mm: constify oom_control, scan_control, and alloc_context nodemask

The nodemasks in these structures may come from a variety of sources,
including tasks and cpusets - and should never be modified by any code
when being passed around inside another context.

Link: https://lore.kernel.org/20260609002919.3967782-1-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Tested-by: SeongJae Park <sj@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 35d1a7643dc4..242ec3cb8b52 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1815,7 +1815,7 @@ static inline int zonelist_node_idx(const struct zoneref *zoneref)
 
 struct zoneref *__next_zones_zonelist(struct zoneref *z,
 					enum zone_type highest_zoneidx,
-					nodemask_t *nodes);
+					const nodemask_t *nodes);
 
 /**
  * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point
@@ -1834,7 +1834,7 @@ struct zoneref *__next_zones_zonelist(struct zoneref *z,
  */
 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
 					enum zone_type highest_zoneidx,
-					nodemask_t *nodes)
+					const nodemask_t *nodes)
 {
 	if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
 		return z;
@@ -1860,7 +1860,7 @@ static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
  */
 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
 					enum zone_type highest_zoneidx,
-					nodemask_t *nodes)
+					const nodemask_t *nodes)
 {
 	return next_zones_zonelist(zonelist->_zonerefs,
 							highest_zoneidx, nodes);