages, NULL);
spin_lock(&gtt->guptasklock);
list_del(&guptask.list);
spin_unlock(&gtt->guptasklock);
if (r < 0) if (r < 0)
goto release_pages; goto release_pages;
@ -783,6 +801,9 @@ int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
gtt->userptr = addr; gtt->userptr = addr;
gtt->usermm = current->mm; gtt->usermm = current->mm;
gtt->userflags = flags; gtt->userflags = flags;
spin_lock_init(&gtt->guptasklock);
INIT_LIST_HEAD(&gtt->guptasks);
return 0; return 0;
} }
@ -800,18 +821,25 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
unsigned long end) unsigned long end)
{ {
struct amdgpu_ttm_tt *gtt = (void *)ttm; struct amdgpu_ttm_tt *gtt = (void *)ttm;
struct amdgpu_ttm_gup_task_list *entry;
unsigned long size; unsigned long size;
if (gtt == NULL) if (gtt == NULL || !gtt->userptr)
return false;
if (gtt->ttm.ttm.state != tt_bound || !gtt->userptr)
return false; return false;
size = (unsigned long)gtt->ttm.ttm.num_pages * PAGE_SIZE; size = (unsigned long)gtt->ttm.ttm.num_pages * PAGE_SIZE;
if (gtt->userptr > end || gtt->userptr + size <= start) if (gtt->userptr > end || gtt->userptr + size <= start)
return false; return false;
spin_lock(&gtt->guptasklock);
list_for_each_entry(entry, &gtt->guptasks, list) {
if (entry->task == current) {
spin_unlock(&gtt->guptasklock);
return false;
}
}
spin_unlock(&gtt->guptasklock);
return true; return true;
} }