[PATCHv4 08/10] mm/kasan: Switch to using __pa_symbol and lm_alias
Mark Rutland
mark.rutland at arm.com
Tue Dec 6 09:44:44 PST 2016
On Tue, Nov 29, 2016 at 10:55:27AM -0800, Laura Abbott wrote:
> __pa_symbol is the correct API to find the physical address of symbols.
> Switch to it to allow for debugging APIs to work correctly. Other
> functions such as p*d_populate may call __pa internally. Ensure that the
> address passed is in the linear region by calling lm_alias.
I've given this a go on Juno with CONFIG_KASAN_INLINE enabled, and
everything seems happy.
We'll need an include of <linux/mm.h> as that appears to be missing. I
guess we're getting lucky with transitive includes. Otherwise this looks
good to me.
With that fixed up:
Reviewed-by: Mark Rutland <mark.rutland at arm.com>
Tested-by: Mark Rutland <mark.rutland at arm.com>
Thanks,
Mark.
> Signed-off-by: Laura Abbott <labbott at redhat.com>
> ---
> Pointed out during review/testing of v3.
> ---
> mm/kasan/kasan_init.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c
> index 3f9a41c..ff04721 100644
> --- a/mm/kasan/kasan_init.c
> +++ b/mm/kasan/kasan_init.c
> @@ -49,7 +49,7 @@ static void __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
> pte_t *pte = pte_offset_kernel(pmd, addr);
> pte_t zero_pte;
>
> - zero_pte = pfn_pte(PFN_DOWN(__pa(kasan_zero_page)), PAGE_KERNEL);
> + zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_zero_page)), PAGE_KERNEL);
> zero_pte = pte_wrprotect(zero_pte);
>
> while (addr + PAGE_SIZE <= end) {
> @@ -69,7 +69,7 @@ static void __init zero_pmd_populate(pud_t *pud, unsigned long addr,
> next = pmd_addr_end(addr, end);
>
> if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) {
> - pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
> + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
> continue;
> }
>
> @@ -94,7 +94,7 @@ static void __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
>
> pud_populate(&init_mm, pud, kasan_zero_pmd);
> pmd = pmd_offset(pud, addr);
> - pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
> + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
> continue;
> }
>
> @@ -135,11 +135,11 @@ void __init kasan_populate_zero_shadow(const void *shadow_start,
> * puds,pmds, so pgd_populate(), pud_populate()
> * is noops.
> */
> - pgd_populate(&init_mm, pgd, kasan_zero_pud);
> + pgd_populate(&init_mm, pgd, lm_alias(kasan_zero_pud));
> pud = pud_offset(pgd, addr);
> - pud_populate(&init_mm, pud, kasan_zero_pmd);
> + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
> pmd = pmd_offset(pud, addr);
> - pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
> + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte));
> continue;
> }
>
> --
> 2.7.4
>
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