Back in early 2008, 4KiB stack support was added to reduce memory
consumption on workloads with lots of threads, using a separate IRQ
stack per CPU to alleviate stack pressure. However the SMP code added a
year and a half later didn't set up the IRQ stack when bringing up
secondary CPUs, resulting in a crash when SMP is configured with 4KiB
stacks, as soon as the first interrupt arrived on a secondary CPU.
Fix with calls to irq_ctx_exit()/irq_ctx_exit() when bringing up/down a
CPU.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: linux-metag@xxxxxxxxxxxxxxx
---
arch/metag/kernel/smp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c
index ac3a199e33e7..c3c6f0864881 100644
--- a/arch/metag/kernel/smp.c
+++ b/arch/metag/kernel/smp.c
@@ -312,6 +312,7 @@ void cpu_die(void)
{
local_irq_disable();
idle_task_exit();
+ irq_ctx_exit(smp_processor_id());
(void)cpu_report_death();
@@ -366,6 +367,7 @@ asmlinkage void secondary_start_kernel(void)
panic("No TBI found!");
per_cpu_trap_init(cpu);
+ irq_ctx_init(cpu);
preempt_disable();
--
2.4.10
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