Re: Clarification needed on use of put_user inside a loop

On Fri, Apr 25, 2014 at 09:39:57PM +0530, Kumar Gaurav wrote: > I have found some codes in the driver which use put_user() in loop. > Can we avoid the overhead of checking the same memory area( where > put_user() writes) again n again using __put_user() in side loop and > checking permission usin

Re: Clarification needed on use of put_user inside a loop

On Fri, Apr 25, 2014 at 09:39:57PM +0530, Kumar Gaurav wrote: > Hence when transferring data involves loops then checking permission > (using access_ok()) once should be good to go then after we can > simply transfer data using __put_user(), instead of using put_user() > itself in loop. > Well, I

Clarification needed on use of put_user inside a loop

Hi All, function put_user() is used to transfer small bytes of data (1-8 byte) from kernel space to user space and before transferring, it checks for the user's access over that memory area (in user space of-course) using function access_ok(). function __put_user() is used for same purpose but