diff options
Diffstat (limited to 'arch/powerpc/mm/kasan/init_32.c')
| -rw-r--r-- | arch/powerpc/mm/kasan/init_32.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/arch/powerpc/mm/kasan/init_32.c b/arch/powerpc/mm/kasan/init_32.c new file mode 100644 index 000000000..a70828a6d --- /dev/null +++ b/arch/powerpc/mm/kasan/init_32.c @@ -0,0 +1,191 @@ +// 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 <asm/pgalloc.h> +#include <asm/code-patching.h> +#include <mm/mmu_decl.h> + +static pgprot_t __init kasan_prot_ro(void) +{ + if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return PAGE_READONLY; + + return PAGE_KERNEL_RO; +} + +static void __init 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), 1); +} + +int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end) +{ + pmd_t *pmd; + unsigned long k_cur, k_next; + + pmd = pmd_off_k(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 = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE); + + if (!new) + return -ENOMEM; + kasan_populate_pte(new, PAGE_KERNEL); + pmd_populate_kernel(&init_mm, pmd, new); + } + return 0; +} + +int __init __weak 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; + + ret = kasan_init_shadow_page_tables(k_start, k_end); + if (ret) + return ret; + + block = memblock_alloc(k_end - k_start, PAGE_SIZE); + if (!block) + return -ENOMEM; + + for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) { + pmd_t *pmd = pmd_off_k(k_cur); + void *va = block + k_cur - k_start; + pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL); + + __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; +} + +void __init +kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte) +{ + unsigned long k_cur; + + for (k_cur = k_start; k_cur != k_end; k_cur += PAGE_SIZE) { + pmd_t *pmd = pmd_off_k(k_cur); + pte_t *ptep = pte_offset_kernel(pmd, k_cur); + + if (pte_page(*ptep) != virt_to_page(lm_alias(kasan_early_shadow_page))) + continue; + + __set_pte_at(&init_mm, k_cur, ptep, pte, 0); + } + + flush_tlb_kernel_range(k_start, k_end); +} + +static void __init kasan_remap_early_shadow_ro(void) +{ + pgprot_t prot = kasan_prot_ro(); + phys_addr_t pa = __pa(kasan_early_shadow_page); + + kasan_populate_pte(kasan_early_shadow_pte, prot); + + kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END, + pfn_pte(PHYS_PFN(pa), prot)); +} + +static void __init kasan_unmap_early_shadow_vmalloc(void) +{ + unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START); + unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END); + + kasan_update_early_region(k_start, k_end, __pte(0)); + +#ifdef MODULES_VADDR + k_start = (unsigned long)kasan_mem_to_shadow((void *)MODULES_VADDR); + k_end = (unsigned long)kasan_mem_to_shadow((void *)MODULES_END); + kasan_update_early_region(k_start, k_end, __pte(0)); +#endif +} + +void __init kasan_mmu_init(void) +{ + int ret; + + if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) { + ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END); + + if (ret) + panic("kasan: kasan_init_shadow_page_tables() failed"); + } +} + +void __init kasan_init(void) +{ + phys_addr_t base, end; + u64 i; + int ret; + + for_each_mem_range(i, &base, &end) { + phys_addr_t top = min(end, total_lowmem); + + if (base >= top) + continue; + + ret = kasan_init_region(__va(base), top - base); + if (ret) + panic("kasan: kasan_init_region() failed"); + } + + if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { + ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END); + + if (ret) + panic("kasan: kasan_init_shadow_page_tables() failed"); + } + + 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"); +} + +void __init kasan_late_init(void) +{ + if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) + kasan_unmap_early_shadow_vmalloc(); +} + +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_off_k(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); +} |