Commit 7dec42ab authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

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: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8c496c0828de2608c7c940c45525d177e91b6f1b.1589866984.git.christophe.leroy@csgroup.eu
parent 7c31c05e

arch/powerpc/mm/kasan/kasan_init_32.c

+18 −21
Original line number Diff line number Diff line
@@ -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);



		if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)

			continue;

	kasan_populate_pte(kasan_early_shadow_pte, prot);



		__set_pte_at(&init_mm, k_cur, ptep, __pte(0), 0);

	kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END,

				  pfn_pte(PHYS_PFN(pa), prot));

}

	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)

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