x86/cpu_entry_area: Prepare for IST guard pages (a4af767a) · Commits · 戴 / test

arch/x86/mm/cpu_entry_area.c

+30 −7

Original line number	Diff line number	Diff line
		@@ -77,6 +77,34 @@ static void __init percpu_setup_debug_store(unsigned int cpu)
		#endif
		}

		#ifdef CONFIG_X86_64

		#define cea_map_stack(name) do { \
		npages = sizeof(estacks->name## _stack) / PAGE_SIZE; \
		cea_map_percpu_pages(cea->estacks.name## _stack, \
		estacks->name## _stack, npages, PAGE_KERNEL); \
		} while (0)

		static void __init percpu_setup_exception_stacks(unsigned int cpu)
		{
		struct exception_stacks *estacks = per_cpu_ptr(&exception_stacks, cpu);
		struct cpu_entry_area *cea = get_cpu_entry_area(cpu);
		unsigned int npages;

		BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0);
		/*
		* The exceptions stack mappings in the per cpu area are protected
		* by guard pages so each stack must be mapped separately.
		*/
		cea_map_stack(DF);
		cea_map_stack(NMI);
		cea_map_stack(DB);
		cea_map_stack(MCE);
		}
		#else
		static inline void percpu_setup_exception_stacks(unsigned int cpu) {}
		#endif

		/* Setup the fixmap mappings only once per-processor */
		static void __init setup_cpu_entry_area(unsigned int cpu)
		{
		@@ -134,13 +162,8 @@ static void __init setup_cpu_entry_area(unsigned int cpu)
		per_cpu(cpu_entry_area, cpu) = cea;
		#endif

		#ifdef CONFIG_X86_64
		BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0);
		BUILD_BUG_ON(sizeof(exception_stacks) !=
		sizeof(((struct cpu_entry_area *)0)->estacks));
		cea_map_percpu_pages(&cea->estacks, &per_cpu(exception_stacks, cpu),
		sizeof(exception_stacks) / PAGE_SIZE, PAGE_KERNEL);
		#endif
		percpu_setup_exception_stacks(cpu);

		percpu_setup_debug_store(cpu);
		}