On 06/11/15 06:21, Laurent Pinchart wrote:
> Hello,
>
> (CC'ing Tomi Valkeinen)
>
> On Wednesday 10 June 2015 06:20:45 Mauro Carvalho Chehab wrote:
>> From: Jan Kara <jack@xxxxxxx>
>>
>> Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns() instead of
>> hand made mapping of virtual address to physical address. Also the
>> function leaked page reference from get_user_pages() so fix that by
>> properly release the reference when omap_vout_buffer_release() is
>> called.
>>
>> Signed-off-by: Jan Kara <jack@xxxxxxx>
>> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>> [hans.verkuil@xxxxxxxxx: remove unused struct omap_vout_device *vout
>> variable]
>>
>> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
>>
>> diff --git a/drivers/media/platform/omap/omap_vout.c
>> b/drivers/media/platform/omap/omap_vout.c index f09c5f17a42f..7feb6394f111
>> 100644
>> --- a/drivers/media/platform/omap/omap_vout.c
>> +++ b/drivers/media/platform/omap/omap_vout.c
>> @@ -195,46 +195,34 @@ static int omap_vout_try_format(struct v4l2_pix_format
>> *pix) }
>>
>> /*
>> - * omap_vout_uservirt_to_phys: This inline function is used to convert user
>> - * space virtual address to physical address.
>> + * omap_vout_get_userptr: Convert user space virtual address to physical
>> + * address.
>> */
>> -static unsigned long omap_vout_uservirt_to_phys(unsigned long virtp)
>> +static int omap_vout_get_userptr(struct videobuf_buffer *vb, u32 virtp,
>> + u32 *physp)
>> {
>> - unsigned long physp = 0;
>> - struct vm_area_struct *vma;
>> - struct mm_struct *mm = current->mm;
>> + struct frame_vector *vec;
>> + int ret;
>>
>> /* For kernel direct-mapped memory, take the easy way */
>> - if (virtp >= PAGE_OFFSET)
>> - return virt_to_phys((void *) virtp);
>> -
>> - down_read(¤t->mm->mmap_sem);
>> - vma = find_vma(mm, virtp);
>> - if (vma && (vma->vm_flags & VM_IO) && vma->vm_pgoff) {
>> - /* this will catch, kernel-allocated, mmaped-to-usermode
>> - addresses */
>> - physp = (vma->vm_pgoff << PAGE_SHIFT) + (virtp - vma->vm_start);
>> - up_read(¤t->mm->mmap_sem);
>> - } else {
>> - /* otherwise, use get_user_pages() for general userland pages */
>> - int res, nr_pages = 1;
>> - struct page *pages;
>> + if (virtp >= PAGE_OFFSET) {
>> + *physp = virt_to_phys((void *)virtp);
>
> Lovely. virtp comes from userspace and as far as I know it arrives here
> completely unchecked. The problem isn't introduced by this patch, but
> omap_vout buffer management seems completely broken to me, and nobody seems to
> care about the driver. Given that omapdrm should now provide the video output
> capabilities that are missing from omapfb and resulted in the development of
> omap_vout, shouldn't we drop the omap_vout driver ?
In addition it uses the old videobuf framework which at some point will be reason
for removal if nobody cares enough to convert to videobuf2.
So I would also be in favor of removal if there are no objections (well, probably
first to staging for one or two kernel cycles followed by removal).
Hans
>
> Tomi, any opinion on this ? Do you see any omap_vout capability missing from
> omapdrm ?
>
>> + return 0;
>> + }
>>
>> - res = get_user_pages(current, current->mm, virtp, nr_pages, 1,
>> - 0, &pages, NULL);
>> - up_read(¤t->mm->mmap_sem);
>> + vec = frame_vector_create(1);
>> + if (!vec)
>> + return -ENOMEM;
>>
>> - if (res == nr_pages) {
>> - physp = __pa(page_address(&pages[0]) +
>> - (virtp & ~PAGE_MASK));
>> - } else {
>> - printk(KERN_WARNING VOUT_NAME
>> - "get_user_pages failed\n");
>> - return 0;
>> - }
>> + ret = get_vaddr_frames(virtp, 1, true, false, vec);
>> + if (ret != 1) {
>> + frame_vector_destroy(vec);
>> + return -EINVAL;
>> }
>> + *physp = __pfn_to_phys(frame_vector_pfns(vec)[0]);
>> + vb->priv = vec;
>>
>> - return physp;
>> + return 0;
>> }
>>
>> /*
>> @@ -784,11 +772,15 @@ static int omap_vout_buffer_prepare(struct
>> videobuf_queue *q, * address of the buffer
>> */
>> if (V4L2_MEMORY_USERPTR == vb->memory) {
>> + int ret;
>> +
>> if (0 == vb->baddr)
>> return -EINVAL;
>> /* Physical address */
>> - vout->queued_buf_addr[vb->i] = (u8 *)
>> - omap_vout_uservirt_to_phys(vb->baddr);
>> + ret = omap_vout_get_userptr(vb, vb->baddr,
>> + (u32 *)&vout->queued_buf_addr[vb->i]);
>> + if (ret < 0)
>> + return ret;
>> } else {
>> unsigned long addr, dma_addr;
>> unsigned long size;
>> @@ -834,12 +826,13 @@ static void omap_vout_buffer_queue(struct
>> videobuf_queue *q, static void omap_vout_buffer_release(struct
>> videobuf_queue *q,
>> struct videobuf_buffer *vb)
>> {
>> - struct omap_vout_device *vout = q->priv_data;
>> -
>> vb->state = VIDEOBUF_NEEDS_INIT;
>> + if (vb->memory == V4L2_MEMORY_USERPTR && vb->priv) {
>> + struct frame_vector *vec = vb->priv;
>>
>> - if (V4L2_MEMORY_MMAP != vout->memory)
>> - return;
>> + put_vaddr_frames(vec);
>> + frame_vector_destroy(vec);
>> + }
>> }
>>
>> /*
>
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