4 files changed, 21 insertions, 14 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index ef46f66bc0d6..f954b37740c0 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -231,12 +231,12 @@ sysc_work:
         jo      sysc_mcck_pending
         tm      __TI_flags+3(%r12),_TIF_NEED_RESCHED
         jo      sysc_reschedule
+        tm      __TI_flags+3(%r12),_TIF_PER_TRAP
+        jo      sysc_singlestep
         tm      __TI_flags+3(%r12),_TIF_SIGPENDING
         jo      sysc_sigpending
         tm      __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
         jo      sysc_notify_resume
-        tm      __TI_flags+3(%r12),_TIF_PER_TRAP
-        jo      sysc_singlestep
         j       sysc_return             # beware of critical section cleanup
 
 #
@@ -259,7 +259,6 @@ sysc_mcck_pending:
 # _TIF_SIGPENDING is set, call do_signal
 #
 sysc_sigpending:
-        ni      __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
         lr      %r2,%r11                # pass pointer to pt_regs
         l       %r1,BASED(.Ldo_signal)
         basr    %r14,%r1                # call do_signal
@@ -286,7 +285,7 @@ sysc_notify_resume:
 # _TIF_PER_TRAP is set, call do_per_trap
 #
 sysc_singlestep:
-        ni      __TI_flags+3(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP)
+        ni      __TI_flags+3(%r12),255-_TIF_PER_TRAP
         lr      %r2,%r11                # pass pointer to pt_regs
         l       %r1,BASED(.Ldo_per_trap)
         la      %r14,BASED(sysc_return)
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index e42842a3072b..7a2d22dda9ef 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -262,12 +262,12 @@ sysc_work:
         jo      sysc_mcck_pending
         tm      __TI_flags+7(%r12),_TIF_NEED_RESCHED
         jo      sysc_reschedule
+        tm      __TI_flags+7(%r12),_TIF_PER_TRAP
+        jo      sysc_singlestep
         tm      __TI_flags+7(%r12),_TIF_SIGPENDING
         jo      sysc_sigpending
         tm      __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
         jo      sysc_notify_resume
-        tm      __TI_flags+7(%r12),_TIF_PER_TRAP
-        jo      sysc_singlestep
         j       sysc_return             # beware of critical section cleanup
 
 #
@@ -288,7 +288,6 @@ sysc_mcck_pending:
 # _TIF_SIGPENDING is set, call do_signal
 #
 sysc_sigpending:
-        ni      __TI_flags+7(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
         lgr     %r2,%r11                # pass pointer to pt_regs
         brasl   %r14,do_signal
         tm      __TI_flags+7(%r12),_TIF_SYSCALL
@@ -313,7 +312,7 @@ sysc_notify_resume:
 # _TIF_PER_TRAP is set, call do_per_trap
 #
 sysc_singlestep:
-        ni      __TI_flags+7(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP)
+        ni      __TI_flags+7(%r12),255-_TIF_PER_TRAP
         lgr     %r2,%r11                # pass pointer to pt_regs
         larl    %r14,sysc_return
         jg      do_per_trap
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index d1259d875074..c3ff70a7b247 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -461,6 +461,8 @@ void do_signal(struct pt_regs *regs)
                         /* Restart system call with magic TIF bit. */
                         regs->gprs[2] = regs->orig_gpr2;
                         set_thread_flag(TIF_SYSCALL);
+                        if (test_thread_flag(TIF_SINGLE_STEP))
+                                set_thread_flag(TIF_PER_TRAP);
                         break;
                 }
         }
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 870a644895f0..42601d6e166f 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -277,10 +277,16 @@ static inline int do_exception(struct pt_regs *regs, int access)
         unsigned int flags;
         int fault;
 
+        tsk = current;
+        /*
+         * The instruction that caused the program check has
+         * been nullified. Don't signal single step via SIGTRAP.
+         */
+        clear_tsk_thread_flag(tsk, TIF_PER_TRAP);
+
         if (notify_page_fault(regs))
                 return 0;
 
-        tsk = current;
         mm = tsk->mm;
         trans_exc_code = regs->int_parm_long;
 
@@ -376,11 +382,6 @@ retry:
                         goto retry;
                 }
         }
-        /*
-         * The instruction that caused the program check will
-         * be repeated. Don't signal single step via SIGTRAP.
-         */
-        clear_tsk_thread_flag(tsk, TIF_PER_TRAP);
         fault = 0;
 out_up:
         up_read(&mm->mmap_sem);
@@ -427,6 +428,12 @@ void __kprobes do_asce_exception(struct pt_regs *regs)
         struct vm_area_struct *vma;
         unsigned long trans_exc_code;
 
+        /*
+         * The instruction that caused the program check has
+         * been nullified. Don't signal single step via SIGTRAP.
+         */
+        clear_tsk_thread_flag(current, TIF_PER_TRAP);
+
         trans_exc_code = regs->int_parm_long;
         if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
                 goto no_context;