[S390] clear TIF_SINGLE_STEP for new process.

Clear the TIF_SINGLE_STEP bit in copy_thread. The new process did not get
a PER event of its own. It is wrong deliver a SIGTRAP that was meant for
the parent process.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 5417eb57271a..b98fe8e6e507 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -217,6 +217,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
         p->thread.mm_segment = get_fs();
         /* Don't copy debug registers */
         memset(&p->thread.per_info, 0, sizeof(p->thread.per_info));
+        clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
         /* Initialize per thread user and system timer values */
         ti = task_thread_info(p);
         ti->user_timer = 0;