On Fri, May 25, 2012 at 03:38:04PM +0100, Will Deacon wrote: > From: Dima Zavin <[email protected]> > > commit 435a7ef52db7d86e67a009b36cac1457f8972391 upstream > > We can't be holding the mmap_sem while calling flush_cache_user_range > because the flush can fault. If we fault on a user address, the > page fault handler will try to take mmap_sem again. Since both places > acquire the read lock, most of the time it succeeds. However, if another > thread tries to acquire the write lock on the mmap_sem (e.g. mmap) in > between the call to flush_cache_user_range and the fault, the down_read > in do_page_fault will deadlock. > > [will: removed drop of vma parameter as already queued by rmk (7365/1)] > > Cc: <[email protected]> # 2.6.32+: 4542b6a0: ARM: 7365/1 > Cc: <[email protected]> # 2.6.32+ > Acked-by: Catalin Marinas <[email protected]> > Signed-off-by: Dima Zavin <[email protected]> > Signed-off-by: John Stultz <[email protected]> > Signed-off-by: Will Deacon <[email protected]> > Signed-off-by: Russell King <[email protected]> > --- > > Greg: This patch is a candidate for -stable, but its dependency (listed > above) wasn't marked as such, hence this retrospective submission.
Both now queued up for 3.0, 3.3, and 3.4-stable trees greg k-h -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
