mm/ptdump: split note_page() into level specific callbacks

Patch series "mm/ptdump: Drop assumption that pxd_val() is u64", v2.

Last argument passed down in note_page() is u64 assuming pxd_val()
returned value (all page table levels) is 64 bit - which might not be the
case going ahead when D128 page tables is enabled on arm64 platform.
Besides pxd_val() is very platform specific and its type should not be
assumed in generic MM.  A similar problem exists for effective_prot(),
although it is restricted to x86 platform.

This series splits note_page() and effective_prot() into individual page
table level specific callbacks which accepts corresponding pxd_t page
table entry as an argument instead and later on all subscribing platforms
could derive pxd_val() from the table entries as required and proceed as
before.

Define ptdesc_t type which describes the basic page table descriptor
layout on arm64 platform.  Subsequently all level specific pxxval_t
descriptors are derived from ptdesc_t thus establishing a common original
format, which can also be appropriate for page table entries, masks and
protection values etc which are used at all page table levels.

This patch (of 3):

Last argument passed down in note_page() is u64 assuming pxd_val()
returned value (all page table levels) is 64 bit - which might not be the
case going ahead when D128 page tables is enabled on arm64 platform.
Besides pxd_val() is very platform specific and its type should not be
assumed in generic MM.

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

Also add a note_page_flush() callback for flushing the last page table
page that was being handled earlier via level = -1.

Link: https://lkml.kernel.org/r/20250407053113.746295-1-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/20250407053113.746295-2-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
index b2931d1ae0fb3022d377af920235de0ecba00c4b..01033c1d38dc210de3ee31786afa84f880387a01 100644 (file)
--- a/arch/arm64/include/asm/ptdump.h
+++ b/arch/arm64/include/asm/ptdump.h
@@ -59,7 +59,13 @@ struct ptdump_pg_state {
 
 void ptdump_walk(struct seq_file *s, struct ptdump_info *info);
 void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
-              u64 val);
+              pteval_t val);
+void note_page_pte(struct ptdump_state *st, unsigned long addr, pte_t pte);
+void note_page_pmd(struct ptdump_state *st, unsigned long addr, pmd_t pmd);
+void note_page_pud(struct ptdump_state *st, unsigned long addr, pud_t pud);
+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);
 #ifdef CONFIG_PTDUMP_DEBUGFS
 #define EFI_RUNTIME_MAP_END    DEFAULT_MAP_WINDOW_64
 void __init ptdump_debugfs_register(struct ptdump_info *info, const char *name);
@@ -69,7 +75,13 @@ static inline void ptdump_debugfs_register(struct ptdump_info *info,
 #endif /* CONFIG_PTDUMP_DEBUGFS */
 #else
 static inline void note_page(struct ptdump_state *pt_st, unsigned long addr,
-                            int level, u64 val) { }
+                            int level, pteval_t val) { }
+static inline void note_page_pte(struct ptdump_state *st, unsigned long addr, pte_t pte) { }
+static inline void note_page_pmd(struct ptdump_state *st, unsigned long addr, pmd_t pmd) { }
+static inline void note_page_pud(struct ptdump_state *st, unsigned long addr, pud_t pud) { }
+static inline void note_page_p4d(struct ptdump_state *st, unsigned long addr, p4d_t p4d) { }
+static inline void note_page_pgd(struct ptdump_state *st, unsigned long addr, pgd_t pgd) { }
+static inline void note_page_flush(struct ptdump_state *st) { }
 #endif /* CONFIG_PTDUMP */
 
 #endif /* __ASM_PTDUMP_H */

diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index 8cec0da4cff287eaf96772bb9124c8ce103a4e83..ac0c20ba0cd9d3693ea00f28248509d84d5bfa63 100644 (file)
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c
@@ -189,7 +189,7 @@ static void note_prot_wx(struct ptdump_pg_state *st, unsigned long addr)
 }
 
 void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
-              u64 val)
+              pteval_t val)
 {
        struct ptdump_pg_state *st = container_of(pt_st, struct ptdump_pg_state, ptdump);
        struct ptdump_pg_level *pg_level = st->pg_level;
@@ -251,6 +251,38 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 
 }
 
