--- /dev/null
+// 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 <linux/vmalloc.h>
+#include <asm/pgalloc.h>
+#include <asm/code-patching.h>
+#include <mm/mmu_decl.h>
+
+static void 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);
+}
+
+static int kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end)
+{
+ pmd_t *pmd;
+ unsigned long k_cur, k_next;
+
+ pmd = pmd_offset(pud_offset(pgd_offset_k(k_start), k_start), 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 = pte_alloc_one_kernel(&init_mm);
+
+ if (!new)
+ return -ENOMEM;
+ kasan_populate_pte(new, PAGE_KERNEL_RO);
+ pmd_populate_kernel(&init_mm, pmd, new);
+ }
+ return 0;
+}
+
+static void __ref *kasan_get_one_page(void)
+{
+ if (slab_is_available())
+ return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+
+ return memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+}
+
+static int __ref 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 = NULL;
+
+ ret = kasan_init_shadow_page_tables(k_start, k_end);
+ if (ret)
+ return ret;
+
+ if (!slab_is_available())
+ block = memblock_alloc(k_end - k_start, PAGE_SIZE);
+
+ for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE) {
+ pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
+ void *va = block ? block + k_cur - k_start : kasan_get_one_page();
+ pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
+
+ if (!va)
+ return -ENOMEM;
+
+ __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;
+}
+
+static void __init kasan_remap_early_shadow_ro(void)
+{
+ kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL_RO);
+
+ flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
+}
+
+void __init kasan_mmu_init(void)
+{
+ int ret;
+ struct memblock_region *reg;
+
+ for_each_memblock(memory, reg) {
+ phys_addr_t base = reg->base;
+ phys_addr_t top = min(base + reg->size, total_lowmem);
+
+ if (base >= top)
+ continue;
+
+ ret = kasan_init_region(__va(base), top - base);
+ if (ret)
+ panic("kasan: kasan_init_region() failed");
+ }
+}
+
+void __init kasan_init(void)
+{
+ 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");
+}
+
+#ifdef CONFIG_MODULES
+void *module_alloc(unsigned long size)
+{
+ void *base = vmalloc_exec(size);
+
+ if (!base)
+ return NULL;
+
+ if (!kasan_init_region(base, size))
+ return base;
+
+ vfree(base);
+
+ return NULL;
+}
+#endif
+
+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_offset(pud_offset(pgd_offset_k(addr), addr), 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);
+
+ if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
+ WARN(true, "KASAN not supported on hash 6xx");
+}
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