mn10300: Fix crash just after starting userspace on !CONFIG_PREEMPT

The mn10300 kernel crashes just after starting userspace programs, if
CONFIG_PREEMPT is disabled:

  Freeing unused kernel memory: 96K (90286000 - 9029e000)
  MISALIGN: 97c33ff9: unsupported instruction f
  MISALIGN: 97c33ff9: unsupported instruction f
  MISALIGN: 97c33ff9: unsupported instruction f
  :

This fixes the problem that was introduced by commit d17fc238ac14
("MN10300: Enable IRQs more in system call exit work path").

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index 222152a3f75195b429a6794e036c279cdb2e6160..177d61de51c938557596658847b6903d13d24ed9 100644 (file)
--- a/arch/mn10300/kernel/entry.S
+++ b/arch/mn10300/kernel/entry.S
@@ -171,10 +171,10 @@ ret_from_intr:
        mov     (REG_EPSW,fp),d0        # need to deliver signals before
                                        # returning to userspace
        and     EPSW_nSL,d0
-       beq     resume_kernel           # returning to supervisor mode
+       bne     resume_userspace        # returning to userspace
 
 #ifdef CONFIG_PREEMPT
-ENTRY(resume_kernel)
+resume_kernel:
        LOCAL_IRQ_DISABLE
        mov     (TI_preempt_count,a2),d0        # non-zero preempt_count ?
        cmp     0,d0
@@ -189,6 +189,8 @@ need_resched:
        bne     restore_all
        call    preempt_schedule_irq[],0
        jmp     need_resched
+#else
+       jmp     resume_kernel
 #endif