Re: Fw: [PATCH] ia64: race flushing icache in do_no_page path

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, 2007-04-27 at 21:55 +1000, Nick Piggin wrote:

> That's the theory. However, I'd still like to know how the arch code can
> make the assertion that icache is known to be at all times other than at
> the time of a fault?
> 

Kernel needs to only worry about the updates that it does.  So, if
kernel is writing into a page that is getting marked with execute
permission then it will need to make sure that caches are coherent.
ia64 Kernel keeps track of whether it has done any write operation on a
page or not using PG_arch_1.  And accordingly flushes icaches.

> Ie. what if an operation which causes incoherency is carried out _after_
> an executable mapping is installed for that page.
> 

You mean by user space? If so, then it is user space responsibility to
do the appropriate operations (like flush icache in this case).

-rohit

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux