Re: [PATCH v2 1/2] of: unittest: add overlay gpio test to catch gpio hog problem
From: Frank Rowand
Date: Fri Mar 13 2020 - 12:40:44 EST
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.
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
>
>