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-rw-r--r--arch/powerpc/platforms/pseries/xics.c14
-rw-r--r--arch/sh/kernel/cpu/sh3/entry.S3
-rw-r--r--arch/sh/kernel/dwarf.c20
-rw-r--r--arch/sh/kernel/entry-common.S8
4 files changed, 41 insertions, 4 deletions
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index 1ee66db..f5f7919 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -784,9 +784,13 @@ static void xics_set_cpu_priority(unsigned char cppr)
{
struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
- BUG_ON(os_cppr->index != 0);
+ /*
+ * we only really want to set the priority when there's
+ * just one cppr value on the stack
+ */
+ WARN_ON(os_cppr->index != 0);
- os_cppr->stack[os_cppr->index] = cppr;
+ os_cppr->stack[0] = cppr;
if (firmware_has_feature(FW_FEATURE_LPAR))
lpar_cppr_info(cppr);
@@ -821,8 +825,14 @@ void xics_setup_cpu(void)
void xics_teardown_cpu(void)
{
+ struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
int cpu = smp_processor_id();
+ /*
+ * we have to reset the cppr index to 0 because we're
+ * not going to return from the IPI
+ */
+ os_cppr->index = 0;
xics_set_cpu_priority(0);
/* Clear any pending IPI request */
diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S
index 3f7e2a2..f6a389c 100644
--- a/arch/sh/kernel/cpu/sh3/entry.S
+++ b/arch/sh/kernel/cpu/sh3/entry.S
@@ -132,7 +132,6 @@ ENTRY(tlb_protection_violation_store)
mov #1, r5
call_handle_tlbmiss:
- setup_frame_reg
mov.l 1f, r0
mov r5, r8
mov.l @r0, r6
@@ -365,6 +364,8 @@ handle_exception:
mov.l @k2, k2 ! read out vector and keep in k2
handle_exception_special:
+ setup_frame_reg
+
! Setup return address and jump to exception handler
mov.l 7f, r9 ! fetch return address
stc r2_bank, r0 ! k2 (vector)
diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c
index 88d28ec..e511680 100644
--- a/arch/sh/kernel/dwarf.c
+++ b/arch/sh/kernel/dwarf.c
@@ -540,6 +540,8 @@ void dwarf_free_frame(struct dwarf_frame *frame)
mempool_free(frame, dwarf_frame_pool);
}
+extern void ret_from_irq(void);
+
/**
* dwarf_unwind_stack - unwind the stack
*
@@ -678,6 +680,24 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc,
addr = frame->cfa + reg->addr;
frame->return_addr = __raw_readl(addr);
+ /*
+ * Ah, the joys of unwinding through interrupts.
+ *
+ * Interrupts are tricky - the DWARF info needs to be _really_
+ * accurate and unfortunately I'm seeing a lot of bogus DWARF
+ * info. For example, I've seen interrupts occur in epilogues
+ * just after the frame pointer (r14) had been restored. The
+ * problem was that the DWARF info claimed that the CFA could be
+ * reached by using the value of the frame pointer before it was
+ * restored.
+ *
+ * So until the compiler can be trusted to produce reliable
+ * DWARF info when it really matters, let's stop unwinding once
+ * we've calculated the function that was interrupted.
+ */
+ if (prev && prev->pc == (unsigned long)ret_from_irq)
+ frame->return_addr = 0;
+
return frame;
bail:
diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S
index f0abd58..2b15ae6 100644
--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -70,8 +70,14 @@ ret_from_exception:
CFI_STARTPROC simple
CFI_DEF_CFA r14, 0
CFI_REL_OFFSET 17, 64
- CFI_REL_OFFSET 15, 0
+ CFI_REL_OFFSET 15, 60
CFI_REL_OFFSET 14, 56
+ CFI_REL_OFFSET 13, 52
+ CFI_REL_OFFSET 12, 48
+ CFI_REL_OFFSET 11, 44
+ CFI_REL_OFFSET 10, 40
+ CFI_REL_OFFSET 9, 36
+ CFI_REL_OFFSET 8, 32
preempt_stop()
ENTRY(ret_from_irq)
!