x86: tracehook: TIF_NOTIFY_RESUME

This adds TIF_NOTIFY_RESUME support for x86, both 64-bit and 32-bit.
When set, we call tracehook_notify_resume() on the way to user mode.

Signed-off-by: Roland McGrath <roland@redhat.com>

2 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 22aae1683c14..4445d26efd47 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -663,5 +663,10 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
         if (thread_info_flags & _TIF_SIGPENDING)
                 do_signal(regs);
 
+        if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+                clear_thread_flag(TIF_NOTIFY_RESUME);
+                tracehook_notify_resume(regs);
+        }
+
         clear_thread_flag(TIF_IRET);
 }
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index cb7cf0216ab7..d01e3f6ef26d 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -523,6 +523,11 @@ void do_notify_resume(struct pt_regs *regs, void *unused,
         /* deal with pending signal delivery */
         if (thread_info_flags & _TIF_SIGPENDING)
                 do_signal(regs);
+
+        if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+                clear_thread_flag(TIF_NOTIFY_RESUME);
+                tracehook_notify_resume(regs);
+        }
 }
 
 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)