[S390] add kprobes support.

Signed-off-by: Michael Grundy <grundym@us.ibm.com>
Signed-off-by: David Wilder <dwilder@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 5b5799ac8f83..0c712b78a7e8 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -505,6 +505,8 @@ pgm_no_vtime2:
         mvc     __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
         mvc     __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
         oi      __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+        tm      SP_PSW+1(%r15),0x01     # kernel per event ?
+        bz      BASED(kernel_per)
         l       %r3,__LC_PGM_ILC         # load program interruption code
         la      %r8,0x7f
         nr      %r8,%r3                  # clear per-event-bit and ilc
@@ -536,6 +538,16 @@ pgm_no_vtime3:
         stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
         b       BASED(sysc_do_svc)
 
+#
+# per was called from kernel, must be kprobes
+#
+kernel_per:
+        mvi     SP_TRAP+1(%r15),0x28    # set trap indication to pgm check
+        la      %r2,SP_PTREGS(%r15)     # address of register-save area
+        l       %r1,BASED(.Lhandle_per) # load adr. of per handler
+        la      %r14,BASED(sysc_leave)  # load adr. of system return
+        br      %r1                     # branch to do_single_step
+
 /*
  * IO interrupt handler routine
  */