diff options
Diffstat (limited to 'arch/riscv/mm/kasan_init.c')
| -rw-r--r-- | arch/riscv/mm/kasan_init.c | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c new file mode 100644 index 0000000000..5e39dcf23f --- /dev/null +++ b/arch/riscv/mm/kasan_init.c @@ -0,0 +1,525 @@ +// 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 <linux/pgtable.h> +#include <asm/tlbflush.h> +#include <asm/fixmap.h> +#include <asm/pgalloc.h> + +/* + * Kasan shadow region must lie at a fixed address across sv39, sv48 and sv57 + * which is right before the kernel. + * + * For sv39, the region is aligned on PGDIR_SIZE so we only need to populate + * the page global directory with kasan_early_shadow_pmd. + * + * For sv48 and sv57, the region start is aligned on PGDIR_SIZE whereas the end + * region is not and then we have to go down to the PUD level. + */ + +static pgd_t tmp_pg_dir[PTRS_PER_PGD] __page_aligned_bss; +static p4d_t tmp_p4d[PTRS_PER_P4D] __page_aligned_bss; +static pud_t tmp_pud[PTRS_PER_PUD] __page_aligned_bss; + +static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end) +{ + phys_addr_t phys_addr; + pte_t *ptep, *p; + + if (pmd_none(*pmd)) { + p = memblock_alloc(PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE); + set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(p)), PAGE_TABLE)); + } + + ptep = pte_offset_kernel(pmd, vaddr); + + do { + if (pte_none(*ptep)) { + phys_addr = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); + set_pte(ptep, pfn_pte(PFN_DOWN(phys_addr), PAGE_KERNEL)); + memset(__va(phys_addr), KASAN_SHADOW_INIT, PAGE_SIZE); + } + } while (ptep++, vaddr += PAGE_SIZE, vaddr != end); +} + +static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned long end) +{ + phys_addr_t phys_addr; + pmd_t *pmdp, *p; + unsigned long next; + + if (pud_none(*pud)) { + p = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE); + set_pud(pud, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE)); + } + + pmdp = pmd_offset(pud, vaddr); + + do { + next = pmd_addr_end(vaddr, end); + + if (pmd_none(*pmdp) && IS_ALIGNED(vaddr, PMD_SIZE) && (next - vaddr) >= PMD_SIZE) { + phys_addr = memblock_phys_alloc(PMD_SIZE, PMD_SIZE); + if (phys_addr) { + set_pmd(pmdp, pfn_pmd(PFN_DOWN(phys_addr), PAGE_KERNEL)); + memset(__va(phys_addr), KASAN_SHADOW_INIT, PMD_SIZE); + continue; + } + } + + kasan_populate_pte(pmdp, vaddr, next); + } while (pmdp++, vaddr = next, vaddr != end); +} + +static void __init kasan_populate_pud(p4d_t *p4d, + unsigned long vaddr, unsigned long end) +{ + phys_addr_t phys_addr; + pud_t *pudp, *p; + unsigned long next; + + if (p4d_none(*p4d)) { + p = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE); + set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE)); + } + + pudp = pud_offset(p4d, vaddr); + + do { + next = pud_addr_end(vaddr, end); + + if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) { + phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE); + if (phys_addr) { + set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL)); + memset(__va(phys_addr), KASAN_SHADOW_INIT, PUD_SIZE); + continue; + } + } + + kasan_populate_pmd(pudp, vaddr, next); + } while (pudp++, vaddr = next, vaddr != end); +} + +static void __init kasan_populate_p4d(pgd_t *pgd, + unsigned long vaddr, unsigned long end) +{ + phys_addr_t phys_addr; + p4d_t *p4dp, *p; + unsigned long next; + + if (pgd_none(*pgd)) { + p = memblock_alloc(PTRS_PER_P4D * sizeof(p4d_t), PAGE_SIZE); + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE)); + } + + p4dp = p4d_offset(pgd, vaddr); + + do { + next = p4d_addr_end(vaddr, end); + + if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE) { + phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE); + if (phys_addr) { + set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL)); + memset(__va(phys_addr), KASAN_SHADOW_INIT, P4D_SIZE); + continue; + } + } + + kasan_populate_pud(p4dp, vaddr, next); + } while (p4dp++, vaddr = next, vaddr != end); +} + +static void __init kasan_populate_pgd(pgd_t *pgdp, + unsigned long vaddr, unsigned long end) +{ + phys_addr_t phys_addr; + unsigned long next; + + do { + next = pgd_addr_end(vaddr, end); + + if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) && + (next - vaddr) >= PGDIR_SIZE) { + phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE); + if (phys_addr) { + set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_KERNEL)); + memset(__va(phys_addr), KASAN_SHADOW_INIT, PGDIR_SIZE); + continue; + } + } + + kasan_populate_p4d(pgdp, vaddr, next); + } while (pgdp++, vaddr = next, vaddr != end); +} + +static void __init kasan_early_clear_pud(p4d_t *p4dp, + unsigned long vaddr, unsigned long end) +{ + pud_t *pudp, *base_pud; + unsigned long next; + + if (!pgtable_l4_enabled) { + pudp = (pud_t *)p4dp; + } else { + base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp))); + pudp = base_pud + pud_index(vaddr); + } + + do { + next = pud_addr_end(vaddr, end); + + if (IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) { + pud_clear(pudp); + continue; + } + + BUG(); + } while (pudp++, vaddr = next, vaddr != end); +} + +static void __init kasan_early_clear_p4d(pgd_t *pgdp, + unsigned long vaddr, unsigned long end) +{ + p4d_t *p4dp, *base_p4d; + unsigned long next; + + if (!pgtable_l5_enabled) { + p4dp = (p4d_t *)pgdp; + } else { + base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp))); + p4dp = base_p4d + p4d_index(vaddr); + } + + do { + next = p4d_addr_end(vaddr, end); + + if (pgtable_l4_enabled && IS_ALIGNED(vaddr, P4D_SIZE) && + (next - vaddr) >= P4D_SIZE) { + p4d_clear(p4dp); + continue; + } + + kasan_early_clear_pud(p4dp, vaddr, next); + } while (p4dp++, vaddr = next, vaddr != end); +} + +static void __init kasan_early_clear_pgd(pgd_t *pgdp, + unsigned long vaddr, unsigned long end) +{ + unsigned long next; + + do { + next = pgd_addr_end(vaddr, end); + + if (pgtable_l5_enabled && IS_ALIGNED(vaddr, PGDIR_SIZE) && + (next - vaddr) >= PGDIR_SIZE) { + pgd_clear(pgdp); + continue; + } + + kasan_early_clear_p4d(pgdp, vaddr, next); + } while (pgdp++, vaddr = next, vaddr != end); +} + +static void __init kasan_early_populate_pud(p4d_t *p4dp, + unsigned long vaddr, + unsigned long end) +{ + pud_t *pudp, *base_pud; + phys_addr_t phys_addr; + unsigned long next; + + if (!pgtable_l4_enabled) { + pudp = (pud_t *)p4dp; + } else { + base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp))); + pudp = base_pud + pud_index(vaddr); + } + + do { + next = pud_addr_end(vaddr, end); + + if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && + (next - vaddr) >= PUD_SIZE) { + phys_addr = __pa((uintptr_t)kasan_early_shadow_pmd); + set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE)); + continue; + } + + BUG(); + } while (pudp++, vaddr = next, vaddr != end); +} + +static void __init kasan_early_populate_p4d(pgd_t *pgdp, + unsigned long vaddr, + unsigned long end) +{ + p4d_t *p4dp, *base_p4d; + phys_addr_t phys_addr; + unsigned long