Re: [PATCH v2 1/2] of: unittest: add overlay gpio test to catch gpio hog problem

From: Anders Roxell
Date: Wed Apr 08 2020 - 08:27:40 EST

On Thu, 26 Mar 2020 at 16:33, Frank Rowand <frowand.list@xxxxxxxxx> wrote:
>
> Hi Anders,
>
> On 3/26/20 5:39 AM, Anders Roxell wrote:
> > On Thu, 26 Mar 2020 at 02:56, Frank Rowand <frowand.list@xxxxxxxxx> wrote:
> >>
> >> On 3/13/20 11:40 AM, Frank Rowand wrote:
> >>> Hi Anders,
> >>>
> >>> On 3/13/20 4:51 AM, Anders Roxell wrote:
> >>>> From: Rob Herring <robh@xxxxxxxxxx>
> >>>>
> >>>>> On Thu, 20 Feb 2020 12:40:20 -0600, frowand.list@xxxxxxxxx wrote:
> >>>>>> From: Frank Rowand <frank.rowand@xxxxxxxx>
> >>>>>>
> >>>>>> Geert reports that gpio hog nodes are not properly processed when
> >>>>>> the gpio hog node is added via an overlay reply and provides an
> >>>>>> RFC patch to fix the problem [1].
> >>>>>>
> >>>>>> Add a unittest that shows the problem. Unittest will report "1 failed"
> >>>>>> test before applying Geert's RFC patch and "0 failed" after applying
> >>>>>> Geert's RFC patch.
> >>>>>>
> >>>>>> [1] https://lore.kernel.org/linux-devicetree/20191230133852.5890-1-geert+renesas@xxxxxxxxx/
> >>>>>>
> >>>>>> Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx>
> >>>>
> >>>> I'm building arm64 on tag next-20200312, and booting in qemu, and I see
> >>>> this "Kernel panic":
> >>>
> >>> Thank you for the panic report.
> >>>
> >>> There has also been an x86_64 failure (with a very different stack trace).
> >>> I am going to investigate the x86_64 failure first.
> >>
> >> I have fixed the x86_64 failure:
> >
> > Great.
> >
> >>
> >> https://lore.kernel.org/linux-devicetree/1585187131-21642-1-git-send-email-frowand.list@xxxxxxxxx/
> >>
> >> Can you check if the two patches in that series fixes the problem that you
> >> are seeing?
> >
> > I got a new error instead.
> >
> > next-20200325 before I applied your patches [1]:
> >
> > [ 1933.602460][ T2795] random: get_random_u64 called from
> > arch_mmap_rnd+0x90/0xb8 with crng_init=1
> > [ 1933.602770][ T2795] random: get_random_u64 called from
> > randomize_stack_top+0x50/0xb8 with crng_init=1
> > [ 1933.603017][ T2795] random: get_random_u32 called from
> > arch_align_stack+0x70/0x90 with crng_init=1
> > [ 1936.391730][ T1] systemd[1]: Mounted Configuration File System.
> > [ [0;32m OK [0m] Mounted Configuration File System.
> > [ 1937.577008][ T2787] Unable to handle kernel paging request at
> > virtual address ccccccccccccccd4
> > [ 1937.604944][ T2787] Mem abort info:
> > [ 1937.622884][ T2787] ESR = 0x96000004
> > [ 1937.624443][ T2787] EC = 0x25: DABT (current EL), IL = 32 bits
> > [ 1937.651817][ T2787] SET = 0, FnV = 0
> > [ 1937.672276][ T2787] EA = 0, S1PTW = 0
> > [ 1937.679201][ T2787] Data abort info:
> > [ 1937.680594][ T2787] ISV = 0, ISS = 0x00000004
> > [ 1937.705713][ T2787] CM = 0, WnR = 0
> > [ 1937.707184][ T2787] [ccccccccccccccd4] address between user and
> > kernel address ranges
