diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt index bd4370487b07..82481c33992d 100644 --- a/Documentation/x86/x86_64/mm.txt +++ b/Documentation/x86/x86_64/mm.txt @@ -12,6 +12,8 @@ ffffc90000000000 - ffffe8ffffffffff (=45 bits) vmalloc/ioremap space ffffe90000000000 - ffffe9ffffffffff (=40 bits) hole ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB) ... unused hole ... +ffffec0000000000 - fffffc0000000000 (=44 bits) kasan shadow memory (16TB) +... unused hole ... ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks ... unused hole ... ffffffff80000000 - ffffffffa0000000 (=512 MB) kernel text mapping, from phys 0 diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 178aa94d930e..c47b9fe41dba 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -77,6 +77,7 @@ config X86 select HAVE_CMPXCHG_LOCAL select HAVE_CMPXCHG_DOUBLE select HAVE_ARCH_KMEMCHECK + select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP select HAVE_USER_RETURN_NOTIFIER select ARCH_BINFMT_ELF_RANDOMIZE_PIE select HAVE_ARCH_JUMP_LABEL diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 6cf0111783d3..262eec56cf36 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -14,6 +14,8 @@ # Set it to -DSVGA_MODE=NORMAL_VGA if you just want the EGA/VGA mode. # The number is the same as you would ordinarily press at bootup. +KASAN_SANITIZE := n + SVGA_MODE := -DSVGA_MODE=NORMAL_VGA targets := vmlinux.bin setup.bin setup.elf bzImage diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 7194d9f094bc..8f3d0bf93f34 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -5,6 +5,7 @@ # targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma vmlinux.bin.xz vmlinux.bin.lzo +KASAN_SANITIZE := n KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 KBUILD_CFLAGS += -fno-strict-aliasing -fPIC diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h new file mode 100644 index 000000000000..8b22422fbad8 --- /dev/null +++ b/arch/x86/include/asm/kasan.h @@ -0,0 +1,31 @@ +#ifndef _ASM_X86_KASAN_H +#define _ASM_X86_KASAN_H + +/* + * Compiler uses shadow offset assuming that addresses start + * from 0. Kernel addresses don't start from 0, so shadow + * for kernel really starts from compiler's shadow offset + + * 'kernel address space start' >> KASAN_SHADOW_SCALE_SHIFT + */ +#define KASAN_SHADOW_START (KASAN_SHADOW_OFFSET + \ + (0xffff800000000000ULL >> 3)) +/* 47 bits for kernel address -> (47 - 3) bits for shadow */ +#define KASAN_SHADOW_END (KASAN_SHADOW_START + (1ULL << (47 - 3))) + +#ifndef __ASSEMBLY__ + +extern pte_t kasan_zero_pte[]; +extern pte_t kasan_zero_pmd[]; +extern pte_t kasan_zero_pud[]; + +#ifdef CONFIG_KASAN +void __init kasan_map_early_shadow(pgd_t *pgd); +void __init kasan_init(void); +#else +static inline void kasan_map_early_shadow(pgd_t *pgd) { } +static inline void kasan_init(void) { } +#endif + +#endif + +#endif diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 111eb356dbea..d8faaa57de7f 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -16,6 +16,8 @@ CFLAGS_REMOVE_ftrace.o = -pg CFLAGS_REMOVE_early_printk.o = -pg endif +KASAN_SANITIZE_head$(BITS).o := n + obj-y := process_$(BITS).o signal.o entry_$(BITS).o obj-y += traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index deb6421c9e69..b10f70a86952 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -258,7 +258,10 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err) printk("SMP "); #endif #ifdef CONFIG_DEBUG_PAGEALLOC - printk("DEBUG_PAGEALLOC"); + printk("DEBUG_PAGEALLOC "); +#endif +#ifdef CONFIG_KASAN + printk("KASAN"); #endif printk("\n"); if (notify_die(DIE_OOPS, str, regs, err, diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 55b67614ed94..2314407311c6 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -27,6 +27,7 @@ #include #include #include +#include /* * Manage page tables very early on. @@ -46,7 +47,7 @@ static void __init reset_early_page_tables(void) next_early_pgt = 0; - write_cr3(__pa(early_level4_pgt)); + write_cr3(__pa_nodebug(early_level4_pgt)); } /* Create a new PMD entry */ @@ -59,7 +60,7 @@ int __init early_make_pgtable(unsigned long address) pmdval_t pmd, *pmd_p; /* Invalid address or early pgt is done ? */ - if (physaddr >= MAXMEM || read_cr3() != __pa(early_level4_pgt)) + if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt)) return -1; again: @@ -158,6 +159,8 @@ void __init x86_64_start_kernel(char * real_mode_data) /* Kill off the identity-map trampoline */ reset_early_page_tables(); + kasan_map_early_shadow(early_level4_pgt); + /* clear bss before set_intr_gate with early_idt_handler */ clear_bss(); @@ -179,6 +182,8 @@ void __init x86_64_start_kernel(char * real_mode_data) /* set init_level4_pgt kernel high mapping*/ init_level4_pgt[511] = early_level4_pgt[511]; + kasan_map_early_shadow(init_level4_pgt); + x86_64_start_reservations(real_mode_data); } diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index f2a9a2aa98f3..8f8290ff3410 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -514,6 +514,23 @@ ENTRY(phys_base) /* This must match the first entry in level2_kernel_pgt */ .quad 0x0000000000000000 +#ifdef CONFIG_KASAN +#define FILL(VAL, COUNT) \ + .rept (COUNT) ; \ + .quad (VAL) ; \ + .endr + +NEXT_PAGE(kasan_zero_pte) + FILL(kasan_zero_page - __START_KERNEL_map + _KERNPG_TABLE, 512) +NEXT_PAGE(kasan_zero_pmd) + FILL(kasan_zero_pte - __START_KERNEL_map + _KERNPG_TABLE, 512) +NEXT_PAGE(kasan_zero_pud) + FILL(kasan_zero_pmd - __START_KERNEL_map + _KERNPG_TABLE, 512) + +#undef FILL +#endif + + #include "../../x86/xen/xen-head.S" .section .bss, "aw", @nobits @@ -528,3 +545,16 @@ ENTRY(nmi_idt_table) __PAGE_ALIGNED_BSS NEXT_PAGE(empty_zero_page) .skip PAGE_SIZE + +#ifdef CONFIG_KASAN +/* + * This page used as early shadow. We don't use empty_zero_page + * at early stages, stack instrumentation could write some garbage + * to this page. + * Latter we reuse it as zero shadow for large ranges of memory + * that allowed to access, but not instrumented by kasan + * (vmalloc/vmemmap ...). + */ +NEXT_PAGE(kasan_zero_page) + .skip PAGE_SIZE +#endif diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index a3627ade4b15..fc381771df24 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -89,6 +89,7 @@ #include #include #include +#include #include #include @@ -1144,6 +1145,8 @@ void __init setup_arch(char **cmdline_p) x86_init.paging.pagetable_init(); + kasan_init(); + if (boot_cpu_data.cpuid_level >= 0) { /* A CPU has %cr4 if and only if it has CPUID */ mmu_cr4_features = read_cr4(); diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index efc25dae2fc7..5bf25337d021 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -18,6 +18,9 @@ obj-$(CONFIG_HIGHMEM) += highmem_32.o obj-$(CONFIG_KMEMCHECK) += kmemcheck/ +KASAN_SANITIZE_kasan_init_$(BITS).o := n +obj-$(CONFIG_KASAN) += kasan_init_$(BITS).o + obj-$(CONFIG_MMIOTRACE) += mmiotrace.o mmiotrace-y := kmmio.o pf_in.o mmio-mod.o obj-$(CONFIG_MMIOTRACE_TEST) += testmmiotrace.o diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c new file mode 100644 index 000000000000..3e4d9a1a39fa --- /dev/null +++ b/arch/x86/mm/kasan_init_64.c @@ -0,0 +1,199 @@ +#include +#include +#include +#include +#include +#include + +#include +#include + +extern pgd_t early_level4_pgt[PTRS_PER_PGD]; +extern struct range pfn_mapped[E820_X_MAX]; + +extern unsigned char kasan_zero_page[PAGE_SIZE]; + +static int __init map_range(struct range *range) +{ + unsigned long start; + unsigned long end; + + start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start)); + end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end)); + + /* + * end + 1 here is intentional. We check several shadow bytes in advance + * to slightly speed up fastpath. In some rare cases we could cross + * boundary of mapped shadow, so we just map some more here. + */ + return vmemmap_populate(start, end + 1, NUMA_NO_NODE); +} + +static void __init clear_pgds(unsigned long start, + unsigned long end) +{ + for (; start < end; start += PGDIR_SIZE) + pgd_clear(pgd_offset_k(start)); +} + +void __init kasan_map_early_shadow(pgd_t *pgd) +{ + int i; + unsigned long start = KASAN_SHADOW_START; + unsigned long end = KASAN_SHADOW_END; + + for (i = pgd_index(start); start < end; i++) { + pgd[i] = __pgd(__pa_nodebug(kasan_zero_pud) + | _KERNPG_TABLE); + start += PGDIR_SIZE; + } +} + +static int __init zero_pte_populate(pmd_t *pmd, unsigned long addr, + unsigned long end) +{ + pte_t *pte = pte_offset_kernel(pmd, addr); + + while (addr + PAGE_SIZE <= end) { + WARN_ON(!pte_none(*pte)); + set_pte(pte, __pte(__pa_nodebug(kasan_zero_page) + | __PAGE_KERNEL_RO)); + addr += PAGE_SIZE; + pte = pte_offset_kernel(pmd, addr); + } + return 0; +} + +static int __init zero_pmd_populate(pud_t *pud, unsigned long addr, + unsigned long end) +{ + int ret = 0; + pmd_t *pmd = pmd_offset(pud, addr); + + while (IS_ALIGNED(addr, PMD_SIZE) && addr + PMD_SIZE <= end) { + WARN_ON(!pmd_none(*pmd)); + set_pmd(pmd, __pmd(__pa_nodebug(kasan_zero_pte) + | __PAGE_KERNEL_RO)); + addr += PMD_SIZE; + pmd = pmd_offset(pud, addr); + } + if (addr < end) { + if (pmd_none(*pmd)) { + void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE); + if (!p) + return -ENOMEM; + set_pmd(pmd, __pmd(__pa_nodebug(p) | _KERNPG_TABLE)); + } + ret = zero_pte_populate(pmd, addr, end); + } + return ret; +} + + +static int __init zero_pud_populate(pgd_t *pgd, unsigned long addr, + unsigned long end) +{ + int ret = 0; + pud_t *pud = pud_offset(pgd, addr); + + while (IS_ALIGNED(addr, PUD_SIZE) && addr + PUD_SIZE <= end) { + WARN_ON(!pud_none(*pud)); + set_pud(pud, __pud(__pa_nodebug(kasan_zero_pmd) + | __PAGE_KERNEL_RO)); + addr += PUD_SIZE; + pud = pud_offset(pgd, addr); + } + + if (addr < end) { + if (pud_none(*pud)) { + void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE); + if (!p) + return -ENOMEM; + set_pud(pud, __pud(__pa_nodebug(p) | _KERNPG_TABLE)); + } + ret = zero_pmd_populate(pud, addr, end); + } + return ret; +} + +static int __init zero_pgd_populate(unsigned long addr, unsigned long end) +{ + int ret = 0; + pgd_t *pgd = pgd_offset_k(addr); + + while (IS_ALIGNED(addr, PGDIR_SIZE) && addr + PGDIR_SIZE <= end) { + WARN_ON(!pgd_none(*pgd)); + set_pgd(pgd, __pgd(__pa_nodebug(kasan_zero_pud) + | __PAGE_KERNEL_RO)); + addr += PGDIR_SIZE; + pgd = pgd_offset_k(addr); + } + + if (addr < end) { + if (pgd_none(*pgd)) { + void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE); + if (!p) + return -ENOMEM; + set_pgd(pgd, __pgd(__pa_nodebug(p) | _KERNPG_TABLE)); + } + ret = zero_pud_populate(pgd, addr, end); + } + return ret; +} + + +static void __init populate_zero_shadow(const void *start, const void *end) +{ + if (zero_pgd_populate((unsigned long)start, (unsigned long)end)) + panic("kasan: unable to map zero shadow!"); +} + + +#ifdef CONFIG_KASAN_INLINE +static int kasan_die_handler(struct notifier_block *self, + unsigned long val, + void *data) +{ + if (val == DIE_GPF) { + pr_emerg("CONFIG_KASAN_INLINE enabled"); + pr_emerg("GPF could be caused by NULL-ptr deref or user memory access"); + } + return NOTIFY_OK; +} + +static struct notifier_block kasan_die_notifier = { + .notifier_call = kasan_die_handler, +}; +#endif + +void __init kasan_init(void) +{ + int i; + +#ifdef CONFIG_KASAN_INLINE + register_die_notifier(&kasan_die_notifier); +#endif + + memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt)); + load_cr3(early_level4_pgt); + + clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END); + + populate_zero_shadow((void *)KASAN_SHADOW_START, + kasan_mem_to_shadow((void *)PAGE_OFFSET)); + + for (i = 0; i < E820_X_MAX; i++) { + if (pfn_mapped[i].end == 0) + break; + + if (map_range(&pfn_mapped[i])) + panic("kasan: unable to allocate shadow!"); + } + + populate_zero_shadow(kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM), + (void *)KASAN_SHADOW_END); + + memset(kasan_zero_page, 0, PAGE_SIZE); + + load_cr3(init_level4_pgt); +} diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile index 94f7fbe97b08..e02c2c6c56a5 100644 --- a/arch/x86/realmode/Makefile +++ b/arch/x86/realmode/Makefile @@ -6,7 +6,7 @@ # for more details. # # - +KASAN_SANITIZE := n subdir- := rm obj-y += init.o diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index 9cac82588cbc..53c6b65c727f 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -6,6 +6,7 @@ # for more details. # # +KASAN_SANITIZE := n always := realmode.bin realmode.relocs diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index fd14be1d1472..20d77a7fa076 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -2,6 +2,8 @@ # Building vDSO images for x86. # +KASAN_SANITIZE := n + VDSO64-$(CONFIG_X86_64) := y VDSOX32-$(CONFIG_X86_X32_ABI) := y VDSO32-$(CONFIG_X86_32) := y diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 85dd3239868d..a11ac0234452 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -16,6 +16,7 @@ config KASAN config KASAN_SHADOW_OFFSET hex + default 0xdffffc0000000000 if X86_64 choice prompt "Instrumentation type"