@@ -41,8 +41,8 @@ Support
Architectures
~~~~~~~~~~~~~
-Generic KASAN is supported on x86_64, arm, arm64, powerpc, riscv, s390, and
-xtensa, and the tag-based KASAN modes are supported only on arm64.
+Generic KASAN is supported on x86_64, arm, arm64, powerpc, riscv, s390, xtensa,
+and loongarch, and the tag-based KASAN modes are supported only on arm64.
Compilers
~~~~~~~~~
@@ -13,7 +13,7 @@
| csky: | TODO |
| hexagon: | TODO |
| ia64: | TODO |
- | loongarch: | TODO |
+ | loongarch: | ok |
| m68k: | TODO |
| microblaze: | TODO |
| mips: | TODO |
@@ -42,7 +42,7 @@ KASAN有三种模式:
体系架构
~~~~~~~~
-在x86_64、arm、arm64、powerpc、riscv、s390和xtensa上支持通用KASAN，
+在x86_64、arm、arm64、powerpc、riscv、s390、xtensa和loongarch上支持通用KASAN，
而基于标签的KASAN模式只在arm64上支持。
编译器
@@ -7,6 +7,7 @@ config LOONGARCH
select ACPI_MCFG if ACPI
select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
select ARCH_BINFMT_ELF_STATE
+ select ARCH_DISABLE_KASAN_INLINE
select ARCH_ENABLE_MEMORY_HOTPLUG
select ARCH_ENABLE_MEMORY_HOTREMOVE
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
@@ -83,6 +84,7 @@ config LOONGARCH
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_SECCOMP_FILTER
+ select HAVE_ARCH_KASAN if 64BIT
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ASM_MODVERSIONS
@@ -626,6 +628,11 @@ config ARCH_MMAP_RND_BITS_MIN
config ARCH_MMAP_RND_BITS_MAX
default 18
+config KASAN_SHADOW_OFFSET
+ hex
+ default 0x0
+ depends on KASAN
+
menu "Power management options"
config ARCH_SUSPEND_POSSIBLE
new file mode 100644
@@ -0,0 +1,125 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_KASAN_H
+#define __ASM_KASAN_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/linkage.h>
+#include <linux/mmzone.h>
+#include <asm/addrspace.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+
+#define __HAVE_ARCH_SHADOW_MAP
+
+#define KASAN_SHADOW_SCALE_SHIFT 3
+#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
+
+#define XRANGE_SHIFT (48)
+
+/* Valid address length */
+#define XRANGE_SHADOW_SHIFT (PGDIR_SHIFT + PAGE_SHIFT - 3)
+/* Used for taking out the valid address */
+#define XRANGE_SHADOW_MASK GENMASK_ULL(XRANGE_SHADOW_SHIFT - 1, 0)
+/* One segment whole address space size */
+#define XRANGE_SIZE (XRANGE_SHADOW_MASK + 1)
+
+/* 64-bit segment value. */
+#define XKPRANGE_UC_SEG (UNCACHE_BASE >> DMW_PABITS)
+#define XKPRANGE_CC_SEG (CACHE_BASE >> DMW_PABITS)
+#define XKVRANGE_VC_SEG (0xffff)
+
+/* Cached */
+#define XKPRANGE_CC_START CACHE_BASE
+#define XKPRANGE_CC_SIZE XRANGE_SIZE
+#define XKPRANGE_CC_KASAN_OFFSET (0)
+#define XKPRANGE_CC_SHADOW_SIZE (XKPRANGE_CC_SIZE >> KASAN_SHADOW_SCALE_SHIFT)
+#define XKPRANGE_CC_SHADOW_END (XKPRANGE_CC_KASAN_OFFSET + XKPRANGE_CC_SHADOW_SIZE)
+
+/* UnCached */
+#define XKPRANGE_UC_START UNCACHE_BASE
+#define XKPRANGE_UC_SIZE XRANGE_SIZE
+#define XKPRANGE_UC_KASAN_OFFSET XKPRANGE_CC_SHADOW_END
+#define XKPRANGE_UC_SHADOW_SIZE (XKPRANGE_UC_SIZE >> KASAN_SHADOW_SCALE_SHIFT)
+#define XKPRANGE_UC_SHADOW_END (XKPRANGE_UC_KASAN_OFFSET + XKPRANGE_UC_SHADOW_SIZE)
+
+/* VMALLOC (Cached or UnCached) */
+#define XKVRANGE_VC_START MODULES_VADDR
+#define XKVRANGE_VC_SIZE round_up(VMEMMAP_END - MODULES_VADDR + 1, PGDIR_SIZE)
+#define XKVRANGE_VC_KASAN_OFFSET XKPRANGE_UC_SHADOW_END
+#define XKVRANGE_VC_SHADOW_SIZE (XKVRANGE_VC_SIZE >> KASAN_SHADOW_SCALE_SHIFT)
+#define XKVRANGE_VC_SHADOW_END (XKVRANGE_VC_KASAN_OFFSET + XKVRANGE_VC_SHADOW_SIZE)
+
+/* Kasan shadow memory start right after vmalloc. */
+#define KASAN_SHADOW_START round_up(VMEMMAP_END, PGDIR_SIZE)
+#define KASAN_SHADOW_SIZE (XKVRANGE_VC_SHADOW_END - XKPRANGE_CC_KASAN_OFFSET)
+#define KASAN_SHADOW_END round_up(KASAN_SHADOW_START + KASAN_SHADOW_SIZE, PGDIR_SIZE)
+
+#define XKPRANGE_CC_SHADOW_OFFSET (KASAN_SHADOW_START + XKPRANGE_CC_KASAN_OFFSET)
+#define XKPRANGE_UC_SHADOW_OFFSET (KASAN_SHADOW_START + XKPRANGE_UC_KASAN_OFFSET)
+#define XKVRANGE_VC_SHADOW_OFFSET (KASAN_SHADOW_START + XKVRANGE_VC_KASAN_OFFSET)
+
+extern bool kasan_early_stage;
+extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
+
+static inline void *kasan_mem_to_shadow(const void *addr)
+{
+ if (kasan_early_stage) {
+ return (void *)(kasan_early_shadow_page);
+ } else {
+ unsigned long maddr = (unsigned long)addr;
+ unsigned long xrange = (maddr >> XRANGE_SHIFT) & 0xffff;
+ unsigned long offset = 0;
+
+ maddr &= XRANGE_SHADOW_MASK;
+ switch (xrange) {
+ case XKPRANGE_CC_SEG:
+ offset = XKPRANGE_CC_SHADOW_OFFSET;
+ break;
+ case XKPRANGE_UC_SEG:
+ offset = XKPRANGE_UC_SHADOW_OFFSET;
+ break;
+ case XKVRANGE_VC_SEG:
+ offset = XKVRANGE_VC_SHADOW_OFFSET;
+ break;
+ default:
+ WARN_ON(1);
+ return NULL;
+ }
+
+ return (void *)((maddr >> KASAN_SHADOW_SCALE_SHIFT) + offset);
+ }
+}
+
+static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
+{
+ unsigned long addr = (unsigned long)shadow_addr;
+
+ if (unlikely(addr > KASAN_SHADOW_END) ||
+ unlikely(addr < KASAN_SHADOW_START)) {
+ WARN_ON(1);
+ return NULL;
+ }
+
+ if (addr >= XKVRANGE_VC_SHADOW_OFFSET)
+ return (void *)(((addr - XKVRANGE_VC_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT) + XKVRANGE_VC_START);
+ else if (addr >= XKPRANGE_UC_SHADOW_OFFSET)
+ return (void *)(((addr - XKPRANGE_UC_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT) + XKPRANGE_UC_START);
+ else if (addr >= XKPRANGE_CC_SHADOW_OFFSET)
+ return (void *)(((addr - XKPRANGE_CC_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT) + XKPRANGE_CC_START);
+ else {
+ WARN_ON(1);
+ return NULL;
+ }
+}
+
+#ifdef CONFIG_KASAN
+void kasan_init(void);
+asmlinkage void kasan_early_init(void);
+#else
+static inline void kasan_early_init(void) { }
+static inline void kasan_init(void) { }
+#endif
+
+#endif
+#endif
@@ -86,9 +86,16 @@ extern unsigned long zero_page_mask;
#define MODULES_END (MODULES_VADDR + SZ_256M)
#define VMALLOC_START MODULES_END
+
+#ifndef CONFIG_KASAN
#define VMALLOC_END \
(vm_map_base + \
min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits)) - PMD_SIZE - VMEMMAP_SIZE)
+#else
+#define VMALLOC_END \
+ (vm_map_base + \
+ min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits) / 2) - PMD_SIZE - VMEMMAP_SIZE)
+#endif
#define vmemmap ((struct page *)((VMALLOC_END + PMD_SIZE) & PMD_MASK))
#define VMEMMAP_END ((unsigned long)vmemmap + VMEMMAP_SIZE - 1)
@@ -7,11 +7,27 @@
#define __HAVE_ARCH_MEMSET
extern void *memset(void *__s, int __c, size_t __count);
+extern void *__memset(void *__s, int __c, size_t __count);
#define __HAVE_ARCH_MEMCPY
extern void *memcpy(void *__to, __const__ void *__from, size_t __n);
+extern void *__memcpy(void *__to, __const__ void *__from, size_t __n);
#define __HAVE_ARCH_MEMMOVE
extern void *memmove(void *__dest, __const__ void *__src, size_t __n);
+extern void *__memmove(void *__dest, __const__ void *__src, size_t __n);
+
+#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
+
+/*
+ * For files that are not instrumented (e.g. mm/slub.c) we
+ * should use not instrumented version of mem* functions.
+ */
+
+#define memset(s, c, n) __memset(s, c, n)
+#define memcpy(dst, src, len) __memcpy(dst, src, len)
+#define memmove(dst, src, len) __memmove(dst, src, len)
+
+#endif
#endif /* _ASM_STRING_H */
@@ -30,6 +30,9 @@ ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_perf_event.o = $(CC_FLAGS_FTRACE)
endif
+KASAN_SANITIZE_vdso.o := n
+KASAN_SANITIZE_efi.o := n
+
obj-$(CONFIG_MODULES) += module.o module-sections.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
@@ -103,6 +103,10 @@ SYM_CODE_START(kernel_entry) # kernel entry point
#endif
#endif
+#ifdef CONFIG_KASAN
+ bl kasan_early_init
+#endif
+
bl start_kernel
ASM_BUG()
@@ -610,4 +610,8 @@ void __init setup_arch(char **cmdline_p)
#endif
paging_init();
+
+#if defined(CONFIG_KASAN)
+ kasan_init();
+#endif
}
@@ -10,16 +10,18 @@
#include <asm/export.h>
#include <asm/regdef.h>
-SYM_FUNC_START(memcpy)
+SYM_FUNC_START_WEAK(memcpy)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __memcpy_generic", \
"b __memcpy_fast", CPU_FEATURE_UAL
SYM_FUNC_END(memcpy)
+SYM_FUNC_ALIAS(__memcpy, memcpy)
_ASM_NOKPROBE(memcpy)
EXPORT_SYMBOL(memcpy)
+EXPORT_SYMBOL(__memcpy)
/*
* void *__memcpy_generic(void *dst, const void *src, size_t n)
@@ -10,7 +10,7 @@
#include <asm/export.h>
#include <asm/regdef.h>
-SYM_FUNC_START(memmove)
+SYM_FUNC_START_WEAK(memmove)
blt a0, a1, 1f /* dst < src, memcpy */
blt a1, a0, 3f /* src < dst, rmemcpy */
jr ra /* dst == src, return */
@@ -19,27 +19,30 @@ SYM_FUNC_START(memmove)
1: ori a3, zero, 64
sub.d t0, a1, a0
blt t0, a3, 2f
- b memcpy
+ b __memcpy
2: b __memcpy_generic
/* if (dst - src) < 64, copy 1 byte at a time */
3: ori a3, zero, 64
sub.d t0, a0, a1
blt t0, a3, 4f
- b rmemcpy
+ b __rmemcpy
4: b __rmemcpy_generic
SYM_FUNC_END(memmove)
+SYM_FUNC_ALIAS(__memmove, memmove)
_ASM_NOKPROBE(memmove)
EXPORT_SYMBOL(memmove)
+EXPORT_SYMBOL(__memmove)
+
+SYM_FUNC_START(__rmemcpy)
-SYM_FUNC_START(rmemcpy)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __rmemcpy_generic", \
"b __rmemcpy_fast", CPU_FEATURE_UAL
-SYM_FUNC_END(rmemcpy)
+SYM_FUNC_END(__rmemcpy)
_ASM_NOKPROBE(rmemcpy)
/*
@@ -16,16 +16,18 @@
bstrins.d \r0, \r0, 63, 32
.endm
-SYM_FUNC_START(memset)
+SYM_FUNC_START_WEAK(memset)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __memset_generic", \
"b __memset_fast", CPU_FEATURE_UAL
SYM_FUNC_END(memset)
+SYM_FUNC_ALIAS(__memset, memset)
_ASM_NOKPROBE(memset)
EXPORT_SYMBOL(memset)
+EXPORT_SYMBOL(__memset)
/*
* void *__memset_generic(void *s, int c, size_t n)
@@ -7,3 +7,5 @@ obj-y += init.o cache.o tlb.o tlbex.o extable.o \
fault.o ioremap.o maccess.o mmap.o pgtable.o page.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+obj-$(CONFIG_KASAN) += kasan_init.o