> > [ 1937.725628][ T2787] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> > [ 1937.727743][ T2787] Modules linked in:
> > [ 1937.729157][ T2787] CPU: 0 PID: 2787 Comm: systemd-journal Tainted:
> > G B W T 5.6.0-rc7-next-20200325-11880-gbae0ebe545c5 #1
> > [ 1937.733403][ T2787] Hardware name: linux,dummy-virt (DT)
> > [ 1937.735393][ T2787] pstate: 40400005 (nZcv daif +PAN -UAO)
> > [ 1937.737480][ T2787] pc : sysfs_file_ops+0xd0/0xf0
> > [ 1937.739292][ T2787] lr : sysfs_file_ops+0xd0/0xf0
> > [ 1937.741052][ T2787] sp : ffff000062287a80
> > [ 1937.742614][ T2787] x29: ffff000062287a80 x28: ffff000060868040
> > [ 1937.744875][ T2787] x27: ffff000068553810 x26: ffff000062287d80
> > [ 1937.747164][ T2787] x25: ffff00006263b200 x24: ffff000068415528
> > [ 1937.749355][ T2787] x23: ffff000068415538 x22: 0000000000000001
> > [ 1937.751610][ T2787] x21: ffff000068553810 x20: 0000000000000000
> > [ 1937.753908][ T2787] x19: cccccccccccccccc x18: 0000000000007ec0
> > [ 1937.756130][ T2787] x17: 0000000000002208 x16: 0000000000001650
> > [ 1937.758384][ T2787] x15: 0000000000000000 x14: 0000000000000000
> > [ 1937.760481][ T2787] x13: 0000000000000000 x12: 0000000000002240
> > [ 1937.762720][ T2787] x11: 00000000f1f1f1f1 x10: ffff000060868040
> > [ 1937.764810][ T2787] x9 : ffffa00010a03d28 x8 : 1fffe0000c3c2730
> > [ 1937.766856][ T2787] x7 : ffff80000c3c2730 x6 : dfffa00000000000
> > [ 1937.768926][ T2787] x5 : ffff000060868040 x4 : 0000000000000000
> > [ 1937.770980][ T2787] x3 : ffffa00010a03bc8 x2 : 0000000000000001
> > [ 1937.773041][ T2787] x1 : ffffa0001626d000 x0 : 0000000000000000
> > [ 1937.775068][ T2787] Call trace:
> > [ 1937.776252][ T2787] sysfs_file_ops+0xd0/0xf0
> > [ 1937.777785][ T2787] sysfs_kf_seq_show+0x70/0x240
> > [ 1937.779429][ T2787] kernfs_seq_show+0xa8/0xc0
> > [ 1937.781004][ T2787] seq_read+0x350/0x860
> > [ 1937.782437][ T2787] kernfs_fop_read+0x94/0x3f8
> > [ 1937.784013][ T2787] __vfs_read+0x68/0xc8
> > [ 1937.785456][ T2787] vfs_read+0x15c/0x2b0
> > [ 1937.786876][ T2787] ksys_read+0x104/0x1e8
> > [ 1937.788318][ T2787] __arm64_sys_read+0x54/0x68
> > [ 1937.789931][ T2787] el0_svc_common.constprop.0+0x294/0x338
> > [ 1937.791822][ T2787] do_el0_svc+0xe8/0x108
> > [ 1937.793287][ T2787] el0_svc+0x74/0x88
> > [ 1937.794656][ T2787] el0_sync_handler+0xcc/0x77c
> > [ 1937.796259][ T2787] el0_sync+0x17c/0x180
> > [ 1937.797758][ T2787] Code: b40000b3 97e8e4d9 91002260 97f6c841 (f9400673)
> > [ 1937.800049][ T2787] ---[ end trace 8e9be5808e45ebb1 ]---
> > [ 1937.801854][ T2787] Kernel panic - not syncing: Fatal exception
> > [ 1937.803844][ T2787] Kernel Offset: disabled
> > [ 1937.805325][ T2787] CPU features: 0x080002,20002004
> > [ 1937.806961][ T2787] Memory Limit: none
> > [ 1937.808349][ T2787] ---[ end Kernel panic - not syncing: Fatal exception ]---
> >
> > and with the two patches applied I see this [2]:
> >
> > node:test-bus:test-unittest0'
> > [ 1839.107618][ T1] PM: Removing info for
> > platform:testcase-data:overlay-node:test-bus:test-unittest0
