From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Tue, 30 May 2017 12:19:33 +0100 Subject: [PATCH] arm64: fault: Print info about page table structure when dumping pte In-Reply-To: <20170530111639.GB11653@leverpostej> References: <1496139047-4677-1-git-send-email-will.deacon@arm.com> <20170530111639.GB11653@leverpostej> Message-ID: <20170530111932.GF32289@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, May 30, 2017 at 12:16:39PM +0100, Mark Rutland wrote: > On Tue, May 30, 2017 at 11:10:47AM +0100, Will Deacon wrote: > > 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 > > --- > > 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); > > 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. > Otherwise, this would be more misleading than presently. > > Assuming that is the case, this looks very useful to me. FWIW: > > Acked-by: Mark Rutland Thanks, Will