+KASAN_SANITIZE_kasan_init.o := n
new file mode 100644
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Loongson Technology Corporation Limited
+ */
+#define pr_fmt(fmt) "kasan: " fmt
+#include <linux/kasan.h>
+#include <linux/memblock.h>
+#include <linux/sched/task.h>
+
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+#include <asm-generic/sections.h>
+
+static pgd_t tmp_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
+
+static inline int __p4d_none(int early, p4d_t p4d) {return 0; }
+
+#ifndef __PAGETABLE_PUD_FOLDED
+#define __p4d_none(early, p4d) (early ? (p4d_val(p4d) == 0) : \
+(__pa(p4d_val(p4d)) == (unsigned long)__pa(kasan_early_shadow_pud)))
+#endif
+
+#define __pud_none(early, pud) (early ? (pud_val(pud) == 0) : \
+(__pa(pud_val(pud)) == (unsigned long)__pa(kasan_early_shadow_pmd)))
+
+#define __pmd_none(early, pmd) (early ? (pmd_val(pmd) == 0) : \
+(__pa(pmd_val(pmd)) == (unsigned long)__pa(kasan_early_shadow_pte)))
+
+#define __pte_none(early, pte) (early ? pte_none(pte) : \
+((pte_val(pte) & _PFN_MASK) == (unsigned long)__pa(kasan_early_shadow_page)))
+
+bool kasan_early_stage = true;
+
+/*
+ * Alloc memory for shadow memory page table.
+ */
+static phys_addr_t __init kasan_alloc_zeroed_page(int node)
+{
+ void *p = memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE,
+ __pa(MAX_DMA_ADDRESS),
+ MEMBLOCK_ALLOC_ACCESSIBLE, node);
+ if (!p)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%llx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE, node, __pa(MAX_DMA_ADDRESS));
+ return __pa(p);
+}
+
+static pte_t *kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node,
+ bool early)
+{
+ if (__pmd_none(early, READ_ONCE(*pmdp))) {
+ phys_addr_t pte_phys = early ?
+ __pa_symbol(kasan_early_shadow_pte)
+ : kasan_alloc_zeroed_page(node);
+ if (!early)
+ memcpy(__va(pte_phys), kasan_early_shadow_pte,
+ sizeof(kasan_early_shadow_pte));
+ pmd_populate_kernel(NULL, pmdp, (pte_t *)__va(pte_phys));
+ }
+
+ return pte_offset_kernel(pmdp, addr);
+}
+
+static inline void kasan_set_pgd(pgd_t *pgdp, pgd_t pgdval)
+{
+ WRITE_ONCE(*pgdp, pgdval);
+}
+
+static pmd_t *kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node,
+ bool early)
+{
+ if (__pud_none(early, READ_ONCE(*pudp))) {
+ phys_addr_t pmd_phys = early ?
+ __pa_symbol(kasan_early_shadow_pmd)
+ : kasan_alloc_zeroed_page(node);
+ if (!early)
+ memcpy(__va(pmd_phys), kasan_early_shadow_pmd,
+ sizeof(kasan_early_shadow_pmd));
+ pud_populate(&init_mm, pudp, (pmd_t *)__va(pmd_phys));
+ }
+
+ return pmd_offset(pudp, addr);
+}
+
+static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node,
+ bool early)
+{
+ if (__p4d_none(early, READ_ONCE(*p4dp))) {
+ phys_addr_t pud_phys = early ?
