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-rw-r--r--include/linux/ptrace.h37
1 files changed, 33 insertions, 4 deletions
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 8f06c6fb22a..1febc541dda 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -155,7 +155,8 @@ int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data);
*
* This can only be called when arch_has_single_step() has returned nonzero.
* Set @task so that when it returns to user mode, it will trap after the
- * next single instruction executes.
+ * next single instruction executes. If arch_has_block_step() is defined,
+ * this must clear the effects of user_enable_block_step() too.
*/
static inline void user_enable_single_step(struct task_struct *task)
{
@@ -166,15 +167,43 @@ static inline void user_enable_single_step(struct task_struct *task)
* user_disable_single_step - cancel user-mode single-step
* @task: either current or a task stopped in %TASK_TRACED
*
- * Clear @task of the effects of user_enable_single_step(). This can
- * be called whether or not user_enable_single_step() was ever called
- * on @task, and even if arch_has_single_step() returned zero.
+ * Clear @task of the effects of user_enable_single_step() and
+ * user_enable_block_step(). This can be called whether or not either
+ * of those was ever called on @task, and even if arch_has_single_step()
+ * returned zero.
*/
static inline void user_disable_single_step(struct task_struct *task)
{
}
#endif /* arch_has_single_step */
+#ifndef arch_has_block_step
+/**
+ * arch_has_block_step - does this CPU support user-mode block-step?
+ *
+ * If this is defined, then there must be a function declaration or inline
+ * for user_enable_block_step(), and arch_has_single_step() must be defined
+ * too. arch_has_block_step() should evaluate to nonzero iff the machine
+ * supports step-until-branch for user mode. It can be a constant or it
+ * can test a CPU feature bit.
+ */
+#define arch_has_single_step() (0)
+
+/**
+ * user_enable_block_step - step until branch in user-mode task
+ * @task: either current or a task stopped in %TASK_TRACED
+ *
+ * This can only be called when arch_has_block_step() has returned nonzero,
+ * and will never be called when single-instruction stepping is being used.
+ * Set @task so that when it returns to user mode, it will trap after the
+ * next branch or trap taken.
+ */
+static inline void user_enable_block_step(struct task_struct *task)
+{
+ BUG(); /* This can never be called. */
+}
+#endif /* arch_has_block_step */
+
#endif
#endif