4 files changed, 332 insertions, 0 deletions
diff --git a/arch/powerpc/mm/kasan/8xx.c b/arch/powerpc/mm/kasan/8xx.c
new file mode 100644
index 000000000..278422405
--- /dev/null
+++ b/arch/powerpc/mm/kasan/8xx.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/kasan.h>
+#include <linux/memblock.h>
+#include <linux/hugetlb.h>
+
+static int __init
+kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
+{
+	pmd_t *pmd = pmd_off_k(k_start);
+	unsigned long k_cur, k_next;
+
+	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
+		pte_basic_t *new;
+
+		k_next = pgd_addr_end(k_cur, k_end);
+		k_next = pgd_addr_end(k_next, k_end);
+		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
+			continue;
+
+		new = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
+		if (!new)
+			return -ENOMEM;
+
+		*new = pte_val(pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block)), PAGE_KERNEL)));
+
+		hugepd_populate_kernel((hugepd_t *)pmd, (pte_t *)new, PAGE_SHIFT_8M);
+		hugepd_populate_kernel((hugepd_t *)pmd + 1, (pte_t *)new, PAGE_SHIFT_8M);
+	}
+	return 0;
+}
+
+int __init kasan_init_region(void *start, size_t size)
+{
+	unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
+	unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
+	unsigned long k_cur;
+	int ret;
+	void *block;
+
+	block = memblock_alloc(k_end - k_start, SZ_8M);
+	if (!block)
+		return -ENOMEM;
+
+	if (IS_ALIGNED(k_start, SZ_8M)) {
+		kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
+		k_cur = ALIGN_DOWN(k_end, SZ_8M);
+		if (k_cur == k_end)
+			goto finish;
+	} else {
+		k_cur = k_start;
+	}
+
+	ret = kasan_init_shadow_page_tables(k_start, k_end);
+	if (ret)
+		return ret;
+
+	for (; k_cur < k_end; k_cur += PAGE_SIZE) {
+		pmd_t *pmd = pmd_off_k(k_cur);
+		void *va = block + k_cur - k_start;
+		pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
+
+		if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
+			pte = pte_mkhuge(pte);
+
+		__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
+	}
+finish:
+	flush_tlb_kernel_range(k_start, k_end);
+	return 0;
+}
diff --git a/arch/powerpc/mm/kasan/Makefile b/arch/powerpc/mm/kasan/Makefile
new file mode 100644
index 000000000..8636b17c6
--- /dev/null
+++ b/arch/powerpc/mm/kasan/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+
+KASAN_SANITIZE := n
+KCOV_INSTRUMENT := n
+
+obj-$(CONFIG_PPC32)           += kasan_init_32.o
+obj-$(CONFIG_PPC_8xx)		+= 8xx.o
+obj-$(CONFIG_PPC_BOOK3S_32)	+= book3s_32.o
diff --git a/arch/powerpc/mm/kasan/book3s_32.c b/arch/powerpc/mm/kasan/book3s_32.c
new file mode 100644
index 000000000..450a67ef0
--- /dev/null
+++ b/arch/powerpc/mm/kasan/book3s_32.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/kasan.h>
+#include <linux/memblock.h>
+#include <mm/mmu_decl.h>
+
+int __init kasan_init_region(void *start, size_t size)
+{
+	unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
+	unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
+	unsigned long k_nobat = k_start;
+	unsigned long k_cur;
+	phys_addr_t phys;
+	int ret;
+
+	while (k_nobat < k_end) {
+		unsigned int k_size = bat_block_size(k_nobat, k_end);
+		int idx = find_free_bat();
+
+		if (idx == -1)
+			break;
+		if (k_size < SZ_128K)
+			break;
+		phys = memblock_phys_alloc_range(k_size, k_size, 0,
+						 MEMBLOCK_ALLOC_ANYWHERE);
+		if (!phys)
+			break;
+
+		setbat(idx, k_nobat, phys, k_size, PAGE_KERNEL);
+		k_nobat += k_size;
+	}
+	if (k_nobat != k_start)
+		update_bats();
+
+	if (k_nobat < k_end) {
+		phys = memblock_phys_alloc_range(k_end - k_nobat, PAGE_SIZE, 0,
+						 MEMBLOCK_ALLOC_ANYWHERE);
+		if (!phys)
+			return -ENOMEM;
+	}
+
+	ret = kasan_init_shadow_page_tables(k_start, k_end);
+	if (ret)
+		return ret;
+
+	kasan_update_early_region(k_start, k_nobat, __pte(0));
+
+	for (k_cur = k_nobat; k_cur < k_end; k_cur += PAGE_SIZE) {
+		pmd_t *pmd = pmd_off_k(k_cur);
+		pte_t pte = pfn_pte(PHYS_PFN(phys + k_cur - k_nobat), PAGE_KERNEL);
+
+		__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
+	}
+	flush_tlb_kernel_range(k_start, k_end);
+	memset(kasan_mem_to_shadow(start), 0, k_end - k_start);
+
+	return 0;
+}
diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
new file mode 100644
index 000000000..f3e4d069e
--- /dev/null
+++ b/arch/powerpc/mm/kasan/kasan_init_32.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/kasan.h>
+#include <linux/printk.h>
+#include <linux/memblock.h>
+#include <linux/sched/task.h>
+#include <asm/pgalloc.h>
+#include <asm/code-patching.h>
+#include <mm/mmu_decl.h>
+
+static pgprot_t __init kasan_prot_ro(void)
+{
+	if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
+		return PAGE_READONLY;
+
+	return PAGE_KERNEL_RO;
+}
+
+static void __init kasan_populate_pte(pte_t *ptep, pgprot_t prot)
+{
+	unsigned long va = (unsigned long)kasan_early_shadow_page;
+	phys_addr_t pa = __pa(kasan_early_shadow_page);
+	int i;
+
+	for (i = 0; i < PTRS_PER_PTE; i++, ptep++)
+		__set_pte_at(&init_mm, va, ptep, pfn_pte(PHYS_PFN(pa), prot), 0);
+}
+
+int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end)
+{
+	pmd_t *pmd;
+	unsigned long k_cur, k_next;
+
+	pmd = pmd_off_k(k_start);
+
+	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
+		pte_t *new;
+
+		k_next = pgd_addr_end(k_cur, k_end);
+		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
+			continue;
+
+		new = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
+
+		if (!new)
+			return -ENOMEM;
+		kasan_populate_pte(new, PAGE_KERNEL);
+		pmd_populate_kernel(&init_mm, pmd, new);
+	}
+	return 0;
+}
+
+int __init __weak kasan_init_region(void *start, size_t size)
+{
+	unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
+	unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
+	unsigned long k_cur;
+	int ret;
+	void *block;
+
+	ret = kasan_init_shadow_page_tables(k_start, k_end);
+	if (ret)
+		return ret;
+
+	block = memblock_alloc(k_end - k_start, PAGE_SIZE);
+	if (!block)
+		return -ENOMEM;
+
+	for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
+		pmd_t *pmd = pmd_off_k(k_cur);
+		void *va = block + k_cur - k_start;
+		pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
+
+		__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
+	}
+	flush_tlb_kernel_range(k_start, k_end);
+	return 0;
+}
+
+void __init
+kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte)
+{
+	unsigned long k_cur;
+
+	for (k_cur = k_start; k_cur != k_end; k_cur += PAGE_SIZE) {
+		pmd_t *pmd = pmd_off_k(k_cur);
+		pte_t *ptep = pte_offset_kernel(pmd, k_cur);
+
+		if (pte_page(*ptep) != virt_to_page(lm_alias(kasan_early_shadow_page)))
+			continue;
+
+		__set_pte_at(&init_mm, k_cur, ptep, pte, 0);
+	}
+
+	flush_tlb_kernel_range(k_start, k_end);
+}
+
+static void __init kasan_remap_early_shadow_ro(void)
+{
+	pgprot_t prot = kasan_prot_ro();
+	phys_addr_t pa = __pa(kasan_early_shadow_page);
+
+	kasan_populate_pte(kasan_early_shadow_pte, prot);
+
+	kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END,
+				  pfn_pte(PHYS_PFN(pa), prot));
+}
+
+static void __init kasan_unmap_early_shadow_vmalloc(void)
+{
+	unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
+	unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
+
+	kasan_update_early_region(k_start, k_end, __pte(0));
+
+#ifdef MODULES_VADDR
+	k_start = (unsigned long)kasan_mem_to_shadow((void *)MODULES_VADDR);
+	k_end = (unsigned long)kasan_mem_to_shadow((void *)MODULES_END);
+	kasan_update_early_region(k_start, k_end, __pte(0));
+#endif
+}
+
+void __init kasan_mmu_init(void)
+{
+	int ret;
+
+	if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) {
+		ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+		if (ret)
+			panic("kasan: kasan_init_shadow_page_tables() failed");
+	}
+}
+
+void __init kasan_init(void)
+{
+	phys_addr_t base, end;
+	u64 i;
+	int ret;
+
+	for_each_mem_range(i, &base, &end) {
+		phys_addr_t top = min(end, total_lowmem);
+
+		if (base >= top)
+			continue;
+
+		ret = kasan_init_region(__va(base), top - base);
+		if (ret)
+			panic("kasan: kasan_init_region() failed");
+	}
+
+	if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
+		ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+		if (ret)
+			panic("kasan: kasan_init_shadow_page_tables() failed");
+	}
+
+	kasan_remap_early_shadow_ro();
+
+	clear_page(kasan_early_shadow_page);
+
+	/* At this point kasan is fully initialized. Enable error messages */
+	init_task.kasan_depth = 0;
+	pr_info("KASAN init done\n");
+}
+
+void __init kasan_late_init(void)
+{
+	if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
+		kasan_unmap_early_shadow_vmalloc();
+}
+
+void __init kasan_early_init(void)
+{
+	unsigned long addr = KASAN_SHADOW_START;
+	unsigned long end = KASAN_SHADOW_END;
+	unsigned long next;
+	pmd_t *pmd = pmd_off_k(addr);
+
+	BUILD_BUG_ON(KASAN_SHADOW_START & ~PGDIR_MASK);
+
+	kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL);
+
+	do {
+		next = pgd_addr_end(addr, end);
+		pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte);
+	} while (pmd++, addr = next, addr != end);
+}