From 928df02bd46e2fe02cfd3127ba1814796d6d80b0 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 15 Sep 2015 22:19:04 +0100 Subject: [PATCH] metag: SMP: Fix 4KiB stack setup on secondary CPUs 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 Cc: linux-metag@vger.kernel.org --- 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(); -- 2.25.1