Message ID | 20090414152151.C659.A69D9226@jp.fujitsu.com |
---|---|
State | RFC, archived |
Delegated to: | David Miller |
Headers | show |
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@jp.fujitsu.com> > Cc: Maciej Sosnowski <maciej.sosnowski@intel.com> > Cc: David S. Miller <davem@davemloft.net> > Cc: Chris Leech <christopher.leech@intel.com> > Cc: netdev@vger.kernel.org > --- > 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. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> 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@jp.fujitsu.com> > > Cc: Maciej Sosnowski <maciej.sosnowski@intel.com> > > Cc: David S. Miller <davem@davemloft.net> > > Cc: Chris Leech <christopher.leech@intel.com> > > Cc: netdev@vger.kernel.org > > --- > > 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 netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
========================= 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@jp.fujitsu.com> Cc: Maciej Sosnowski <maciej.sosnowski@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Leech <christopher.leech@intel.com> Cc: netdev@vger.kernel.org --- 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); if (ret != page_list->nr_pages) goto unpin; @@ -127,6 +119,8 @@ void dma_unpin_iovec_pages(struct dma_pi if (!pinned_list) return; + up_read(¤t->mm->mm_pinned_sem); + for (i = 0; i < pinned_list->nr_iovecs; i++) { struct dma_page_list *page_list = &pinned_list->page_list[i]; for (j = 0; j < page_list->nr_pages; j++) {