Use struct pid parameter in copy_process()

Modify copy_process() to take a struct pid * parameter instead of a pid_t.
This simplifies the code a bit and also avoids having to call find_pid() to
convert the pid_t to a struct pid.

Changelog:
	- Fixed Badari Pulavarty's comments and passed in &init_struct_pid
	  from fork_idle().
	- Fixed Eric Biederman's comments and simplified this patch and
	  used a new patch to remove the likely(pid) check.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: <containers@lists.osdl.org>
Acked-by: Eric W. Biederman <ebiederm@xmission.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 6031800..cf13c44 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -956,7 +956,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                                        unsigned long stack_size,
                                        int __user *parent_tidptr,
                                        int __user *child_tidptr,
-                                       int pid)
+                                       struct pid *pid)
 {
        int retval;
        struct task_struct *p = NULL;
@@ -1023,7 +1023,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        p->did_exec = 0;
        delayacct_tsk_init(p);  /* Must remain after dup_task_struct() */
        copy_flags(clone_flags, p);
-       p->pid = pid;
+       p->pid = pid_nr(pid);
        retval = -EFAULT;
        if (clone_flags & CLONE_PARENT_SETTID)
                if (put_user(p->pid, parent_tidptr))
@@ -1261,7 +1261,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                        list_add_tail_rcu(&p->tasks, &init_task.tasks);
                        __get_cpu_var(process_counts)++;
                }
-               attach_pid(p, PIDTYPE_PID, find_pid(p->pid));
+               attach_pid(p, PIDTYPE_PID, pid);
                nr_threads++;
        }
 
@@ -1325,7 +1325,8 @@ struct task_struct * __cpuinit fork_idle(int cpu)
        struct task_struct *task;
        struct pt_regs regs;
 
-       task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL, 0);
+       task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL,
+                               &init_struct_pid);
        if (!IS_ERR(task))
                init_idle(task, cpu);
 
@@ -1375,7 +1376,7 @@ long do_fork(unsigned long clone_flags,
                        clone_flags |= CLONE_PTRACE;
        }
 
-       p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, nr);
+       p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, pid);
        /*
         * Do this prior waking up the new thread - the thread pointer
         * might get invalid after that point, if the thread exits quickly.