+ __pa_symbol(kasan_early_shadow_pud)
+ : kasan_alloc_zeroed_page(node);
+ if (!early)
+ memcpy(__va(pud_phys), kasan_early_shadow_pud,
+ sizeof(kasan_early_shadow_pud));
+ p4d_populate(&init_mm, p4dp, (pud_t *)__va(pud_phys));
+ }
+
+ return pud_offset(p4dp, addr);
+}
+
+static void kasan_pte_populate(pmd_t *pmdp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ pte_t *ptep = kasan_pte_offset(pmdp, addr, node, early);
+
+ do {
+ phys_addr_t page_phys = early ?
+ __pa_symbol(kasan_early_shadow_page)
+ : kasan_alloc_zeroed_page(node);
+ next = addr + PAGE_SIZE;
+ set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL));
+ } while (ptep++, addr = next, addr != end && __pte_none(early, READ_ONCE(*ptep)));
+}
+
+static void kasan_pmd_populate(pud_t *pudp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ pmd_t *pmdp = kasan_pmd_offset(pudp, addr, node, early);
+
+ do {
+ next = pmd_addr_end(addr, end);
+ kasan_pte_populate(pmdp, addr, next, node, early);
+ } while (pmdp++, addr = next, addr != end && __pmd_none(early, READ_ONCE(*pmdp)));
+}
+
+static void __init kasan_pud_populate(p4d_t *p4dp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ pud_t *pudp = kasan_pud_offset(p4dp, addr, node, early);
+
+ do {
+ next = pud_addr_end(addr, end);
+ kasan_pmd_populate(pudp, addr, next, node, early);
+ } while (pudp++, addr = next, addr != end);
+}
+
+static void __init kasan_p4d_populate(pgd_t *pgdp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ p4d_t *p4dp = p4d_offset(pgdp, addr);
+
+ do {
+ next = p4d_addr_end(addr, end);
+ kasan_pud_populate(p4dp, addr, next, node, early);
+ } while (p4dp++, addr = next, addr != end);
+}
+
+static void __init kasan_pgd_populate(unsigned long addr, unsigned long end,
+ int node, bool early)
+{
+ unsigned long next;
+ pgd_t *pgdp;
+
+ pgdp = pgd_offset_k(addr);
+
+ do {
+ next = pgd_addr_end(addr, end);
+ kasan_p4d_populate(pgdp, addr, next, node, early);
+ } while (pgdp++, addr = next, addr != end);
+
+}
+
+asmlinkage void __init kasan_early_init(void)
+{
+ BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PGDIR_SIZE));
+ BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE));
+}
+
+/* Set up full kasan mappings, ensuring that the mapped pages are zeroed */
+static void __init kasan_map_populate(unsigned long start, unsigned long end,
+ int node)
+{
+ kasan_pgd_populate(start & PAGE_MASK, PAGE_ALIGN(end), node, false);
+}
+
+static void __init clear_pgds(unsigned long start, unsigned long end)
+{
+ /*
+ * Remove references to kasan page tables from
+ * swapper_pg_dir. pgd_clear() can't be used
+ * here because it's nop on 2,3-level pagetable setups
+ */
+ for (; start < end; start += PGDIR_SIZE)
+ kasan_set_pgd((pgd_t *)pgd_offset_k(start), __pgd(0));
+}
+
+void __init kasan_init(void)
+{
+ u64 i;
+ phys_addr_t pa_start, pa_end;
+ /*
+ * PGD was populated as invalid_pmd_table or invalid_pud_table
+ * in pagetable_init() which depends on how many levels of page
+ * table you are using, but we had to clean the gpd of kasan
+ * shadow memory, as the pgd value is none-zero.
+ * The assertion pgd_none is going to be false and the formal populate
+ * afterwards is not going to create any new pgd at all.
