s390: split TIF bits into CIF, PIF and TIF bits

The oi and ni instructions used in entry[64].S to set and clear bits
in the thread-flags are not guaranteed to be atomic in regard to other
CPUs. Split the TIF bits into CPU, pt_regs and thread-info specific
bits. Updates on the TIF bits are done with atomic instructions,
updates on CPU and pt_regs bits are done with non-atomic instructions.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index dd145321d215..93b9ca42e5c0 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -64,7 +64,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 void arch_cpu_idle(void)
 {
 	local_mcck_disable();
-	if (test_thread_flag(TIF_MCCK_PENDING)) {
+	if (test_cpu_flag(CIF_MCCK_PENDING)) {
 		local_mcck_enable();
 		local_irq_enable();
 		return;
@@ -76,7 +76,7 @@ void arch_cpu_idle(void)
 
 void arch_cpu_idle_exit(void)
 {
-	if (test_thread_flag(TIF_MCCK_PENDING))
+	if (test_cpu_flag(CIF_MCCK_PENDING))
 		s390_handle_mcck();
 }
 
@@ -123,7 +123,6 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
 	memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
 	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
 	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
-	clear_tsk_thread_flag(p, TIF_PER_TRAP);
 	/* Initialize per thread user and system timer values */
 	ti = task_thread_info(p);
 	ti->user_timer = 0;
@@ -152,6 +151,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
 	}
 	frame->childregs = *current_pt_regs();
 	frame->childregs.gprs[2] = 0;	/* child returns 0 on fork. */
+	frame->childregs.flags = 0;
 	if (new_stackp)
 		frame->childregs.gprs[15] = new_stackp;