On Mon, Nov 12, 2018 at 7:45 AM Keith Busch <[email protected]> wrote: > > On Sat, Nov 10, 2018 at 12:50:36AM -0800, [email protected] wrote: > > From: John Hubbard <[email protected]> > > > > An upcoming patch wants to be able to operate on each page that > > get_user_pages has retrieved. In order to do that, it's best to > > have a common exit point from the routine. Most of this has been > > taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while > > pinning pages"), but there was one case remaining. > > > > Also, there was still an unnecessary shadow declaration (with a > > different type) of the "ret" variable, which this commit removes. > > > > Cc: Keith Busch <[email protected]> > > Cc: Dan Williams <[email protected]> > > Cc: Kirill A. Shutemov <[email protected]> > > Cc: Dave Hansen <[email protected]> > > Signed-off-by: John Hubbard <[email protected]> > > --- > > mm/gup.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/mm/gup.c b/mm/gup.c > > index f76e77a2d34b..55a41dee0340 100644 > > --- a/mm/gup.c > > +++ b/mm/gup.c > > @@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk, > > struct mm_struct *mm, > > if (!vma || start >= vma->vm_end) { > > vma = find_extend_vma(mm, start); > > if (!vma && in_gate_area(mm, start)) { > > - int ret; > > ret = get_gate_page(mm, start & PAGE_MASK, > > gup_flags, &vma, > > pages ? &pages[i] : NULL); > > if (ret) > > - return i ? : ret; > > + goto out; > > ctx.page_mask = 0; > > goto next_page; > > } > > This also fixes a potentially leaked dev_pagemap reference count if a > failure occurs when an iteration crosses a vma boundary. I don't think > it's normal to have different vma's on a users mapped zone device memory, > but good to fix anyway.
Does not sound abnormal to me, we should promote this as a fix for the current cycle with an updated changelog.
