kernel/fork.c: check error and return early

Thus reducing one indentation level while maintaining the same rationale.

Link: http://lkml.kernel.org/r/20171117002929.5155-1-marcos.souza.org@gmail.com
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/fork.c b/kernel/fork.c
index 5c372c954f3b9213fe3d2e22c4fa9816b788afa3..0d62524c66600310c3717d2c7f86a8e253b06d56 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2062,6 +2062,8 @@ long _do_fork(unsigned long clone_flags,
              int __user *child_tidptr,
              unsigned long tls)
 {
+       struct completion vfork;
+       struct pid *pid;
        struct task_struct *p;
        int trace = 0;
        long nr;
@@ -2087,43 +2089,40 @@ long _do_fork(unsigned long clone_flags,
        p = copy_process(clone_flags, stack_start, stack_size,
                         child_tidptr, NULL, trace, tls, NUMA_NO_NODE);
        add_latent_entropy();
+
+       if (IS_ERR(p))
+               return PTR_ERR(p);
+
        /*
         * Do this prior waking up the new thread - the thread pointer
         * might get invalid after that point, if the thread exits quickly.
         */
-       if (!IS_ERR(p)) {
-               struct completion vfork;
-               struct pid *pid;
-
-               trace_sched_process_fork(current, p);
+       trace_sched_process_fork(current, p);
 
-               pid = get_task_pid(p, PIDTYPE_PID);
-               nr = pid_vnr(pid);
+       pid = get_task_pid(p, PIDTYPE_PID);
+       nr = pid_vnr(pid);
 
-               if (clone_flags & CLONE_PARENT_SETTID)
-                       put_user(nr, parent_tidptr);
-
-               if (clone_flags & CLONE_VFORK) {
-                       p->vfork_done = &vfork;
-                       init_completion(&vfork);
-                       get_task_struct(p);
-               }
+       if (clone_flags & CLONE_PARENT_SETTID)
+               put_user(nr, parent_tidptr);
 
-               wake_up_new_task(p);
+       if (clone_flags & CLONE_VFORK) {
+               p->vfork_done = &vfork;
+               init_completion(&vfork);
+               get_task_struct(p);
+       }
 
-               /* forking complete and child started to run, tell ptracer */
-               if (unlikely(trace))
-                       ptrace_event_pid(trace, pid);
+       wake_up_new_task(p);
 
-               if (clone_flags & CLONE_VFORK) {
-                       if (!wait_for_vfork_done(p, &vfork))
-                               ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
-               }
+       /* forking complete and child started to run, tell ptracer */
+       if (unlikely(trace))
+               ptrace_event_pid(trace, pid);
 
-               put_pid(pid);
-       } else {
-               nr = PTR_ERR(p);
+       if (clone_flags & CLONE_VFORK) {
+               if (!wait_for_vfork_done(p, &vfork))
+                       ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
        }
+
+       put_pid(pid);
        return nr;
 }