[PATCH] use ptrace_get_task_struct in various places

The ptrace_get_task_struct() helper that I added as part of the ptrace
consolidation is useful in variety of places that currently opencode it.
Switch them to the common helpers.

Add a ptrace_traceme() helper that needs to be explicitly called, and simplify
the ptrace_get_task_struct() interface.  We don't need the request argument
now, and we return the task_struct directly, using ERR_PTR() for error
returns.  It's a bit more code in the callers, but we have two sane routines
that do one thing well now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 19 deletions

diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c
index bbd37536d14e..9969d212e94d 100644
--- a/arch/alpha/kernel/ptrace.c
+++ b/arch/alpha/kernel/ptrace.c
@@ -265,30 +265,16 @@ do_sys_ptrace(long request, long pid, long addr, long data,
         lock_kernel();
         DBG(DBG_MEM, ("request=%ld pid=%ld addr=0x%lx data=0x%lx\n",
                       request, pid, addr, data));
-        ret = -EPERM;
         if (request == PTRACE_TRACEME) {
-                /* are we already being traced? */
-                if (current->ptrace & PT_PTRACED)
-                        goto out_notsk;
-                ret = security_ptrace(current->parent, current);
-                if (ret)
-                        goto out_notsk;
-                /* set the ptrace bit in the process ptrace flags. */
-                current->ptrace |= PT_PTRACED;
-                ret = 0;
+                ret = ptrace_traceme();
                 goto out_notsk;
         }
-        if (pid == 1)           /* you may not mess with init */
-                goto out_notsk;
 
-        ret = -ESRCH;
-        read_lock(&tasklist_lock);
-        child = find_task_by_pid(pid);
-        if (child)
-                get_task_struct(child);
-        read_unlock(&tasklist_lock);
-        if (!child)
+        child = ptrace_get_task_struct(pid);
+        if (IS_ERR(child)) {
+                ret = PTR_ERR(child);
                 goto out_notsk;
+        }
 
         if (request == PTRACE_ATTACH) {
                 ret = ptrace_attach(child);