[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, 11 insertions, 33 deletions

diff --git a/arch/x86_64/ia32/ptrace32.c b/arch/x86_64/ia32/ptrace32.c
index 2a925e2af390..5f4cdfa56901 100644
--- a/arch/x86_64/ia32/ptrace32.c
+++ b/arch/x86_64/ia32/ptrace32.c
@@ -196,36 +196,6 @@ static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 
 #undef R32
 
-static struct task_struct *find_target(int request, int pid, int *err)
-{ 
-        struct task_struct *child;
-
-        *err = -EPERM; 
-        if (pid == 1)
-                return NULL; 
-
-        *err = -ESRCH;
-        read_lock(&tasklist_lock);
-        child = find_task_by_pid(pid);
-        if (child)
-                get_task_struct(child);
-        read_unlock(&tasklist_lock);
-        if (child) { 
-                *err = -EPERM;
-                if (child->pid == 1) 
-                        goto out;
-                *err = ptrace_check_attach(child, request == PTRACE_KILL); 
-                if (*err < 0) 
-                        goto out;
-                return child; 
-        } 
- out:
-        if (child)
-        put_task_struct(child);
-        return NULL; 
-        
-} 
-
 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 {
         struct task_struct *child;
@@ -254,9 +224,16 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
                 break;
         } 
 
-        child = find_target(request, pid, &ret);
-        if (!child)
-                return ret;
+        if (request == PTRACE_TRACEME)
+                return ptrace_traceme();
+
+        child = ptrace_get_task_struct(pid);
+        if (IS_ERR(child))
+                return PTR_ERR(child);
+
+        ret = ptrace_check_attach(child, request == PTRACE_KILL);
+        if (ret < 0)
+                goto out;
 
         childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs)); 
 
@@ -373,6 +350,7 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
                 break;
         }
 
+ out:
         put_task_struct(child);
         return ret;
 }