diff options
Diffstat (limited to 'arch/riscv/mm/kasan_init.c')
-rw-r--r-- | arch/riscv/mm/kasan_init.c | 250 |
1 files changed, 193 insertions, 57 deletions
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c index 54294f83513d..cd1a145257b7 100644 --- a/arch/riscv/mm/kasan_init.c +++ b/arch/riscv/mm/kasan_init.c @@ -11,45 +11,27 @@ #include <asm/fixmap.h> #include <asm/pgalloc.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); - - 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, - mk_pte(virt_to_page(kasan_early_shadow_page), - PAGE_KERNEL)); +/* + * 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 is not aligned on PGDIR_SIZE so the mapping + * must be divided as follows: + * - the first PGD entry, although incomplete, is populated with + * kasan_early_shadow_pud/p4d + * - the PGD entries in the middle are populated with kasan_early_shadow_pud/p4d + * - the last PGD entry is shared with the kernel mapping so populated at the + * lower levels pud/p4d + * + * In addition, when shallow populating a kasan region (for example vmalloc), + * this region may also not be aligned on PGDIR size, so we must go down to the + * pud level too. + */ - 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))); - - local_flush_tlb_all(); -} +extern pgd_t early_pg_dir[PTRS_PER_PGD]; static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end) { @@ -73,15 +55,19 @@ static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(base_pte)), PAGE_TABLE)); } -static void __init kasan_populate_pmd(pgd_t *pgd, unsigned long vaddr, unsigned long end) +static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned long end) { phys_addr_t phys_addr; pmd_t *pmdp, *base_pmd; unsigned long next; - base_pmd = (pmd_t *)pgd_page_vaddr(*pgd); - if (base_pmd == lm_alias(kasan_early_shadow_pmd)) + if (pud_none(*pud)) { base_pmd = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE); + } else { + base_pmd = (pmd_t *)pud_pgtable(*pud); + if (base_pmd == lm_alias(kasan_early_shadow_pmd)) + base_pmd = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE); + } pmdp = base_pmd + pmd_index(vaddr); @@ -105,59 +91,209 @@ static void __init kasan_populate_pmd(pgd_t *pgd, unsigned long vaddr, unsigned * it entirely, memblock could allocate a page at a physical address * where KASAN is not populated yet and then we'd get a page fault. */ - set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE)); + set_pud(pud, pfn_pud(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE)); +} + +static void __init kasan_populate_pud(pgd_t *pgd, + unsigned long vaddr, unsigned long end, + bool early) +{ + phys_addr_t phys_addr; + pud_t *pudp, *base_pud; + unsigned long next; + + if (early) { + /* + * 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. + */ + base_pud = pt_ops.get_pud_virt(pfn_to_phys(_pgd_pfn(*pgd))); + } else { + base_pud = (pud_t *)pgd_page_vaddr(*pgd); + if (base_pud == lm_alias(kasan_early_shadow_pud)) { + base_pud = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE); + memcpy(base_pud, (void *)kasan_early_shadow_pud, + sizeof(pud_t) * PTRS_PER_PUD); + } + } + + 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) { + if (early) { + phys_addr = __pa(((uintptr_t)kasan_early_shadow_pmd)); + set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE)); + continue; + } else { + phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE); + if (phys_addr) { + set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL)); + continue; + } + } + } + + kasan_populate_pmd(pudp, vaddr, next); + } while (pudp++, vaddr = next, vaddr != end); + + /* + * Wait for the whole PGD to be populated before setting the PGD in + * the page table, otherwise, if we did set the PGD before populating + * it entirely, memblock could allocate a page at a physical address + * where KASAN is not populated