From 7dec42ab57f2f59feba82abf0353164479bfde4c Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 19 May 2020 05:48:47 +0000 Subject: [PATCH] powerpc/kasan: Refactor update of early shadow mappings kasan_remap_early_shadow_ro() and kasan_unmap_early_shadow_vmalloc() are both updating the early shadow mapping: the first one sets the mapping read-only while the other clears the mapping. Refactor and create kasan_update_early_region() Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/8c496c0828de2608c7c940c45525d177e91b6f1b.1589866984.git.christophe.leroy@csgroup.eu --- arch/powerpc/mm/kasan/kasan_init_32.c | 39 +++++++++++++-------------- 1 file changed, 18 insertions(+), 21 deletions(-) diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c index 91e2ade75192..10481d904fea 100644 --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -79,45 +79,42 @@ static int __init kasan_init_region(void *start, size_t size) return 0; } -static void __init kasan_remap_early_shadow_ro(void) +static void __init +kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte) { - pgprot_t prot = kasan_prot_ro(); - unsigned long k_start = KASAN_SHADOW_START; - unsigned long k_end = KASAN_SHADOW_END; unsigned long k_cur; phys_addr_t pa = __pa(kasan_early_shadow_page); - kasan_populate_pte(kasan_early_shadow_pte, prot); - - for (k_cur = k_start & PAGE_MASK; k_cur != k_end; k_cur += PAGE_SIZE) { + for (k_cur = k_start; k_cur != k_end; k_cur += PAGE_SIZE) { pmd_t *pmd = pmd_ptr_k(k_cur); pte_t *ptep = pte_offset_kernel(pmd, k_cur); if ((pte_val(*ptep) & PTE_RPN_MASK) != pa) continue; - __set_pte_at(&init_mm, k_cur, ptep, pfn_pte(PHYS_PFN(pa), prot), 0); + __set_pte_at(&init_mm, k_cur, ptep, pte, 0); } - flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END); + + flush_tlb_kernel_range(k_start, k_end); } -static void __init kasan_unmap_early_shadow_vmalloc(void) +static void __init kasan_remap_early_shadow_ro(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); - unsigned long k_cur; + pgprot_t prot = kasan_prot_ro(); phys_addr_t pa = __pa(kasan_early_shadow_page); - for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) { - pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur); - pte_t *ptep = pte_offset_kernel(pmd, k_cur); + kasan_populate_pte(kasan_early_shadow_pte, prot); - if ((pte_val(*ptep) & PTE_RPN_MASK) != pa) - continue; + kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END, + pfn_pte(PHYS_PFN(pa), prot)); +} - __set_pte_at(&init_mm, k_cur, ptep, __pte(0), 0); - } - flush_tlb_kernel_range(k_start, k_end); +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)); } static void __init kasan_mmu_init(void) -- 2.20.1