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authorChristophe Leroy <christophe.leroy@c-s.fr>2019-08-21 10:20:00 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-11 18:36:00 +0200
commite946a841a9b3adfb0024b3c7840b404200a5abd2 (patch)
tree81f6143382e4ed15131594bfc89533c7d181c7ac /arch
parentd3b8b5c87fe13591a30ec577167e5ce33a354144 (diff)
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powerpc/mm: Add a helper to select PAGE_KERNEL_RO or PAGE_READONLY
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.1566382750.git.christophe.leroy@c-s.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/mm/kasan/kasan_init_32.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
index 802387b231ad..e8ab3cc5f6e4 100644
--- 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_tables(unsigned long k_start, unsigned l
{
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_tables(unsigned long k_start, unsigned l
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 *start, size_t size)
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);
}