[PATCH] arm64: fault: Print info about page table structure when dumping pte

Will Deacon
2017-05-30T10:10:47Z

Whilst debugging a remote crash, I noticed that show_pte is unhelpful
when it comes to describing the structure of the page table being walked.
This is easily fixed by printing out the page table (swapper vs user),
page size and virtual address size when displaying the PGD address.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/arm64/mm/fault.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 37b95dff0b07..ee6085a922b6 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -89,7 +89,9 @@ void show_pte(struct mm_struct *mm, unsigned long addr)
if (!mm)
mm = &init_mm;

- pr_alert("pgd = %p\n", mm->pgd);
+ pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgd = %p\n",
+ mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,
+ VA_BITS, mm->pgd);
pgd = pgd_offset(mm, addr);
pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd));

--
2.1.4