> > [ 1839.111218][ T1] kobject:
> > 'testcase-data:overlay-node:test-bus:test-unittest0'
> > ((____ptrval____)): kobject_uevent_env
> > [ 1839.116021][ T1] kobject:
> > 'testcase-data:overlay-node:test-bus:test-unittest0'
> > ((____ptrval____)): fill_kobj_path: path =
> > '/devices/platform/testcase-data:overlay-node:test-bus:test-unittest0'
> > [ 1839.124287][ T1] kobject:
> > 'testcase-data:overlay-node:test-bus:test-unittest0'
> > ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed
> > 1000)
> > [ 1839.130497][ T1] Unexpected kernel BRK exception at EL1
> > [ 1839.132466][ T1] Internal error: ptrace BRK handler: f20003e8
> > [#1] PREEMPT SMP
> > [ 1839.134933][ T1] Modules linked in:
> > [ 1839.136395][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B
> > W T 5.6.0-rc7-next-20200325-11882-ge7ffe3ef0d63 #1
> > [ 1839.140051][ T1] Hardware name: linux,dummy-virt (DT)
> > [ 1839.141976][ T1] pstate: 80400005 (Nzcv daif +PAN -UAO)
> > [ 1839.143958][ T1] pc : of_unittest_untrack_overlay+0x6c/0x13c
> > [ 1839.146026][ T1] lr : of_unittest_untrack_overlay+0x6c/0x13c
> > [ 1839.148046][ T1] sp : ffff000069807af0
> > [ 1839.149468][ T1] x29: ffff000069807af0 x28: ffffa00017258000
> > [ 1839.151579][ T1] x27: ffffa00017258400 x26: 0000000000000000
> > [ 1839.153635][ T1] x25: ffffa00017258480 x24: ffffa00013418a20
> > [ 1839.155735][ T1] x23: 0000000000000000 x22: ffffa000152dc880
> > [ 1839.157828][ T1] x21: 0000000000000000 x20: 00000000ffffffff
> > [ 1839.160076][ T1] x19: 00000000ffffffff x18: 0000000000001ca0
> > [ 1839.162198][ T1] x17: 00000000000019d8 x16: 0000000000001c60
> > [ 1839.164321][ T1] x15: 00000000000019b8 x14: 616c65642820295f
> > [ 1839.166388][ T1] x13: 5f5f5f6c61767274 x12: 705f5f5f5f282074
> > [ 1839.168503][ T1] x11: 00000000f1f1f1f1 x10: ffff00006a3f8040
> > [ 1839.170589][ T1] x9 : ffffa00013d6f370 x8 : 1ffff40002a5a688
> > [ 1839.172686][ T1] x7 : ffff940002a5a688 x6 : dfffa00000000000
> > [ 1839.174781][ T1] x5 : ffff00006a3f8040 x4 : 0000000000000000
> > [ 1839.176871][ T1] x3 : ffffa00011f234ac x2 : 00000000ffffffff
> > [ 1839.178947][ T1] x1 : ffff00006a3f8040 x0 : 0000000000000000
> > [ 1839.181034][ T1] Call trace:
> > [ 1839.182286][ T1] of_unittest_untrack_overlay+0x6c/0x13c
> > [ 1839.184295][ T1] of_unittest+0x3330/0x3638
> > [ 1839.185892][ T1] do_one_initcall+0x480/0xa40
> > [ 1839.187598][ T1] kernel_init_freeable+0x794/0x95c
> > [ 1839.189394][ T1] kernel_init+0x20/0x1f8
> > [ 1839.190924][ T1] ret_from_fork+0x10/0x18
> > [ 1839.192523][ T1] Code: 97955a2c d4210000 14000024 97955a29 (d4207d00)
> > [ 1839.194889][ T1] ---[ end trace 39370fb7c4bf9e64 ]---
> > [ 1839.196706][ T1] Kernel panic - not syncing: Fatal exception
> > [ 1839.198735][ T1] Kernel Offset: disabled
> > [ 1839.200246][ T1] CPU features: 0x080002,20002004
> > [ 1839.201900][ T1] Memory Limit: none
> > [ 1839.203340][ T1] ---[ end Kernel panic - not syncing: Fatal exception ]---
>

