lkml.org 
[lkml]   [2009]   [Jan]   [6]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateTue, 6 Jan 2009 00:54:58 -0500
From"Mike Frysinger" <>
SubjectRe: debugfs & vfs file permission issue?
On Tue, Jan 6, 2009 at 00:48, Greg KH wrote:
> On Mon, Jan 05, 2009 at 09:57:07PM -0500, Robin Getz wrote:
>> On 2.6.28-rc2, If I create a debugfs file with
>>
>>     debugfs_create_x16("SPORT1_TX", 0200 , parent, 0xFFC00910);
>
> Um, are you are passing in a pointer to a known memory location
> properly?  Why would it be ok for the kernel to directly read that
> location?

it's a nommu system and the 0xffc00000+ addresses are always available
>> Although the file shows up as write only (no read):
>>
>> root:/> ls -l /sys/kernel/debug/blackfin/SPORT/SPORT1_TX
>> --w-------    1 root     root            0 Jan  1
>> 2007 /sys/kernel/debug/blackfin/SPORT/SPORT1_TX
>>
>> root:/> cat /sys/kernel/debug/blackfin/SPORT/SPORT1_TX
>>
>> Still works - and causes the read to occur, which crashes :(
>
> You're root, you can do anything :)

any thoughts on how to declare debugfs files that are read or write
only ?  we'll have to add new helper functions or have it be a
parameter or declare our own debugfs file ?
-mike


\
 
 \ /
  Last update: 2009-01-06 06:57    [from the cache]
©2003-2008