diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h index 3d52b094850a90acf22c3b6953998b2db61f9d53..669e5d4df4fe10ef0e51ae4692b90914a804a8d2 100644 --- a/arch/x86/include/asm/cpu_entry_area.h +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -124,10 +124,6 @@ struct cpu_entry_area { }; #define CPU_ENTRY_AREA_SIZE (sizeof(struct cpu_entry_area)) -#define CPU_ENTRY_AREA_ARRAY_SIZE (CPU_ENTRY_AREA_SIZE * NR_CPUS) - -/* Total size includes the readonly IDT mapping page as well: */ -#define CPU_ENTRY_AREA_TOTAL_SIZE (CPU_ENTRY_AREA_ARRAY_SIZE + PAGE_SIZE) DECLARE_PER_CPU(struct cpu_entry_area *, cpu_entry_area); DECLARE_PER_CPU(struct cea_exception_stacks *, cea_exception_stacks); diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h index 13e70da38bedaaba39ad1624d78d57a0de947a35..de75306b932efd25d8ed4183f4b475fffe4d3bd1 100644 --- a/arch/x86/include/asm/kasan.h +++ b/arch/x86/include/asm/kasan.h @@ -28,9 +28,12 @@ #ifdef CONFIG_KASAN void __init kasan_early_init(void); void __init kasan_init(void); +void __init kasan_populate_shadow_for_vaddr(void *va, size_t size, int nid); #else static inline void kasan_early_init(void) { } static inline void kasan_init(void) { } +static inline void kasan_populate_shadow_for_vaddr(void *va, size_t size, + int nid) { } #endif #endif diff --git a/arch/x86/include/asm/pgtable_areas.h b/arch/x86/include/asm/pgtable_areas.h index d34cce1b995cf133b81058c4f53808880f0efe0a..4f056fb88174bb20036a53e809a9cb4759bd4dc3 100644 --- a/arch/x86/include/asm/pgtable_areas.h +++ b/arch/x86/include/asm/pgtable_areas.h @@ -11,6 +11,12 @@ #define CPU_ENTRY_AREA_RO_IDT_VADDR ((void *)CPU_ENTRY_AREA_RO_IDT) -#define CPU_ENTRY_AREA_MAP_SIZE (CPU_ENTRY_AREA_PER_CPU + CPU_ENTRY_AREA_ARRAY_SIZE - CPU_ENTRY_AREA_BASE) +#ifdef CONFIG_X86_32 +#define CPU_ENTRY_AREA_MAP_SIZE (CPU_ENTRY_AREA_PER_CPU + \ + (CPU_ENTRY_AREA_SIZE * NR_CPUS) - \ + CPU_ENTRY_AREA_BASE) +#else +#define CPU_ENTRY_AREA_MAP_SIZE P4D_SIZE +#endif #endif /* _ASM_X86_PGTABLE_AREAS_H */ diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index 668a4a6533d923c7eddef457f3f2ebac0040a00b..bbb0f737aab1904e82a54f08e4ad41b90d435ef5 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -266,7 +266,7 @@ static inline bool within_cpu_entry(unsigned long addr, unsigned long end) /* CPU entry erea is always used for CPU entry */ if (within_area(addr, end, CPU_ENTRY_AREA_BASE, - CPU_ENTRY_AREA_TOTAL_SIZE)) + CPU_ENTRY_AREA_MAP_SIZE)) return true; /* diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c index f5e1e60c9095fffb8210e39aefc58a5807252026..cd653d9815600faf28ff18301bcc9177adbf0ac5 100644 --- a/arch/x86/mm/cpu_entry_area.c +++ b/arch/x86/mm/cpu_entry_area.c @@ -5,26 +5,69 @@ #include #include #include +#include #include #include #include +#include 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 -#ifdef CONFIG_X86_32 +static DEFINE_PER_CPU_READ_MOSTLY(unsigned long, _cea_offset); + +static __always_inline unsigned int cea_offset(unsigned int cpu) +{ + return per_cpu(_cea_offset, cpu); +} + +static __init void init_cea_offsets(void) +{ + unsigned int max_cea; + unsigned int i, j; + + max_cea = (CPU_ENTRY_AREA_MAP_SIZE - PAGE_SIZE) / CPU_ENTRY_AREA_SIZE; + + /* O(sodding terrible) */ + for_each_possible_cpu(i) { + unsigned int cea; + +again: + /* + * Directly use get_random_u32() instead of prandom_u32_max + * to avoid seed can't be generated when CONFIG_RANDOMIZE_BASE=n. + */ + cea = (u32)(((u64) get_random_u32() * max_cea) >> 32); + + for_each_possible_cpu(j) { + if (cea_offset(j) == cea) + goto again; + + if (i == j) + break; + } + + per_cpu(_cea_offset, i) = cea; + } +} +#else /* !X86_64 */ DECLARE_PER_CPU_PAGE_ALIGNED(struct doublefault_stack, doublefault_stack); + +static __always_inline unsigned int cea_offset(unsigned int cpu) +{ + return cpu; +} +static inline void init_cea_offsets(void) { } #endif /* Is called from entry code, so must be noinstr */ noinstr struct cpu_entry_area *get_cpu_entry_area(int cpu) { - unsigned long va = CPU_ENTRY_AREA_PER_CPU + cpu * CPU_ENTRY_AREA_SIZE; + unsigned long va = CPU_ENTRY_AREA_PER_CPU + cea_offset(cpu) * CPU_ENTRY_AREA_SIZE; BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0); return (struct cpu_entry_area *) va; @@ -145,6 +188,9 @@ static void __init setup_cpu_entry_area(unsigned int cpu) pgprot_t tss_prot = PAGE_KERNEL; #endif + kasan_populate_shadow_for_vaddr(cea, CPU_ENTRY_AREA_SIZE, + early_cpu_to_node(cpu)); + cea_set_pte(&cea->gdt, get_cpu_gdt_paddr(cpu), gdt_prot); cea_map_percpu_pages(&cea->entry_stack_page, @@ -198,7 +244,6 @@ static __init void setup_cpu_entry_area_ptes(void) /* The +1 is for the readonly IDT: */ BUILD_BUG_ON((CPU_ENTRY_AREA_PAGES+1)*PAGE_SIZE != CPU_ENTRY_AREA_MAP_SIZE); - BUILD_BUG_ON(CPU_ENTRY_AREA_TOTAL_SIZE != CPU_ENTRY_AREA_MAP_SIZE); BUG_ON(CPU_ENTRY_AREA_BASE & ~PMD_MASK); start = CPU_ENTRY_AREA_BASE; @@ -214,6 +259,8 @@ void __init setup_cpu_entry_areas(void) { unsigned int cpu; + init_cea_offsets(); + setup_cpu_entry_area_ptes(); for_each_possible_cpu(cpu) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 1a50434c8a4dab44d6d23742d3bcd2dbbc1e2d99..b4b187960dd0ff4e29cd910559c5c460b6c681fc 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -318,10 +318,33 @@ void __init kasan_early_init(void) kasan_map_early_shadow(init_top_pgt); } +static unsigned long kasan_mem_to_shadow_align_down(unsigned long va) +{ + unsigned long shadow = (unsigned long)kasan_mem_to_shadow((void *)va); + + return round_down(shadow, PAGE_SIZE); +} + +static unsigned long kasan_mem_to_shadow_align_up(unsigned long va) +{ + unsigned long shadow = (unsigned long)kasan_mem_to_shadow((void *)va); + + return round_up(shadow, PAGE_SIZE); +} + +void __init kasan_populate_shadow_for_vaddr(void *va, size_t size, int nid) +{ + unsigned long shadow_start, shadow_end; + + shadow_start = kasan_mem_to_shadow_align_down((unsigned long)va); + shadow_end = kasan_mem_to_shadow_align_up((unsigned long)va + size); + kasan_populate_shadow(shadow_start, shadow_end, nid); +} + void __init kasan_init(void) { + unsigned long shadow_cea_begin, shadow_cea_per_cpu_begin, shadow_cea_end; int i; - void *shadow_cpu_entry_begin, *shadow_cpu_entry_end; memcpy(early_top_pgt, init_top_pgt, sizeof(early_top_pgt)); @@ -362,16 +385,10 @@ void __init kasan_init(void) map_range(&pfn_mapped[i]); } - shadow_cpu_entry_begin = (void *)CPU_ENTRY_AREA_BASE; - shadow_cpu_entry_begin = kasan_mem_to_shadow(shadow_cpu_entry_begin); - shadow_cpu_entry_begin = (void *)round_down( - (unsigned long)shadow_cpu_entry_begin, PAGE_SIZE); - - shadow_cpu_entry_end = (void *)(CPU_ENTRY_AREA_BASE + - CPU_ENTRY_AREA_MAP_SIZE); - shadow_cpu_entry_end = kasan_mem_to_shadow(shadow_cpu_entry_end); - shadow_cpu_entry_end = (void *)round_up( - (unsigned long)shadow_cpu_entry_end, PAGE_SIZE); + shadow_cea_begin = kasan_mem_to_shadow_align_down(CPU_ENTRY_AREA_BASE); + shadow_cea_per_cpu_begin = kasan_mem_to_shadow_align_up(CPU_ENTRY_AREA_PER_CPU); + shadow_cea_end = kasan_mem_to_shadow_align_up(CPU_ENTRY_AREA_BASE + + CPU_ENTRY_AREA_MAP_SIZE); kasan_populate_early_shadow( kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM), @@ -393,12 +410,18 @@ void __init kasan_init(void) kasan_populate_early_shadow( kasan_mem_to_shadow((void *)VMALLOC_END + 1), - shadow_cpu_entry_begin); + (void *)shadow_cea_begin); - kasan_populate_shadow((unsigned long)shadow_cpu_entry_begin, - (unsigned long)shadow_cpu_entry_end, 0); + /* + * Populate the shadow for the shared portion of the CPU entry area. + * Shadows for the per-CPU areas are mapped on-demand, as each CPU's + * area is randomly placed somewhere in the 512GiB range and mapping + * the entire 512GiB range is prohibitively expensive. + */ + kasan_populate_shadow(shadow_cea_begin, + shadow_cea_per_cpu_begin, 0); - kasan_populate_early_shadow(shadow_cpu_entry_end, + kasan_populate_early_shadow((void *)shadow_cea_end, kasan_mem_to_shadow((void *)__START_KERNEL_map)); kasan_populate_shadow((unsigned long)kasan_mem_to_shadow(_stext),