Messages in this thread | | | Subject | Re: [PATCH] [BUGFIX] media: vb2: Fix videobuf2 to map correct area | From | Marek Szyprowski <> | Date | Mon, 05 Feb 2018 09:47:46 +0100 |
| |
Hi Masami,
On 2018-02-05 03:30, 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 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@kernel.org> > Reported-by: Takao Orito <orito.takao@socionext.com> > --- > 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);
Thanks for reporting this issue. However the above line doesn't look like a proper fix. Please note that at the end of that function there is already "buf->vaddr += offset;".
IMHO the proper fix is to create a larger mapping, which would include the in-page start offset:
ioremap_nocache(__pfn_to_phys(nums[0]), offset + size);
BTW, thanks for updating "<< PAGE_SHIFT" to better __pfn_to_phys() macro!
> } 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
| |