diff options
| -rw-r--r-- | kernel/kprobes.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 17ec4af..6fcf8dd 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); |
