x86, bts: add fork and exit handling
Impact: introduce new ptrace facility
Add arch_ptrace_untrace() function that is called when the tracer
detaches (either voluntarily or when the tracing task dies);
ptrace_disable() is only called on a voluntary detach.
Add ptrace_fork() and arch_ptrace_fork(). They are called when a
traced task is forked.
Clear DS and BTS related fields on fork.
Release DS resources and reclaim memory in ptrace_untrace(). This
releases resources already when the tracing task dies. We used to do
that when the traced task dies.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 22641d5..98b93ca 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -94,6 +94,7 @@
extern void __ptrace_link(struct task_struct *child,
struct task_struct *new_parent);
extern void __ptrace_unlink(struct task_struct *child);
+extern void ptrace_fork(struct task_struct *task, unsigned long clone_flags);
#define PTRACE_MODE_READ 1
#define PTRACE_MODE_ATTACH 2
/* Returns 0 on success, -errno on denial. */
@@ -313,6 +314,27 @@
#define arch_ptrace_stop(code, info) do { } while (0)
#endif
+#ifndef arch_ptrace_untrace
+/*
+ * Do machine-specific work before untracing child.
+ *
+ * This is called for a normal detach as well as from ptrace_exit()
+ * when the tracing task dies.
+ *
+ * Called with write_lock(&tasklist_lock) held.
+ */
+#define arch_ptrace_untrace(task) do { } while (0)
+#endif
+
+#ifndef arch_ptrace_fork
+/*
+ * Do machine-specific work to initialize a new task.
+ *
+ * This is called from copy_process().
+ */
+#define arch_ptrace_fork(child, clone_flags) do { } while (0)
+#endif
+
extern int task_current_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc);