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[PATCH 5/5] ptdump: add state parameter for non-leaf callback

Maxwell Bland posted 5 patches 1 year, 10 months ago
[PATCH 5/5] ptdump: add state parameter for non-leaf callback
Posted by Maxwell Bland 1 year, 10 months ago 
ptdump can now note non-leaf descriptor entries, a useful addition for
debugging table descriptor permissions when working on related code

Signed-off-by: Maxwell Bland <mbland@motorola.com>
---
 arch/arm64/mm/ptdump.c          |  6 ++++--
 arch/powerpc/mm/ptdump/ptdump.c |  2 ++
 arch/riscv/mm/ptdump.c          |  6 ++++--
 arch/s390/mm/dump_pagetables.c  |  6 ++++--
 arch/x86/mm/dump_pagetables.c   |  3 ++-
 include/linux/ptdump.h          |  1 +
 mm/ptdump.c                     | 13 +++++++++++++
 7 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index 796231a4fd63..1a6f4a3513e5 100644
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c
@@ -299,7 +299,8 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
 			.range = (struct ptdump_range[]){
 				{info->base_addr, end},
 				{0, 0}
-			}
+			},
+			.note_non_leaf = false
 		}
 	};
 
@@ -335,7 +336,8 @@ bool ptdump_check_wx(void)
 			.range = (struct ptdump_range[]) {
 				{_PAGE_OFFSET(vabits_actual), ~0UL},
 				{0, 0}
-			}
+			},
+			.note_non_leaf = false
 		}
 	};
 
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 9dc239967b77..89e673f5fd3d 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -307,6 +307,7 @@ static int ptdump_show(struct seq_file *m, void *v)
 		.ptdump = {
 			.note_page = note_page,
 			.range = ptdump_range,
+			.note_non_leaf = false
 		}
 	};
 
@@ -340,6 +341,7 @@ bool ptdump_check_wx(void)
 		.ptdump = {
 			.note_page = note_page,
 			.range = ptdump_range,
+			.note_non_leaf = false
 		}
 	};
 
diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index 1289cc6d3700..b355633afcaf 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/arch/riscv/mm/ptdump.c
@@ -328,7 +328,8 @@ static void ptdump_walk(struct seq_file *s, struct ptd_mm_info *pinfo)
 			.range = (struct ptdump_range[]) {
 				{pinfo->base_addr, pinfo->end},
 				{0, 0}
-			}
+			},
+			.note_non_leaf = false
 		}
 	};
 
@@ -350,7 +351,8 @@ bool ptdump_check_wx(void)
 			.range = (struct ptdump_range[]) {
 				{KERN_VIRT_START, ULONG_MAX},
 				{0, 0}
-			}
+			},
+			.note_non_leaf = false
 		}
 	};
 
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index ffd07ed7b4af..6468cfd53e2a 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -200,7 +200,8 @@ bool ptdump_check_wx(void)
 			.range = (struct ptdump_range[]) {
 				{.start = 0, .end = max_addr},
 				{.start = 0, .end = 0},
-			}
+			},
+			.note_non_leaf = false
 		},
 		.seq = NULL,
 		.level = -1,
@@ -239,7 +240,8 @@ static int ptdump_show(struct seq_file *m, void *v)
 			.range = (struct ptdump_range[]) {
 				{.start = 0, .end = max_addr},
 				{.start = 0, .end = 0},
-			}
+			},
+			.note_non_leaf = false
 		},
 		.seq = m,
 		.level = -1,
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 89079ea73e65..43f00dfb955f 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -380,7 +380,8 @@ bool ptdump_walk_pgd_level_core(struct seq_file *m,
 		.ptdump = {
 			.note_page	= note_page,
 			.effective_prot = effective_prot,
-			.range		= ptdump_ranges
+			.range		= ptdump_ranges,
+			.note_non_leaf  = false
 		},
 		.level = -1,
 		.to_dmesg	= dmesg,
diff --git a/include/linux/ptdump.h b/include/linux/ptdump.h
index 8dbd51ea8626..b3e793a5c77f 100644
--- a/include/linux/ptdump.h
+++ b/include/linux/ptdump.h
@@ -16,6 +16,7 @@ struct ptdump_state {
 			  int level, u64 val);
 	void (*effective_prot)(struct ptdump_state *st, int level, u64 val);
 	const struct ptdump_range *range;
+	bool note_non_leaf;
 };
 
