1. Patchew
  2. linux
  3. [PATCH v7 0/6] arm64: ptdump: View the second stage page-tables
  4. View patch

[PATCH v7 2/6] arm64: ptdump: Expose the attribute parsing functionality

Sebastian Ene posted 6 patches 1 year, 5 months ago
There is a newer version of this series
[PATCH v7 2/6] arm64: ptdump: Expose the attribute parsing functionality
Posted by Sebastian Ene 1 year, 5 months ago 
Reuse the descriptor parsing functionality to keep the same output format
as the original ptdump code. In order for this to happen, move the state
tracking objects into a common header.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/include/asm/ptdump.h | 41 ++++++++++++++++++++++++++++++++-
 arch/arm64/mm/ptdump.c          | 37 ++---------------------------
 2 files changed, 42 insertions(+), 36 deletions(-)

diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
index 5b1701c76d1c..c550b2afcab7 100644
--- a/arch/arm64/include/asm/ptdump.h
+++ b/arch/arm64/include/asm/ptdump.h
@@ -9,6 +9,7 @@
 
 #include <linux/mm_types.h>
 #include <linux/seq_file.h>
+#include <linux/ptdump.h>
 
 struct addr_marker {
 	unsigned long start_address;
@@ -21,14 +22,52 @@ struct ptdump_info {
 	unsigned long			base_addr;
 };
 
+struct prot_bits {
+	u64		mask;
+	u64		val;
+	const char	*set;
+	const char	*clear;
+};
+
+struct pg_level {
+	const struct prot_bits *bits;
+	char name[4];
+	int num;
+	u64 mask;
+};
+
+/*
+ * The page dumper groups page table entries of the same type into a single
+ * description. It uses pg_state to track the range information while
+ * iterating over the pte entries. When the continuity is broken it then
+ * dumps out a description of the range.
+ */
+struct pg_state {
+	struct ptdump_state ptdump;
+	struct seq_file *seq;
+	const struct addr_marker *marker;
+	const struct mm_struct *mm;
+	unsigned long start_address;
+	int level;
+	u64 current_prot;
+	bool check_wx;
+	unsigned long wx_pages;
+	unsigned long uxn_pages;
+};
+
 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);
 #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);
 #else
 static inline void ptdump_debugfs_register(struct ptdump_info *info,
 					   const char *name) { }
-#endif
+#endif /* CONFIG_PTDUMP_DEBUGFS */
+#else
+static inline void note_page(void *pt_st, unsigned long addr,
+			     int level, u64 val) { }
 #endif /* CONFIG_PTDUMP_CORE */
 
 #endif /* __ASM_PTDUMP_H */
diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index 6986827e0d64..e370b7a945de 100644
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c
@@ -38,32 +38,6 @@
 		seq_printf(m, fmt);	\
 })
 
-/*
- * The page dumper groups page table entries of the same type into a single
- * description. It uses pg_state to track the range information while
- * iterating over the pte entries. When the continuity is broken it then
- * dumps out a description of the range.
- */
-struct pg_state {
-	struct ptdump_state ptdump;
-	struct seq_file *seq;
-	const struct addr_marker *marker;
-	const struct mm_struct *mm;
-	unsigned long start_address;
-	int level;
-	u64 current_prot;
-	bool check_wx;
-	unsigned long wx_pages;
-	unsigned long uxn_pages;
-};
-
-struct prot_bits {
-	u64		mask;
-	u64		val;
-	const char	*set;
-	const char	*clear;
-};
-
 static const struct prot_bits pte_bits[] = {
 	{
 		.mask	= PTE_VALID,
@@ -143,13 +117,6 @@ static const struct prot_bits pte_bits[] = {
 	}
 };
 
-struct pg_level {
-	const struct prot_bits *bits;
-	char name[4];
-	int num;
-	u64 mask;
-};
-
 static struct pg_level pg_level[] __ro_after_init = {
 	{ /* pgd */
 		.name	= "PGD",
@@ -221,8 +188,8 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
 	st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
 }
 
