diff mbox series

[RFT,09/13] kprobes: Free kprobe_insn_page asynchronously

Message ID 157918594575.29301.16307406359272775745.stgit@devnote2
State RFC
Headers show
Series tracing: kprobes: Introduce async unregistration | expand

Commit Message

Masami Hiramatsu (Google) Jan. 16, 2020, 2:45 p.m. UTC 
Free the kprobe_insn_page data structure asynchronously
using call_rcu().

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 kernel/kprobes.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a9114923da4c..60ffc9d54d87 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -87,6 +87,7 @@  static LIST_HEAD(kprobe_blacklist);
  */
 struct kprobe_insn_page {
 	struct list_head list;
+	struct rcu_head rcu;
 	kprobe_opcode_t *insns;		/* Page of instruction slots */
 	struct kprobe_insn_cache *cache;
 	int nused;
@@ -192,6 +193,13 @@  kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
 	return slot;
 }
 
+static void free_kprobe_insn_page(struct rcu_head *head)
+{
+	struct kprobe_insn_page *kip = container_of(head, typeof(*kip), rcu);
+
+	kfree(kip);
+}
+
 /* Return 1 if all garbages are collected, otherwise 0. */
 static int collect_one_slot(struct kprobe_insn_page *kip, int idx)
 {
@@ -206,9 +214,8 @@  static int collect_one_slot(struct kprobe_insn_page *kip, int idx)
 		 */
 		if (!list_is_singular(&kip->list)) {
 			list_del_rcu(&kip->list);
-			synchronize_rcu();
 			kip->cache->free(kip->insns);
-			kfree(kip);
+			call_rcu(&kip->rcu, free_kprobe_insn_page);
 		}
 		return 1;
 	}