diff options
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 3afd354c46f1..29e87921437d 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -69,7 +69,7 @@ static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; /* NOTE: change this value only with kprobe_mutex held */ static bool kprobe_enabled; -DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ +static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; static struct { spinlock_t lock ____cacheline_aligned_in_smp; @@ -115,6 +115,7 @@ enum kprobe_slot_state { SLOT_USED = 2, }; +static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */ static struct hlist_head kprobe_insn_pages; static int kprobe_garbage_slots; static int collect_garbage_slots(void); @@ -144,10 +145,10 @@ loop_end: } /** - * get_insn_slot() - Find a slot on an executable page for an instruction. + * __get_insn_slot() - Find a slot on an executable page for an instruction. * We allocate an executable page if there's no room on existing ones. */ -kprobe_opcode_t __kprobes *get_insn_slot(void) +static kprobe_opcode_t __kprobes *__get_insn_slot(void) { struct kprobe_insn_page *kip; struct hlist_node *pos; @@ -196,6 +197,15 @@ kprobe_opcode_t __kprobes *get_insn_slot(void) return kip->insns; } +kprobe_opcode_t __kprobes *get_insn_slot(void) +{ + kprobe_opcode_t *ret; + mutex_lock(&kprobe_insn_mutex); + ret = __get_insn_slot(); + mutex_unlock(&kprobe_insn_mutex); + return ret; +} + /* Return 1 if all garbages are collected, otherwise 0. */ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) { @@ -226,9 +236,13 @@ static int __kprobes collect_garbage_slots(void) { struct kprobe_insn_page *kip; struct hlist_node *pos, *next; + int safety; /* Ensure no-one is preepmted on the garbages */ - if (check_safety() != 0) + mutex_unlock(&kprobe_insn_mutex); + safety = check_safety(); + mutex_lock(&kprobe_insn_mutex); + if (safety != 0) return -EAGAIN; hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) { @@ -251,6 +265,7 @@ 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) { if (kip->insns <= slot && slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) { @@ -267,6 +282,8 @@ void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE) collect_garbage_slots(); + + mutex_unlock(&kprobe_insn_mutex); } #endif |