sh: resume_kernel fix for kernel oops built with CONFIG_BKL_PREEMPT=y.

This patch fixes a problem within the SH implementation of resume_kernel code,
that implements in assembly the bulk of preempt_schedule_irq function without
taking care of the extra code needed to handle the BKL preemptible.

The patch basically consists of removing this asm code and calling the common
C implementation (see kernel/sched.c) as other archs do.

Another change is the missing 'cli' macro invocation at the beginning of
the resume_kernel.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S
index 0bc17de..efbb426 100644 (file)
--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -92,6 +92,7 @@ ENTRY(ret_from_irq)
        bra     resume_userspace
         nop
 ENTRY(resume_kernel)
+       cli
        mov.l   @(TI_PRE_COUNT,r8), r0  ! current_thread_info->preempt_count
        tst     r0, r0
        bf      noresched
@@ -105,28 +106,9 @@ need_resched:
        and     #0xf0, r0               ! interrupts off (exception path)?
        cmp/eq  #0xf0, r0
        bt      noresched
-
-       mov.l   1f, r0
-       mov.l   r0, @(TI_PRE_COUNT,r8)
-
-#ifdef CONFIG_TRACE_IRQFLAGS
        mov.l   3f, r0
-       jsr     @r0
-        nop
-#endif
-       sti
-       mov.l   2f, r0
-       jsr     @r0
-        nop
-       mov     #0, r0
-       mov.l   r0, @(TI_PRE_COUNT,r8)
-       cli
-#ifdef CONFIG_TRACE_IRQFLAGS
-       mov.l   4f, r0
-       jsr     @r0
+       jsr     @r0                     ! call preempt_schedule_irq
         nop
-#endif
-
        bra     need_resched
         nop
 
@@ -137,10 +119,7 @@ noresched:
        .align 2
 1:     .long   PREEMPT_ACTIVE
 2:     .long   schedule
-#ifdef CONFIG_TRACE_IRQFLAGS
-3:     .long   trace_hardirqs_on
-4:     .long   trace_hardirqs_off
-#endif
+3:     .long   preempt_schedule_irq
 #endif
 
 ENTRY(resume_userspace)