Hi Mauro, On Sunday 06 January 2013 11:02:25 Mauro Carvalho Chehab wrote: > Em Sat, 15 Dec 2012 20:38:29 +0000 Al Viro escreveu: > > On Sat, Dec 15, 2012 at 08:12:37PM +0000, Al Viro wrote: > > > Walking rbtree while it's modified is a Bad Idea(tm); besides, > > > > > > the result of find_vma() can be freed just as it's getting returned > > > to caller. Fortunately, it's easy to fix - just take ->mmap_sem a bit > > > earlier (and don't bother with find_vma() at all if virtp >= PAGE_OFFSET > > > - > > > in that case we don't even look at its result). > > > > While we are at it, what prevents VIDIOC_PREPARE_BUF calling > > > > v4l_prepare_buf() -> (e.g) vb2_ioctl_prepare_buf() -> vb2_prepare_buf() -> > > __buf_prepare() -> __qbuf_userptr() -> vb2_vmalloc_get_userptr() -> > > find_vma(), AFAICS without having taken ->mmap_sem anywhere in process? > > The code flow is bloody convoluted and depends on a bunch of things done > > by initialization, so I certainly might've missed something... > > This driver is currently missing an active maintainer, as it is for an old > hardware (AFAIK, omap is now at version 4, and this is for the first one), The omap_vout driver is for OMAP2+ if I'm not mistaken. I use it with the OMAP3. > but I'm c/c a few developers that might help to test and analyze it. > > In any case, /me is assuming that your patch is right (as nobody > complained), and I'm applying it right now on my tree. This will hopefully > allow some people to test. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
