On 2017.10.12 7:43AM Dmitry Osipenko [mailto:digetx@xxxxxxxxx] wrote: >Shouldn't all __pgprot's contain L_PTE_MT_WRITETHROUGH ? > >[...] > >-- >Dmitry Thanks for your review. I'm sorry that my replay is so late. I don't think L_PTE_MT_WRITETHROUGH is need for all arm soc. So I think kasan's mapping can use PAGE_KERNEL which can be initialized for different arm soc and __pgprot(pgprot_val(PAGE_KERNEL) | L_PTE_RDONLY)). I don't think the mapping table flags in kasan_early_init need be changed because of the follow reason: 1) PAGE_KERNEL can't be used in early_kasan_init because the pgprot_kernel which is used to define PAGE_KERNEL doesn't be initialized. 2) all of the kasan shadow's mapping table is going to be created again in kasan_init function. All what I say is: I think only the mapping table flags in kasan_init function need to be changed into PAGE_KERNEL or __pgprot(pgprot_val(PAGE_KERNEL) | L_PTE_RDONLY)). Here is the code, I has already tested: --- a/arch/arm/mm/kasan_init.c +++ b/arch/arm/mm/kasan_init.c @@ -124,7 +124,7 @@ pte_t * __meminit kasan_pte_populate(pmd_t *pmd, unsigned long addr, int node) void *p = kasan_alloc_block(PAGE_SIZE, node); if (!p) return NULL; - entry = pfn_pte(virt_to_pfn(p), __pgprot(_L_PTE_DEFAULT | L_PTE_DIRTY | L_PTE_XN)); + entry = pfn_pte(virt_to_pfn(p), __pgprot(pgprot_val(PAGE_KERNEL))); set_pte_at(&init_mm, addr, pte, entry); } return pte; @@ -253,7 +254,7 @@ void __init kasan_init(void) set_pte_at(&init_mm, KASAN_SHADOW_START + i*PAGE_SIZE, &kasan_zero_pte[i], pfn_pte( virt_to_pfn(kasan_zero_page), - __pgprot(_L_PTE_DEFAULT | L_PTE_DIRTY | L_PTE_XN | L_PTE_RDONLY))); + __pgprot(pgprot_val(PAGE_KERNEL) | L_PTE_RDONLY))); memset(kasan_zero_page, 0, PAGE_SIZE); cpu_set_ttbr0(orig_ttbr0); flush_cache_all(); ��.n������g��� �a��� �&ޖ)���)��h���&������梷���� �Ǟ�m������)������^�����������v���O��zf������
