diff options
Diffstat (limited to 'arch/arm64/mm/kasan_init.c')
| -rw-r--r-- | arch/arm64/mm/kasan_init.c | 79 |
1 files changed, 62 insertions, 17 deletions
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index cf038c7d9fa9..757009daa9ed 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -16,9 +16,12 @@ #include <linux/memblock.h> #include <linux/start_kernel.h> +#include <asm/mmu_context.h> +#include <asm/kernel-pgtable.h> #include <asm/page.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> +#include <asm/sections.h> #include <asm/tlbflush.h> static pgd_t tmp_pg_dir[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE); @@ -32,7 +35,7 @@ static void __init kasan_early_pte_populate(pmd_t *pmd, unsigned long addr, if (pmd_none(*pmd)) pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); - pte = pte_offset_kernel(pmd, addr); + pte = pte_offset_kimg(pmd, addr); do { next = addr + PAGE_SIZE; set_pte(pte, pfn_pte(virt_to_pfn(kasan_zero_page), @@ -50,7 +53,7 @@ static void __init kasan_early_pmd_populate(pud_t *pud, if (pud_none(*pud)) pud_populate(&init_mm, pud, kasan_zero_pmd); - pmd = pmd_offset(pud, addr); + pmd = pmd_offset_kimg(pud, addr); do { next = pmd_addr_end(addr, end); kasan_early_pte_populate(pmd, addr, next); @@ -67,7 +70,7 @@ static void __init kasan_early_pud_populate(pgd_t *pgd, if (pgd_none(*pgd)) pgd_populate(&init_mm, pgd, kasan_zero_pud); - pud = pud_offset(pgd, addr); + pud = pud_offset_kimg(pgd, addr); do { next = pud_addr_end(addr, end); kasan_early_pmd_populate(pud, addr, next); @@ -96,6 +99,21 @@ asmlinkage void __init kasan_early_init(void) kasan_map_early_shadow(); } +/* + * Copy the current shadow region into a new pgdir. + */ +void __init kasan_copy_shadow(pgd_t *pgdir) +{ + pgd_t *pgd, *pgd_new, *pgd_end; + + pgd = pgd_offset_k(KASAN_SHADOW_START); + pgd_end = pgd_offset_k(KASAN_SHADOW_END); + pgd_new = pgd_offset_raw(pgdir, KASAN_SHADOW_START); + do { + set_pgd(pgd_new, *pgd); + } while (pgd++, pgd_new++, pgd != pgd_end); +} + static void __init clear_pgds(unsigned long start, unsigned long end) { @@ -108,18 +126,18 @@ static void __init clear_pgds(unsigned long start, set_pgd(pgd_offset_k(start), __pgd(0)); } -static void __init cpu_set_ttbr1(unsigned long ttbr1) -{ - asm( - " msr ttbr1_el1, %0\n" - " isb" - : - : "r" (ttbr1)); -} - void __init kasan_init(void) { + u64 kimg_shadow_start, kimg_shadow_end; + u64 mod_shadow_start, mod_shadow_end; struct memblock_region *reg; + int i; + + kimg_shadow_start = (u64)kasan_mem_to_shadow(_text); + kimg_shadow_end = (u64)kasan_mem_to_shadow(_end); + + mod_shadow_start = (u64)kasan_mem_to_shadow((void *)MODULES_VADDR); + mod_shadow_end = (u64)kasan_mem_to_shadow((void *)MODULES_END); /* * We are going to perform proper setup of shadow memory. @@ -129,13 +147,33 @@ void __init kasan_init(void) * setup will be finished. */ memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(tmp_pg_dir)); - cpu_set_ttbr1(__pa(tmp_pg_dir)); - flush_tlb_all(); + dsb(ishst); + cpu_replace_ttbr1(tmp_pg_dir); clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END); + vmemmap_populate(kimg_shadow_start, kimg_shadow_end, + pfn_to_nid(virt_to_pfn(_text))); + + /* + * vmemmap_populate() has populated the shadow region that covers the + * kernel image with SWAPPER_BLOCK_SIZE mappings, so we have to round + * the start and end addresses to SWAPPER_BLOCK_SIZE as well, to prevent + * kasan_populate_zero_shadow() from replacing the page table entries + * (PMD or PTE) at the edges of the shadow region for the kernel + * image. + */ + kimg_shadow_start = round_down(kimg_shadow_start, SWAPPER_BLOCK_SIZE); + kimg_shadow_end = round_up(kimg_shadow_end, SWAPPER_BLOCK_SIZE); + kasan_populate_zero_shadow((void *)KASAN_SHADOW_START, - kasan_mem_to_shadow((void *)MODULES_VADDR)); + (void *)mod_shadow_start); + kasan_populate_zero_shadow((void *)kimg_shadow_end, + kasan_mem_to_shadow((void *)PAGE_OFFSET)); + + if (kimg_shadow_start > mod_shadow_end) + kasan_populate_zero_shadow((void *)mod_shadow_end, + (void *)kimg_shadow_start); for_each_memblock(memory, reg) { void *start = (void *)__phys_to_virt(reg->base); @@ -155,9 +193,16 @@ void __init kasan_init(void) pfn_to_nid(virt_to_pfn(start))); } + /* + * KAsan may reuse the contents of kasan_zero_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_zero_pte[i], + pfn_pte(virt_to_pfn(kasan_zero_page), PAGE_KERNEL_RO)); + memset(kasan_zero_page, 0, PAGE_SIZE); - cpu_set_ttbr1(__pa(swapper_pg_dir)); - flush_tlb_all(); + cpu_replace_ttbr1(swapper_pg_dir); /* At this point kasan is fully initialized. Enable error messages */ init_task.kasan_depth = 0; |