diff options
Diffstat (limited to 'arch/powerpc/mm/kasan/init_book3e_64.c')
| -rw-r--r-- | arch/powerpc/mm/kasan/init_book3e_64.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/arch/powerpc/mm/kasan/init_book3e_64.c b/arch/powerpc/mm/kasan/init_book3e_64.c new file mode 100644 index 000000000000..11519e88dc6b --- /dev/null +++ b/arch/powerpc/mm/kasan/init_book3e_64.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KASAN for 64-bit Book3e powerpc + * + * Copyright 2022, Christophe Leroy, CS GROUP France + */ + +#define DISABLE_BRANCH_PROFILING + +#include <linux/kasan.h> +#include <linux/printk.h> +#include <linux/memblock.h> +#include <linux/set_memory.h> + +#include <asm/pgalloc.h> + +static inline bool kasan_pud_table(p4d_t p4d) +{ + return p4d_page(p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud)); +} + +static inline bool kasan_pmd_table(pud_t pud) +{ + return pud_page(pud) == virt_to_page(lm_alias(kasan_early_shadow_pmd)); +} + +static inline bool kasan_pte_table(pmd_t pmd) +{ + return pmd_page(pmd) == virt_to_page(lm_alias(kasan_early_shadow_pte)); +} + +static int __init kasan_map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot) +{ + pgd_t *pgdp; + p4d_t *p4dp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + pgdp = pgd_offset_k(ea); + p4dp = p4d_offset(pgdp, ea); + if (kasan_pud_table(*p4dp)) { + pudp = memblock_alloc(PUD_TABLE_SIZE, PUD_TABLE_SIZE); + memcpy(pudp, kasan_early_shadow_pud, PUD_TABLE_SIZE); + p4d_populate(&init_mm, p4dp, pudp); + } + pudp = pud_offset(p4dp, ea); + if (kasan_pmd_table(*pudp)) { + pmdp = memblock_alloc(PMD_TABLE_SIZE, PMD_TABLE_SIZE); + memcpy(pmdp, kasan_early_shadow_pmd, PMD_TABLE_SIZE); + pud_populate(&init_mm, pudp, pmdp); + } + pmdp = pmd_offset(pudp, ea); + if (kasan_pte_table(*pmdp)) { + ptep = memblock_alloc(PTE_TABLE_SIZE, PTE_TABLE_SIZE); + memcpy(ptep, kasan_early_shadow_pte, PTE_TABLE_SIZE); + pmd_populate_kernel(&init_mm, pmdp, ptep); + } + ptep = pte_offset_kernel(pmdp, ea); + + __set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot), 0); + + return 0; +} + +static void __init kasan_init_phys_region(void *start, void *end) +{ + unsigned long k_start, k_end, k_cur; + void *va; + + if (start >= end) + return; + + k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE); + k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE); + + va = memblock_alloc(k_end - k_start, PAGE_SIZE); + for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE, va += PAGE_SIZE) + kasan_map_kernel_page(k_cur, __pa(va), PAGE_KERNEL); +} + +void __init kasan_early_init(void) +{ + int i; + unsigned long addr; + pgd_t *pgd = pgd_offset_k(KASAN_SHADOW_START); + pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL); + + BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PGDIR_SIZE)); + BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE)); + + for (i = 0; i < PTRS_PER_PTE; i++) + __set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page, + &kasan_early_shadow_pte[i], zero_pte, 0); + + for (i = 0; i < PTRS_PER_PMD; i++) + pmd_populate_kernel(&init_mm, &kasan_early_shadow_pmd[i], + kasan_early_shadow_pte); + + for (i = 0; i < PTRS_PER_PUD; i++) + pud_populate(&init_mm, &kasan_early_shadow_pud[i], + kasan_early_shadow_pmd); + + for (addr = KASAN_SHADOW_START; addr != KASAN_SHADOW_END; addr += PGDIR_SIZE) + p4d_populate(&init_mm, p4d_offset(pgd++, addr), kasan_early_shadow_pud); +} + +void __init kasan_init(void) +{ + phys_addr_t start, end; + u64 i; + pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL_RO); + + for_each_mem_range(i, &start, &end) + kasan_init_phys_region((void *)start, (void *)end); + + if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) + kasan_remove_zero_shadow((void *)VMALLOC_START, VMALLOC_SIZE); + + for (i = 0; i < PTRS_PER_PTE; i++) + __set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page, + &kasan_early_shadow_pte[i], zero_pte, 0); + + flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END); + + memset(kasan_early_shadow_page, 0, PAGE_SIZE); + + /* Enable error messages */ + init_task.kasan_depth = 0; + pr_info("KASAN init done\n"); +} + +void __init kasan_late_init(void) { } |