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>

1 files changed, 25 insertions, 26 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 5c372c954f3b..0d62524c6660 100644
--- 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;
 }