lkml.org 
[lkml]   [2014]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] uio: Fix memory size check with vma in uio_mmap_physical()
(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

\
 
 \ /
  Last update: 2014-03-20 10:21    [W:0.054 / U:0.244 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site