2018-02-06 08:04:01

by Masami Hiramatsu

Subject: [PATCH v2] media: vb2: Fix videobuf2 to map correct area

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 size + 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 <[email protected]>
Reported-by: Takao Orito <[email protected]>
Reported-by: Fumihiro ATSUMI <[email protected]>
---
Chanegs in v2:
- Fix to pass size + offset instead of changing address.
---
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..359fb9804d16 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]), size + offset);
} else {
buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
PAGE_KERNEL);

2018-02-06 08:14:42

by Marek Szyprowski

Subject: Re: [PATCH v2] media: vb2: Fix videobuf2 to map correct area

Hi Masami,

On 2018-02-06 09:02, Masami Hiramatsu 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 size + 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 <[email protected]>
> Reported-by: Takao Orito <[email protected]>
> Reported-by: Fumihiro ATSUMI <[email protected]>

Reviewed-by: Marek Szyprowski <[email protected]>

> ---
> Chanegs in v2:
> - Fix to pass size + offset instead of changing address.
> ---
> 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..359fb9804d16 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]), size + offset);
> } else {
> buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
> PAGE_KERNEL);
>
>
>
>

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland