From 7623f37e411156e6e09b95cf5c76e509c5fda640 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 14 Apr 2019 17:59:49 +0200 Subject: [PATCH] x86/cpu_entry_area: Provide exception stack accessor Store a pointer to the per cpu entry area exception stack mappings to allow fast retrieval. Required for converting various places from using the shadow IST array to directly doing address calculations on the actual mapping address. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Andy Lutomirski Cc: Dave Hansen Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Sean Christopherson Cc: x86-ml Link: https://lkml.kernel.org/r/20190414160144.680960459@linutronix.de --- arch/x86/include/asm/cpu_entry_area.h | 4 ++++ arch/x86/mm/cpu_entry_area.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h index af8c312673de..9b406f067ecf 100644 --- a/arch/x86/include/asm/cpu_entry_area.h +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -99,6 +99,7 @@ struct cpu_entry_area { #define CPU_ENTRY_AREA_TOT_SIZE (CPU_ENTRY_AREA_SIZE * NR_CPUS) DECLARE_PER_CPU(struct cpu_entry_area *, cpu_entry_area); +DECLARE_PER_CPU(struct cea_exception_stacks *, cea_exception_stacks); extern void setup_cpu_entry_areas(void); extern void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags); @@ -118,4 +119,7 @@ static inline struct entry_stack *cpu_entry_stack(int cpu) return &get_cpu_entry_area(cpu)->entry_stack_page.stack; } +#define __this_cpu_ist_top_va(name) \ + CEA_ESTACK_TOP(__this_cpu_read(cea_exception_stacks), name) + #endif diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c index 2b1407662a6d..a00d0d059c8a 100644 --- a/arch/x86/mm/cpu_entry_area.c +++ b/arch/x86/mm/cpu_entry_area.c @@ -14,6 +14,7 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(struct entry_stack_page, entry_stack_storage) #ifdef CONFIG_X86_64 static DEFINE_PER_CPU_PAGE_ALIGNED(struct exception_stacks, exception_stacks); +DEFINE_PER_CPU(struct cea_exception_stacks*, cea_exception_stacks); #endif struct cpu_entry_area *get_cpu_entry_area(int cpu) @@ -92,6 +93,9 @@ static void __init percpu_setup_exception_stacks(unsigned int cpu) unsigned int npages; BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0); + + per_cpu(cea_exception_stacks, cpu) = &cea->estacks; + /* * The exceptions stack mappings in the per cpu area are protected * by guard pages so each stack must be mapped separately. -- 2.30.2