From: Christophe Leroy christophe.leroy@c-s.fr
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@c-s.fr Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/9f33f44b9cd741c4a02b3dce7b8ef9438fe2cd2a.156638275... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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); }