+void note_page_pte(struct ptdump_state *pt_st, unsigned long addr, pte_t pte)
+{
+       note_page(pt_st, addr, 4, pte_val(pte));
+}
+
+void note_page_pmd(struct ptdump_state *pt_st, unsigned long addr, pmd_t pmd)
+{
+       note_page(pt_st, addr, 3, pmd_val(pmd));
+}
+
+void note_page_pud(struct ptdump_state *pt_st, unsigned long addr, pud_t pud)
+{
+       note_page(pt_st, addr, 2, pud_val(pud));
+}
+
+void note_page_p4d(struct ptdump_state *pt_st, unsigned long addr, p4d_t p4d)
+{
+       note_page(pt_st, addr, 1, p4d_val(p4d));
+}
+
+void note_page_pgd(struct ptdump_state *pt_st, unsigned long addr, pgd_t pgd)
+{
+       note_page(pt_st, addr, 0, pgd_val(pgd));
+}
+
+void note_page_flush(struct ptdump_state *pt_st)
+{
+       pte_t pte_zero = {0};
+
+       note_page(pt_st, 0, -1, pte_val(pte_zero));
+}
+
 void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
 {
        unsigned long end = ~0UL;
@@ -266,7 +298,12 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
                .pg_level = &kernel_pg_levels[0],
                .level = -1,
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = (struct ptdump_range[]){
                                {info->base_addr, end},
                                {0, 0}
@@ -303,7 +340,12 @@ bool ptdump_check_wx(void)
                .level = -1,
                .check_wx = true,
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = (struct ptdump_range[]) {
                                {_PAGE_OFFSET(vabits_actual), ~0UL},
                                {0, 0}

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 9dc239967b77f79d8e47b8c3cc476d307d4b17a3..b2358d794855caea08abafbafcd854ab678504eb 100644 (file)
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -298,6 +298,38 @@ static void populate_markers(void)
 #endif
 }
 
+static void note_page_pte(struct ptdump_state *pt_st, unsigned long addr, pte_t pte)
+{
+       note_page(pt_st, addr, 4, pte_val(pte));
+}
+
+static void note_page_pmd(struct ptdump_state *pt_st, unsigned long addr, pmd_t pmd)
+{
+       note_page(pt_st, addr, 3, pmd_val(pmd));
+}
+
+static void note_page_pud(struct ptdump_state *pt_st, unsigned long addr, pud_t pud)
+{
+       note_page(pt_st, addr, 2, pud_val(pud));
+}
+
+static void note_page_p4d(struct ptdump_state *pt_st, unsigned long addr, p4d_t p4d)
+{
+       note_page(pt_st, addr, 1, p4d_val(p4d));
+}
+
+static void note_page_pgd(struct ptdump_state *pt_st, unsigned long addr, pgd_t pgd)
+{
+       note_page(pt_st, addr, 0, pgd_val(pgd));
+}
+
+static void note_page_flush(struct ptdump_state *pt_st)
+{
+       pte_t pte_zero = {0};
+
+       note_page(pt_st, 0, -1, pte_val(pte_zero));
+}
+
 static int ptdump_show(struct seq_file *m, void *v)
 {
        struct pg_state st = {
@@ -305,7 +337,12 @@ static int ptdump_show(struct seq_file *m, void *v)
                .marker = address_markers,
                .level = -1,
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = ptdump_range,
                }
        };
@@ -338,7 +375,12 @@ bool ptdump_check_wx(void)
                .level = -1,
                .check_wx = true,
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = ptdump_range,
                }
        };

diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index 9d5f657a251b328dffb0ea807b4576ab15cc4e92..32922550a50a3abe04c3c4227e2704760b66be9e 100644 (file)
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c
@@ -318,6 +318,38 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr,
        }
 }
 
+static void note_page_pte(struct ptdump_state *pt_st, unsigned long addr, pte_t pte)
+{
+       note_page(pt_st, addr, 4, pte_val(pte));
+}
+
+static void note_page_pmd(struct ptdump_state *pt_st, unsigned long addr, pmd_t pmd)
+{
+       note_page(pt_st, addr, 3, pmd_val(pmd));
+}
+
+static void note_page_pud(struct ptdump_state *pt_st, unsigned long addr, pud_t pud)
+{
+       note_page(pt_st, addr, 2, pud_val(pud));
+}
+
+static void note_page_p4d(struct ptdump_state *pt_st, unsigned long addr, p4d_t p4d)
+{
+       note_page(pt_st, addr, 1, p4d_val(p4d));
+}
+
+static void note_page_pgd(struct ptdump_state *pt_st, unsigned long addr, pgd_t pgd)
+{
+       note_page(pt_st, addr, 0, pgd_val(pgd));
+}
+
+static void note_page_flush(struct ptdump_state *pt_st)
+{
+       pte_t pte_zero = {0};
+
+       note_page(pt_st, 0, -1, pte_val(pte_zero));
+}
+
 static void ptdump_walk(struct seq_file *s, struct ptd_mm_info *pinfo)
 {
        struct pg_state st = {
@@ -325,7 +357,12 @@ static void ptdump_walk(struct seq_file *s, struct ptd_mm_info *pinfo)
                .marker = pinfo->markers,
                .level = -1,
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = (struct ptdump_range[]) {
                                {pinfo->base_addr, pinfo->end},
                                {0, 0}
@@ -347,7 +384,12 @@ bool ptdump_check_wx(void)
                .level = -1,
                .check_wx = true,
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = (struct ptdump_range[]) {
                                {KERN_VIRT_START, ULONG_MAX},
                                {0, 0}

diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index d3e943752fa0a46aae4167837b2da55875e26998..ac604b17666095c2c78225ed70bfc4e768c4e01a 100644 (file)
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -147,11 +147,48 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
        }
 }
 
+static void note_page_pte(struct ptdump_state *pt_st, unsigned long addr, pte_t pte)
+{
+       note_page(pt_st, addr, 4, pte_val(pte));
+}
+
+static void note_page_pmd(struct ptdump_state *pt_st, unsigned long addr, pmd_t pmd)
+{
+       note_page(pt_st, addr, 3, pmd_val(pmd));
+}
+
+static void note_page_pud(struct ptdump_state *pt_st, unsigned long addr, pud_t pud)
+{
+       note_page(pt_st, addr, 2, pud_val(pud));
+}
+
+static void note_page_p4d(struct ptdump_state *pt_st, unsigned long addr, p4d_t p4d)
+{
+       note_page(pt_st, addr, 1, p4d_val(p4d));
+}
+
+static void note_page_pgd(struct ptdump_state *pt_st, unsigned long addr, pgd_t pgd)
+{
+       note_page(pt_st, addr, 0, pgd_val(pgd));
+}
+
+static void note_page_flush(struct ptdump_state *pt_st)
+{
+       pte_t pte_zero = {0};
+
+       note_page(pt_st, 0, -1, pte_val(pte_zero));
+}
+
 bool ptdump_check_wx(void)
 {
        struct pg_state st = {
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = (struct ptdump_range[]) {
                                {.start = 0, .end = max_addr},
                                {.start = 0, .end = 0},
@@ -190,7 +227,12 @@ static int ptdump_show(struct seq_file *m, void *v)
 {
        struct pg_state st = {
                .ptdump = {
-                       .note_page = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .range = (struct ptdump_range[]) {
                                {.start = 0, .end = max_addr},
                                {.start = 0, .end = 0},

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 89079ea73e65b6b134ad0270681aee90745fa70f..2e1c2d006aceb7f69e47f32f2d4cd33330e907b8 100644 (file)
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -362,6 +362,38 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
        }
 }
 
+static void note_page_pte(struct ptdump_state *pt_st, unsigned long addr, pte_t pte)
+{
+       note_page(pt_st, addr, 4, pte_val(pte));
+}
+
+static void note_page_pmd(struct ptdump_state *pt_st, unsigned long addr, pmd_t pmd)
+{
+       note_page(pt_st, addr, 3, pmd_val(pmd));
+}
+
+static void note_page_pud(struct ptdump_state *pt_st, unsigned long addr, pud_t pud)
+{
+       note_page(pt_st, addr, 2, pud_val(pud));
+}
+
+static void note_page_p4d(struct ptdump_state *pt_st, unsigned long addr, p4d_t p4d)
+{
+       note_page(pt_st, addr, 1, p4d_val(p4d));
+}
+
+static void note_page_pgd(struct ptdump_state *pt_st, unsigned long addr, pgd_t pgd)
+{
+       note_page(pt_st, addr, 0, pgd_val(pgd));
+}
+
+static void note_page_flush(struct ptdump_state *pt_st)
+{
+       pte_t pte_zero = {0};
+
+       note_page(pt_st, 0, -1, pte_val(pte_zero));
+}
+
 bool ptdump_walk_pgd_level_core(struct seq_file *m,
                                struct mm_struct *mm, pgd_t *pgd,
                                bool checkwx, bool dmesg)
@@ -378,7 +410,12 @@ bool ptdump_walk_pgd_level_core(struct seq_file *m,
 
        struct pg_state st = {
                .ptdump = {
-                       .note_page      = note_page,
+                       .note_page_pte = note_page_pte,
+                       .note_page_pmd = note_page_pmd,
+                       .note_page_pud = note_page_pud,
+                       .note_page_p4d = note_page_p4d,
+                       .note_page_pgd = note_page_pgd,
+                       .note_page_flush = note_page_flush,
                        .effective_prot = effective_prot,
                        .range          = ptdump_ranges
                },

