Re: [RFC PATCH v2 2/3] mm: make pXd_addr_end() functions page-table entry aware

Alexander Gordeev
2020-09-08T07:47:57Z

On Tue, Sep 08, 2020 at 07:14:38AM +0200, Christophe Leroy wrote:
> You forgot arch/powerpc/mm/book3s64/subpage_prot.c it seems.

Yes, and also two more sources :/
arch/powerpc/mm/kasan/8xx.c
arch/powerpc/mm/kasan/kasan_init_32.c

But these two are not quite obvious wrt pgd_addr_end() used
while traversing pmds. Could you please clarify a bit?

diff --git a/arch/powerpc/mm/kasan/8xx.c b/arch/powerpc/mm/kasan/8xx.c
index 2784224..89c5053 100644
--- a/arch/powerpc/mm/kasan/8xx.c
+++ b/arch/powerpc/mm/kasan/8xx.c
@@ -15,8 +15,8 @@
for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
pte_basic_t *new;

- k_next = pgd_addr_end(k_cur, k_end);
- k_next = pgd_addr_end(k_next, k_end);
+ k_next = pmd_addr_end(k_cur, k_end);
+ k_next = pmd_addr_end(k_next, k_end);
if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
continue;

diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
index fb29404..3f7d6dc6 100644
--- a/arch/powerpc/mm/kasan/kasan_init_32.c
+++ b/arch/powerpc/mm/kasan/kasan_init_32.c
@@ -38,7 +38,7 @@ int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_
for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
pte_t *new;

- k_next = pgd_addr_end(k_cur, k_end);
+ k_next = pmd_addr_end(k_cur, k_end);
if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
continue;

@@ -196,7 +196,7 @@ void __init kasan_early_init(void)
kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL);

do {
- next = pgd_addr_end(addr, end);
+ next = pmd_addr_end(addr, end);
pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte);
} while (pmd++, addr = next, addr != end);

> Christophe