 bool ptdump_walk_pgd_level_core(struct seq_file *m,
diff --git a/mm/ptdump.c b/mm/ptdump.c
index 106e1d66e9f9..97da7a765b22 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c
@@ -41,6 +41,9 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
 	if (st->effective_prot)
 		st->effective_prot(st, 0, pgd_val(val));
 
+	if (st->note_non_leaf && !pgd_leaf(val))
+		st->note_page(st, addr, 0, pgd_val(val));
+
 	if (pgd_leaf(val)) {
 		st->note_page(st, addr, 0, pgd_val(val));
 		walk->action = ACTION_CONTINUE;
@@ -64,6 +67,9 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
 	if (st->effective_prot)
 		st->effective_prot(st, 1, p4d_val(val));
 
+	if (st->note_non_leaf && !p4d_leaf(val))
+		st->note_page(st, addr, 1, p4d_val(val));
+
 	if (p4d_leaf(val)) {
 		st->note_page(st, addr, 1, p4d_val(val));
 		walk->action = ACTION_CONTINUE;
@@ -87,6 +93,9 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
 	if (st->effective_prot)
 		st->effective_prot(st, 2, pud_val(val));
 
+	if (st->note_non_leaf && !pud_leaf(val))
+		st->note_page(st, addr, 2, pud_val(val));
+
 	if (pud_leaf(val)) {
 		st->note_page(st, addr, 2, pud_val(val));
 		walk->action = ACTION_CONTINUE;
@@ -108,6 +117,10 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
 
 	if (st->effective_prot)
 		st->effective_prot(st, 3, pmd_val(val));
+
+	if (st->note_non_leaf && !pmd_leaf(val))
+		st->note_page(st, addr, 3, pmd_val(val));
+
 	if (pmd_leaf(val)) {
 		st->note_page(st, addr, 3, pmd_val(val));
 		walk->action = ACTION_CONTINUE;
-- 
2.39.2
Re: [PATCH 5/5] ptdump: add state parameter for non-leaf callback
Posted by Andrew Morton 1 year, 9 months ago 
On Mon, 15 Apr 2024 14:51:32 -0500 Maxwell Bland <mbland@motorola.com> wrote:

> ptdump can now note non-leaf descriptor entries, a useful addition for
> debugging table descriptor permissions when working on related code
> 
> Signed-off-by: Maxwell Bland <mbland@motorola.com>
> ---
>  arch/arm64/mm/ptdump.c          |  6 ++++--
>  arch/powerpc/mm/ptdump/ptdump.c |  2 ++
>  arch/riscv/mm/ptdump.c          |  6 ++++--
>  arch/s390/mm/dump_pagetables.c  |  6 ++++--
>  arch/x86/mm/dump_pagetables.c   |  3 ++-
>  include/linux/ptdump.h          |  1 +
>  mm/ptdump.c                     | 13 +++++++++++++
>  7 files changed, 30 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
> index 796231a4fd63..1a6f4a3513e5 100644
> --- a/arch/arm64/mm/ptdump.c
> +++ b/arch/arm64/mm/ptdump.c
> @@ -299,7 +299,8 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
>  			.range = (struct ptdump_range[]){
>  				{info->base_addr, end},
>  				{0, 0}
> -			}
> +			},
> +			.note_non_leaf = false
>  		}

It would be acceptable to omit all of these and rely upon the runtime
zeroing which the compiler will emit.

Documentation/arch/arm64/ptdump.rst might need updating.

Please include sample output in the changelog so we can better
understand the user's view of this change.

Patchew 2.1-devel-b67e4c2

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