[S390] fix loading of PER control registers for utrace.

If the current task enables / disables PER tracing for itself the
PER control registers need to be loaded in FixPerRegisters.

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

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 13815d3..7cf4642 100644 (file)
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -65,6 +65,7 @@ FixPerRegisters(struct task_struct *task)
 {
        struct pt_regs *regs;
        per_struct *per_info;
+       per_cr_words cr_words;
 
        regs = task_pt_regs(task);
        per_info = (per_struct *) &task->thread.per_info;
@@ -98,6 +99,13 @@ FixPerRegisters(struct task_struct *task)
                per_info->control_regs.bits.storage_alt_space_ctl = 1;
        else
                per_info->control_regs.bits.storage_alt_space_ctl = 0;
+
+       if (task == current) {
+               __ctl_store(cr_words, 9, 11);
+               if (memcmp(&cr_words, &per_info->control_regs.words,
+                          sizeof(cr_words)) != 0)
+                       __ctl_load(per_info->control_regs.words, 9, 11);
+       }
 }
 
 void user_enable_single_step(struct task_struct *task)