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

wildea01 · wildea01 · commit 1eb34b6e5160 · 2017-06-12T12:33:54.000+01:00
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.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
@@ -104,7 +104,9 @@ void show_pte(unsigned long addr)
 		return;
 	}
 
-	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("[%016lx] *pgd=%016llx", addr, pgd_val(*pgd));
 

Original file line number	Diff line number	Diff line change
`@@ -104,7 +104,9 @@ void show_pte(unsigned long addr)`
`104`	`104`	`return;`
`105`	`105`	`}`
`106`	`106`
`107`		`- pr_alert("pgd = %p\n", mm->pgd);`
	`107`	`+ pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgd = %p\n",`
	`108`	`+ mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,`
	`109`	`+ VA_BITS, mm->pgd);`
`108`	`110`	`pgd = pgd_offset(mm, addr);`
`109`	`111`	`pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd));`
`110`	`112`