yet and then we'd get a page fault. + */ + if (!early) + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pud)), PAGE_TABLE)); } -static void __init kasan_populate_pgd(unsigned long vaddr, unsigned long end) +#define kasan_early_shadow_pgd_next (pgtable_l4_enabled ? \ + (uintptr_t)kasan_early_shadow_pud : \ + (uintptr_t)kasan_early_shadow_pmd) +#define kasan_populate_pgd_next(pgdp, vaddr, next, early) \ + (pgtable_l4_enabled ? \ + kasan_populate_pud(pgdp, vaddr, next, early) : \ + kasan_populate_pmd((pud_t *)pgdp, vaddr, next)) + +static void __init kasan_populate_pgd(pgd_t *pgdp, + unsigned long vaddr, unsigned long end, + bool early) { phys_addr_t phys_addr; - pgd_t *pgdp = pgd_offset_k(vaddr); unsigned long next; do { next = pgd_addr_end(vaddr, end); - /* - * pgdp can't be none since kasan_early_init initialized all KASAN - * shadow region with kasan_early_shadow_pmd: if this is stillthe case, - * that means we can try to allocate a hugepage as a replacement. - */ - if (pgd_page_vaddr(*pgdp) == (unsigned long)lm_alias(kasan_early_shadow_pmd) && - 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)); + if (IS_ALIGNED(vaddr, PGDIR_SIZE) && (next - vaddr) >= PGDIR_SIZE) { + if (early) { + phys_addr = __pa((uintptr_t)kasan_early_shadow_pgd_next); + set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_TABLE)); continue; + } else if (pgd_page_vaddr(*pgdp) == + (unsigned long)lm_alias(kasan_early_shadow_pgd_next)) { + /* + * pgdp can't be none since kasan_early_init + * initialized all KASAN shadow region with + * kasan_early_shadow_pud: if this is still the + * case, that means we can try to allocate a + * hugepage as a replacement. + */ + phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE); + if (phys_addr) { + set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_KERNEL)); + continue; + } } } - kasan_populate_pmd(pgdp, vaddr, next); + kasan_populate_pgd_next(pgdp, vaddr, next, early); } 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)); + } + + kasan_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START), + KASAN_SHADOW_START, KASAN_SHADOW_END, true); + + local_flush_tlb_all(); +} + +void __init kasan_swapper_init(void) +{ + kasan_populate_pgd(pgd_offset_k(KASAN_SHADOW_START), + KASAN_SHADOW_START, KASAN_SHADOW_END, true); + + 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(vaddr, vend); + kasan_populate_pgd(pgd_offset_k(vaddr), vaddr, vend, false); local_flush_tlb_all(); memset(start, KASAN_SHADOW_INIT, end - start); } +static void __init kasan_shallow_populate_pud(pgd_t *pgdp, + unsigned long vaddr, unsigned long end, + bool kasan_populate) +{ + unsigned long next; + pud_t *pudp, *base_pud; + pmd_t *base_pmd; + bool is_kasan_pmd; + + base_pud = (pud_t *)pgd_page_vaddr(*pgdp); + pudp = base_pud + pud_index(vaddr); + + if (kasan_populate) + memcpy(base_pud, (void *)kasan_early_shadow_pgd_next, + sizeof(pud_t) * PTRS_PER_PUD); + + do { + next = pud_addr_end(vaddr, end); + is_kasan_pmd = (pud_pgtable(*pudp) == lm_alias(kasan_early_shadow_pmd)); + + if (is_kasan_pmd) { + base_pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + set_pud(pudp, pfn_pud(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE)); + } + } while (pudp++, 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); + bool is_kasan_pgd_next; do { next = pgd_addr_end(vaddr, end); - if (pgd_page_vaddr(*pgd_k) == (unsigned long)lm_alias(kasan_early_shadow_pmd)) { + is_kasan_pgd_next = (pgd_page_vaddr(*pgd_k) == + (unsigned long)lm_alias(kasan_early_shadow_pgd_next)); + + if (is_kasan_pgd_next) { p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE)); } + + if (IS_ALIGNED(vaddr, PGDIR_SIZE) && (next - vaddr) >= PGDIR_SIZE) + continue; + + kasan_shallow_populate_pud(pgd_k, vaddr, next, is_kasan_pgd_next); } while (pgd_k++, vaddr = next, vaddr != end); } |