x86/irq/64: Remove stack overflow debug code (117ed454) · Commits · 戴 / test

arch/x86/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -14,6 +14,7 @@ config X86_32
		select ARCH_WANT_IPC_PARSE_VERSION
		select CLKSRC_I8253
		select CLONE_BACKWARDS
		select HAVE_DEBUG_STACKOVERFLOW
		select MODULES_USE_ELF_REL
		select OLD_SIGACTION

		@@ -138,7 +139,6 @@ config X86
		select HAVE_COPY_THREAD_TLS
		select HAVE_C_RECORDMCOUNT
		select HAVE_DEBUG_KMEMLEAK
		select HAVE_DEBUG_STACKOVERFLOW
		select HAVE_DMA_CONTIGUOUS
		select HAVE_DYNAMIC_FTRACE
		select HAVE_DYNAMIC_FTRACE_WITH_REGS

arch/x86/kernel/irq_64.c

+0 −56

Original line number	Diff line number	Diff line
		@@ -26,64 +26,8 @@
		DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
		DECLARE_INIT_PER_CPU(irq_stack_backing_store);

		int sysctl_panic_on_stackoverflow;

		/*
		* Probabilistic stack overflow check:
		*
		* Regular device interrupts can enter on the following stacks:
		*
		* - User stack
		*
		* - Kernel task stack
		*
		* - Interrupt stack if a device driver reenables interrupts
		* which should only happen in really old drivers.
		*
		* - Debug IST stack
		*
		* All other contexts are invalid.
		*/
		static inline void stack_overflow_check(struct pt_regs *regs)
		{
		#ifdef CONFIG_DEBUG_STACKOVERFLOW
		#define STACK_MARGIN 128
		u64 irq_stack_top, irq_stack_bottom, estack_top, estack_bottom;
		u64 curbase = (u64)task_stack_page(current);
		struct cea_exception_stacks *estacks;

		if (user_mode(regs))
		return;

		if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_MARGIN &&
		regs->sp <= curbase + THREAD_SIZE)
		return;

		irq_stack_top = (u64)__this_cpu_read(hardirq_stack_ptr);
		irq_stack_bottom = irq_stack_top - IRQ_STACK_SIZE + STACK_MARGIN;
		if (regs->sp >= irq_stack_bottom && regs->sp <= irq_stack_top)
		return;

		estacks = __this_cpu_read(cea_exception_stacks);
		estack_top = CEA_ESTACK_TOP(estacks, DB);
		estack_bottom = CEA_ESTACK_BOT(estacks, DB) + STACK_MARGIN;
		if (regs->sp >= estack_bottom && regs->sp <= estack_top)
		return;

		WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx, irq stack:%Lx-%Lx, exception stack: %Lx-%Lx, ip:%pF)\n",
		current->comm, curbase, regs->sp,
		irq_stack_bottom, irq_stack_top,
		estack_bottom, estack_top, (void *)regs->ip);

		if (sysctl_panic_on_stackoverflow)
		panic("low stack detected by irq handler - check messages\n");
		#endif
		}

		bool handle_irq(struct irq_desc desc, struct pt_regs regs)
		{
		stack_overflow_check(regs);

		if (IS_ERR_OR_NULL(desc))
		return false;

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