+ */
+ memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(tmp_pg_dir));
+ __sync();
+ csr_write64(__pa_symbol(tmp_pg_dir), LOONGARCH_CSR_PGDH);
+ local_flush_tlb_all();
+
+ clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ /* Maps everything to a single page of zeroes */
+ kasan_pgd_populate(KASAN_SHADOW_START, KASAN_SHADOW_END,
+ NUMA_NO_NODE, true);
+
+ kasan_populate_early_shadow(kasan_mem_to_shadow((void *)MODULES_END),
+ kasan_mem_to_shadow((void *)VMEMMAP_END));
+
+ if (!IS_ENABLED(CONFIG_KASAN_VMALLOC))
+ kasan_populate_early_shadow(kasan_mem_to_shadow((void *)VMALLOC_START),
+ kasan_mem_to_shadow((void *)VMALLOC_END));
+
+ kasan_early_stage = false;
+
+ /* Populate the linear mapping */
+ for_each_mem_range(i, &pa_start, &pa_end) {
+ void *start = (void *)phys_to_virt(pa_start);
+ void *end = (void *)phys_to_virt(pa_end);
+
+ if (start >= end)
+ break;
+
+ kasan_map_populate((unsigned long)kasan_mem_to_shadow(start),
+ (unsigned long)kasan_mem_to_shadow(end), NUMA_NO_NODE);
+ }
+
+ /* Populate modules mapping */
+ kasan_map_populate((unsigned long)kasan_mem_to_shadow((void *)MODULES_VADDR),
+ (unsigned long)kasan_mem_to_shadow((void *)MODULES_END), NUMA_NO_NODE);
+ /*
+ * Kasan may reuse the contents of kasan_early_shadow_pte directly, so we
+ * should make sure that it maps the zero page read-only.
+ */
+ for (i = 0; i < PTRS_PER_PTE; i++)
+ set_pte(&kasan_early_shadow_pte[i],
+ pfn_pte(__phys_to_pfn(__pa_symbol(kasan_early_shadow_page)),
+ PAGE_KERNEL_RO));
+
+ memset(kasan_early_shadow_page, 0, PAGE_SIZE);
+ __sync();
+ csr_write64(__pa_symbol(swapper_pg_dir), LOONGARCH_CSR_PGDH);
+ local_flush_tlb_all();
+
+ /* At this point kasan is fully initialized. Enable error messages */
+ init_task.kasan_depth = 0;
+ pr_info("KernelAddressSanitizer initialized.\n");
+}
@@ -1,6 +1,10 @@
# SPDX-License-Identifier: GPL-2.0
# Objects to go into the VDSO.
+ifdef CONFIG_KASAN
+KASAN_SANITIZE := n
+endif
+
# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
# the inclusion of generic Makefile.
ARCH_REL_TYPE_ABS := R_LARCH_32|R_LARCH_64|R_LARCH_MARK_LA|R_LARCH_JUMP_SLOT
1/8 of kernel addresses reserved for shadow memory. But for LoongArch, There are a lot of holes between different segments and valid address space(256T available) is insufficient to map all these segments to kasan shadow memory with the common formula provided by kasan core, saying addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET So LoongArch has a ARCH specific mapping formula,different segments are mapped individually, and only limited length of space of that specific segment is mapped to shadow. At early boot stage the whole shadow region populated with just one physical page (kasan_early_shadow_page). Later, this page is reused as readonly zero shadow for some memory that Kasan currently don't track. After mapping the physical memory, pages for shadow memory are allocated and mapped. Functions like memset/memmove/memcpy do a lot of memory accesses. If bad pointer passed to one of these function it is important to catch this. Compiler's instrumentation cannot do this since these functions are written in assembly. KASan replaces memory functions with manually instrumented variants. Original functions declared as weak symbols so strong definitions in mm/kasan/kasan.c could replace them. Original functions have aliases with '__' prefix in name, so we could call non-instrumented variant if needed. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> --- Documentation/dev-tools/kasan.rst | 4 +- .../features/debug/KASAN/arch-support.txt | 2 +- .../translations/zh_CN/dev-tools/kasan.rst | 2 +- arch/loongarch/Kconfig | 7 + arch/loongarch/include/asm/kasan.h | 125 +++++++++ arch/loongarch/include/asm/pgtable.h | 7 + arch/loongarch/include/asm/string.h | 16 ++ arch/loongarch/kernel/Makefile | 3 + arch/loongarch/kernel/head.S | 4 + arch/loongarch/kernel/setup.c | 4 + arch/loongarch/lib/memcpy.S | 4 +- arch/loongarch/lib/memmove.S | 13 +- arch/loongarch/lib/memset.S | 4 +- arch/loongarch/mm/Makefile | 2 + arch/loongarch/mm/kasan_init.c | 255 ++++++++++++++++++ arch/loongarch/vdso/Makefile | 4 + 16 files changed, 445 insertions(+), 11 deletions(-) create mode 100644 arch/loongarch/include/asm/kasan.h create mode 100644 arch/loongarch/mm/kasan_init.c