On 3/17/25 11:48, Anshuman Khandual wrote:
> 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.
Does this look good OR is there any concern OR an alternate approach ?
>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Madhavan Srinivasan <maddy@xxxxxxxxxxxxx>
> Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
> Cc: linux-s390@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> arch/arm64/include/asm/ptdump.h | 16 +++++++++--
> arch/arm64/mm/ptdump.c | 48 ++++++++++++++++++++++++++++++---
> arch/powerpc/mm/ptdump/ptdump.c | 46 +++++++++++++++++++++++++++++--
> arch/riscv/mm/ptdump.c | 46 +++++++++++++++++++++++++++++--
> arch/s390/mm/dump_pagetables.c | 46 +++++++++++++++++++++++++++++--
> arch/x86/mm/dump_pagetables.c | 39 ++++++++++++++++++++++++++-
> include/linux/ptdump.h | 9 ++++---
> mm/ptdump.c | 42 ++++++++++++++++++++++-------
> 8 files changed, 267 insertions(+), 25 deletions(-)
>
> diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
> index 6cf4aae05219..e5da9ce8a515 100644
> --- 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_CORE */
>
> #endif /* __ASM_PTDUMP_H */
> diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
> index 688fbe0271ca..fd1610b4fd15 100644
> --- 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 9dc239967b77..b2358d794855 100644
> --- 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 9d5f657a251b..32922550a50a 100644
> --- 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 fa54f3bc0c8d..e7cc52542f71 100644
> --- a/arch/s390/mm/dump_pagetables.c
> +++ b/arch/s390/mm/dump_pagetables.c
> @@ -145,11 +145,48 @@ 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},
> @@ -188,7 +225,12 @@ 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 89079ea73e65..2e1c2d006ace 100644
> --- 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 8dbd51ea8626..1c1eb1fae199 100644
> --- 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 106e1d66e9f9..706cfc19439b 100644
> --- 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)