I'm sorry for the late reply. =/

> At least this time the call trace is inside the unittest code. :-)

yeah =)

>
> Can you send me the exact qemu command you use?

sudo qemu-system-aarch64 --enable-kvm -cpu cortex-a53 -kernel
Image-20200408 -serial stdio -monitor none -nographic -m 2G -M virt
-fsdev local,id=root,path=/srv/kvm/tmp/stretch/arm64,security_model=none,writeout=immediate
-device virtio-rng-pci -device
virtio-9p-pci,fsdev=root,mount_tag=/dev/root -append "root=/dev/root
rootfstype=9p rootflags=trans=virtio console=ttyA
MA0,38400n8 earlycon=pl011,0x9000000 initcall_debug softlockup_panic=0
security=none kpti=no"

>
> Can I do the qemu command without an initrd image? If not, any pointers
> to an arm64 initrd?

I used debootstrap

sudo qemu-debootstrap --arch=arm64 stretch /srv/kvm/tmp/stretch/arm64
http://ftp.de.debian.org/debian/
echo "/dev/root / 9p
rw,relatime,sync,dirsync,access=client,trans=virtio 1 1" | sudo tee
/srv/kvm/tmp/stretch/arm64/etc/fstab
sudo chroot /srv/kvm/tmp/stretch/arm64 passwd

