> On Tuesday 14 April 2009 16:23:13 KOSAKI Motohiro wrote: > > I don't have NET-DMA usable device. I hope to get expert review. > > > > ========================= > > Subject: [Untested][RFC][PATCH] fix wrong get_user_pages usage in iovlock.c > > > > down_read(mmap_sem) > > get_user_pages() > > up_read(mmap_sem) > > > > is fork unsafe. > > fix it. > > > > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> > > Cc: Maciej Sosnowski <maciej.sosnowski@xxxxxxxxx> > > Cc: David S. Miller <davem@xxxxxxxxxxxxx> > > Cc: Chris Leech <christopher.leech@xxxxxxxxx> > > Cc: netdev@xxxxxxxxxxxxxxx > > --- > > drivers/dma/iovlock.c | 18 ++++++------------ > > 1 file changed, 6 insertions(+), 12 deletions(-) > > > > Index: b/drivers/dma/iovlock.c > > =================================================================== > > --- a/drivers/dma/iovlock.c 2009-02-21 16:53:23.000000000 +0900 > > +++ b/drivers/dma/iovlock.c 2009-04-13 04:46:02.000000000 +0900 > > @@ -94,18 +94,10 @@ struct dma_pinned_list *dma_pin_iovec_pa > > pages += page_list->nr_pages; > > > > /* pin pages down */ > > - down_read(¤t->mm->mmap_sem); > > - ret = get_user_pages( > > - current, > > - current->mm, > > - (unsigned long) iov[i].iov_base, > > - page_list->nr_pages, > > - 1, /* write */ > > - 0, /* force */ > > - page_list->pages, > > - NULL); > > - up_read(¤t->mm->mmap_sem); > > - > > + down_read(¤t->mm->mm_pinned_sem); > > + ret = get_user_pages_fast((unsigned long) iov[i].iov_base, > > + page_list->nr_pages, 1, > > + page_list->pages); > > I would perhaps not fold gup_fast conversions into the same patch as > the fix. OK. I'll fix. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html