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/kernel/fork.c b/kernel/fork.c
index 7b93da7..65ce60a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1096,6 +1096,8 @@
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif
+ if (unlikely(ptrace_reparented(current)))
+ ptrace_fork(p, clone_flags);
/* Perform scheduler related setup. Assign this task to a CPU. */
sched_fork(p, clone_flags);
