1 files changed, 28 insertions, 8 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 35d674c1f12e..e89acea22ecf 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -615,19 +615,39 @@ static void free_used_maps(struct bpf_prog_aux *aux)
 	kfree(aux->used_maps);
 }
 
+int __bpf_prog_charge(struct user_struct *user, u32 pages)
+{
+	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+	unsigned long user_bufs;
+
+	if (user) {
+		user_bufs = atomic_long_add_return(pages, &user->locked_vm);
+		if (user_bufs > memlock_limit) {
+			atomic_long_sub(pages, &user->locked_vm);
+			return -EPERM;
+		}
+	}
+
+	return 0;
+}
+
+void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
+{
+	if (user)
+		atomic_long_sub(pages, &user->locked_vm);
+}
+
 static int bpf_prog_charge_memlock(struct bpf_prog *prog)
 {
 	struct user_struct *user = get_current_user();
-	unsigned long memlock_limit;
-
-	memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+	int ret;
 
-	atomic_long_add(prog->pages, &user->locked_vm);
-	if (atomic_long_read(&user->locked_vm) > memlock_limit) {
-		atomic_long_sub(prog->pages, &user->locked_vm);
+	ret = __bpf_prog_charge(user, prog->pages);
+	if (ret) {
 		free_uid(user);
-		return -EPERM;
+		return ret;
 	}
+
 	prog->aux->user = user;
 	return 0;
 }
@@ -636,7 +656,7 @@ static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
 {
 	struct user_struct *user = prog->aux->user;
 
-	atomic_long_sub(prog->pages, &user->locked_vm);
+	__bpf_prog_uncharge(user, prog->pages);
 	free_uid(user);
 }