From: Andrey Ryabinin a.ryabinin@samsung.com
This patch adds arch specific code for kernel address sanitizer.
16TB of virtual addressed used for shadow memory. It's located in range [ffffec0000000000 - fffffc0000000000] between vmemmap and %esp fixup stacks.
At early stage we map whole shadow region with zero page. Latter, after pages mapped to direct mapping address range we unmap zero pages from corresponding shadow (see kasan_map_shadow()) and allocate and map a real shadow memory reusing vmemmap_populate() function.
Also replace __pa with __pa_nodebug before shadow initialized. __pa with CONFIG_DEBUG_VIRTUAL=y make external function call (__phys_addr) __phys_addr is instrumented, so __asan_load could be called before shadow area initialized.
Signed-off-by: Andrey Ryabinin a.ryabinin@samsung.com Cc: Dmitry Vyukov dvyukov@google.com Cc: Konstantin Serebryany kcc@google.com Cc: Dmitry Chernenkov dmitryc@google.com Signed-off-by: Andrey Konovalov adech.fo@gmail.com Cc: Yuri Gribov tetra2005@gmail.com Cc: Konstantin Khlebnikov koct9i@gmail.com Cc: Sasha Levin sasha.levin@oracle.com Cc: Christoph Lameter cl@linux.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Dave Hansen dave.hansen@intel.com Cc: Andi Kleen andi@firstfloor.org Cc: Ingo Molnar mingo@elte.hu Cc: Thomas Gleixner tglx@linutronix.de Cc: "H. Peter Anvin" hpa@zytor.com Cc: Christoph Lameter cl@linux.com Cc: Pekka Enberg penberg@kernel.org Cc: David Rientjes rientjes@google.com Cc: Jim Davis jim.epost@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org (cherry picked from commit ef7f0d6a6ca8c9e4b27d78895af86c2fbfaeedb2) Signed-off-by: Alex Shi alex.shi@linaro.org --- Documentation/x86/x86_64/mm.txt | 2 + arch/x86/Kconfig | 1 + arch/x86/boot/Makefile | 2 + arch/x86/boot/compressed/Makefile | 2 + arch/x86/include/asm/kasan.h | 31 ++++++ arch/x86/kernel/Makefile | 2 + arch/x86/kernel/dumpstack.c | 5 +- arch/x86/kernel/head64.c | 9 +- arch/x86/kernel/head_64.S | 30 ++++++ arch/x86/kernel/setup.c | 3 + arch/x86/mm/Makefile | 3 + arch/x86/mm/kasan_init_64.c | 199 ++++++++++++++++++++++++++++++++++++++ arch/x86/realmode/Makefile | 2 +- arch/x86/realmode/rm/Makefile | 1 + arch/x86/vdso/Makefile | 1 + lib/Kconfig.kasan | 1 + 16 files changed, 290 insertions(+), 4 deletions(-) create mode 100644 arch/x86/include/asm/kasan.h create mode 100644 arch/x86/mm/kasan_init_64.c
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt index 052ee64..05712ac 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 c9148e2..642a358 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -83,6 +83,7 @@ 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 3db07f3..57bbf2f 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 30c0acf..2959cca 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -4,6 +4,8 @@ # create a compressed vmlinux image from the original vmlinux #
+KASAN_SANITIZE := n + targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h new file mode 100644 index 0000000..8b22422 --- /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 8f1e774..9d46ee8 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$(BITS).o := n + CFLAGS_irq.o := -I$(src)/../include/asm/trace
obj-y := process_$(BITS).o signal.o entry_$(BITS).o diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index b74ebc7..cf3df1d 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -265,7 +265,10 @@ int __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 957fdb5..b111ab5 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -27,6 +27,7 @@ #include <asm/bios_ebda.h> #include <asm/bootparam_utils.h> #include <asm/microcode.h> +#include <asm/kasan.h>
/* * 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: @@ -160,6 +161,8 @@ asmlinkage __visible 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();
@@ -181,6 +184,8 @@ asmlinkage __visible 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 a2dc0ad..f8a8406 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -516,8 +516,38 @@ 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" __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 87b6496..28a8506 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -89,6 +89,7 @@ #include <asm/cacheflush.h> #include <asm/processor.h> #include <asm/bugs.h> +#include <asm/kasan.h>
#include <asm/vsyscall.h> #include <asm/cpu.h> @@ -1174,6 +1175,8 @@ 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 6a19ad9..9648838 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -20,6 +20,9 @@ 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 0000000..3e4d9a1 --- /dev/null +++ b/arch/x86/mm/kasan_init_64.c @@ -0,0 +1,199 @@ +#include <linux/bootmem.h> +#include <linux/kasan.h> +#include <linux/kdebug.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/vmalloc.h> + +#include <asm/tlbflush.h> +#include <asm/sections.h> + +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 94f7fbe..e02c2c6 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 7c0d7be..2730d77 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 5a4affe..2aacd7c 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -3,6 +3,7 @@ #
KBUILD_CFLAGS += $(DISABLE_LTO) +KASAN_SANITIZE := n
VDSO64-$(CONFIG_X86_64) := y VDSOX32-$(CONFIG_X86_X32_ABI) := y diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index e5b3fbe..0052b1b 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -15,6 +15,7 @@ config KASAN
config KASAN_SHADOW_OFFSET hex + default 0xdffffc0000000000 if X86_64
choice prompt "Instrumentation type"