next; + + /* + * We can't use pgd_page_vaddr here as it would return a linear + * mapping address but it is not mapped yet, but when populating + * early_pg_dir, we need the physical address and when populating + * swapper_pg_dir, we need the kernel virtual address so use + * pt_ops facility. + * Note that this test is then completely equivalent to + * p4dp = p4d_offset(pgdp, vaddr) + */ + if (!pgtable_l5_enabled) { + p4dp = (p4d_t *)pgdp; + } else { + base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp))); + p4dp = base_p4d + p4d_index(vaddr); + } + + do { + next = p4d_addr_end(vaddr, end); + + if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && + (next - vaddr) >= P4D_SIZE) { + phys_addr = __pa((uintptr_t)kasan_early_shadow_pud); + set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE)); + continue; + } + + kasan_early_populate_pud(p4dp, vaddr, next); + } while (p4dp++, vaddr = next, vaddr != end); +} + +static void __init kasan_early_populate_pgd(pgd_t *pgdp, + unsigned long vaddr, + unsigned long end) +{ + phys_addr_t phys_addr; + unsigned long next; + + do { + next = pgd_addr_end(vaddr, end); + + if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) && + (next - vaddr) >= PGDIR_SIZE) { + phys_addr = __pa((uintptr_t)kasan_early_shadow_p4d); + set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_TABLE)); + continue; + } + + kasan_early_populate_p4d(pgdp, vaddr, next); + } while (pgdp++, vaddr = next, vaddr != end); +} + +asmlinkage void __init kasan_early_init(void) +{ + uintptr_t i; + + BUILD_BUG_ON(KASAN_SHADOW_OFFSET != + KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT))); + + for (i = 0; i < PTRS_PER_PTE; ++i) + set_pte(kasan_early_shadow_pte + i, + pfn_pte(virt_to_pfn(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)), + PAGE_TABLE)); + + if (pgtable_l4_enabled) { + for (i = 0; i < PTRS_PER_PUD; ++i) + set_pud(kasan_early_shadow_pud + i, + pfn_pud(PFN_DOWN + (__pa(((uintptr_t)kasan_early_shadow_pmd))), + PAGE_TABLE)); + } + + if (pgtable_l5_enabled) { + for (i = 0; i < PTRS_PER_P4D; ++i) + set_p4d(kasan_early_shadow_p4d + i, + pfn_p4d(PFN_DOWN + (__pa(((uintptr_t)kasan_early_shadow_pud))), + PAGE_TABLE)); + } + + kasan_early_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START), + KASAN_SHADOW_START, KASAN_SHADOW_END); + + local_flush_tlb_all(); +} + +void __init kasan_swapper_init(void) +{ + kasan_early_populate_pgd(pgd_offset_k(KASAN_SHADOW_START), + KASAN_SHADOW_START, KASAN_SHADOW_END); + + local_flush_tlb_all(); +} + +static void __init kasan_populate(void *start, void *end) +{ + unsigned long vaddr = (unsigned long)start & PAGE_MASK; + unsigned long vend = PAGE_ALIGN((unsigned long)end); + + kasan_populate_pgd(pgd_offset_k(vaddr), vaddr, vend); +} + +static void __init kasan_shallow_populate_pud(p4d_t *p4d, + unsigned long vaddr, unsigned long end) +{ + unsigned long next; + void *p; + pud_t *pud_k = pud_offset(p4d, vaddr); + + do { + next = pud_addr_end(vaddr, end); + + if (pud_none(*pud_k)) { + p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + set_pud(pud_k, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE)); + continue; + } + + BUG(); + } while (pud_k++, vaddr = next, vaddr != end); +} + +static void __init kasan_shallow_populate_p4d(pgd_t *pgd, + unsigned long vaddr, unsigned long end) +{ + unsigned long next; + void *p; + p4d_t *p4d_k = p4d_offset(pgd, vaddr); + + do { + next = p4d_addr_end(vaddr, end); + + if (p4d_none(*p4d_k)) { + p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + