[PATCH] consolidate sys_ptrace()

The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.

Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations.  For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-By: David Howells <dhowells@redhat.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 41 deletions

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 568ea335d616..3d2abd95c7ae 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -248,46 +248,10 @@ void ptrace_disable(struct task_struct *child)
         clear_single_step(child);
 }
 
-long sys_ptrace(long request, long pid, long addr, long data)
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
-        struct task_struct *child;
         int ret = -EPERM;
 
-        lock_kernel();
-        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;
-                /* set the ptrace bit in the process flags. */
-                current->ptrace |= PT_PTRACED;
-                ret = 0;
-                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)
-                goto out;
-
-        ret = -EPERM;
-        if (pid == 1)           /* you may not mess with init */
-                goto out_tsk;
-
-        if (request == PTRACE_ATTACH) {
-                ret = ptrace_attach(child);
-                goto out_tsk;
-        }
-
-        ret = ptrace_check_attach(child, request == PTRACE_KILL);
-        if (ret < 0)
-                goto out_tsk;
-
         switch (request) {
         /* when I and D space are separate, these will need to be fixed. */
         case PTRACE_PEEKTEXT: /* read word at location addr. */
@@ -540,10 +504,7 @@ long sys_ptrace(long request, long pid, long addr, long data)
                 ret = ptrace_request(child, request, addr, data);
                 break;
         }
-out_tsk:
-        put_task_struct(child);
-out:
-        unlock_kernel();
+
         return ret;
 }