From: Christophe Leroy <christophe.leroy@xxxxxx> commit 4c0f5d1eb4072871c34530358df45f05ab80edd6 upstream. In a couple of places there is a need to select whether read-only protection of shadow pages is performed with PAGE_KERNEL_RO or with PAGE_READONLY. Add a helper to avoid duplicating the choice. Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/9f33f44b9cd741c4a02b3dce7b8ef9438fe2cd2a.1566382750.git.christophe.leroy@xxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/mm/kasan/kasan_init_32.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -12,6 +12,14 @@ #include <asm/code-patching.h> #include <mm/mmu_decl.h> +static pgprot_t kasan_prot_ro(void) +{ + if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return PAGE_READONLY; + + return PAGE_KERNEL_RO; +} + static void kasan_populate_pte(pte_t *ptep, pgprot_t prot) { unsigned long va = (unsigned long)kasan_early_shadow_page; @@ -26,6 +34,7 @@ static int __ref kasan_init_shadow_page_ { pmd_t *pmd; unsigned long k_cur, k_next; + pgprot_t prot = kasan_prot_ro(); pmd = pmd_offset(pud_offset(pgd_offset_k(k_start), k_start), k_start); @@ -43,10 +52,7 @@ static int __ref kasan_init_shadow_page_ if (!new) return -ENOMEM; - if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) - kasan_populate_pte(new, PAGE_READONLY); - else - kasan_populate_pte(new, PAGE_KERNEL_RO); + kasan_populate_pte(new, prot); smp_wmb(); /* See comment in __pte_alloc */ @@ -103,10 +109,9 @@ static int __ref kasan_init_region(void static void __init kasan_remap_early_shadow_ro(void) { - if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) - kasan_populate_pte(kasan_early_shadow_pte, PAGE_READONLY); - else - kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL_RO); + pgprot_t prot = kasan_prot_ro(); + + kasan_populate_pte(kasan_early_shadow_pte, prot); flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END); }
