Re: [PATCH] [BUGFIX] media: vb2: Fix videobuf2 to map correct area

From: Masami Hiramatsu
Date: Sun Feb 04 2018 - 23:54:37 EST


On Mon, 5 Feb 2018 11:30:41 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Fixes vb2_vmalloc_get_userptr() to ioremap correct area.
> Since the current code does ioremap the page address, if the offset > 0,
> it does not do ioremap the last page and results in kernel panic.
>
> This fixes to pass the page address + offset to ioremap so that ioremap
> can map correct area. Also, this uses __pfn_to_phys() to get the physical
> address of given PFN.
>
> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Reported-by: Takao Orito <orito.takao@xxxxxxxxxxxxx>

Oops, I've missed the original reporter.

Reported-by: Fumihiro ATSUMI <atsumi@xxxxxxxxxxxxxxxxx>

Thank you,

> ---
> drivers/media/v4l2-core/videobuf2-vmalloc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
> index 3a7c80cd1a17..896f2f378b40 100644
> --- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
> +++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
> @@ -106,7 +106,7 @@ static void *vb2_vmalloc_get_userptr(struct device *dev, unsigned long vaddr,
> if (nums[i-1] + 1 != nums[i])
> goto fail_map;
> buf->vaddr = (__force void *)
> - ioremap_nocache(nums[0] << PAGE_SHIFT, size);
> + ioremap_nocache(__pfn_to_phys(nums[0]) + offset, size);
> } else {
> buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
> PAGE_KERNEL);
>


--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>