Cheers,
Anders

>
> -Frank
>
>
> >
> > Cheers,
> > Anders
> > [1] https://people.linaro.org/~anders.roxell/output-next-20200325.log
> > [2] https://people.linaro.org/~anders.roxell/output-next-20200325.test.log
> >
> >>
> >> Thanks,
> >>
> >> Frank
> >>
> >>
> >>>
> >>> Can you please send the kernel .config?
> >>>
> >>> Thanks,
> >>>
> >>> Frank
> >>>
> >>>
> >>>>
> >>>> [...]
> >>>> [ 172.779435][ T1] systemd[1]: Mounted POSIX Message Queue File System.
> >>>> [[0;32m OK [0m] Mounted POSIX Message Queue File System.
> >>>> [ 172.844551][ T1] systemd[1]: Mounted Huge Pages File System.
> >>>> [[0;32m OK [0m] Mounted Huge Pages File System.
> >>>> [ 172.917332][ T1] systemd[1]: Mounted Debug File System.
> >>>> [[0;32m OK [0m] Mounted Debug File System.
> >>>> [ 173.465694][ T251] _warn_unseeded_randomness: 6 callbacks suppressed
> >>>> [ 173.465803][ T251] random: get_random_u64 called from arch_mmap_rnd+0x94/0xb0 with crng_init=1
> >>>> [ 173.466000][ T251] random: get_random_u64 called from randomize_stack_top+0x4c/0xb0 with crng_init=1
> >>>> [ 173.466163][ T251] random: get_random_u32 called from arch_align_stack+0x6c/0x88 with crng_init=1
> >>>> [ 173.544157][ T1] systemd[1]: Started Create Static Device Nodes in /dev.
> >>>> [[0;32m OK [0m] Started Create Static Device Nodes in /dev.
> >>>> [ 174.283422][ T240] Unable to handle kernel paging request at virtual address 978061b552800000
> >>>> [ 174.286169][ T240] Mem abort info:
> >>>> [ 174.303268][ T240] ESR = 0x96000004
> >>>> [ 174.304652][ T240] EC = 0x25: DABT (current EL), IL = 32 bits
> >>>> [ 174.323298][ T240] SET = 0, FnV = 0
> >>>> [ 174.324677][ T240] EA = 0, S1PTW = 0
> >>>> [ 174.325937][ T240] Data abort info:
> >>>> [ 174.345383][ T240] ISV = 0, ISS = 0x00000004
> >>>> [ 174.359310][ T240] CM = 0, WnR = 0
> >>>> [ 174.360641][ T240] [978061b552800000] address between user and kernel address ranges
> >>>> [ 174.378712][ T240] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> >>>> [ 174.381030][ T240] Modules linked in:
> >>>> [ 174.382362][ T240] CPU: 0 PID: 240 Comm: systemd-journal Tainted: G B W 5.6.0-rc5-next-20200312-00018-g5c00c2e7cf27 #6
> >>>> [ 174.386251][ T240] Hardware name: linux,dummy-virt (DT)
> >>>> [ 174.388056][ T240] pstate: 40400005 (nZcv daif +PAN -UAO)
> >>>> [ 174.389892][ T240] pc : sysfs_kf_seq_show+0x114/0x250
> >>>> [ 174.391638][ T240] lr : sysfs_kf_seq_show+0x114/0x250
> >>>> [ 174.393325][ T240] sp : ffff00006374faa0
> >>>> [ 174.394697][ T240] x29: ffff00006374faa0 x28: ffff000062620040
> >>>> [ 174.396751][ T240] x27: ffff000062b0a010 x26: 978061b552800000
> >>>> [ 174.398779][ T240] x25: ffff000068aae020 x24: ffff000068aae010
> >>>> [ 174.400798][ T240] x23: ffff00006311c000 x22: ffff000064f4f800
> >>>> [ 174.402794][ T240] x21: 0000000000001000 x20: ffff000068aae008
> >>>> [ 174.404820][ T240] x19: 0000000000001000 x18: 0000000000000000
> >>>> [ 174.406792][ T240] x17: 0000000000000000 x16: 0000000000000000
> >>>> [ 174.408814][ T240] x15: 0000000000000000 x14: 0000000000000000
> >>>> [ 174.410805][ T240] x13: ffff80000c623a00 x12: 1fffe0000c623800
> >>>> [ 174.412829][ T240] x11: 1fffe0000c6239ff x10: ffff80000c6239ff
> >>>> [ 174.414821][ T240] x9 : 0000000000000000 x8 : ffff00006311d000
> >>>> [ 174.416865][ T240] x7 : 0000000000000000 x6 : 000000000000003f
> >>>> [ 174.418907][ T240] x5 : 0000000000000040 x4 : 000000000000002d
> >>>> [ 174.420932][ T240] x3 : ffffa000109a1274 x2 : 0000000000000001
> >>>> [ 174.422924][ T240] x1 : ffffa00016010000 x0 : 0000000000000000
> >>>> [ 174.424954][ T240] Call trace:
> >>>> [ 174.426097][ T240] sysfs_kf_seq_show+0x114/0x250
> >>>> [ 174.427769][ T240] kernfs_seq_show+0xa4/0xb8
> >>>> [ 174.429306][ T240] seq_read+0x3a4/0x8e8
> >>>> [ 174.430678][ T240] kernfs_fop_read+0x8c/0x6e0
