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>

1 files changed, 14 insertions, 21 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 550294d..e35be53 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -334,11 +334,10 @@ static inline void reset_kprobe_instance(void)
 struct kprobe __kprobes *get_kprobe(void *addr)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 
 	head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)];
-	hlist_for_each_entry_rcu(p, node, head, hlist) {
+	hlist_for_each_entry_rcu(p, head, hlist) {
 		if (p->addr == addr)
 			return p;
 	}
@@ -799,7 +798,6 @@ out:
 static void __kprobes optimize_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -810,7 +808,7 @@ static void __kprobes optimize_all_kprobes(void)
 	kprobes_allow_optimization = true;
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist)
+		hlist_for_each_entry_rcu(p, head, hlist)
 			if (!kprobe_disabled(p))
 				optimize_kprobe(p);
 	}
@@ -821,7 +819,6 @@ static void __kprobes optimize_all_kprobes(void)
 static void __kprobes unoptimize_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -832,7 +829,7 @@ static void __kprobes unoptimize_all_kprobes(void)
 	kprobes_allow_optimization = false;
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist) {
+		hlist_for_each_entry_rcu(p, head, hlist) {
 			if (!kprobe_disabled(p))
 				unoptimize_kprobe(p, false);
 		}
@@ -1148,7 +1145,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 {
 	struct kretprobe_instance *ri;
 	struct hlist_head *head, empty_rp;
-	struct hlist_node *node, *tmp;
+	struct hlist_node *tmp;
 	unsigned long hash, flags = 0;
 
 	if (unlikely(!kprobes_initialized))
@@ -1159,12 +1156,12 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 	hash = hash_ptr(tk, KPROBE_HASH_BITS);
 	head = &kretprobe_inst_table[hash];
 	kretprobe_table_lock(hash, &flags);
-	hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
 		if (ri->task == tk)
 			recycle_rp_inst(ri, &empty_rp);
 	}
 	kretprobe_table_unlock(hash, &flags);
-	hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+	hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
 		hlist_del(&ri->hlist);
 		kfree(ri);
 	}
@@ -1173,9 +1170,9 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 static inline void free_rp_inst(struct kretprobe *rp)
 {
 	struct kretprobe_instance *ri;
-	struct hlist_node *pos, *next;
+	struct hlist_node *next;
 
-	hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) {
+	hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) {
 		hlist_del(&ri->hlist);
 		kfree(ri);
 	}
@@ -1185,14 +1182,14 @@ static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
 {
 	unsigned long flags, hash;
 	struct kretprobe_instance *ri;
-	struct hlist_node *pos, *next;
+	struct hlist_node *next;
 	struct hlist_head *head;
 
 	/* No race here */
 	for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
 		kretprobe_table_lock(hash, &flags);
 		head = &kretprobe_inst_table[hash];
-		hlist_for_each_entry_safe(ri, pos, next, head, hlist) {
+		hlist_for_each_entry_safe(ri, next, head, hlist) {
 			if (ri->rp == rp)
 				ri->rp = NULL;
 		}
@@ -2028,7 +2025,6 @@ static int __kprobes kprobes_module_callback(struct notifier_block *nb,
 {
 	struct module *mod = data;
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 	int checkcore = (val == MODULE_STATE_GOING);
@@ -2045,7 +2041,7 @@ static int __kprobes kprobes_module_callback(struct notifier_block *nb,
 	mutex_lock(&kprobe_mutex);
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist)
+		hlist_for_each_entry_rcu(p, head, hlist)
 			if (within_module_init((unsigned long)p->addr, mod) ||
 			    (checkcore &&
 			     within_module_core((unsigned long)p->addr, mod))) {
@@ -2192,7 +2188,6 @@ static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v)
 static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p, *kp;
 	const char *sym = NULL;
 	unsigned int i = *(loff_t *) v;
@@ -2201,7 +2196,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v)
 
 	head = &kprobe_table[i];
 	preempt_disable();
-	hlist_for_each_entry_rcu(p, node, head, hlist) {
+	hlist_for_each_entry_rcu(p, head, hlist) {
 		sym = kallsyms_lookup((unsigned long)p->addr, NULL,
 					&offset, &modname, namebuf);
 		if (kprobe_aggrprobe(p)) {
@@ -2236,7 +2231,6 @@ static const struct file_operations debugfs_kprobes_operations = {
 static void __kprobes arm_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -2249,7 +2243,7 @@ static void __kprobes arm_all_kprobes(void)
 	/* Arming kprobes doesn't optimize kprobe itself */
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist)
+		hlist_for_each_entry_rcu(p, head, hlist)
 			if (!kprobe_disabled(p))
 				arm_kprobe(p);
 	}
@@ -2265,7 +2259,6 @@ already_enabled:
 static void __kprobes disarm_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -2282,7 +2275,7 @@ static void __kprobes disarm_all_kprobes(void)
 
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist) {
+		hlist_for_each_entry_rcu(p, head, hlist) {
 			if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p))
 				disarm_kprobe(p, false);
 		}