<div style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial"><div>Dear <span style="font-family: arial; white-space: pre-wrap;">Ulrich，</span></div><div><span style="font-family: arial; white-space: pre-wrap;"><br></span></div><div><span style="font-family: arial; white-space: pre-wrap;">Thanks for your suggest. I have added some debug info, but not display. I will add more.</span></div><div><span style="font-family: arial; white-space: pre-wrap;">I want ask a question, </span><font face="arial"><span style="white-space: pre-wrap;">What commands does udevadm in systemd execute and what functions are corresponding to the driver?</span></font></div><div><font face="arial"><span style="white-space: pre-wrap;"><br></span></font></div><div><font face="arial"><span style="white-space: pre-wrap;">thanks,</span></font></div><div>Byron</div><br><br><br><br><div style="position:relative;zoom:1"></div><div id="divNeteaseMailCard"></div><br><pre><br>At 2019-10-15 20:36:41, "Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de> wrote:
>Hi!
>
>I think your driver loads OK, but it is not working correctly. Maybe enable
>kernel debug messages and add debug prints to your driver, especially regarding
>any queries. I suspect some NULL pointer or empty string being returned.
>
>Regards,
>Ulrich
>
>>>> www <ouyangxuan10@163.com> schrieb am 15.10.2019 um 13:46 in Nachricht
><252176e7.9975.16dcf3de51e.Coremail.ouyangxuan10@163.com>:
>> Dear all,
>>
>>
>> I add a new driver to kernel, and it probe success. When enter into systemd,
>
>> the udevadm generate a kernel panic.
>> I want to ask how to debug it and find out where the error occurred? When
>> did udevadm load? What commands are used by udevadm, and what are the
>> specific operations?
>>
>>
>> [ 3.291819] pmbus 13-0058: PMBus status register not found
>> [ 3.297940] pmbus 13-0059: PMBus status register not found
>> [ 3.305830] usbcore: registered new interface driver usbhid
>> [ 3.311417] usbhid: USB HID core driver
>> [ 3.326527] aspeed_jtag: driver successfully loaded. -->
>
>> load the driver success
>> [ 3.335427] NET: Registered protocol family 10
>> [ 3.345639] Segment Routing with IPv6
>> [ 3.349995] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
>> [ 3.357507] NET: Registered protocol family 17
>> [ 3.362012] 8021q: 802.1Q VLAN Support v1.8
>> [ 3.379650] printk: console [netcon0] enabled
>> [ 3.384027] netconsole: network logging started
>> [ 3.390140] input: gpio-keys as /devices/platform/gpio-keys/input/input0
>> [ 3.398913] hctosys: unable to open rtc device (rtc0)
>> [ 3.411203] Freeing unused kernel memory: 1024K
>> [ 3.419068] Checked W+X mappings: passed, no W+X pages found
>> [ 3.424841] Run /init as init process
>> rofs = mtd4 squashfs rwfs = mtd5 jffs2
>> [ 4.392201] jffs2: notice: (681) jffs2_build_xattr_subsystem: complete
>> building xattr subsystem, 8 of xdatum (0 unchecked, 1 orphan) and 11 of xref
>
>> (1 dead, 0 orphan) found.
>> [ 4.448757] overlayfs: upper fs does not support tmpfile.
>> [ 6.760748] systemd[1]: System time before build time, advancing clock.
>> [ 6.893492] systemd[1]: systemd 242-19-gdb2e367+ running in system mode.
>
>> (+PAM -AUDIT -SELINUX -IMA -APPARMOR -SMACK +SYSVINIT -UTMP -LIBCRYPTSETUP
>> -GCRYPT -GNUTLS -ACL +XZ -LZ4 -SECCOMP +BLKID -ELFUTILS -KMOD -IDN2 -IDN
>> -PCRE2 default-hierarchy=hybrid)
>> [ 6.917878] systemd[1]: Detected architecture arm.
>>
>>
>> Welcome to Phosphor OpenBMC (Phosphor OpenBMC Project Reference Distro)
>> 2.7.0-dev!
>>
>>
>> [ 7.033813] systemd[1]: Set hostname to <demoboard>.
>> [ 7.769096] systemd[1]: File
>> /lib/systemd/system/systemd-journald.service:12 configures an IP firewall
>> (IPAddressDeny=any), but the local system does not support BPF/cgroup based
>
>> firewalling.
>> [ 7.786341] systemd[1]: Proceeding WITHOUT firewalling in effect! (This
>> warning is only shown for the first loaded unit using IP firewalling.)
