hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 7 insertions, 15 deletions

diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 55a6271bce7a..ff63fe00c195 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -45,12 +45,11 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value)
 {
         struct ima_queue_entry *qe, *ret = NULL;
         unsigned int key;
-        struct hlist_node *pos;
         int rc;
 
         key = ima_hash_key(digest_value);
         rcu_read_lock();
-        hlist_for_each_entry_rcu(qe, pos, &ima_htable.queue[key], hnext) {
+        hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
                 rc = memcmp(qe->entry->digest, digest_value, IMA_DIGEST_SIZE);
                 if (rc == 0) {
                         ret = qe;
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 4d3fab47e643..dad36a6ab45f 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -188,11 +188,9 @@ int avc_get_hash_stats(char *page)
         for (i = 0; i < AVC_CACHE_SLOTS; i++) {
                 head = &avc_cache.slots[i];
                 if (!hlist_empty(head)) {
-                        struct hlist_node *next;
-
                         slots_used++;
                         chain_len = 0;
-                        hlist_for_each_entry_rcu(node, next, head, list)
+                        hlist_for_each_entry_rcu(node, head, list)
                                 chain_len++;
                         if (chain_len > max_chain_len)
                                 max_chain_len = chain_len;
@@ -241,7 +239,6 @@ static inline int avc_reclaim_node(void)
         int hvalue, try, ecx;
         unsigned long flags;
         struct hlist_head *head;
-        struct hlist_node *next;
         spinlock_t *lock;
 
         for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) {
@@ -253,7 +250,7 @@ static inline int avc_reclaim_node(void)
                         continue;
 
                 rcu_read_lock();
-                hlist_for_each_entry(node, next, head, list) {
+                hlist_for_each_entry(node, head, list) {
                         avc_node_delete(node);
                         avc_cache_stats_incr(reclaims);
                         ecx++;
@@ -301,11 +298,10 @@ static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass)
         struct avc_node *node, *ret = NULL;
         int hvalue;
         struct hlist_head *head;
-        struct hlist_node *next;
 
         hvalue = avc_hash(ssid, tsid, tclass);
         head = &avc_cache.slots[hvalue];
-        hlist_for_each_entry_rcu(node, next, head, list) {
+        hlist_for_each_entry_rcu(node, head, list) {
                 if (ssid == node->ae.ssid &&
                     tclass == node->ae.tclass &&
                     tsid == node->ae.tsid) {
@@ -394,7 +390,6 @@ static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct av_dec
         node = avc_alloc_node();
         if (node) {
                 struct hlist_head *head;
-                struct hlist_node *next;
                 spinlock_t *lock;
 
                 hvalue = avc_hash(ssid, tsid, tclass);
@@ -404,7 +399,7 @@ static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct av_dec
                 lock = &avc_cache.slots_lock[hvalue];
 
                 spin_lock_irqsave(lock, flag);
-                hlist_for_each_entry(pos, next, head, list) {
+                hlist_for_each_entry(pos, head, list) {
                         if (pos->ae.ssid == ssid &&
                             pos->ae.tsid == tsid &&
                             pos->ae.tclass == tclass) {
@@ -541,7 +536,6 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass,
         unsigned long flag;
         struct avc_node *pos, *node, *orig = NULL;
         struct hlist_head *head;
-        struct hlist_node *next;
         spinlock_t *lock;
 
         node = avc_alloc_node();
@@ -558,7 +552,7 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass,
 
         spin_lock_irqsave(lock, flag);
 
-        hlist_for_each_entry(pos, next, head, list) {
+        hlist_for_each_entry(pos, head, list) {
                 if (ssid == pos->ae.ssid &&
                     tsid == pos->ae.tsid &&
                     tclass == pos->ae.tclass &&
@@ -614,7 +608,6 @@ out:
 static void avc_flush(void)
 {
         struct hlist_head *head;
-        struct hlist_node *next;
         struct avc_node *node;
         spinlock_t *lock;
         unsigned long flag;
@@ -630,7 +623,7 @@ static void avc_flush(void)
                  * prevent RCU grace periods from ending.
                  */
                 rcu_read_lock();
-                hlist_for_each_entry(node, next, head, list)
+                hlist_for_each_entry(node, head, list)
                         avc_node_delete(node);
                 rcu_read_unlock();
                 spin_unlock_irqrestore(lock, flag);