diff options
| author | Qian Cai <cai@lca.pw> | 2020-01-31 07:15:01 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-01-31 19:30:39 +0100 |
| commit | 3d680bdf60a5bade3e8cbd049927e7f8b1d3fe97 (patch) | |
| tree | b755d6cf6f1fd2c19dd7eb28f5ab4f2beab5607b /mm/page_isolation.c | |
| parent | mm/hotplug: silence a lockdep splat with printk() (diff) | |
| download | linux-3d680bdf60a5bade3e8cbd049927e7f8b1d3fe97.tar.xz linux-3d680bdf60a5bade3e8cbd049927e7f8b1d3fe97.zip | |
mm/page_isolation: fix potential warning from user
It makes sense to call the WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE)
from start_isolate_page_range(), but should avoid triggering it from
userspace, i.e, from is_mem_section_removable() because it could crash
the system by a non-root user if warn_on_panic is set.
While at it, simplify the code a bit by removing an unnecessary jump
label.
Link: http://lkml.kernel.org/r/20200120163915.1469-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_isolation.c')
| -rw-r--r-- | mm/page_isolation.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c index e70586523ca3..a9fd7c740c23 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -54,14 +54,18 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_ out: spin_unlock_irqrestore(&zone->lock, flags); - if (!ret) + if (!ret) { drain_all_pages(zone); - else if ((isol_flags & REPORT_FAILURE) && unmovable) - /* - * printk() with zone->lock held will guarantee to trigger a - * lockdep splat, so defer it here. - */ - dump_page(unmovable, "unmovable page"); + } else { + WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE); + + if ((isol_flags & REPORT_FAILURE) && unmovable) + /* + * printk() with zone->lock held will likely trigger a + * lockdep splat, so defer it here. + */ + dump_page(unmovable, "unmovable page"); + } return ret; } |