lkml.org 
[lkml]   [2005]   [Feb]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH/RFC] Futex mmap_sem deadlock
On Tue, Feb 22, 2005 at 01:30:27PM -0800, Linus Torvalds wrote:
>
> We really have this already, and it's called "current->preempt". It
> handles any lock at all, and doesn't add yet another special case to all
> the architectures.
>
> Just do
>
> repeat:
> down_read(&current->mm->mmap_sem);
> get_futex_key(...) etc.
> queue_me(...) etc.
> inc_preempt_count();
> ret = get_user(...);
> dec_preempt_count();

Perhaps this should be preempt_disable .... preempt_enable.
Otherwise, a preempt attempt in get_user would not be seen
until some future preempt_enable was executed.

Regards,
Joe
--
"Money can buy bandwidth, but latency is forever" -- John Mashey
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:10    [from the cache]
©2003-2011 Jasper Spaans