2.6.24

 kernel

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 3eca7a5..c25db86 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -19,6 +19,7 @@
 #include <linux/security.h>
 #include <linux/signal.h>
 #include <linux/audit.h>
+#include <linux/pid_namespace.h>
 
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
@@ -119,7 +120,7 @@ int ptrace_check_attach(struct task_struct *child, int kill)
    return ret;
 }
 
-static int may_attach(struct task_struct *task)
+int __ptrace_may_attach(struct task_struct *task)
 {
    /* May we inspect the given task?
     * This check is used both for attaching with ptrace
@@ -153,7 +154,7 @@ int ptrace_may_attach(struct task_struct *task)
 {
    int err;
    task_lock(task);
-   err = may_attach(task);
+   err = __ptrace_may_attach(task);
    task_unlock(task);
    return !err;
 }
@@ -168,7 +169,7 @@ int ptrace_attach(struct task_struct *task)
    retval = -EPERM;
    if (task->pid <= 1)
       goto out;
-   if (task->tgid == current->tgid)
+   if (same_thread_group(task, current))
       goto out;
 
 repeat:
@@ -195,7 +196,7 @@ repeat:
    /* the same process cannot be attached many times */
    if (task->ptrace & PT_PTRACED)
       goto bad;
-   retval = may_attach(task);
+   retval = __ptrace_may_attach(task);
    if (retval)
       goto bad;
 
@@ -386,6 +387,9 @@ int ptrace_request(struct task_struct *child, long request,
    case PTRACE_SETSIGINFO:
       ret = ptrace_setsiginfo(child, (siginfo_t __user *) data);
       break;
+   case PTRACE_DETACH:    /* detach a process that was attached. */
+      ret = ptrace_detach(child, data);
+      break;
    default:
       break;
    }
@@ -440,7 +444,7 @@ struct task_struct *ptrace_get_task_struct(pid_t pid)
       return ERR_PTR(-EPERM);
 
    read_lock(&tasklist_lock);
-   child = find_task_by_pid(pid);
+   child = find_task_by_vpid(pid);
    if (child)
       get_task_struct(child);
 
@@ -450,6 +454,10 @@ struct task_struct *ptrace_get_task_struct(pid_t pid)
    return child;
 }
 
+#ifndef arch_ptrace_attach
+#define arch_ptrace_attach(child)   do { } while (0)
+#endif
+
 #ifndef __ARCH_SYS_PTRACE
 asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
 {
@@ -473,6 +481,12 @@ asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
 
    if (request == PTRACE_ATTACH) {
       ret = ptrace_attach(child);
+      /*
+       * Some architectures need to do book-keeping after
+       * a ptrace attach.
+       */
+      if (!ret)
+         arch_ptrace_attach(child);
       goto out_put_task_struct;
    }