>> [ 8.942114] systemd[1]: /lib/systemd/system/phosphor-ipmi-net@.socket:3:
>
>> Invalid interface name, ignoring: sys-subsystem-net-devices-%i.device
>> [ 8.982380] systemd[1]: /lib/systemd/system/dbus.socket:4: ListenStream=
>
>> references a path below legacy directory /var/run/, updating
>> /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please
>> update the unit file accordingly.
>> [ 9.111166] systemd[1]: Reached target Fans Ready.
>> [ OK ] Reached target Fans Ready.
>> [ 9.148717] systemd[1]: Created slice
>> system-phosphor\x2dipmi\x2dkcs.slice.
>> [ OK ] Created slice system-phosphor\x2dipmi\x2dkcs.slice.
>> [ 9.199247] systemd[1]: Listening on udev Kernel Socket.
>> [ OK ] Listening on udev Kernel Socket.
>> [ OK ] Reached target Slices.
>> [ OK ] Created slice system-phosphor\x2dipmi\x2dnet.slice.
>> [ OK ] Reached target Remote File Systems.
>> [ OK ] Created slice system-mapper\x2dwait.slice.
>> [ OK ] Started Forward Password Râ€|uests to Wall Directory Watch.
>> [ OK ] Created slice system-phosphor\x2dgpio\x2dmonitor.slice.
>> [ OK ] Listening on Journal Socket.
>> Mounting Kernel Configuration File System...
>> [ OK ] Started Dispatch Password â€|ts to Console Directory Watch.
>> [ OK ] Reached target Paths.
>> [ OK ] Created slice system-phospâ€|dcertificate\x2dmanager.slice.
>> [ OK ] Listening on initctl Compatibility Named Pipe.
>> Mounting Kernel Debug File System...
>> [ OK ] Created slice system-obmc\x2dled\x2dgroup\x2dstart.slice.
>> [ OK ] Reached target Swap.
>> Mounting Temporary Directory (/tmp)...
>> [ OK ] Listening on Network Service Netlink Socket.
>> [ OK ] Started Hardware RNG Entropy Gatherer Daemon.
>> [ OK ] Created slice system-getty.slice.
>> [ OK ] Listening on udev Control Socket.
>> Starting udev Coldplug all Devices...
>> [ OK ] Listening on Syslog Socket.
>> [ OK ] Created slice system-obmc\x2dconsole.slice.
>> [ OK ] Created slice system-serial\x2dgetty.slice.
>> [ OK ] Created slice system-obmc\x2dread\x2deeprom.slice.
>> Starting Apply Kernel Variables...
>> Starting Remount Root and Kernel File Systems...
>> [ OK ] Started Set initial fan speed when BMC starts..
>> [ OK ] Listening on Journal Socket (/dev/log).
>> Starting Journal Service...
>> [ OK ] Mounted Kernel Configuration File System.
>> [ OK ] Mounted Kernel Debug File System.
>> [ OK ] Mounted Temporary Directory (/tmp).
>> [ OK ] Started Remount Root and Kernel File Systems.
>> Starting Rebuild Hardware Database...
>> Starting Create System Users...
>> [ OK ] Started Apply Kernel Variables.
>> [ OK ] Started Rebuild Hardware Database.
>> [ OK ] Started Create System Users.
>> [ OK ] Started Journal Service.
>> Starting Flush Journal to Persistent Storage...
>> Starting Create Static Device Nodes in /dev...
>> [ OK ] Started Create Static Device Nodes in /dev.
>> [ 12.129145] systemd-journald[710]: Received request to flush runtime
>> journal from PID 1
>> Starting udev Kernel Device Manager...
>> [ OK ] Reached target Local File Systems (Pre).
>> Mounting /var/volatile...
>> [ OK ] Started Flush Journal to Persistent Storage.
>> [ OK ] Mounted /var/volatile.
>> Starting Load/Save Random Seed...
>> [ OK ] Reached target Local File Systems.
>> Starting Create Volatile Files and Directories...
>> [ OK ] Started Load/Save Random Seed.
