arm64: fault: Print info about page table structure when dumping pte
PATCH 1/1 arm64: fault: Print info about page table structure when dumping pte
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.
--- arch/arm64/mm/fault.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
arch/arm64/mm/fault.c +3 -1
@@ -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));
Signature · 1 line
2.1.4
Mark Rutland
reviewerPATCH 1/1 arm64: fault: Print info about page table structure when dumping pte
Quoted 15 lines · Will Deacon
Whilst debugging a remote crash, I noticed that
show_pteis 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 <[email protected]>--- arch/arm64/mm/fault.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)arch/arm64/mm/fault.c +0
-0
arch/arm64/mm/fault.c void show_pte(struct mm_struct *mm, unsigned long addr) · line 94
Quoted 7 lines
arch/arm64/mm/fault.c +3
-1@@ -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);
I take it this will go with Kristina's fix [1] to dump the correct page table?
Otherwise, this would be more misleading than presently.
Assuming that is the case, this looks very useful to me. FWIW:
Mark.
Quoted 11 lines
arch/arm64/mm/fault.c +0
-0pgd =pgd_offset (mm, addr);pr_alert ("[%08lx] *pgd=%016llx" , addr,pgd_val (*pgd));Signature · 7 lines
2.1.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
PATCH 1/1 arm64: fault: Print info about page table structure when dumping pte
Quoted 19 lines · Mark Rutland
Quoted 18 lines · Will Deacon
Whilst debugging a remote crash, I noticed that
show_pteis 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 <[email protected]>--- arch/arm64/mm/fault.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)arch/arm64/mm/fault.c +0
-0@@ -89,7 +89,9 @@ void show_pte(struct mm_struct *mm, unsigned long addr)if (!mm) mm = &init_mm;
Quoted 7 lines
arch/arm64/mm/fault.c void show_pte(struct mm_struct *mm, unsigned long addr) · line 94
Quoted 4 lines
arch/arm64/mm/fault.c +3
-1-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);I take it this will go with Kristina's fix [1] to dump the correct page table?
Yup, just waiting for her to respin those patches and I'll apply this one on top.
Quoted 5 lines
Otherwise, this would be more misleading than presently.
Assuming that is the case, this looks very useful to me. FWIW:
Acked-by Mark Rutland <[email protected]>
Thanks,
Will