2 files changed, 38 insertions, 16 deletions

diff --git a/include/linux/capability.h b/include/linux/capability.h
index 02673846d205..9d1fe30b6f6c 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -503,8 +503,19 @@ extern const kernel_cap_t __cap_init_eff_set;
 
 kernel_cap_t cap_set_effective(const kernel_cap_t pE_new);
 
-int capable(int cap);
-int __capable(struct task_struct *t, int cap);
+/**
+ * has_capability - Determine if a task has a superior capability available
+ * @t: The task in question
+ * @cap: The capability to be tested for
+ *
+ * Return true if the specified task has the given superior capability
+ * currently in effect, false if not.
+ *
+ * Note that this does not set PF_SUPERPRIV on the task.
+ */
+#define has_capability(t, cap) (security_capable((t), (cap)) == 0)
+
+extern int capable(int cap);
 
 #endif /* __KERNEL__ */
 
diff --git a/include/linux/security.h b/include/linux/security.h
index fd96e7f8a6f9..2ee5ecfb2393 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -46,8 +46,8 @@ struct audit_krule;
  */
 extern int cap_capable(struct task_struct *tsk, int cap);
 extern int cap_settime(struct timespec *ts, struct timezone *tz);
-extern int cap_ptrace(struct task_struct *parent, struct task_struct *child,
-                      unsigned int mode);
+extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode);
+extern int cap_ptrace_traceme(struct task_struct *parent);
 extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted);
 extern int cap_capset_check(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted);
 extern void cap_capset_set(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted);
@@ -1157,17 +1157,24 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *      @alter contains the flag indicating whether changes are to be made.
  *      Return 0 if permission is granted.
  *
- * @ptrace:
- *      Check permission before allowing the @parent process to trace the
+ * @ptrace_may_access:
+ *      Check permission before allowing the current process to trace the
  *      @child process.
  *      Security modules may also want to perform a process tracing check
  *      during an execve in the set_security or apply_creds hooks of
  *      binprm_security_ops if the process is being traced and its security
  *      attributes would be changed by the execve.
- *      @parent contains the task_struct structure for parent process.
- *      @child contains the task_struct structure for child process.
+ *      @child contains the task_struct structure for the target process.
  *      @mode contains the PTRACE_MODE flags indicating the form of access.
  *      Return 0 if permission is granted.
+ * @ptrace_traceme:
+ *      Check that the @parent process has sufficient permission to trace the
+ *      current process before allowing the current process to present itself
+ *      to the @parent process for tracing.
+ *      The parent process will still have to undergo the ptrace_may_access
+ *      checks before it is allowed to trace this one.
+ *      @parent contains the task_struct structure for debugger process.
+ *      Return 0 if permission is granted.
  * @capget:
  *      Get the @effective, @inheritable, and @permitted capability sets for
  *      the @target process.  The hook may also perform permission checking to
@@ -1287,8 +1294,8 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
 struct security_operations {
         char name[SECURITY_NAME_MAX + 1];
 
-        int (*ptrace) (struct task_struct *parent, struct task_struct *child,
-                       unsigned int mode);
+        int (*ptrace_may_access) (struct task_struct *child, unsigned int mode);
+        int (*ptrace_traceme) (struct task_struct *parent);
         int (*capget) (struct task_struct *target,
                        kernel_cap_t *effective,
                        kernel_cap_t *inheritable, kernel_cap_t *permitted);
@@ -1560,8 +1567,8 @@ extern struct dentry *securityfs_create_dir(const char *name, struct dentry *par
 extern void securityfs_remove(struct dentry *dentry);
 
 /* Security operations */
-int security_ptrace(struct task_struct *parent, struct task_struct *child,
-                    unsigned int mode);
+int security_ptrace_may_access(struct task_struct *child, unsigned int mode);
+int security_ptrace_traceme(struct task_struct *parent);
 int security_capget(struct task_struct *target,
                     kernel_cap_t *effective,
                     kernel_cap_t *inheritable,
@@ -1742,11 +1749,15 @@ static inline int security_init(void)
         return 0;
 }
 
-static inline int security_ptrace(struct task_struct *parent,
-                                  struct task_struct *child,
-                                  unsigned int mode)
+static inline int security_ptrace_may_access(struct task_struct *child,
+                                             unsigned int mode)
+{
+        return cap_ptrace_may_access(child, mode);
+}
+
+static inline int security_ptrace_traceme(struct task_struct *child)
 {
-        return cap_ptrace(parent, child, mode);
+        return cap_ptrace_traceme(parent);
 }
 
 static inline int security_capget(struct task_struct *target,