x86: user_regset user-copy helpers

This defines two new inlines in linux/regset.h, for use in arch_ptrace
implementations and the like.  These provide simplified wrappers for using
the user_regset interfaces to copy thread regset data into the caller's
user-space memory.  The inlines are trivial, but make the common uses in
places such as ptrace implementation much more concise, easier to read, and
less prone to code-copying errors.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/linux/regset.h b/include/linux/regset.h
index 761c931af975087408b3fa9c1786cab3fdc3b20c..8abee65562230fe05174d2ded6bc8ec50249348b 100644 (file)
--- a/include/linux/regset.h
+++ b/include/linux/regset.h
@@ -318,5 +318,51 @@ static inline int user_regset_copyin_ignore(unsigned int *pos,
        return 0;
 }
 
+/**
+ * copy_regset_to_user - fetch a thread's user_regset data into user memory
+ * @target:    thread to be examined
+ * @view:      &struct user_regset_view describing user thread machine state
+ * @setno:     index in @view->regsets
+ * @offset:    offset into the regset data, in bytes
+ * @size:      amount of data to copy, in bytes
+ * @data:      user-mode pointer to copy into
+ */
+static inline int copy_regset_to_user(struct task_struct *target,
+                                     const struct user_regset_view *view,
+                                     unsigned int setno,
+                                     unsigned int offset, unsigned int size,
+                                     void __user *data)
+{
+       const struct user_regset *regset = &view->regsets[setno];
+
+       if (!access_ok(VERIFY_WRITE, data, size))
+               return -EIO;
+
+       return regset->get(target, regset, offset, size, NULL, data);
+}
+
+/**
+ * copy_regset_from_user - store into thread's user_regset data from user memory
+ * @target:    thread to be examined
+ * @view:      &struct user_regset_view describing user thread machine state
+ * @setno:     index in @view->regsets
+ * @offset:    offset into the regset data, in bytes
+ * @size:      amount of data to copy, in bytes
+ * @data:      user-mode pointer to copy from
+ */
+static inline int copy_regset_from_user(struct task_struct *target,
+                                       const struct user_regset_view *view,
+                                       unsigned int setno,
+                                       unsigned int offset, unsigned int size,
+                                       const void __user *data)
+{
+       const struct user_regset *regset = &view->regsets[setno];
+
+       if (!access_ok(VERIFY_READ, data, size))
+               return -EIO;
+
+       return regset->set(target, regset, offset, size, NULL, data);
+}
+
 
 #endif /* <linux/regset.h> */