> >>>> [ 174.432244][ T240] __vfs_read+0x64/0xc0
> >>>> [ 174.433622][ T240] vfs_read+0x158/0x2b0
> >>>> [ 174.435014][ T240] ksys_read+0xfc/0x1e0
> >>>> [ 174.436427][ T240] __arm64_sys_read+0x50/0x60
> >>>> [ 174.437944][ T240] el0_svc_common.constprop.1+0x294/0x330
> >>>> [ 174.439795][ T240] do_el0_svc+0xe4/0x100
> >>>> [ 174.441218][ T240] el0_svc+0x70/0x80
> >>>> [ 174.442550][ T240] el0_sync_handler+0xd0/0x7b4
> >>>> [ 174.444143][ T240] el0_sync+0x164/0x180
> >>>> [ 174.445578][ T240] Code: aa1703e0 97f6e03a aa1a03e0 97f6e880 (f9400355)
> >>>> [ 174.447885][ T240] ---[ end trace 5bcb796ff4270d74 ]---
> >>>> [ 174.449629][ T240] Kernel panic - not syncing: Fatal exception
> >>>> [ 174.451590][ T240] Kernel Offset: disabled
> >>>> [ 174.453005][ T240] CPU features: 0x80002,20002004
> >>>> [ 174.454597][ T240] Memory Limit: none
> >>>> [ 174.455955][ T240] ---[ end Kernel panic - not syncing: Fatal exception ]---
> >>>>
> >>>> When I say CONFIG_OF_UNITTEST=n it works.
> >>>> If I revert there it starts to work when I revert the last one,
> >>>> f4056e705b2e, from the list below:
> >>>>
> >>>> 485bb19d0b3e of: unittest: make gpio overlay test dependent on CONFIG_OF_GPIO
> >>>> 0ac174397940 of: unittest: annotate warnings triggered by unittest
> >>>> f4056e705b2e of: unittest: add overlay gpio test to catch gpio hog problem
> >>>>
> >>>> Cheers,
> >>>> Anders
> >>>>
> >>>>>> ---
> >>>>>>
> >>>>>> changes since v1:
> >>>>>> - base on 5.6-rc1
> >>>>>> - fixed node names in overlays
> >>>>>> - removed unused fields from struct unittest_gpio_dev
> >>>>>> - of_unittest_overlay_gpio() cleaned up comments
> >>>>>> - of_unittest_overlay_gpio() moved saving global values into
> >>>>>> probe_pass_count and chip_request_count more tightly around
> >>>>>> test code expected to trigger changes in the global values
> >>>>>>
> >>>>>> v1 of this patch incorrectly reported that it had made changes
> >>>>>> since the RFC version, but it was mistakenly created from the
> >>>>>> wrong branch.
> >>>>>>
> >>>>>> There are checkpatch warnings.
> >>>>>> - New files are in a directory already covered by MAINTAINERS
> >>>>>> - The undocumented compatibles are restricted to use by unittest
> >>>>>> and should not be documented under Documentation
> >>>>>> - The printk() KERN_<LEVEL> warnings are false positives. The level
> >>>>>> is supplied by a define parameter instead of a hard coded constant
> >>>>>> - The lines over 80 characters are consistent with unittest.c style
> >>>>>>
> >>>>>> This unittest was also valuable in that it allowed me to explore
> >>>>>> possible issues related to the proposed solution to the gpio hog
> >>>>>> problem.
> >>>>>>
> >>>>>>
> >>>>>> drivers/of/unittest-data/Makefile | 8 +-
> >>>>>> drivers/of/unittest-data/overlay_gpio_01.dts | 23 +++
> >>>>>> drivers/of/unittest-data/overlay_gpio_02a.dts | 16 ++
> >>>>>> drivers/of/unittest-data/overlay_gpio_02b.dts | 16 ++
> >>>>>> drivers/of/unittest-data/overlay_gpio_03.dts | 23 +++
> >>>>>> drivers/of/unittest-data/overlay_gpio_04a.dts | 16 ++
> >>>>>> drivers/of/unittest-data/overlay_gpio_04b.dts | 16 ++
> >>>>>> drivers/of/unittest.c | 253 ++++++++++++++++++++++++++
> >>>>>> 8 files changed, 370 insertions(+), 1 deletion(-)
> >>>>>> create mode 100644 drivers/of/unittest-data/overlay_gpio_01.dts
> >>>>>> create mode 100644 drivers/of/unittest-data/overlay_gpio_02a.dts
> >>>>>> create mode 100644 drivers/of/unittest-data/overlay_gpio_02b.dts
> >>>>>> create mode 100644 drivers/of/unittest-data/overlay_gpio_03.dts
> >>>>>> create mode 100644 drivers/of/unittest-data/overlay_gpio_04a.dts
> >>>>>> create mode 100644 drivers/of/unittest-data/overlay_gpio_04b.dts
> >>>>>>
> >>>>>
> >>>>> Applied, thanks.
> >>>>>
> >>>>> Rob
> >>>>
> >>>>
> >>>
> >>>
> >>
> >
>