[patch V3 04/32] x86/irq/64: Remove a hardcoded irq_stack_union access

Thomas Gleixner
2019-04-14T16:02:24Z

From: Andy Lutomirski <luto@kernel.org>

stack_overflow_check() is using both irq_stack_ptr and irq_stack_union to
find the IRQ stack. That's going to break when vmapped irq stacks are
introduced.

Change it to just use irq_stack_ptr.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>

---
arch/x86/kernel/irq_64.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -55,9 +55,8 @@ static inline void stack_overflow_check(
regs->sp <= curbase + THREAD_SIZE)
return;

- irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) +
- STACK_TOP_MARGIN;
irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
+ irq_stack_top = irq_stack_bottom - IRQ_STACK_SIZE + STACK_TOP_MARGIN;
if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
return;