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-rw-r--r--kernel/kprobes.c30
1 files changed, 20 insertions, 10 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3fed7f0cbcdf..bddf3b201a48 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -467,6 +467,7 @@ static struct kprobe *__kprobes get_optimized_kprobe(unsigned long addr)
/* Optimization staging list, protected by kprobe_mutex */
static LIST_HEAD(optimizing_list);
static LIST_HEAD(unoptimizing_list);
+static LIST_HEAD(freeing_list);
static void kprobe_optimizer(struct work_struct *work);
static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
@@ -504,7 +505,7 @@ static __kprobes void do_optimize_kprobes(void)
* Unoptimize (replace a jump with a breakpoint and remove the breakpoint
* if need) kprobes listed on unoptimizing_list.
*/
-static __kprobes void do_unoptimize_kprobes(struct list_head *free_list)
+static __kprobes void do_unoptimize_kprobes(void)
{
struct optimized_kprobe *op, *tmp;
@@ -515,9 +516,9 @@ static __kprobes void do_unoptimize_kprobes(struct list_head *free_list)
/* Ditto to do_optimize_kprobes */
get_online_cpus();
mutex_lock(&text_mutex);
- arch_unoptimize_kprobes(&unoptimizing_list, free_list);
+ arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list);
/* Loop free_list for disarming */
- list_for_each_entry_safe(op, tmp, free_list, list) {
+ list_for_each_entry_safe(op, tmp, &freeing_list, list) {
/* Disarm probes if marked disabled */
if (kprobe_disabled(&op->kp))
arch_disarm_kprobe(&op->kp);
@@ -536,11 +537,11 @@ static __kprobes void do_unoptimize_kprobes(struct list_head *free_list)
}
/* Reclaim all kprobes on the free_list */
-static __kprobes void do_free_cleaned_kprobes(struct list_head *free_list)
+static __kprobes void do_free_cleaned_kprobes(void)
{
struct optimized_kprobe *op, *tmp;
- list_for_each_entry_safe(op, tmp, free_list, list) {
+ list_for_each_entry_safe(op, tmp, &freeing_list, list) {
BUG_ON(!kprobe_unused(&op->kp));
list_del_init(&op->list);
free_aggr_kprobe(&op->kp);
@@ -556,8 +557,6 @@ static __kprobes void kick_kprobe_optimizer(void)
/* Kprobe jump optimizer */
static __kprobes void kprobe_optimizer(struct work_struct *work)
{
- LIST_HEAD(free_list);
-
mutex_lock(&kprobe_mutex);
/* Lock modules while optimizing kprobes */
mutex_lock(&module_mutex);
@@ -566,7 +565,7 @@ static __kprobes void kprobe_optimizer(struct work_struct *work)
* Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed)
* kprobes before waiting for quiesence period.
*/
- do_unoptimize_kprobes(&free_list);
+ do_unoptimize_kprobes();
/*
* Step 2: Wait for quiesence period to ensure all running interrupts
@@ -581,7 +580,7 @@ static __kprobes void kprobe_optimizer(struct work_struct *work)
do_optimize_kprobes();
/* Step 4: Free cleaned kprobes after quiesence period */
- do_free_cleaned_kprobes(&free_list);
+ do_free_cleaned_kprobes();
mutex_unlock(&module_mutex);
mutex_unlock(&kprobe_mutex);
@@ -723,8 +722,19 @@ static void __kprobes kill_optimized_kprobe(struct kprobe *p)
if (!list_empty(&op->list))
/* Dequeue from the (un)optimization queue */
list_del_init(&op->list);
-
op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
+
+ if (kprobe_unused(p)) {
+ /* Enqueue if it is unused */
+ list_add(&op->list, &freeing_list);
+ /*
+ * Remove unused probes from the hash list. After waiting
+ * for synchronization, this probe is reclaimed.
+ * (reclaiming is done by do_free_cleaned_kprobes().)
+ */
+ hlist_del_rcu(&op->kp.hlist);
+ }
+
/* Don't touch the code, because it is already freed. */
arch_remove_optimized_kprobe(op);
}