Beispiel #1
0
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);
	__flush_tlb_all();

	clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);

	kasan_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!");
	}
	kasan_populate_zero_shadow(
		kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
		kasan_mem_to_shadow((void *)__START_KERNEL_map));

	vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
			(unsigned long)kasan_mem_to_shadow(_end),
			NUMA_NO_NODE);

	kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
			(void *)KASAN_SHADOW_END);

	load_cr3(init_level4_pgt);
	__flush_tlb_all();

	/*
	 * kasan_zero_page has been used as early shadow memory, thus it may
	 * contain some garbage. Now we can clear and write protect it, since
	 * after the TLB flush no one should write to it.
	 */
	memset(kasan_zero_page, 0, PAGE_SIZE);
	for (i = 0; i < PTRS_PER_PTE; i++) {
		pte_t pte = __pte(__pa(kasan_zero_page) | __PAGE_KERNEL_RO);
		set_pte(&kasan_zero_pte[i], pte);
	}
	/* Flush TLBs again to be sure that write protection applied. */
	__flush_tlb_all();

	init_task.kasan_depth = 0;
	pr_info("KernelAddressSanitizer initialized\n");
}
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) & PAGE_MASK;
	kimg_shadow_end = PAGE_ALIGN((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.
	 * At first we should unmap early shadow (clear_pgds() call below).
	 * However, instrumented code couldn't execute without shadow memory.
	 * tmp_pg_dir used to keep early shadow mapped until full shadow
	 * setup will be finished.
	 */
	memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(tmp_pg_dir));
	dsb(ishst);
	cpu_replace_ttbr1(lm_alias(tmp_pg_dir));

	clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);

	kasan_map_populate(kimg_shadow_start, kimg_shadow_end,
			   early_pfn_to_nid(virt_to_pfn(lm_alias(_text))));

	kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
				    (void *)mod_shadow_start);
	kasan_populate_early_shadow((void *)kimg_shadow_end,
				    kasan_mem_to_shadow((void *)PAGE_OFFSET));

	if (kimg_shadow_start > mod_shadow_end)
		kasan_populate_early_shadow((void *)mod_shadow_end,
					    (void *)kimg_shadow_start);

	for_each_memblock(memory, reg) {
		void *start = (void *)__phys_to_virt(reg->base);
		void *end = (void *)__phys_to_virt(reg->base + reg->size);

		if (start >= end)
			break;

		kasan_map_populate((unsigned long)kasan_mem_to_shadow(start),
				   (unsigned long)kasan_mem_to_shadow(end),
				   early_pfn_to_nid(virt_to_pfn(start)));
	}
Beispiel #3
0
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.
	 * At first we should unmap early shadow (clear_pgds() call bellow).
	 * However, instrumented code couldn't execute without shadow memory.
	 * tmp_pg_dir used to keep early shadow mapped until full shadow
	 * setup will be finished.
	 */
	memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(tmp_pg_dir));
	dsb(ishst);
	cpu_replace_ttbr1(lm_alias(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,
				   (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);
		void *end = (void *)__phys_to_virt(reg->base + reg->size);

		if (start >= end)
			break;

		/*
		 * 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.
		 */
		vmemmap_populate((unsigned long)kasan_mem_to_shadow(start),
				(unsigned long)kasan_mem_to_shadow(end) + 1,
				pfn_to_nid(virt_to_pfn(start)));
	}
Beispiel #4
0
void __init kasan_init(void)
{
	int i;
	void *shadow_cpu_entry_begin, *shadow_cpu_entry_end;

#ifdef CONFIG_KASAN_INLINE
	register_die_notifier(&kasan_die_notifier);
#endif

	memcpy(early_top_pgt, init_top_pgt, sizeof(early_top_pgt));

	/*
	 * We use the same shadow offset for 4- and 5-level paging to
	 * facilitate boot-time switching between paging modes.
	 * As result in 5-level paging mode KASAN_SHADOW_START and
	 * KASAN_SHADOW_END are not aligned to PGD boundary.
	 *
	 * KASAN_SHADOW_START doesn't share PGD with anything else.
	 * We claim whole PGD entry to make things easier.
	 *
	 * KASAN_SHADOW_END lands in the last PGD entry and it collides with
	 * bunch of things like kernel code, modules, EFI mapping, etc.
	 * We need to take extra steps to not overwrite them.
	 */
	if (pgtable_l5_enabled()) {
		void *ptr;

		ptr = (void *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END));
		memcpy(tmp_p4d_table, (void *)ptr, sizeof(tmp_p4d_table));
		set_pgd(&early_top_pgt[pgd_index(KASAN_SHADOW_END)],
				__pgd(__pa(tmp_p4d_table) | _KERNPG_TABLE));
	}

	load_cr3(early_top_pgt);
	__flush_tlb_all();

	clear_pgds(KASAN_SHADOW_START & PGDIR_MASK, KASAN_SHADOW_END);

	kasan_populate_early_shadow((void *)(KASAN_SHADOW_START & PGDIR_MASK),
			kasan_mem_to_shadow((void *)PAGE_OFFSET));

	for (i = 0; i < E820_MAX_ENTRIES; i++) {
		if (pfn_mapped[i].end == 0)
			break;

		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);

	kasan_populate_early_shadow(
		kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
		shadow_cpu_entry_begin);

	kasan_populate_shadow((unsigned long)shadow_cpu_entry_begin,
			      (unsigned long)shadow_cpu_entry_end, 0);

	kasan_populate_early_shadow(shadow_cpu_entry_end,
			kasan_mem_to_shadow((void *)__START_KERNEL_map));

	kasan_populate_shadow((unsigned long)kasan_mem_to_shadow(_stext),
			      (unsigned long)kasan_mem_to_shadow(_end),
			      early_pfn_to_nid(__pa(_stext)));

	kasan_populate_early_shadow(kasan_mem_to_shadow((void *)MODULES_END),
					(void *)KASAN_SHADOW_END);

	load_cr3(init_top_pgt);
	__flush_tlb_all();

	/*
	 * kasan_early_shadow_page has been used as early shadow memory, thus
	 * it may contain some garbage. Now we can clear and write protect it,
	 * since after the TLB flush no one should write to it.
	 */
	memset(kasan_early_shadow_page, 0, PAGE_SIZE);
	for (i = 0; i < PTRS_PER_PTE; i++) {
		pte_t pte;
		pgprot_t prot;

		prot = __pgprot(__PAGE_KERNEL_RO | _PAGE_ENC);
		pgprot_val(prot) &= __default_kernel_pte_mask;

		pte = __pte(__pa(kasan_early_shadow_page) | pgprot_val(prot));
		set_pte(&kasan_early_shadow_pte[i], pte);
	}
	/* Flush TLBs again to be sure that write protection applied. */
	__flush_tlb_all();

	init_task.kasan_depth = 0;
	pr_info("KernelAddressSanitizer initialized\n");
}