Hi Will,

On Tue, Aug 13, 2019 at 3:10 PM Will Deacon <will@kernel.org> wrote:
> On Tue, Aug 13, 2019 at 02:43:23PM +0200, Geert Uytterhoeven wrote:
> > On Fri, Aug 9, 2019 at 6:47 PM Will Deacon <will@kernel.org> wrote:
> > > On Wed, Aug 07, 2019 at 04:55:12PM +0100, Steve Capper wrote:
> > > > This patch series adds support for 52-bit kernel VAs using some of the
> > > > machinery already introduced by the 52-bit userspace VA code in 5.0.
> > >
> > > Cheers, I've pushed this out on a for-next/52-bit-kva branch with one
> > > small patch on top and Catalin's tags added.
> >
> > As of commit 14c127c957c1c607 ("arm64: mm: Flip kernel VA space"), the
> > kernel log is spammed with
> >
> >     virt_to_phys used for non-linear address: (____ptrval____)
> > (__func__.6603+0x14d681/0x17fb3d)
> >     WARNING: CPU: 0 PID: 264 at arch/arm64/mm/physaddr.c:15
> > __virt_to_phys+0x28/0x58
> >     Modules linked in:
> >     CPU: 0 PID: 264 Comm: mdev Not tainted
> > 5.3.0-rc3-rcar3-initrd-00002-g14c127c957c1c607 #38
> >     Hardware name: Renesas Ebisu-4D board based on r8a77990 (DT)
> >     pstate: 60000005 (nZCv daif -PAN -UAO)
> >     pc : __virt_to_phys+0x28/0x58
> >     lr : __virt_to_phys+0x28/0x58
> >     sp : ffffffc011953c80
> >     x29: ffffffc011953c80 x28: ffffff8078790140
> >     x27: 0000000000000000 x26: 0000000000000000
> >     x25: ffffffc010a539b9 x24: ffffffc010a86000
> >     x23: ffffffc010a539ba x22: 0000000000000001
> >     x21: 0000000000202038 x20: 0000000000000001
> >     x19: ffffffc010a539b9 x18: 000000000000000a
> >     x17: 0000000000000000 x16: 0000000000000000
> >     x15: 00000000000ca51d x14: 0720072007200720
> >     x13: 0720072007200720 x12: 0720072007200720
> >     x11: 0720072007200720 x10: 0720072007200720
> >     x9 : 0720072007200720 x8 : 0000000000000001
> >     x7 : 0000000000000007 x6 : ffffff8079824f00
> >     x5 : 0000000000000140 x4 : 0000000000000000
> >     x3 : 0000000000000000 x2 : 00000000ffffffff
> >     x1 : 0713abbc9281cf00 x0 : 0000000000000000
> >     Call trace:
> >      __virt_to_phys+0x28/0x58
> >      __check_object_size+0xd0/0x1e0
> >      filldir64+0x1d8/0x2b0
> >      kernfs_fop_readdir+0x64/0x200
> >      iterate_dir+0x68/0x144
> >      ksys_getdents64+0x88/0x154
> >      __arm64_sys_getdents64+0x18/0x24
> >      el0_svc_common.constprop.0+0x84/0xe8
> >      el0_svc_compat_handler+0x18/0x20
> >      el0_svc_compat+0x8/0x10
> >     ---[ end trace 6980a45f636e18be ]---
> >
> > as soon as userspace starts.
>
> Can you try the hack I posted here, please?
>
> https://lkml.org/lkml/2019/8/13/555

Thanks, that seems to do the trick!

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

> Also, what .config are you using?

Attached.

Probably CONFIG_DEBUG_VIRTUAL=y is what you're missing.


Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds