arm64: panic from init_IRQ if IRQ handler stacks cannot be allocated

init_irq_stacks() and init_irq_scs() may fail when arch_alloc_vmap_stack
or scs_alloc return NULL. Return -ENOMEM from both and call panic() once
from init_IRQ(), covering per-CPU IRQ stacks and shadow IRQ stacks
consistently.

Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 15dedb385b9e4c2e454e1590445364956c90263c..9fafd826002b730c4de8c6ee662bec19c9a98e58 100644 (file)
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -10,6 +10,7 @@
  * Copyright (C) 2012 ARM Ltd.
  */
 
+#include <linux/errno.h>
 #include <linux/hardirq.h>
 #include <linux/init.h>
 #include <linux/irq.h>
@@ -32,34 +33,43 @@ DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
 
 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
 
-
 DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
 
 #ifdef CONFIG_SHADOW_CALL_STACK
 DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
 #endif
 
-static void init_irq_scs(void)
+static int __init init_irq_scs(void)
 {
        int cpu;
+       void *s;
 
        if (!scs_is_enabled())
-               return;
+               return 0;
+
+       for_each_possible_cpu(cpu) {
+               s = scs_alloc(early_cpu_to_node(cpu));
+               if (!s)
+                       return -ENOMEM;
+               per_cpu(irq_shadow_call_stack_ptr, cpu) = s;
+       }
 
-       for_each_possible_cpu(cpu)
-               per_cpu(irq_shadow_call_stack_ptr, cpu) =
-                       scs_alloc(early_cpu_to_node(cpu));
+       return 0;
 }
 
-static void __init init_irq_stacks(void)
+static int __init init_irq_stacks(void)
 {
        int cpu;
        unsigned long *p;
 
        for_each_possible_cpu(cpu) {
                p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, early_cpu_to_node(cpu));
+               if (!p)
+                       return -ENOMEM;
                per_cpu(irq_stack_ptr, cpu) = p;
        }
+
+       return 0;
 }
 
 #ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
@@ -109,8 +119,9 @@ int __init set_handle_fiq(void (*handle_fiq)(struct pt_regs *))
 
 void __init init_IRQ(void)
 {
-       init_irq_stacks();
-       init_irq_scs();
+       if (init_irq_stacks() || init_irq_scs())
+               panic("Failed to allocate IRQ stack resources\n");
+
        irqchip_init();
 
        if (system_uses_irq_prio_masking()) {