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

[PATCH v7 3/6] arm64: ptdump: Use the mask from the state structure

Sebastian Ene posted 6 patches 1 year, 5 months ago
There is a newer version of this series
[PATCH v7 3/6] arm64: ptdump: Use the mask from the state structure
Posted by Sebastian Ene 1 year, 5 months ago 
Printing the descriptor attributes requires accessing a mask which has a
different set of attributes for stage-2. In preparation for adding support
for the stage-2 pagetables dumping, use the mask from the local context
and not from the globally defined pg_level array. Store a pointer to
the pg_level array in the ptdump state structure. This will allow us to
extract the mask which is wrapped in the pg_level array and use it for
descriptor parsing in the note_page.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/include/asm/ptdump.h |  1 +
 arch/arm64/mm/ptdump.c          | 13 ++++++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
index c550b2afcab7..a4125d8d5a32 100644
--- a/arch/arm64/include/asm/ptdump.h
+++ b/arch/arm64/include/asm/ptdump.h
@@ -44,6 +44,7 @@ struct pg_level {
  */
 struct pg_state {
 	struct ptdump_state ptdump;
+	struct pg_level *pg_level;
 	struct seq_file *seq;
 	const struct addr_marker *marker;
 	const struct mm_struct *mm;
diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index e370b7a945de..9637a6415ea7 100644
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c
@@ -192,6 +192,7 @@ 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);
+	struct pg_level *pg_info = st->pg_level;
 	static const char units[] = "KMGTPE";
 	u64 prot = 0;
 
@@ -201,7 +202,7 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 		level = 0;
 
 	if (level >= 0)
-		prot = val & pg_level[level].mask;
+		prot = val & pg_info[level].mask;
 
 	if (st->level == -1) {
 		st->level = level;
@@ -227,10 +228,10 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 			unit++;
 		}
 		pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
-				   pg_level[st->level].name);
-		if (st->current_prot && pg_level[st->level].bits)
-			dump_prot(st, pg_level[st->level].bits,
-				  pg_level[st->level].num);
+				   pg_info[st->level].name);
+		if (st->current_prot && pg_info[st->level].bits)
+			dump_prot(st, pg_info[st->level].bits,
+				  pg_info[st->level].num);
 		pt_dump_seq_puts(st->seq, "\n");
 
 		if (addr >= st->marker[1].start_address) {
@@ -262,6 +263,7 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
 		.seq = s,
 		.marker = info->markers,
 		.mm = info->mm,
+		.pg_level = &pg_level[0],
 		.level = -1,
 		.ptdump = {
 			.note_page = note_page,
@@ -297,6 +299,7 @@ bool ptdump_check_wx(void)
 			{ 0, NULL},
 			{ -1, NULL},
 		},
+		.pg_level = &pg_level[0],
 		.level = -1,
 		.check_wx = true,
 		.ptdump = {
-- 
2.45.2.741.gdbec12cfda-goog
Re: [PATCH v7 3/6] arm64: ptdump: Use the mask from the state structure
Posted by Will Deacon 1 year, 5 months ago 
On Fri, Jun 21, 2024 at 12:32:27PM +0000, Sebastian Ene wrote:
> Printing the descriptor attributes requires accessing a mask which has a
> different set of attributes for stage-2. In preparation for adding support
> for the stage-2 pagetables dumping, use the mask from the local context
> and not from the globally defined pg_level array. Store a pointer to
> the pg_level array in the ptdump state structure. This will allow us to
> extract the mask which is wrapped in the pg_level array and use it for
> descriptor parsing in the note_page.
> 
> Signed-off-by: Sebastian Ene <sebastianene@google.com>
> ---
>  arch/arm64/include/asm/ptdump.h |  1 +
>  arch/arm64/mm/ptdump.c          | 13 ++++++++-----
>  2 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
> index c550b2afcab7..a4125d8d5a32 100644
> --- a/arch/arm64/include/asm/ptdump.h
> +++ b/arch/arm64/include/asm/ptdump.h
> @@ -44,6 +44,7 @@ struct pg_level {
>   */
>  struct pg_state {
>  	struct ptdump_state ptdump;
> +	struct pg_level *pg_level;
>  	struct seq_file *seq;
>  	const struct addr_marker *marker;
>  	const struct mm_struct *mm;
> diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
> index e370b7a945de..9637a6415ea7 100644
> --- a/arch/arm64/mm/ptdump.c
> +++ b/arch/arm64/mm/ptdump.c
> @@ -192,6 +192,7 @@ 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);
> +	struct pg_level *pg_info = st->pg_level;
>  	static const char units[] = "KMGTPE";
>  	u64 prot = 0;
>  
> @@ -201,7 +202,7 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
>  		level = 0;
>  
>  	if (level >= 0)
> -		prot = val & pg_level[level].mask;
> +		prot = val & pg_info[level].mask;

If you rename the existing 'pg_level' array to something like
'kernel_pg_levels' then I think your local 'pg_info' variable can be
called 'pg_level' and this line doesn't need to change.

