lkml.org 
[lkml]   [1999]   [Feb]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: No user space access during irq?

On Mon, 8 Feb 1999, Till Harbaum wrote:

> I know i am not allowed to call the scheduler during the irq. Is
> there another way of gaining access to the correct user space?

The hard way is to make your device mmap()-able and lock (& make present)
the pages whenever you start IO, and save the (address)->(page_struct *)
for the IRQ handler. The IRQ handler is free to access a page-cache page
that is locked. The easier way (if your semantics allow this) is to shape
your device as a block-device. The hacky way is to ioremap() it and make
it's pages visible to user-space (ie. everybody in the system), this is a
security hole but might be the easiest solution for special isolated
appliances.

-- mingo


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:50    [W:0.045 / U:0.264 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site