1 files changed, 13 insertions, 7 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 17ec4afb0994..6fcf8dd148d0 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -87,6 +87,12 @@ struct kprobe_insn_page {
         int ngarbage;
 };
 
+enum kprobe_slot_state {
+        SLOT_CLEAN = 0,
+        SLOT_DIRTY = 1,
+        SLOT_USED = 2,
+};
+
 static struct hlist_head kprobe_insn_pages;
 static int kprobe_garbage_slots;
 static int collect_garbage_slots(void);
@@ -130,8 +136,8 @@ kprobe_opcode_t __kprobes *get_insn_slot(void)
                 if (kip->nused < INSNS_PER_PAGE) {
                         int i;
                         for (i = 0; i < INSNS_PER_PAGE; i++) {
-                                if (!kip->slot_used[i]) {
-                                        kip->slot_used[i] = 1;
+                                if (kip->slot_used[i] == SLOT_CLEAN) {
+                                        kip->slot_used[i] = SLOT_USED;
                                         kip->nused++;
                                         return kip->insns + (i * MAX_INSN_SIZE);
                                 }
@@ -163,8 +169,8 @@ kprobe_opcode_t __kprobes *get_insn_slot(void)
         }
         INIT_HLIST_NODE(&kip->hlist);
         hlist_add_head(&kip->hlist, &kprobe_insn_pages);
-        memset(kip->slot_used, 0, INSNS_PER_PAGE);
-        kip->slot_used[0] = 1;
+        memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
+        kip->slot_used[0] = SLOT_USED;
         kip->nused = 1;
         kip->ngarbage = 0;
         return kip->insns;
@@ -173,7 +179,7 @@ kprobe_opcode_t __kprobes *get_insn_slot(void)
 /* Return 1 if all garbages are collected, otherwise 0. */
 static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
 {
-        kip->slot_used[idx] = 0;
+        kip->slot_used[idx] = SLOT_CLEAN;
         kip->nused--;
         if (kip->nused == 0) {
                 /*
@@ -212,7 +218,7 @@ static int __kprobes collect_garbage_slots(void)
                         continue;
                 kip->ngarbage = 0;      /* we will collect all garbages */
                 for (i = 0; i < INSNS_PER_PAGE; i++) {
-                        if (kip->slot_used[i] == -1 &&
+                        if (kip->slot_used[i] == SLOT_DIRTY &&
                             collect_one_slot(kip, i))
                                 break;
                 }
@@ -232,7 +238,7 @@ void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
                     slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
                         int i = (slot - kip->insns) / MAX_INSN_SIZE;
                         if (dirty) {
-                                kip->slot_used[i] = -1;
+                                kip->slot_used[i] = SLOT_DIRTY;
                                 kip->ngarbage++;
                         } else {
                                 collect_one_slot(kip, i);