>> [ 13.497500] Unable to handle kernel paging request at virtual address
>> 0179a7b0
>> [ 13.504866] pgd = 6cf98158
>> [ 13.507598] [0179a7b0] *pgd=00000000
>> [ 13.511199] Internal error: Oops: 5 [#1] ARM
>> [ 13.515489] CPU: 0 PID: 846 Comm: udevadm Not tainted
>> 5.1.5-yocto-s-dirty-e03b6d3 #1 --> udevadm lead to kernel
>> panic
>> [ 13.523227] Hardware name: Generic DT based system
>> [ 13.528031] PC is at strlen+0xc/0x38
>> [ 13.531624] LR is at kstrdup+0x28/0x60
>> [ 13.535369] pc : [<806f08ac>] lr : [<8020dc7c>] psr: 20000013
>> [ 13.541625] sp : 999edcf0 ip : 999edd00 fp : 999edcfc
>> [ 13.546842] r10: 00001000 r9 : 9e753d80 r8 : 80a07008
>> [ 13.552061] r7 : 999edd5e r6 : 0179a7b0 r5 : 804004f4 r4 : 00000cc0
>> [ 13.558579] r3 : 9ac737c0 r2 : 00000000 r1 : 00000cc0 r0 : 0179a7b0
>> [ 13.565097] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment
>
>> none
>> [ 13.572220] Control: 00c5387d Table: 999f8008 DAC: 00000051
>> [ 13.577964] Process udevadm (pid: 846, stack limit = 0x1ca521ae)
>> [ 13.583965] Stack: (0x999edcf0 to 0x999ee000)
>> [ 13.588320] dce0: 999edd1c 999edd00
>> 8020dc7c 806f08ac
>> [ 13.596495] dd00: 9ac47608 9ac47600 999edd60 999edd5e 999edd2c 999edd20
>> 804004f4 8020dc60
>> [ 13.604668] dd20: 999edd4c 999edd30 804475c0 804004c0 9ac47608 9adb5000
>> 9ac47600 9ac47608
>> [ 13.612839] dd40: 999edd94 999edd50 804477bc 8044754c 999edd60 999edd60
>> 00000894 0000ff1c
>> [ 13.621013] dd60: 00000000 00000000 00000000 b7accb6a 9ac47608 9e487940
>> 9ac47608 9adb5000
>> [ 13.629186] dd80: 9ac47608 99965000 999eddbc 999edd98 80445d54 80447630
>> 9accee10 80a38ba4
>> [ 13.637356] dda0: 99965000 9ac47608 00000fff 9e753d80 999eddd4 999eddc0
>> 80445ba4 80445cb8
>> [ 13.645531] ddc0: 9accee10 8073f7e4 999ede04 999eddd8 802acd08 80445b84
>> 802acc78 9accee10
>> [ 13.653702] dde0: 9990ba40 00400cc0 00000000 999edf60 9accee28 00000001
>> 999ede14 999ede08
>> [ 13.661876] de00: 802ab5f4 802acc84 999ede5c 999ede18 8025efb0 802ab5cc
>> 9e6fc000 999edf60
>> [ 13.670048] de20: 9990ba40 9accee40 01b071f8 00001000 7eb787f8 9e753d80
>> 00001000 802ac0a0
>> [ 13.678221] de40: 999edf60 999edf60 999edf60 00000000 999ede9c 999ede60
>> 802ac0e0 8025ee60
>> [ 13.686393] de60: 999edefc 999ede70 8023f368 01b071f8 0000000d 9990ba40
>> 80a07008 802ac0a0
>> [ 13.694566] de80: 999edf60 00001000 999edf60 00000000 999edf24 999edea0
>> 80239348 802ac0ac
>> [ 13.702737] dea0: 00001000 00000000 00001000 00000000 00000000 00000000
>> 5da3e857 2b82ea81
>> [ 13.710911] dec0: 5da3e857 2b82ea81 5da3e857 2b82ea81 00001d14 00000000
>> 80a07008 b7accb6a
>> [ 13.719084] dee0: 01b071f8 80a07008 7eb787f8 802394fc 999edfa4 b7accb6a
>> 8023fc40 00001000
>> [ 13.727255] df00: 9990ba40 01b071f8 999edf60 00000001 00000000 00000000
>> 999edf54 999edf28
>> [ 13.735429] df20: 80239520 80239310 0000000d 8025930c 9990ba40 9990ba40
>> 80a07008 01b071f8
>> [ 13.743600] df40: 00000000 00000000 999edf94 999edf58 8023994c 80239498
>> 00000000 00000000
>> [ 13.751775] df60: 00000000 00000000 2b82ea81 b7accb6a 01ad4150 01b071f8
>> 457f1654 00000003
>> [ 13.759947] df80: 801011e4 999ec000 999edfa4 999edf98 802399dc 802398e8
>> 00000000 999edfa8
>> [ 13.768118] dfa0: 80101000 802399d0 01ad4150 01b071f8 00000005 01b071f8
