1 files changed, 104 insertions, 0 deletions
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
new file mode 100644
index 000000000000..f0cc86040587
--- /dev/null
+++ b/arch/riscv/mm/kasan_init.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2019 Andes Technology Corporation
+
+#include <linux/pfn.h>
+#include <linux/init_task.h>
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/memblock.h>
+#include <asm/tlbflush.h>
+#include <asm/pgtable.h>
+#include <asm/fixmap.h>
+
+extern pgd_t early_pg_dir[PTRS_PER_PGD];
+asmlinkage void __init kasan_early_init(void)
+{
+	uintptr_t i;
+	pgd_t *pgd = early_pg_dir + pgd_index(KASAN_SHADOW_START);
+
+	for (i = 0; i < PTRS_PER_PTE; ++i)
+		set_pte(kasan_early_shadow_pte + i,
+			mk_pte(virt_to_page(kasan_early_shadow_page),
+			PAGE_KERNEL));
+
+	for (i = 0; i < PTRS_PER_PMD; ++i)
+		set_pmd(kasan_early_shadow_pmd + i,
+		 pfn_pmd(PFN_DOWN(__pa((uintptr_t)kasan_early_shadow_pte)),
+			__pgprot(_PAGE_TABLE)));
+
+	for (i = KASAN_SHADOW_START; i < KASAN_SHADOW_END;
+	     i += PGDIR_SIZE, ++pgd)
+		set_pgd(pgd,
+		 pfn_pgd(PFN_DOWN(__pa(((uintptr_t)kasan_early_shadow_pmd))),
+			__pgprot(_PAGE_TABLE)));
+
+	/* init for swapper_pg_dir */
+	pgd = pgd_offset_k(KASAN_SHADOW_START);
+
+	for (i = KASAN_SHADOW_START; i < KASAN_SHADOW_END;
+	     i += PGDIR_SIZE, ++pgd)
+		set_pgd(pgd,
+		 pfn_pgd(PFN_DOWN(__pa(((uintptr_t)kasan_early_shadow_pmd))),
+			__pgprot(_PAGE_TABLE)));
+
+	flush_tlb_all();
+}
+
+static void __init populate(void *start, void *end)
+{
+	unsigned long i;
+	unsigned long vaddr = (unsigned long)start & PAGE_MASK;
+	unsigned long vend = PAGE_ALIGN((unsigned long)end);
+	unsigned long n_pages = (vend - vaddr) / PAGE_SIZE;
+	unsigned long n_pmds =
+		(n_pages % PTRS_PER_PTE) ? n_pages / PTRS_PER_PTE + 1 :
+						n_pages / PTRS_PER_PTE;
+	pgd_t *pgd = pgd_offset_k(vaddr);
+	pmd_t *pmd = memblock_alloc(n_pmds * sizeof(pmd_t), PAGE_SIZE);
+	pte_t *pte = memblock_alloc(n_pages * sizeof(pte_t), PAGE_SIZE);
+
+	for (i = 0; i < n_pages; i++) {
+		phys_addr_t phys = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+
+		set_pte(pte + i, pfn_pte(PHYS_PFN(phys), PAGE_KERNEL));
+	}
+
+	for (i = 0; i < n_pmds; ++pgd, i += PTRS_PER_PMD)
+		set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(((uintptr_t)(pmd + i)))),
+				__pgprot(_PAGE_TABLE)));
+
+	for (i = 0; i < n_pages; ++pmd, i += PTRS_PER_PTE)
+		set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa((uintptr_t)(pte + i))),
+				__pgprot(_PAGE_TABLE)));
+
+	flush_tlb_all();
+	memset(start, 0, end - start);
+}
+
+void __init kasan_init(void)
+{
+	struct memblock_region *reg;
+	unsigned long i;
+
+	kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
+			(void *)kasan_mem_to_shadow((void *)VMALLOC_END));
+
+	for_each_memblock(memory, reg) {
+		void *start = (void *)__va(reg->base);
+		void *end = (void *)__va(reg->base + reg->size);
+
+		if (start >= end)
+			break;
+
+		populate(kasan_mem_to_shadow(start),
+			 kasan_mem_to_shadow(end));
+	};
+
+	for (i = 0; i < PTRS_PER_PTE; i++)
+		set_pte(&kasan_early_shadow_pte[i],
+			mk_pte(virt_to_page(kasan_early_shadow_page),
+			__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_ACCESSED)));
+
+	memset(kasan_early_shadow_page, 0, PAGE_SIZE);
+	init_task.kasan_depth = 0;
+}