| Message ID | 20210223235010.2296915-1-Liam.Howlett@Oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] mm/mmap: Don't unlock VMAs in remap_file_pages() | expand |
On Tue, Feb 23, 2021 at 11:50:23PM +0000, Liam Howlett wrote: > Since this call uses MAP_FIXED, do_mmap() will munlock the necessary > range. There is also an error in the loop test expression which will > evaluate as false and the loop body has never execute. > > Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> > Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
On 24.02.21 00:50, Liam Howlett wrote: > Since this call uses MAP_FIXED, do_mmap() will munlock the necessary > range. There is also an error in the loop test expression which will > evaluate as false and the loop body has never execute. > > Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> > Acked-by: Hugh Dickins <hughd@google.com> > --- > mm/mmap.c | 18 +----------------- > 1 file changed, 1 insertion(+), 17 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index dc7206032387c..e22b048733269 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -3025,25 +3025,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, > > flags &= MAP_NONBLOCK; > flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE; > - if (vma->vm_flags & VM_LOCKED) { > - struct vm_area_struct *tmp; > + if (vma->vm_flags & VM_LOCKED) > flags |= MAP_LOCKED; > > - /* drop PG_Mlocked flag for over-mapped range */ > - for (tmp = vma; tmp->vm_start >= start + size; > - tmp = tmp->vm_next) { > - /* > - * Split pmd and munlock page on the border > - * of the range. > - */ > - vma_adjust_trans_huge(tmp, start, start + size, 0); > - > - munlock_vma_pages_range(tmp, > - max(tmp->vm_start, start), > - min(tmp->vm_end, start + size)); > - } > - } > - > file = get_file(vma->vm_file); > ret = do_mmap(vma->vm_file, start, size, > prot, flags, pgoff, &populate, NULL); > Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/mm/mmap.c b/mm/mmap.c index dc7206032387c..e22b048733269 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3025,25 +3025,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, flags &= MAP_NONBLOCK; flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE; - if (vma->vm_flags & VM_LOCKED) { - struct vm_area_struct *tmp; + if (vma->vm_flags & VM_LOCKED) flags |= MAP_LOCKED; - /* drop PG_Mlocked flag for over-mapped range */ - for (tmp = vma; tmp->vm_start >= start + size; - tmp = tmp->vm_next) { - /* - * Split pmd and munlock page on the border - * of the range. - */ - vma_adjust_trans_huge(tmp, start, start + size, 0); - - munlock_vma_pages_range(tmp, - max(tmp->vm_start, start), - min(tmp->vm_end, start + size)); - } - } - file = get_file(vma->vm_file); ret = do_mmap(vma->vm_file, start, size, prot, flags, pgoff, &populate, NULL);