diff --git a/include/linux/ptdump.h b/include/linux/ptdump.h
index 8dbd51ea862678b8ec7a4684b986e3e574b921bd..1c1eb1fae199a17ed901f98c48cb31c2ed91ea35 100644 (file)
--- a/include/linux/ptdump.h
+++ b/include/linux/ptdump.h
@@ -11,9 +11,12 @@ struct ptdump_range {
 };
 
 struct ptdump_state {
-       /* level is 0:PGD to 4:PTE, or -1 if unknown */
-       void (*note_page)(struct ptdump_state *st, unsigned long addr,
-                         int level, u64 val);
+       void (*note_page_pte)(struct ptdump_state *st, unsigned long addr, pte_t pte);
+       void (*note_page_pmd)(struct ptdump_state *st, unsigned long addr, pmd_t pmd);
+       void (*note_page_pud)(struct ptdump_state *st, unsigned long addr, pud_t pud);
+       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);
        const struct ptdump_range *range;
 };

diff --git a/mm/ptdump.c b/mm/ptdump.c
index 106e1d66e9f9ee0612c9005f9fdb1faa3053610f..706cfc19439bfbea71024715b43d620bd1406d79 100644 (file)
--- a/mm/ptdump.c
+++ b/mm/ptdump.c
@@ -18,7 +18,7 @@ static inline int note_kasan_page_table(struct mm_walk *walk,
 {
        struct ptdump_state *st = walk->private;
 
-       st->note_page(st, addr, 4, pte_val(kasan_early_shadow_pte[0]));
+       st->note_page_pte(st, addr, kasan_early_shadow_pte[0]);
 
        walk->action = ACTION_CONTINUE;
 
@@ -42,7 +42,7 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
                st->effective_prot(st, 0, pgd_val(val));
 
        if (pgd_leaf(val)) {
-               st->note_page(st, addr, 0, pgd_val(val));
+               st->note_page_pgd(st, addr, val);
                walk->action = ACTION_CONTINUE;
        }
 
@@ -65,7 +65,7 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
                st->effective_prot(st, 1, p4d_val(val));
 
        if (p4d_leaf(val)) {
-               st->note_page(st, addr, 1, p4d_val(val));
+               st->note_page_p4d(st, addr, val);
                walk->action = ACTION_CONTINUE;
        }
 
@@ -88,7 +88,7 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
                st->effective_prot(st, 2, pud_val(val));
 
        if (pud_leaf(val)) {
-               st->note_page(st, addr, 2, pud_val(val));
+               st->note_page_pud(st, addr, val);
                walk->action = ACTION_CONTINUE;
        }
 
@@ -109,7 +109,7 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
        if (st->effective_prot)
                st->effective_prot(st, 3, pmd_val(val));
        if (pmd_leaf(val)) {
-               st->note_page(st, addr, 3, pmd_val(val));
+               st->note_page_pmd(st, addr, val);
                walk->action = ACTION_CONTINUE;
        }
 
@@ -125,7 +125,7 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
        if (st->effective_prot)
                st->effective_prot(st, 4, pte_val(val));
 
-       st->note_page(st, addr, 4, pte_val(val));
+       st->note_page_pte(st, addr, val);
 
        return 0;
 }
@@ -134,9 +134,31 @@ static int ptdump_hole(unsigned long addr, unsigned long next,
                       int depth, struct mm_walk *walk)
 {
        struct ptdump_state *st = walk->private;
-
-       st->note_page(st, addr, depth, 0);
-
+       pte_t pte_zero = {0};
+       pmd_t pmd_zero = {0};
+       pud_t pud_zero = {0};
+       p4d_t p4d_zero = {0};
+       pgd_t pgd_zero = {0};
+
+       switch (depth) {
+       case 4:
+               st->note_page_pte(st, addr, pte_zero);
+               break;
+       case 3:
+               st->note_page_pmd(st, addr, pmd_zero);
+               break;
+       case 2:
+               st->note_page_pud(st, addr, pud_zero);
+               break;
+       case 1:
+               st->note_page_p4d(st, addr, p4d_zero);
+               break;
+       case 0:
+               st->note_page_pgd(st, addr, pgd_zero);
+               break;
+       default:
+               break;
+       }
        return 0;
 }
 
@@ -162,7 +184,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd)
        mmap_write_unlock(mm);
 
        /* Flush out the last page */
-       st->note_page(st, 0, -1, 0);
+       st->note_page_flush(st);
 }
 
 static int check_wx_show(struct seq_file *m, void *v)