[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>

2 files changed, 6 insertions, 19 deletions

diff --git a/arch/ia64/ia32/sys_ia32.c b/arch/ia64/ia32/sys_ia32.c
index dc282710421a..9f8e8d558873 100644
--- a/arch/ia64/ia32/sys_ia32.c
+++ b/arch/ia64/ia32/sys_ia32.c
@@ -1761,21 +1761,15 @@ sys32_ptrace (int request, pid_t pid, unsigned int addr, unsigned int data)
 
         lock_kernel();
         if (request == PTRACE_TRACEME) {
-                ret = sys_ptrace(request, pid, addr, data);
+                ret = ptrace_traceme();
                 goto out;
         }
 
-        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;
-        ret = -EPERM;
-        if (pid == 1)           /* no messing around with init! */
-                goto out_tsk;
+        }
 
         if (request == PTRACE_ATTACH) {
                 ret = sys_ptrace(request, pid, addr, data);
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index 4b19d0410632..8d88eeea02d1 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -1422,14 +1422,7 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
         lock_kernel();
         ret = -EPERM;
         if (request == PTRACE_TRACEME) {
-                /* are we already being traced? */
-                if (current->ptrace & PT_PTRACED)
-                        goto out;
-                ret = security_ptrace(current->parent, current);
-                if (ret)
-                        goto out;
-                current->ptrace |= PT_PTRACED;
-                ret = 0;
+                ret = ptrace_traceme();
                 goto out;
         }