kprobes: Clean up insn_pages by using list instead of hlist

Use struct list instead of struct hlist for managing
insn_pages, because insn_pages doesn't use hash table.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20090630210814.17851.64651.stgit@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 19 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 16b5739c516a..6fe9dc6d1a81 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -103,7 +103,7 @@ static struct kprobe_blackpoint kprobe_blacklist[] = {
 #define INSNS_PER_PAGE  (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
 
 struct kprobe_insn_page {
-        struct hlist_node hlist;
+        struct list_head list;
         kprobe_opcode_t *insns;         /* Page of instruction slots */
         char slot_used[INSNS_PER_PAGE];
         int nused;
@@ -117,7 +117,7 @@ enum kprobe_slot_state {
 };
 
 static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */
-static struct hlist_head kprobe_insn_pages;
+static LIST_HEAD(kprobe_insn_pages);
 static int kprobe_garbage_slots;
 static int collect_garbage_slots(void);
 
@@ -152,10 +152,9 @@ loop_end:
 static kprobe_opcode_t __kprobes *__get_insn_slot(void)
 {
         struct kprobe_insn_page *kip;
-        struct hlist_node *pos;
 
  retry:
-        hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+        list_for_each_entry(kip, &kprobe_insn_pages, list) {
                 if (kip->nused < INSNS_PER_PAGE) {
                         int i;
                         for (i = 0; i < INSNS_PER_PAGE; i++) {
@@ -189,8 +188,8 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(void)
                 kfree(kip);
                 return NULL;
         }
-        INIT_HLIST_NODE(&kip->hlist);
-        hlist_add_head(&kip->hlist, &kprobe_insn_pages);
+        INIT_LIST_HEAD(&kip->list);
+        list_add(&kip->list, &kprobe_insn_pages);
         memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
         kip->slot_used[0] = SLOT_USED;
         kip->nused = 1;
@@ -219,12 +218,8 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
                  * so as not to have to set it up again the
                  * next time somebody inserts a probe.
                  */
-                hlist_del(&kip->hlist);
-                if (hlist_empty(&kprobe_insn_pages)) {
-                        INIT_HLIST_NODE(&kip->hlist);
-                        hlist_add_head(&kip->hlist,
-                                       &kprobe_insn_pages);
-                } else {
+                if (!list_is_singular(&kprobe_insn_pages)) {
+                        list_del(&kip->list);
                         module_free(NULL, kip->insns);
                         kfree(kip);
                 }
@@ -235,14 +230,13 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
 
 static int __kprobes collect_garbage_slots(void)
 {
-        struct kprobe_insn_page *kip;
-        struct hlist_node *pos, *next;
+        struct kprobe_insn_page *kip, *next;
 
         /* Ensure no-one is preepmted on the garbages */
         if (check_safety())
                 return -EAGAIN;
 
-        hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {
+        list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) {
                 int i;
                 if (kip->ngarbage == 0)
                         continue;
@@ -260,19 +254,17 @@ static int __kprobes collect_garbage_slots(void)
 void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
 {
         struct kprobe_insn_page *kip;
-        struct hlist_node *pos;
 
         mutex_lock(&kprobe_insn_mutex);
-        hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+        list_for_each_entry(kip, &kprobe_insn_pages, list) {
                 if (kip->insns <= slot &&
                     slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
                         int i = (slot - kip->insns) / MAX_INSN_SIZE;
                         if (dirty) {
                                 kip->slot_used[i] = SLOT_DIRTY;
                                 kip->ngarbage++;
-                        } else {
+                        } else
                                 collect_one_slot(kip, i);
-                        }
                         break;
                 }
         }