[nacked] mm-mempolicy-convert-from-atomic_t-to-refcount_t-on-mempolicy-refcnt.patch removed from -mm tree

[nacked] mm-mempolicy-convert-from-atomic_t-to-refcount_t-on-mempolicy-refcnt.patch removed from -mm tree

[Andrew Morton]

The patch titled
     Subject: mm/mempolicy: convert from atomic_t to refcount_t on mempolicy->refcnt
has been removed from the -mm tree.  Its filename was
     mm-mempolicy-convert-from-atomic_t-to-refcount_t-on-mempolicy-refcnt.patch

This patch was dropped because it was nacked

------------------------------------------------------
From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Subject: mm/mempolicy: convert from atomic_t to refcount_t on mempolicy->refcnt

refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.

[akpm@linux-foundation.org: fix warnings]
Link: https://lkml.kernel.org/r/1626683671-64407-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Acked-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mempolicy.h |    5 +++--
 mm/mempolicy.c            |   12 ++++++------
 2 files changed, 9 insertions(+), 8 deletions(-)

--- a/include/linux/mempolicy.h~mm-mempolicy-convert-from-atomic_t-to-refcount_t-on-mempolicy-refcnt
+++ a/include/linux/mempolicy.h
@@ -6,6 +6,7 @@
 #ifndef _LINUX_MEMPOLICY_H
 #define _LINUX_MEMPOLICY_H 1
 
+#include <linux/refcount.h>
 #include <linux/sched.h>
 #include <linux/mmzone.h>
 #include <linux/slab.h>
@@ -42,7 +43,7 @@ struct mm_struct;
  * to 1, representing the caller of mpol_dup().
  */
 struct mempolicy {
-	atomic_t refcnt;
+	refcount_t refcnt;
 	unsigned short mode; 	/* See MPOL_* above */
 	unsigned short flags;	/* See set_mempolicy() MPOL_F_* above */
 	nodemask_t nodes;	/* interleave/bind/perfer */
@@ -94,7 +95,7 @@ static inline struct mempolicy *mpol_dup
 static inline void mpol_get(struct mempolicy *pol)
 {
 	if (pol)
-		atomic_inc(&pol->refcnt);
+		refcount_inc(&pol->refcnt);
 }
 
 extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
--- a/mm/mempolicy.c~mm-mempolicy-convert-from-atomic_t-to-refcount_t-on-mempolicy-refcnt
+++ a/mm/mempolicy.c
@@ -123,7 +123,7 @@ enum zone_type policy_zone = 0;
  * run-time system-wide default policy => local allocation
  */
 static struct mempolicy default_policy = {
-	.refcnt = ATOMIC_INIT(1), /* never free it */
+	.refcnt = { ATOMIC_INIT(1), }, /* never free it */
 	.mode = MPOL_LOCAL,
 };
 
@@ -295,7 +295,7 @@ static struct mempolicy *mpol_new(unsign
 	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
 	if (!policy)
 		return ERR_PTR(-ENOMEM);
-	atomic_set(&policy->refcnt, 1);
+	refcount_set(&policy->refcnt, 1);
 	policy->mode = mode;
 	policy->flags = flags;
 	policy->home_node = NUMA_NO_NODE;
@@ -306,7 +306,7 @@ static struct mempolicy *mpol_new(unsign
 /* Slow path of a mpol destructor. */
 void __mpol_put(struct mempolicy *p)
 {
-	if (!atomic_dec_and_test(&p->refcnt))
+	if (!refcount_dec_and_test(&p->refcnt))
 		return;
 	kmem_cache_free(policy_cache, p);
 }
@@ -2400,7 +2400,7 @@ struct mempolicy *__mpol_dup(struct memp
 		nodemask_t mems = cpuset_mems_allowed(current);
 		mpol_rebind_policy(new, &mems);
 	}
-	atomic_set(&new->refcnt, 1);
+	refcount_set(&new->refcnt, 1);
 	return new;
 }
 
@@ -2697,7 +2697,7 @@ restart:
 					goto alloc_new;
 
 				*mpol_new = *n->policy;
-				atomic_set(&mpol_new->refcnt, 1);
+				refcount_set(&mpol_new->refcnt, 1);
 				sp_node_init(n_new, end, n->end, mpol_new);
 				n->end = start;
 				sp_insert(sp, n_new);
@@ -2891,7 +2891,7 @@ void __init numa_policy_init(void)
 
 	for_each_node(nid) {
 		preferred_node_policy[nid] = (struct mempolicy) {
-			.refcnt = ATOMIC_INIT(1),
+			.refcnt = { ATOMIC_INIT(1), },
 			.mode = MPOL_PREFERRED,
 			.flags = MPOL_F_MOF | MPOL_F_MORON,
 			.nodes = nodemask_of_node(nid),
_

Patches currently in -mm which might be from xiyuyang19@fudan.edu.cn are

mm-rmap-convert-from-atomic_t-to-refcount_t-on-anon_vma-refcount.patch