Hi Daniel,

Le 16/04/2021 à 01:29, Daniel Axtens a écrit :

Hi Christophe,

quoted

Which hugepd, page table entries can be at any level
and can be of any size.

Add support for them.

Signed-off-by: Christophe Leroy <redacted>
---
  mm/ptdump.c | 17 +++++++++++++++--
  1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/mm/ptdump.c b/mm/ptdump.c
index 61cd16afb1c8..6efdb8c15a7d 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c

@@ -112,11 +112,24 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
  {
  	struct ptdump_state *st = walk->private;
  	pte_t val = ptep_get(pte);
+	unsigned long page_size = next - addr;
+	int level;
+
+	if (page_size >= PGDIR_SIZE)
+		level = 0;
+	else if (page_size >= P4D_SIZE)
+		level = 1;
+	else if (page_size >= PUD_SIZE)
+		level = 2;
+	else if (page_size >= PMD_SIZE)
+		level = 3;
+	else
+		level = 4;
  
  	if (st->effective_prot)
-		st->effective_prot(st, 4, pte_val(val));
+		st->effective_prot(st, level, pte_val(val));
  
-	st->note_page(st, addr, 4, pte_val(val), PAGE_SIZE);
+	st->note_page(st, addr, level, pte_val(val), page_size);

It seems to me that passing both level and page_size is a bit redundant,
but I guess it does reduce the impact on each arch's code?

Exactly, as shown above, the level can be re-calculated based on the page size, but it would be a 
unnecessary impact on all architectures and would duplicate the re-calculation of the level whereas 
in most cases we get it for free from the caller.

Kind regards,
Daniel

quoted

  
  	return 0;
  }
-- 
2.25.0