set_p4d(p4d_k, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE)); + continue; + } + + kasan_shallow_populate_pud(p4d_k, vaddr, end); + } while (p4d_k++, vaddr = next, vaddr != end); +} + +static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end) +{ + unsigned long next; + void *p; + pgd_t *pgd_k = pgd_offset_k(vaddr); + + do { + next = pgd_addr_end(vaddr, end); + + if (pgd_none(*pgd_k)) { + p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE)); + continue; + } + + kasan_shallow_populate_p4d(pgd_k, vaddr, next); + } while (pgd_k++, vaddr = next, vaddr != end); +} + +static void __init kasan_shallow_populate(void *start, void *end) +{ + unsigned long vaddr = (unsigned long)start & PAGE_MASK; + unsigned long vend = PAGE_ALIGN((unsigned long)end); + + kasan_shallow_populate_pgd(vaddr, vend); +} + +static void __init create_tmp_mapping(void) +{ + void *ptr; + p4d_t *base_p4d; + + /* + * We need to clean the early mapping: this is hard to achieve "in-place", + * so install a temporary mapping like arm64 and x86 do. + */ + memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(pgd_t) * PTRS_PER_PGD); + + /* Copy the last p4d since it is shared with the kernel mapping. */ + if (pgtable_l5_enabled) { + ptr = (p4d_t *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END)); + memcpy(tmp_p4d, ptr, sizeof(p4d_t) * PTRS_PER_P4D); + set_pgd(&tmp_pg_dir[pgd_index(KASAN_SHADOW_END)], + pfn_pgd(PFN_DOWN(__pa(tmp_p4d)), PAGE_TABLE)); + base_p4d = tmp_p4d; + } else { + base_p4d = (p4d_t *)tmp_pg_dir; + } + + /* Copy the last pud since it is shared with the kernel mapping. */ + if (pgtable_l4_enabled) { + ptr = (pud_t *)p4d_page_vaddr(*(base_p4d + p4d_index(KASAN_SHADOW_END))); + memcpy(tmp_pud, ptr, sizeof(pud_t) * PTRS_PER_PUD); + set_p4d(&base_p4d[p4d_index(KASAN_SHADOW_END)], + pfn_p4d(PFN_DOWN(__pa(tmp_pud)), PAGE_TABLE)); + } +} + +void __init kasan_init(void) +{ + phys_addr_t p_start, p_end; + u64 i; + + create_tmp_mapping(); + csr_write(CSR_SATP, PFN_DOWN(__pa(tmp_pg_dir)) | satp_mode); + + kasan_early_clear_pgd(pgd_offset_k(KASAN_SHADOW_START), + KASAN_SHADOW_START, KASAN_SHADOW_END); + + kasan_populate_early_shadow((void *)kasan_mem_to_shadow((void *)FIXADDR_START), + (void *)kasan_mem_to_shadow((void *)VMALLOC_START)); + + if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { + kasan_shallow_populate( + (void *)kasan_mem_to_shadow((void *)VMALLOC_START), + (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); + /* Shallow populate modules and BPF which are vmalloc-allocated */ + kasan_shallow_populate( + (void *)kasan_mem_to_shadow((void *)MODULES_VADDR), + (void *)kasan_mem_to_shadow((void *)MODULES_END)); + } else { + kasan_populate_early_shadow((void *)kasan_mem_to_shadow((void *)VMALLOC_START), + (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); + } + + /* Populate the linear mapping */ + for_each_mem_range(i, &p_start, &p_end) { + void *start = (void *)__va(p_start); + void *end = (void *)__va(p_end); + + if (start >= end) + break; + + kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end)); + } + + /* Populate kernel */ + kasan_populate(kasan_mem_to_shadow((const void *)MODULES_END), + kasan_mem_to_shadow((const void *)MODULES_VADDR + SZ_2G)); + + 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, KASAN_SHADOW_INIT, PAGE_SIZE); + init_task.kasan_depth = 0; + + csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | satp_mode); + local_flush_tlb_all(); +} |