lkml.org 
[lkml]   [2019]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH AUTOSEL 4.19 11/29] binder: take read mode of mmap_sem in binder_alloc_free_page()
On 2019-08-30 08:29:10, Greg Kroah-Hartman wrote:
> On Thu, Aug 29, 2019 at 10:13:20AM -0500, Tyler Hicks wrote:
> > Hello, Sasha!
> >
> > On 2019-08-29 06:49:51, Sasha Levin wrote:
> > > From: Tyler Hicks <tyhicks@canonical.com>
> > >
> > > [ Upstream commit 60d4885710836595192c42d3e04b27551d30ec91 ]
> > >
> > > Restore the behavior of locking mmap_sem for reading in
> > > binder_alloc_free_page(), as was first done in commit 3013bf62b67a
> > > ("binder: reduce mmap_sem write-side lock"). That change was
> > > inadvertently reverted by commit 5cec2d2e5839 ("binder: fix race between
> > > munmap() and direct reclaim").
> > >
> > > In addition, change the name of the label for the error path to
> > > accurately reflect that we're taking the lock for reading.
> > >
> > > Backporting note: This fix is only needed when *both* of the commits
> > > mentioned above are applied. That's an unlikely situation since they
> > > both landed during the development of v5.1 but only one of them is
> > > targeted for stable.
> >
> > This patch isn't meant to be applied to 4.19 since commit 3013bf62b67a
> > ("binder: reduce mmap_sem write-side lock") was never brought back to
> > 4.19.
> >
> > Tyler
> >
> > >
> > > Fixes: 5cec2d2e5839 ("binder: fix race between munmap() and direct reclaim")
>
> But this commit is in 4.19.49

That's correct but commit 3013bf62b67a isn't present in 4.19.y. See the
"Backporting note" above.

Tyler

>
> thanks,
>
> greg k-h

\
 
 \ /
  Last update: 2019-08-30 09:31    [W:0.076 / U:4.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site