>  
>  	if (st->level == -1) {
>  		st->level = level;
> @@ -227,10 +228,10 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
>  			unit++;
>  		}
>  		pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
> -				   pg_level[st->level].name);
> -		if (st->current_prot && pg_level[st->level].bits)
> -			dump_prot(st, pg_level[st->level].bits,
> -				  pg_level[st->level].num);
> +				   pg_info[st->level].name);
> +		if (st->current_prot && pg_info[st->level].bits)
> +			dump_prot(st, pg_info[st->level].bits,
> +				  pg_info[st->level].num);

I think this could then stay as-is too.

>  		pt_dump_seq_puts(st->seq, "\n");
>  
>  		if (addr >= st->marker[1].start_address) {
> @@ -262,6 +263,7 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
>  		.seq = s,
>  		.marker = info->markers,
>  		.mm = info->mm,
> +		.pg_level = &pg_level[0],

Can't this just be '.pg_level = kernel_pg_levels'?

Will
Re: [PATCH v7 3/6] arm64: ptdump: Use the mask from the state structure
Posted by Sebastian Ene 1 year, 5 months ago 
On Fri, Jul 05, 2024 at 12:12:29PM +0100, Will Deacon wrote:
> On Fri, Jun 21, 2024 at 12:32:27PM +0000, Sebastian Ene wrote:
> > Printing the descriptor attributes requires accessing a mask which has a
> > different set of attributes for stage-2. In preparation for adding support
> > for the stage-2 pagetables dumping, use the mask from the local context
> > and not from the globally defined pg_level array. Store a pointer to
> > the pg_level array in the ptdump state structure. This will allow us to
> > extract the mask which is wrapped in the pg_level array and use it for
> > descriptor parsing in the note_page.
> > 
> > Signed-off-by: Sebastian Ene <sebastianene@google.com>
> > ---
> >  arch/arm64/include/asm/ptdump.h |  1 +
> >  arch/arm64/mm/ptdump.c          | 13 ++++++++-----
> >  2 files changed, 9 insertions(+), 5 deletions(-)
> > 
> > diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
> > index c550b2afcab7..a4125d8d5a32 100644
> > --- a/arch/arm64/include/asm/ptdump.h
> > +++ b/arch/arm64/include/asm/ptdump.h
> > @@ -44,6 +44,7 @@ struct pg_level {
> >   */
> >  struct pg_state {
> >  	struct ptdump_state ptdump;
> > +	struct pg_level *pg_level;
> >  	struct seq_file *seq;
> >  	const struct addr_marker *marker;
> >  	const struct mm_struct *mm;
> > diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
> > index e370b7a945de..9637a6415ea7 100644
> > --- a/arch/arm64/mm/ptdump.c
> > +++ b/arch/arm64/mm/ptdump.c
> > @@ -192,6 +192,7 @@ 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);
> > +	struct pg_level *pg_info = st->pg_level;
> >  	static const char units[] = "KMGTPE";
> >  	u64 prot = 0;
> >  
> > @@ -201,7 +202,7 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
> >  		level = 0;
> >  
> >  	if (level >= 0)
> > -		prot = val & pg_level[level].mask;
> > +		prot = val & pg_info[level].mask;
> 
> If you rename the existing 'pg_level' array to something like
> 'kernel_pg_levels' then I think your local 'pg_info' variable can be
> called 'pg_level' and this line doesn't need to change.
> 

This is a good ideea, thanks. I applied your suggestion

> >  
> >  	if (st->level == -1) {
> >  		st->level = level;
> > @@ -227,10 +228,10 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
> >  			unit++;
> >  		}
> >  		pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
> > -				   pg_level[st->level].name);
> > -		if (st->current_prot && pg_level[st->level].bits)
> > -			dump_prot(st, pg_level[st->level].bits,
> > -				  pg_level[st->level].num);
> > +				   pg_info[st->level].name);
> > +		if (st->current_prot && pg_info[st->level].bits)
> > +			dump_prot(st, pg_info[st->level].bits,
> > +				  pg_info[st->level].num);
> 
> I think this could then stay as-is too.
> 
> >  		pt_dump_seq_puts(st->seq, "\n");
> >  
> >  		if (addr >= st->marker[1].start_address) {
> > @@ -262,6 +263,7 @@ void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
> >  		.seq = s,
> >  		.marker = info->markers,
> >  		.mm = info->mm,
> > +		.pg_level = &pg_level[0],
> 
> Can't this just be '.pg_level = kernel_pg_levels'?
> 
> Will


Seb

Patchew 2.1-devel-b67e4c2

© 2016 - 2025 Red Hat, Inc.