Commit 3da06ed7 authored Sep 10, 2013 by Akira Takeuchi Committed by Linus Torvalds Sep 10, 2013

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 d17fc238
("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>

parent 31f7c3a6

arch/mn10300/kernel/entry.S

+4 −2

Original line number	Diff line number	Diff line
		@@ -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