[PATCH] powerpc/ptdump: Fix display of RW pages on FSL_BOOK3E

[PATCH] powerpc/ptdump: Fix display of RW pages on FSL_BOOK3E

[Christophe Leroy]

On FSL_BOOK3E, _PAGE_RW is defined with two bits, one for user and one
for supervisor. As soon as one of the two bits is set, the page has
to be display as RW. But the way it is implemented today requires both
bits to be set in order to display it as RW.

Instead of display RW when _PAGE_RW bits are set and R otherwise,
reverse the logic and display R when _PAGE_RW bits are all 0 and
RW otherwise.

This change has no impact on other platforms as _PAGE_RW is a single
bit on all of them.

Fixes: 8eb07b187000 ("powerpc/mm: Dump linux pagetables")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/ptdump/shared.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/ptdump/shared.c b/arch/powerpc/mm/ptdump/shared.c
index 03607ab90c66..f884760ca5cf 100644
--- a/arch/powerpc/mm/ptdump/shared.c
+++ b/arch/powerpc/mm/ptdump/shared.c
@@ -17,9 +17,9 @@ static const struct flag_info flag_array[] = {
 		.clear	= "    ",
 	}, {
 		.mask	= _PAGE_RW,
-		.val	= _PAGE_RW,
-		.set	= "rw",
-		.clear	= "r ",
+		.val	= 0,
+		.set	= "r ",
+		.clear	= "rw",
 	}, {
 		.mask	= _PAGE_EXEC,
 		.val	= _PAGE_EXEC,
-- 
2.36.1

Re: [PATCH] powerpc/ptdump: Fix display of RW pages on FSL_BOOK3E

[Michael Ellerman]

On Tue, 28 Jun 2022 16:43:35 +0200, Christophe Leroy wrote:
> On FSL_BOOK3E, _PAGE_RW is defined with two bits, one for user and one
> for supervisor. As soon as one of the two bits is set, the page has
> to be display as RW. But the way it is implemented today requires both
> bits to be set in order to display it as RW.
> 
> Instead of display RW when _PAGE_RW bits are set and R otherwise,
> reverse the logic and display R when _PAGE_RW bits are all 0 and
> RW otherwise.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/ptdump: Fix display of RW pages on FSL_BOOK3E
      https://git.kernel.org/powerpc/c/dd8de84b57b02ba9c1fe530a6d916c0853f136bd

cheers