Re: [PATCH v2 2/4] kasan: use MAX_PTRS_PER_* for early shadow

Balbir Singh
2019-12-10T09:36:34Z

On 10/12/19 3:47 pm, Daniel Axtens wrote:
> This helps with powerpc support, and should have no effect on
> anything else.
>
> Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Signed-off-by: Daniel Axtens <dja@axtens.net>

If you follow the recommendations by Christophe and I, you don't need this patch

Balbir Singh.

> ---
> include/linux/kasan.h | 6 +++---
> mm/kasan/init.c | 6 +++---
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index e18fe54969e9..d2f2a4ffcb12 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -15,9 +15,9 @@ struct task_struct;
> #include <asm/pgtable.h>
>
> extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
> -extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE];
> -extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD];
> -extern pud_t kasan_early_shadow_pud[PTRS_PER_PUD];
> +extern pte_t kasan_early_shadow_pte[MAX_PTRS_PER_PTE];
> +extern pmd_t kasan_early_shadow_pmd[MAX_PTRS_PER_PMD];
> +extern pud_t kasan_early_shadow_pud[MAX_PTRS_PER_PUD];
> extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
>
> int kasan_populate_early_shadow(const void *shadow_start,
> diff --git a/mm/kasan/init.c b/mm/kasan/init.c
> index ce45c491ebcd..8b54a96d3b3e 100644
> --- a/mm/kasan/init.c
> +++ b/mm/kasan/init.c
> @@ -46,7 +46,7 @@ static inline bool kasan_p4d_table(pgd_t pgd)
> }
> #endif
> #if CONFIG_PGTABLE_LEVELS > 3
> -pud_t kasan_early_shadow_pud[PTRS_PER_PUD] __page_aligned_bss;
> +pud_t kasan_early_shadow_pud[MAX_PTRS_PER_PUD] __page_aligned_bss;
> static inline bool kasan_pud_table(p4d_t p4d)
> {
> return p4d_page(p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud));
> @@ -58,7 +58,7 @@ static inline bool kasan_pud_table(p4d_t p4d)
> }
> #endif
> #if CONFIG_PGTABLE_LEVELS > 2
> -pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD] __page_aligned_bss;
> +pmd_t kasan_early_shadow_pmd[MAX_PTRS_PER_PMD] __page_aligned_bss;
> static inline bool kasan_pmd_table(pud_t pud)
> {
> return pud_page(pud) == virt_to_page(lm_alias(kasan_early_shadow_pmd));
> @@ -69,7 +69,7 @@ static inline bool kasan_pmd_table(pud_t pud)
> return false;
> }
> #endif
> -pte_t kasan_early_shadow_pte[PTRS_PER_PTE] __page_aligned_bss;
> +pte_t kasan_early_shadow_pte[MAX_PTRS_PER_PTE] __page_aligned_bss;
>
> static inline bool kasan_pte_table(pmd_t pmd)
> {
>