Jan Hudec wrote:
Are you sure? The sys_mlock manipulates userspace memory. But a driver does not have any userspace memory to manipulate. It only has kernel memory and that is not swappable.
We use sys_mlock() to lock user-space memory. We need to create a list of physical addresses for every page in the app's buffer. This buffer needs to be locked down and then its contents DMA'd to our hardware.
Because that function is a syscall. You should call it as a syscall. But since it only affects userspace memory, the userspace should call it. Really.
Userspace can't call it because only root can call sys_mlock() and we can't require that the calling process be root.
Could you please tell us what you want to do? It seems quite likely that there is a better solution than trying to call sys_mlock.
I agree, but I haven't been able to find it yet.
-- Timur Tabi Staff Software Engineer timur.tabi@ammasso.com
-- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
