net: bpfilter: restart bpfilter_umh when error occurred

[platform/kernel/linux-starfive.git] / net / bpfilter / bpfilter_kern.c

diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
index 7acfc83..c0fcde9 100644 (file)
--- a/net/bpfilter/bpfilter_kern.c
+++ b/net/bpfilter/bpfilter_kern.c
@@ -13,32 +13,27 @@
 extern char bpfilter_umh_start;
 extern char bpfilter_umh_end;
 
-static struct umh_info info;
 /* since ip_getsockopt() can run in parallel, serialize access to umh */
 static DEFINE_MUTEX(bpfilter_lock);
 
-static void shutdown_umh(struct umh_info *info)
+static void shutdown_umh(void)
 {
        struct task_struct *tsk;
 
-       if (!info->pid)
+       if (bpfilter_ops.stop)
                return;
-       tsk = get_pid_task(find_vpid(info->pid), PIDTYPE_PID);
+
+       tsk = get_pid_task(find_vpid(bpfilter_ops.info.pid), PIDTYPE_PID);
        if (tsk) {
                force_sig(SIGKILL, tsk);
                put_task_struct(tsk);
        }
-       fput(info->pipe_to_umh);
-       fput(info->pipe_from_umh);
-       info->pid = 0;
 }
 
 static void __stop_umh(void)
 {
-       if (IS_ENABLED(CONFIG_INET)) {
-               bpfilter_process_sockopt = NULL;
-               shutdown_umh(&info);
-       }
+       if (IS_ENABLED(CONFIG_INET))
+               shutdown_umh();
 }
 
 static void stop_umh(void)
@@ -64,9 +59,10 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname,
        req.addr = (long __force __user)optval;
        req.len = optlen;
        mutex_lock(&bpfilter_lock);
-       if (!info.pid)
+       if (!bpfilter_ops.info.pid)
                goto out;
-       n = __kernel_write(info.pipe_to_umh, &req, sizeof(req), &pos);
+       n = __kernel_write(bpfilter_ops.info.pipe_to_umh, &req, sizeof(req),
+                          &pos);
        if (n != sizeof(req)) {
                pr_err("write fail %zd\n", n);
                __stop_umh();
@@ -74,7 +70,8 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname,
                goto out;
        }
        pos = 0;
-       n = kernel_read(info.pipe_from_umh, &reply, sizeof(reply), &pos);
+       n = kernel_read(bpfilter_ops.info.pipe_from_umh, &reply, sizeof(reply),
+                       &pos);
        if (n != sizeof(reply)) {
                pr_err("read fail %zd\n", n);
                __stop_umh();
@@ -87,32 +84,49 @@ out:
        return ret;
 }
 
-static int __init load_umh(void)
+static int start_umh(void)
 {
        int err;
 
        /* fork usermode process */
-       info.cmdline = "bpfilter_umh";
        err = fork_usermode_blob(&bpfilter_umh_start,
                                 &bpfilter_umh_end - &bpfilter_umh_start,
-                                &info);
+                                &bpfilter_ops.info);
        if (err)
                return err;
-       pr_info("Loaded bpfilter_umh pid %d\n", info.pid);
+       bpfilter_ops.stop = false;
+       pr_info("Loaded bpfilter_umh pid %d\n", bpfilter_ops.info.pid);
 
        /* health check that usermode process started correctly */
        if (__bpfilter_process_sockopt(NULL, 0, NULL, 0, 0) != 0) {
                stop_umh();
                return -EFAULT;
        }
-       if (IS_ENABLED(CONFIG_INET))
-               bpfilter_process_sockopt = &__bpfilter_process_sockopt;
 
        return 0;
 }
 
+static int __init load_umh(void)
+{
+       int err;
+
+       if (!bpfilter_ops.stop)
+               return -EFAULT;
+       err = start_umh();
+       if (!err && IS_ENABLED(CONFIG_INET)) {
+               bpfilter_ops.sockopt = &__bpfilter_process_sockopt;
+               bpfilter_ops.start = &start_umh;
+       }
+
+       return err;
+}
+
 static void __exit fini_umh(void)
 {
+       if (IS_ENABLED(CONFIG_INET)) {
+               bpfilter_ops.start = NULL;
+               bpfilter_ops.sockopt = NULL;
+       }
        stop_umh();
 }
 module_init(load_umh);