Messages in this thread Patch in this message | | | Date | Thu, 20 Mar 2014 17:24:54 +0900 | From | Nobuhiro Iwamatsu <> | Subject | Re: [PATCH] uio: Fix memory size check with vma in uio_mmap_physical() |
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(2014/03/18 8:26), Greg KH wrote: > On Wed, Mar 12, 2014 at 10:24:21AM +0900, Nobuhiro Iwamatsu wrote: >> Register for the device are mapped in uio_mmap_physical(). >> In this case, it might not be the same as the size of VMA always. > > Why wouldn't this be the case?
size contained in the "mem-> size" is the size of the actual always. However, in this case, "if (vma-> vm_end - vma-> vm_start> mem-> size)" is an error by always. This is because the address contained in the vma is because it is always aligned by PAGE_SIZE.
> >> This uses PAGE_ALIGN to memory size, fix the check of the memory size >> to be mapped. >> >> Signed-off-by: Nobuhiro Iwamatsu<nobuhiro.iwamatsu.yj@renesas.com> >> --- >> drivers/uio/uio.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c >> index a673e5b..e371f5a 100644 >> --- a/drivers/uio/uio.c >> +++ b/drivers/uio/uio.c >> @@ -655,7 +655,7 @@ static int uio_mmap_physical(struct vm_area_struct *vma) >> >> if (mem->addr& ~PAGE_MASK) >> return -ENODEV; >> - if (vma->vm_end - vma->vm_start> mem->size) >> + if (vma->vm_end - vma->vm_start> PAGE_ALIGN(mem->size)) > > You just increased the size for the check, that seems wrong. Why > wouldn't mem->size be correct here? > > What hardware is failing for this with a valid size and end/start > addresses?
For example, when I have the following settings in in platform device setup, the size of the mem->size will be 344.
static struct resource vpu_resources[] = { [0] = { .name = "VPU", .start = 0xfe900000, .end = 0xfe900157, .flags = IORESOURCE_MEM, }, };
And vma->vm_start was set 0xB6F9F000, vma->start was set B6FA0000. Therefore, this is "if (vma-> vm_end - vma-> vm_start> mem-> size)" will result in an error. Am I wrong how to use UIO?
> > thanks, > > greg k-h
Best regards, Nobuhiro
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