-static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
-		      u64 val)
+void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
+	       u64 val)
 {
 	struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
 	static const char units[] = "KMGTPE";
-- 
2.45.2.741.gdbec12cfda-goog
Re: [PATCH v7 2/6] arm64: ptdump: Expose the attribute parsing functionality
Posted by Will Deacon 1 year, 5 months ago 
On Fri, Jun 21, 2024 at 12:32:26PM +0000, Sebastian Ene wrote:
> Reuse the descriptor parsing functionality to keep the same output format
> as the original ptdump code. In order for this to happen, move the state
> tracking objects into a common header.
> 
> Signed-off-by: Sebastian Ene <sebastianene@google.com>
> ---
>  arch/arm64/include/asm/ptdump.h | 41 ++++++++++++++++++++++++++++++++-
>  arch/arm64/mm/ptdump.c          | 37 ++---------------------------
>  2 files changed, 42 insertions(+), 36 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
> index 5b1701c76d1c..c550b2afcab7 100644
> --- a/arch/arm64/include/asm/ptdump.h
> +++ b/arch/arm64/include/asm/ptdump.h
> @@ -9,6 +9,7 @@
>  
>  #include <linux/mm_types.h>
>  #include <linux/seq_file.h>
> +#include <linux/ptdump.h>
>  
>  struct addr_marker {
>  	unsigned long start_address;
> @@ -21,14 +22,52 @@ struct ptdump_info {
>  	unsigned long			base_addr;
>  };
>  
> +struct prot_bits {
> +	u64		mask;
> +	u64		val;
> +	const char	*set;
> +	const char	*clear;
> +};
> +
> +struct pg_level {
> +	const struct prot_bits *bits;
> +	char name[4];
> +	int num;
> +	u64 mask;
> +};
> +
> +/*
> + * The page dumper groups page table entries of the same type into a single
> + * description. It uses pg_state to track the range information while
> + * iterating over the pte entries. When the continuity is broken it then
> + * dumps out a description of the range.
> + */
> +struct pg_state {
> +	struct ptdump_state ptdump;
> +	struct seq_file *seq;
> +	const struct addr_marker *marker;
> +	const struct mm_struct *mm;
> +	unsigned long start_address;
> +	int level;
> +	u64 current_prot;
> +	bool check_wx;
> +	unsigned long wx_pages;
> +	unsigned long uxn_pages;
> +};

Minor nit, but if we're moving these structure definitions into the
header then I'd be inclined to give them some more specific names (e.g.
prefix them with 'ptdump_'). Granted, this header isn't used widely, but
it's included by arch/arm64/mm/mmu.c and claiming 'struct prot_bits' is
a bit over-reaching imo!

Will
Re: [PATCH v7 2/6] arm64: ptdump: Expose the attribute parsing functionality
Posted by Sebastian Ene 1 year, 5 months ago 
On Fri, Jul 05, 2024 at 12:07:48PM +0100, Will Deacon wrote:
> On Fri, Jun 21, 2024 at 12:32:26PM +0000, Sebastian Ene wrote:
> > Reuse the descriptor parsing functionality to keep the same output format
> > as the original ptdump code. In order for this to happen, move the state
> > tracking objects into a common header.
> > 
> > Signed-off-by: Sebastian Ene <sebastianene@google.com>
> > ---
> >  arch/arm64/include/asm/ptdump.h | 41 ++++++++++++++++++++++++++++++++-
> >  arch/arm64/mm/ptdump.c          | 37 ++---------------------------
> >  2 files changed, 42 insertions(+), 36 deletions(-)
> > 
> > diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
> > index 5b1701c76d1c..c550b2afcab7 100644
> > --- a/arch/arm64/include/asm/ptdump.h
> > +++ b/arch/arm64/include/asm/ptdump.h
> > @@ -9,6 +9,7 @@
> >  
> >  #include <linux/mm_types.h>
> >  #include <linux/seq_file.h>
> > +#include <linux/ptdump.h>
> >  
> >  struct addr_marker {
> >  	unsigned long start_address;
> > @@ -21,14 +22,52 @@ struct ptdump_info {
> >  	unsigned long			base_addr;
> >  };
> >  
> > +struct prot_bits {
> > +	u64		mask;
> > +	u64		val;
> > +	const char	*set;
> > +	const char	*clear;
> > +};
> > +
> > +struct pg_level {
> > +	const struct prot_bits *bits;
> > +	char name[4];
> > +	int num;
> > +	u64 mask;
> > +};
> > +
> > +/*
> > + * The page dumper groups page table entries of the same type into a single
> > + * description. It uses pg_state to track the range information while
> > + * iterating over the pte entries. When the continuity is broken it then
> > + * dumps out a description of the range.
> > + */
> > +struct pg_state {
> > +	struct ptdump_state ptdump;
> > +	struct seq_file *seq;
> > +	const struct addr_marker *marker;
> > +	const struct mm_struct *mm;
> > +	unsigned long start_address;
> > +	int level;
> > +	u64 current_prot;
> > +	bool check_wx;
> > +	unsigned long wx_pages;
> > +	unsigned long uxn_pages;
> > +};

Hello Will,

> 
> Minor nit, but if we're moving these structure definitions into the
> header then I'd be inclined to give them some more specific names (e.g.
> prefix them with 'ptdump_'). Granted, this header isn't used widely, but
> it's included by arch/arm64/mm/mmu.c and claiming 'struct prot_bits' is
> a bit over-reaching imo!
> 
> Will

Thanks for having a look. I applied the prefix.

Cheers,
Seb

Patchew 2.1-devel-b67e4c2

© 2016 - 2025 Red Hat, Inc.