]> nv-tegra.nvidia Code Review - linux-3.10.git/blobdiff - kernel/kprobes.c
[PATCH] kprobes: replace magic numbers with enum
[linux-3.10.git] / kernel / kprobes.c
index 17ec4afb0994e48adc1c7a9cfde971f04b08d512..6fcf8dd148d06b868d1ab1212b420f2e73833848 100644 (file)
@@ -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);