>> 00001000 00000000
>> [ 13.776292] dfc0: 01ad4150 01b071f8 457f1654 00000003 00001001 457f11bc
>> 00001001 000005e8
>> [ 13.784463] dfe0: 00000070 7eb78868 4571bad4 45774f28 60000010 00000005
>> 00000000 00000000
>> [ 13.792626] Backtrace:
>> [ 13.795094] [<806f08a0>] (strlen) from [<8020dc7c>] (kstrdup+0x28/0x60)
>> [ 13.801731] [<8020dc54>] (kstrdup) from [<804004f4>]
>(misc_devnode+0x40/0x44)
>> [ 13.808869] r7:999edd5e r6:999edd60 r5:9ac47600 r4:9ac47608
>> [ 13.814546] [<804004b4>] (misc_devnode) from [<804475c0>]
>> (device_get_devnode+0x80/0xe4)
>> [ 13.822639] [<80447540>] (device_get_devnode) from [<804477bc>]
>> (dev_uevent+0x198/0x2cc)
>> [ 13.830724] r7:9ac47608 r6:9ac47600 r5:9adb5000 r4:9ac47608
>> [ 13.836390] [<80447624>] (dev_uevent) from [<80445d54>]
>> (uevent_show+0xa8/0x124)
>> [ 13.843788] r8:99965000 r7:9ac47608 r6:9adb5000 r5:9ac47608 r4:9e487940
>> [ 13.850491] [<80445cac>] (uevent_show) from [<80445ba4>]
>> (dev_attr_show+0x2c/0x58)
>> [ 13.858064] r9:9e753d80 r8:00000fff r7:9ac47608 r6:99965000 r5:80a38ba4
>
>> r4:9accee10
>> [ 13.865825] [<80445b78>] (dev_attr_show) from [<802acd08>]
>> (sysfs_kf_seq_show+0x90/0x108)
>> [ 13.873994] r5:8073f7e4 r4:9accee10
>> [ 13.877581] [<802acc78>] (sysfs_kf_seq_show) from [<802ab5f4>]
>> (kernfs_seq_show+0x34/0x38)
>> [ 13.885839] r10:00000001 r9:9accee28 r8:999edf60 r7:00000000 r6:00400cc0
>
>> r5:9990ba40
>> [ 13.893658] r4:9accee10 r3:802acc78
>> [ 13.897250] [<802ab5c0>] (kernfs_seq_show) from [<8025efb0>]
>> (seq_read+0x15c/0x4ec)
>> [ 13.904913] [<8025ee54>] (seq_read) from [<802ac0e0>]
>> (kernfs_fop_read+0x40/0x1c4)
>> [ 13.912481] r10:00000000 r9:999edf60 r8:999edf60 r7:999edf60 r6:802ac0a0
>
>> r5:00001000
>> [ 13.920296] r4:9e753d80
>> [ 13.922850] [<802ac0a0>] (kernfs_fop_read) from [<80239348>]
>> (__vfs_read+0x44/0x188)
>> [ 13.930595] r10:00000000 r9:999edf60 r8:00001000 r7:999edf60 r6:802ac0a0
>
>> r5:80a07008
>> [ 13.938411] r4:9990ba40
>> [ 13.940952] [<80239304>] (__vfs_read) from [<80239520>]
>(vfs_read+0x94/0x120)
>> [ 13.948082] r10:00000000 r9:00000000 r8:00000001 r7:999edf60 r6:01b071f8
>
>> r5:9990ba40
>> [ 13.955900] r4:00001000
>> [ 13.958442] [<8023948c>] (vfs_read) from [<8023994c>]
>(ksys_read+0x70/0xe8)
>> [ 13.965399] r9:00000000 r8:00000000 r7:01b071f8 r6:80a07008 r5:9990ba40
>
>> r4:9990ba40
>> [ 13.973141] [<802398dc>] (ksys_read) from [<802399dc>]
>(sys_read+0x18/0x1c)
>> [ 13.980099] r9:999ec000 r8:801011e4 r7:00000003 r6:457f1654 r5:01b071f8
>
>> r4:01ad4150
>> [ 13.987841] [<802399c4>] (sys_read) from [<80101000>]
>> (ret_fast_syscall+0x0/0x54)
>> [ 13.995319] Exception stack(0x999edfa8 to 0x999edff0)
>> [ 14.000368] dfa0: 01ad4150 01b071f8 00000005 01b071f8
>> 00001000 00000000
>> [ 14.008542] dfc0: 01ad4150 01b071f8 457f1654 00000003 00001001 457f11bc
>> 00001001 000005e8
>> [ 14.016710] dfe0: 00000070 7eb78868 4571bad4 45774f28
>> [ 14.021762] Code: e89da800 e1a0c00d e92dd800 e24cb004 (e5d03000)
>> [ 14.028037] ---[ end trace 850b9c31df4945cf ]---
>> [ 14.032675] Kernel panic - not syncing: Fatal exception
>> [ 14.037912] ---[ end Kernel panic - not syncing: Fatal exception ]---
>>
>>
>>
>>
>> thanks，
>> Byron
>
>
</pre></div><br><br><span title="neteasefooter"><p> </p></span>