This is a preliminary work that allows to make the code more understandable. Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx> --- arch/riscv/mm/kasan_init.c | 187 +++++++++++++++++++++++-------------- 1 file changed, 117 insertions(+), 70 deletions(-) diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c index e1226709490f..9a5211ca8368 100644 --- a/arch/riscv/mm/kasan_init.c +++ b/arch/riscv/mm/kasan_init.c @@ -95,23 +95,13 @@ static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned } static void __init kasan_populate_pud(pgd_t *pgd, - unsigned long vaddr, unsigned long end, - bool early) + unsigned long vaddr, unsigned long end) { 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 if (pgd_none(*pgd)) { + if (pgd_none(*pgd)) { 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); @@ -130,16 +120,10 @@ static void __init kasan_populate_pud(pgd_t *pgd, 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)); + phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE); + if (phys_addr) { + set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL)); 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; - } } } @@ -152,35 +136,22 @@ static void __init kasan_populate_pud(pgd_t *pgd, * 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)); + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pud)), PAGE_TABLE)); } static void __init kasan_populate_p4d(pgd_t *pgd, - unsigned long vaddr, unsigned long end, - bool early) + unsigned long vaddr, unsigned long end) { phys_addr_t phys_addr; p4d_t *p4dp, *base_p4d; 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_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgd))); - } else { - base_p4d = (p4d_t *)pgd_page_vaddr(*pgd); - if (base_p4d == lm_alias(kasan_early_shadow_p4d)) { - base_p4d = memblock_alloc(PTRS_PER_PUD * sizeof(p4d_t), PAGE_SIZE); - memcpy(base_p4d, (void *)kasan_early_shadow_p4d, - sizeof(p4d_t) * PTRS_PER_P4D); - } - } + base_p4d = (p4d_t *)pgd_page_vaddr(*pgd); + if (base_p4d == lm_alias(kasan_early_shadow_p4d)) { + base_p4d = memblock_alloc(PTRS_PER_PUD * sizeof(p4d_t), PAGE_SIZE); + memcpy(base_p4d, (void *)kasan_early_shadow_p4d, + sizeof(p4d_t) * PTRS_PER_P4D); + } p4dp = base_p4d + p4d_index(vaddr); @@ -188,20 +159,14 @@ static void __init kasan_populate_p4d(pgd_t *pgd, next = p4d_addr_end(vaddr, end); if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE) { - if (early) { - phys_addr = __pa(((uintptr_t)kasan_early_shadow_pud)); - set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE)); + phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE); + if (phys_addr) { + set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL)); continue; - } else { - phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE); - if (phys_addr) { - set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL)); - continue; - } } } - kasan_populate_pud((pgd_t *)p4dp, vaddr, next, early); + kasan_populate_pud((pgd_t *)p4dp, vaddr, next); } while (p4dp++, vaddr = next, vaddr != end); /* @@ -210,8 +175,7 @@ static void __init kasan_populate_p4d(pgd_t *pgd, * 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_p4d)), PAGE_TABLE)); + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_p4d)), PAGE_TABLE)); } #define kasan_early_shadow_pgd_next (pgtable_l5_enabled ? \ @@ -219,16 +183,15 @@ static void __init kasan_populate_p4d(pgd_t *pgd, (pgtable_l4_enabled ? \ (uintptr_t)kasan_early_shadow_pud : \ (uintptr_t)kasan_early_shadow_pmd)) -#define kasan_populate_pgd_next(pgdp, vaddr, next, early) \ +#define kasan_populate_pgd_next(pgdp, vaddr, next) \ (pgtable_l5_enabled ? \ - kasan_populate_p4d(pgdp, vaddr, next, early) : \ + kasan_populate_p4d(pgdp, vaddr, next) : \ (pgtable_l4_enabled ? \ - kasan_populate_pud(pgdp, vaddr, next, early) : \ + kasan_populate_pud(pgdp, vaddr, next) : \ 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) + unsigned long vaddr, unsigned long end) { phys_addr_t phys_addr; unsigned long next; @@ -237,11 +200,7 @@ static void __init kasan_populate_pgd(pgd_t *pgdp, next = pgd_addr_end(vaddr, end); 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) == + if (pgd_page_vaddr(*pgdp) == (unsigned long)lm_alias(kasan_early_shadow_pgd_next)) { /* * pgdp can't be none since kasan_early_init @@ -258,7 +217,95 @@ static void __init kasan_populate_pgd(pgd_t *pgdp, } } - kasan_populate_pgd_next(pgdp, vaddr, next, early); + kasan_populate_pgd_next(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); } @@ -295,16 +342,16 @@ asmlinkage void __init kasan_early_init(void) PAGE_TABLE)); } - kasan_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START), - KASAN_SHADOW_START, KASAN_SHADOW_END, true); + 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_populate_pgd(pgd_offset_k(KASAN_SHADOW_START), - KASAN_SHADOW_START, KASAN_SHADOW_END, true); + kasan_early_populate_pgd(pgd_offset_k(KASAN_SHADOW_START), + KASAN_SHADOW_START, KASAN_SHADOW_END); local_flush_tlb_all(); } @@ -314,7 +361,7 @@ 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, false); + kasan_populate_pgd(pgd_offset_k(vaddr), vaddr, vend); local_flush_tlb_all(); memset(start, KASAN_SHADOW_INIT, end - start); -- 2.37.2