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/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 98d271e..da91701 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -1017,3 +1017,14 @@
update_debugctlmsr(next->thread.debugctlmsr);
}
+
+void ds_copy_thread(struct task_struct *tsk, struct task_struct *father)
+{
+ clear_tsk_thread_flag(tsk, TIF_DS_AREA_MSR);
+ tsk->thread.ds_ctx = NULL;
+}
+
+void ds_exit_thread(struct task_struct *tsk)
+{
+ WARN_ON(tsk->thread.ds_ctx);
+}