[PATCH 3/4] powerpc/ptdump: Use kasan_pXX_table()

From: Christophe Leroy
Date: Wed Feb 02 2022 - 03:45:12 EST


Instead of opencoding, use the new kasan_pXX_table() helpers.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
mm/ptdump.c | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/mm/ptdump.c b/mm/ptdump.c
index da751448d0e4..bb6782de8203 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c
@@ -4,7 +4,6 @@
#include <linux/ptdump.h>
#include <linux/kasan.h>

-#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
/*
* This is an optimization for KASAN=y case. Since all kasan page tables
* eventually point to the kasan_early_shadow_page we could call note_page()
@@ -15,15 +14,16 @@
static inline int note_kasan_page_table(struct mm_walk *walk,
unsigned long addr)
{
+#ifdef CONFIG_KASAN_SOFTWARE
struct ptdump_state *st = walk->private;

st->note_page(st, addr, 4, pte_val(kasan_early_shadow_pte[0]));

walk->action = ACTION_CONTINUE;
+#endif

return 0;
}
-#endif

static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
@@ -31,11 +31,8 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
struct ptdump_state *st = walk->private;
pgd_t val = READ_ONCE(*pgd);

-#if CONFIG_PGTABLE_LEVELS > 4 && \
- (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
- if (pgd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_p4d)))
+ if (kasan_p4d_table(val))
return note_kasan_page_table(walk, addr);
-#endif

if (st->effective_prot)
st->effective_prot(st, 0, pgd_val(val));
@@ -52,11 +49,8 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
struct ptdump_state *st = walk->private;
p4d_t val = READ_ONCE(*p4d);

-#if CONFIG_PGTABLE_LEVELS > 3 && \
- (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
- if (p4d_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pud)))
+ if (kasan_pud_table(val))
return note_kasan_page_table(walk, addr);
-#endif

if (st->effective_prot)
st->effective_prot(st, 1, p4d_val(val));
@@ -73,11 +67,8 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
struct ptdump_state *st = walk->private;
pud_t val = READ_ONCE(*pud);

-#if CONFIG_PGTABLE_LEVELS > 2 && \
- (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
- if (pud_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pmd)))
+ if (kasan_pmd_table(val))
return note_kasan_page_table(walk, addr);
-#endif

if (st->effective_prot)
st->effective_prot(st, 2, pud_val(val));
@@ -94,10 +85,8 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
struct ptdump_state *st = walk->private;
pmd_t val = READ_ONCE(*pmd);

-#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
- if (pmd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pte)))
+ if (kasan_pte_table(val))
return note_kasan_page_table(walk, addr);
-#endif

if (st->effective_prot)
st->effective_prot(st, 3, pmd_val(val));
--
2.33.1