[PATCH V2 2/3] mm/ptdump: Split effective_prot() into level specific callbacks

[Anshuman Khandual]

Last argument in effective_prot() is u64 assuming pxd_val() returned value
(all page table levels) is 64 bit. pxd_val() is very platform specific and
its type should not be assumed in generic MM.

Split effective_prot() into individual page table level specific callbacks
which accepts corresponding pxd_t argument instead and then the subscribing
platform (only x86) just derive pxd_val() from the entries as required and
proceed as earlier.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
 arch/x86/mm/dump_pagetables.c | 32 +++++++++++++++++++++++++++++++-
 include/linux/ptdump.h        |  6 +++++-
 mm/ptdump.c                   | 20 ++++++++++----------
 3 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 2e1c2d006ace..a4700ef6eb64 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -266,6 +266,32 @@ static void effective_prot(struct ptdump_state *pt_st, int level, u64 val)
 	st->prot_levels[level] = effective;
 }
 
+static void effective_prot_pte(struct ptdump_state *st, pte_t pte)
+{
+	effective_prot(st, 4, pte_val(pte));
+}
+
+static void effective_prot_pmd(struct ptdump_state *st, pmd_t pmd)
+{
+	effective_prot(st, 3, pmd_val(pmd));
+}
+
+static void effective_prot_pud(struct ptdump_state *st, pud_t pud)
+{
+	effective_prot(st, 2, pud_val(pud));
+}
+
+static void effective_prot_p4d(struct ptdump_state *st, p4d_t p4d)
+{
+	effective_prot(st, 1, p4d_val(p4d));
+}
+
+static void effective_prot_pgd(struct ptdump_state *st, pgd_t pgd)
+{
+	effective_prot(st, 0, pgd_val(pgd));
+}
+
+
 /*
  * This function gets called on a break in a continuous series
  * of PTE entries; the next one is different so we need to
@@ -416,7 +442,11 @@ bool ptdump_walk_pgd_level_core(struct seq_file *m,
 			.note_page_p4d = note_page_p4d,
 			.note_page_pgd = note_page_pgd,
 			.note_page_flush = note_page_flush,
-			.effective_prot = effective_prot,
+			.effective_prot_pte = effective_prot_pte,
+			.effective_prot_pmd = effective_prot_pmd,
+			.effective_prot_pud = effective_prot_pud,
+			.effective_prot_p4d = effective_prot_p4d,
+			.effective_prot_pgd = effective_prot_pgd,
 			.range		= ptdump_ranges
 		},
 		.level = -1,
diff --git a/include/linux/ptdump.h b/include/linux/ptdump.h
index 1c1eb1fae199..240bd3bff18d 100644
--- a/include/linux/ptdump.h
+++ b/include/linux/ptdump.h
@@ -17,7 +17,11 @@ struct ptdump_state {
 	void (*note_page_p4d)(struct ptdump_state *st, unsigned long addr, p4d_t p4d);
 	void (*note_page_pgd)(struct ptdump_state *st, unsigned long addr, pgd_t pgd);
 	void (*note_page_flush)(struct ptdump_state *st);
-	void (*effective_prot)(struct ptdump_state *st, int level, u64 val);
+	void (*effective_prot_pte)(struct ptdump_state *st, pte_t pte);
+	void (*effective_prot_pmd)(struct ptdump_state *st, pmd_t pmd);
+	void (*effective_prot_pud)(struct ptdump_state *st, pud_t pud);
+	void (*effective_prot_p4d)(struct ptdump_state *st, p4d_t p4d);
+	void (*effective_prot_pgd)(struct ptdump_state *st, pgd_t pgd);
 	const struct ptdump_range *range;
 };
 
diff --git a/mm/ptdump.c b/mm/ptdump.c
index 706cfc19439b..9374f29cdc6f 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c
@@ -38,8 +38,8 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
 		return note_kasan_page_table(walk, addr);
 #endif
 
-	if (st->effective_prot)
-		st->effective_prot(st, 0, pgd_val(val));
+	if (st->effective_prot_pgd)
+		st->effective_prot_pgd(st, val);
 
 	if (pgd_leaf(val)) {
 		st->note_page_pgd(st, addr, val);
@@ -61,8 +61,8 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
 		return note_kasan_page_table(walk, addr);
 #endif
 
-	if (st->effective_prot)
-		st->effective_prot(st, 1, p4d_val(val));
+	if (st->effective_prot_p4d)
+		st->effective_prot_p4d(st, val);
 
 	if (p4d_leaf(val)) {
 		st->note_page_p4d(st, addr, val);
@@ -84,8 +84,8 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
 		return note_kasan_page_table(walk, addr);
 #endif
 
-	if (st->effective_prot)
-		st->effective_prot(st, 2, pud_val(val));
+	if (st->effective_prot_pud)
+		st->effective_prot_pud(st, val);
 
 	if (pud_leaf(val)) {
 		st->note_page_pud(st, addr, val);
@@ -106,8 +106,8 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
 		return note_kasan_page_table(walk, addr);
 #endif
 
-	if (st->effective_prot)
-		st->effective_prot(st, 3, pmd_val(val));
+	if (st->effective_prot_pmd)
+		st->effective_prot_pmd(st, val);
 	if (pmd_leaf(val)) {
 		st->note_page_pmd(st, addr, val);
 		walk->action = ACTION_CONTINUE;
@@ -122,8 +122,8 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
 	struct ptdump_state *st = walk->private;
 	pte_t val = ptep_get_lockless(pte);
 
-	if (st->effective_prot)
-		st->effective_prot(st, 4, pte_val(val));
+	if (st->effective_prot_pte)
+		st->effective_prot_pte(st, val);
 
 	st->note_page_pte(st, addr, val);
 
-- 
2.25.1