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[PATCHv2 0/4] WX checking for arm64

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  [PATCHv2 0/4] WX checking for arm64 Laura Abbott <labbott@redhat.com> - 2016-10-13 00:40 +0200
    [PATCHv2 2/4] arm64: dump: Make the page table dumping seq_file optional Laura Abbott <labbott@redhat.com> - 2016-10-13 00:40 +0200
      Re: [PATCHv2 2/4] arm64: dump: Make the page table dumping seq_file  optional Mark Rutland <mark.rutland@arm.com> - 2016-10-17 13:10 +0200
    [PATCHv2 3/4] arm64: dump: Remove max_addr Laura Abbott <labbott@redhat.com> - 2016-10-13 00:40 +0200
      Re: [PATCHv2 3/4] arm64: dump: Remove max_addr Mark Rutland <mark.rutland@arm.com> - 2016-10-17 13:10 +0200

#1499945 — [PATCHv2 0/4] WX checking for arm64

Hi,

This is v2 of the implementation to check for writable and executable pages on
arm64.

Major changes since v1:
- I realized my concerns about initialization and registration were unfounded
  so registration to register page tables with debugfs is simplified.
- New patch to remove max_addr since it was pointed out it was unused.
- Rebased to include changes for the EFI page tables as well.
- Checking is now only done on the init_mm page tables. It was mentioned that
  we should check the hyp page tables as well but that can be follow on work.
- Checking for UXN per suggestion from Mark Rutland.

Laura Abbott (4):
  arm64: dump: Make ptdump debugfs a separate option
  arm64: dump: Make the page table dumping seq_file optional
  arm64: dump: Remove max_addr
  arm64: dump: Add checking for writable and exectuable pages

 arch/arm64/Kconfig.debug           | 34 ++++++++++++++-
 arch/arm64/include/asm/ptdump.h    | 22 +++++++---
 arch/arm64/mm/Makefile             |  3 +-
 arch/arm64/mm/dump.c               | 89 ++++++++++++++++++++++++++------------
 arch/arm64/mm/mmu.c                |  2 +
 arch/arm64/mm/ptdump_debugfs.c     | 31 +++++++++++++
 drivers/firmware/efi/arm-runtime.c |  5 +--
 7 files changed, 147 insertions(+), 39 deletions(-)
 create mode 100644 arch/arm64/mm/ptdump_debugfs.c

-- 
2.7.4

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#1499946 — [PATCHv2 2/4] arm64: dump: Make the page table dumping seq_file optional

The page table dumping code always assumes it will be dumping to a
seq_file to userspace. Future code will be taking advantage of
the page table dumping code but will not need the seq_file. Make
the seq_file optional for these cases.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
---
v2: Tweak commit text per Mark Rutland's suggestion
---
 arch/arm64/mm/dump.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index f0f0be7..bb36649 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -50,6 +50,18 @@ static const struct addr_marker address_markers[] = {
 	{ -1,				NULL },
 };
 
+#define pt_dump_seq_printf(m, fmt, args...)	\
+({						\
+	if (m)					\
+		seq_printf(m, fmt, ##args);	\
+})
+
+#define pt_dump_seq_puts(m, fmt)	\
+({					\
+	if (m)				\
+		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
@@ -186,7 +198,7 @@ static void dump_prot(struct pg_state *st, const struct prot_bits *bits,
 			s = bits->clear;
 
 		if (s)
-			seq_printf(st->seq, " %s", s);
+			pt_dump_seq_printf(st->seq, " %s", s);
 	}
 }
 
@@ -200,14 +212,14 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
 		st->level = level;
 		st->current_prot = prot;
 		st->start_address = addr;
-		seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+		pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
 	} else if (prot != st->current_prot || level != st->level ||
 		   addr >= st->marker[1].start_address) {
 		const char *unit = units;
 		unsigned long delta;
 
 		if (st->current_prot) {
-			seq_printf(st->seq, "0x%016lx-0x%016lx   ",
+			pt_dump_seq_printf(st->seq, "0x%016lx-0x%016lx   ",
 				   st->start_address, addr);
 
 			delta = (addr - st->start_address) >> 10;
@@ -215,17 +227,17 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
 				delta >>= 10;
 				unit++;
 			}
-			seq_printf(st->seq, "%9lu%c %s", delta, *unit,
+			pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
 				   pg_level[st->level].name);
 			if (pg_level[st->level].bits)
 				dump_prot(st, pg_level[st->level].bits,
 					  pg_level[st->level].num);
-			seq_puts(st->seq, "\n");
+			pt_dump_seq_puts(st->seq, "\n");
 		}
 
 		if (addr >= st->marker[1].start_address) {
 			st->marker++;
-			seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+			pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
 		}
 
 		st->start_address = addr;
@@ -235,7 +247,7 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
 
 	if (addr >= st->marker[1].start_address) {
 		st->marker++;
-		seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+		pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
 	}
 
 }
-- 
2.7.4

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#1501880 — Re: [PATCHv2 2/4] arm64: dump: Make the page table dumping seq_file optional

On Wed, Oct 12, 2016 at 03:32:00PM -0700, Laura Abbott wrote:
> 
> The page table dumping code always assumes it will be dumping to a
> seq_file to userspace. Future code will be taking advantage of
> the page table dumping code but will not need the seq_file. Make
> the seq_file optional for these cases.
> 
> Acked-by: Mark Rutland <mark.rutland@arm.com>

Now that I'm back in the office with access to hardware, I've been able
to give this a spin. FWIW, feel free to upgrade the above to:

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.

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#1499947 — [PATCHv2 3/4] arm64: dump: Remove max_addr

max_addr was added as part of struct ptdump_info but has never actually
been used. Remove it.

Signed-off-by: Laura Abbott <labbott@redhat.com>
---
New for v2 of the series
---
 arch/arm64/include/asm/ptdump.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
index 7c35689..8fc0957 100644
--- a/arch/arm64/include/asm/ptdump.h
+++ b/arch/arm64/include/asm/ptdump.h
@@ -30,7 +30,6 @@ struct ptdump_info {
 	struct mm_struct		*mm;
 	const struct addr_marker	*markers;
 	unsigned long			base_addr;
-	unsigned long			max_addr;
 };
 
 void ptdump_walk_pgd(struct seq_file *s, struct ptdump_info *info);
-- 
2.7.4

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#1501877 — Re: [PATCHv2 3/4] arm64: dump: Remove max_addr

On Wed, Oct 12, 2016 at 03:32:01PM -0700, Laura Abbott wrote:
> 
> max_addr was added as part of struct ptdump_info but has never actually
> been used. Remove it.
> 
> Signed-off-by: Laura Abbott <labbott@redhat.com>

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.

> ---
> New for v2 of the series
> ---
>  arch/arm64/include/asm/ptdump.h | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
> index 7c35689..8fc0957 100644
> --- a/arch/arm64/include/asm/ptdump.h
> +++ b/arch/arm64/include/asm/ptdump.h
> @@ -30,7 +30,6 @@ struct ptdump_info {
>  	struct mm_struct		*mm;
>  	const struct addr_marker	*markers;
>  	unsigned long			base_addr;
> -	unsigned long			max_addr;
>  };
>  
>  void ptdump_walk_pgd(struct seq_file *s, struct ptdump_info *info);
> -- 
> 2.7.4
> 

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