2.6.25-rc7

 kernel

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index c25db86..fdb34e8 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -20,6 +20,7 @@
 #include <linux/signal.h>
 #include <linux/audit.h>
 #include <linux/pid_namespace.h>
+#include <linux/syscalls.h>
 
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
@@ -51,9 +52,9 @@ void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
 void ptrace_untrace(struct task_struct *child)
 {
    spin_lock(&child->sighand->siglock);
-   if (child->state == TASK_TRACED) {
+   if (task_is_traced(child)) {
       if (child->signal->flags & SIGNAL_STOP_STOPPED) {
-         child->state = TASK_STOPPED;
+         __set_task_state(child, TASK_STOPPED);
       } else {
          signal_wake_up(child, 1);
       }
@@ -79,7 +80,7 @@ void __ptrace_unlink(struct task_struct *child)
       add_parent(child);
    }
 
-   if (child->state == TASK_TRACED)
+   if (task_is_traced(child))
       ptrace_untrace(child);
 }
 
@@ -98,23 +99,23 @@ int ptrace_check_attach(struct task_struct *child, int kill)
     * be changed by us so it's not changing right after this.
     */
    read_lock(&tasklist_lock);
-   if ((child->ptrace & PT_PTRACED) && child->parent == current &&
-       (!(child->ptrace & PT_ATTACHED) || child->real_parent != current)
-       && child->signal != NULL) {
+   if ((child->ptrace & PT_PTRACED) && child->parent == current) {
       ret = 0;
+      /*
+       * child->sighand can't be NULL, release_task()
+       * does ptrace_unlink() before __exit_signal().
+       */
       spin_lock_irq(&child->sighand->siglock);
-      if (child->state == TASK_STOPPED) {
+      if (task_is_stopped(child))
          child->state = TASK_TRACED;
-      } else if (child->state != TASK_TRACED && !kill) {
+      else if (!task_is_traced(child) && !kill)
          ret = -ESRCH;
-      }
       spin_unlock_irq(&child->sighand->siglock);
    }
    read_unlock(&tasklist_lock);
 
-   if (!ret && !kill) {
+   if (!ret && !kill)
       wait_task_inactive(child);
-   }
 
    /* All systems go.. */
    return ret;
@@ -201,8 +202,7 @@ repeat:
       goto bad;
 
    /* Go */
-   task->ptrace |= PT_PTRACED | ((task->real_parent != current)
-                  ? PT_ATTACHED : 0);
+   task->ptrace |= PT_PTRACED;
    if (capable(CAP_SYS_PTRACE))
       task->ptrace |= PT_PTRACE_CAP;
 
@@ -366,12 +366,73 @@ static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data)
    return error;
 }
 
+
+#ifdef PTRACE_SINGLESTEP
+#define is_singlestep(request)      ((request) == PTRACE_SINGLESTEP)
+#else
+#define is_singlestep(request)      0
+#endif
+
+#ifdef PTRACE_SINGLEBLOCK
+#define is_singleblock(request)      ((request) == PTRACE_SINGLEBLOCK)
+#else
+#define is_singleblock(request)      0
+#endif
+
+#ifdef PTRACE_SYSEMU
+#define is_sysemu_singlestep(request)   ((request) == PTRACE_SYSEMU_SINGLESTEP)
+#else
+#define is_sysemu_singlestep(request)   0
+#endif
+
+static int ptrace_resume(struct task_struct *child, long request, long data)
+{
+   if (!valid_signal(data))
+      return -EIO;
+
+   if (request == PTRACE_SYSCALL)
+      set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+   else
+      clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+
+#ifdef TIF_SYSCALL_EMU
+   if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
+      set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+   else
+      clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+#endif
+
+   if (is_singleblock(request)) {
+      if (unlikely(!arch_has_block_step()))
+         return -EIO;
+      user_enable_block_step(child);
+   } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
+      if (unlikely(!arch_has_single_step()))
+         return -EIO;
+      user_enable_single_step(child);
+   }
+   else
+      user_disable_single_step(child);
+
+   child->exit_code = data;
+   wake_up_process(child);
+
+   return 0;
+}
+
 int ptrace_request(struct task_struct *child, long request,
          long addr, long data)
 {
    int ret = -EIO;
 
    switch (request) {
+   case PTRACE_PEEKTEXT:
+   case PTRACE_PEEKDATA:
+      return generic_ptrace_peekdata(child, addr, data);
+   case PTRACE_POKETEXT:
+   case PTRACE_POKEDATA:
+      return generic_ptrace_pokedata(child, addr, data);
+
 #ifdef PTRACE_OLDSETOPTIONS
    case PTRACE_OLDSETOPTIONS:
 #endif
@@ -390,6 +451,26 @@ int ptrace_request(struct task_struct *child, long request,
    case PTRACE_DETACH:    /* detach a process that was attached. */
       ret = ptrace_detach(child, data);
       break;
+
+#ifdef PTRACE_SINGLESTEP
+   case PTRACE_SINGLESTEP:
+#endif
+#ifdef PTRACE_SINGLEBLOCK
+   case PTRACE_SINGLEBLOCK:
+#endif
+#ifdef PTRACE_SYSEMU
+   case PTRACE_SYSEMU:
+   case PTRACE_SYSEMU_SINGLESTEP:
+#endif
+   case PTRACE_SYSCALL:
+   case PTRACE_CONT:
+      return ptrace_resume(child, request, data);
+
+   case PTRACE_KILL:
+      if (child->exit_state)   /* already dead */
+         return 0;
+      return ptrace_resume(child, request, SIGKILL);
+
    default:
       break;
    }
@@ -470,6 +551,8 @@ asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
    lock_kernel();
    if (request == PTRACE_TRACEME) {
       ret = ptrace_traceme();
+      if (!ret)
+         arch_ptrace_attach(current);
       goto out;
    }
 
@@ -524,3 +607,87 @@ int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data)
    copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
    return (copied == sizeof(data)) ? 0 : -EIO;
 }
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+
+int compat_ptrace_request(struct task_struct *child, compat_long_t request,
+           compat_ulong_t addr, compat_ulong_t data)
+{
+   compat_ulong_t __user *datap = compat_ptr(data);
+   compat_ulong_t word;
+   int ret;
+
+   switch (request) {
+   case PTRACE_PEEKTEXT:
+   case PTRACE_PEEKDATA:
+      ret = access_process_vm(child, addr, &word, sizeof(word), 0);
+      if (ret != sizeof(word))
+         ret = -EIO;
+      else
+         ret = put_user(word, datap);
+      break;
+
+   case PTRACE_POKETEXT:
+   case PTRACE_POKEDATA:
+      ret = access_process_vm(child, addr, &data, sizeof(data), 1);
+      ret = (ret != sizeof(data) ? -EIO : 0);
+      break;
+
+   case PTRACE_GETEVENTMSG:
+      ret = put_user((compat_ulong_t) child->ptrace_message, datap);
+      break;
+
+   default:
+      ret = ptrace_request(child, request, addr, data);
+   }
+
+   return ret;
+}
+
+#ifdef __ARCH_WANT_COMPAT_SYS_PTRACE
+asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
+              compat_long_t addr, compat_long_t data)
+{
+   struct task_struct *child;
+   long ret;
+
+   /*
+    * This lock_kernel fixes a subtle race with suid exec
+    */
+   lock_kernel();
+   if (request == PTRACE_TRACEME) {
+      ret = ptrace_traceme();
+      goto out;
+   }
+
+   child = ptrace_get_task_struct(pid);
+   if (IS_ERR(child)) {
+      ret = PTR_ERR(child);
+      goto out;
+   }
+
+   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;
+   }
+
+   ret = ptrace_check_attach(child, request == PTRACE_KILL);
+   if (!ret)
+      ret = compat_arch_ptrace(child, request, addr, data);
+
+ out_put_task_struct:
+   put_task_struct(child);
+ out:
+   unlock_kernel();
+   return ret;
+}
+#endif /* __ARCH_WANT_COMPAT_SYS_PTRACE */
+
+#endif   /* CONFIG_COMPAT */