[S390] duplicate SIGTRAP on signal delivery.

The code in do_signal sets the TIF_SINGLE_STEP bit and calls
tracehook_signal_handler after the signal frame has been set up.
This causes two SIGTRAP signals to be delivered to the tracer.
Stop setting the TIF_SINGLE_STEP bit in do_signal to get the
correct number of SIGTRAPs.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 1 insertions, 9 deletions

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 6b4fef877f9d..1675c48b9145 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -500,18 +500,10 @@ void do_signal(struct pt_regs *regs)
                                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 
                         /*
-                         * If we would have taken a single-step trap
-                         * for a normal instruction, act like we took
-                         * one for the handler setup.
-                         */
-                        if (current->thread.per_info.single_step)
-                                set_thread_flag(TIF_SINGLE_STEP);
-
-                        /*
                          * Let tracing know that we've done the handler setup.
                          */
                         tracehook_signal_handler(signr, &info, &ka, regs,
-                                         test_thread_flag(TIF_SINGLE_STEP));
+                                        current->thread.per_info.single_step);
                 }
                 return;
         }