On Tue, 2005-08-16 at 19:14 +0300, Stavros Passas wrote: > Hi All, > > I working on a kernel module and I have been a little bit comfused with > Linux memory manager. > > When a user opens the device,the module stores somewhere user's > active_mm pointer.We can assume that only one user can open the device > at the same time. When a interrupt comes to my handler, I want to write > some data to a page of the user. The interrupt handler has the > destination address,and the length of the data that must be copied and > of course the data. The problem is that the destination address is from > address space of the user. At first,through user's active_mm, I find if > the user have access to the memory region that device must write. AFAIK > I cannot use copy_to_user function, or something like this, because > these functions can used only from the user proccess. > > So the question is how to "convert" the destination memory address to > interrupt handler address space, so the handler can write the data to > the correct place. > an interrupt handler has no address space. Also.. what if the memory in userspace is actually swapped out? you just can't do this in linux; you need to do this from user context; and wake that user context up from the irq. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
