summaryrefslogtreecommitdiffstats
path: root/kernel/kprobes.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c25
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