[dni_dps460] Read, Write on 'fan1_target' reports failure

[ArunSaravananBalachandran]

Description

Read and write to ‘fan1_target’ attribute of ‘dni_dps460’ driver fails with a kernel crash (list_add corruption) and error respectively.

• Write on the attribute fails with 'Bad address' error.
• Read on the attribute results in ‘list_add’ corruption (similar to Console shows Kernel crash during boot up with Mater debug image .339 on Dell S6000-ACS/S6000 sonic-linux-kernel#152 - reported for write operation)

Steps to reproduce the issue:

1. Load latest SONiC master image in Dell S6000 platform.
2. Execute 'set-fan-speed 15000'

Describe the results you received:

• Write

root@sonic:/home/admin# ls -l /sys/class/i2c-adapter/i2c-1/1-0059/fan1_target
-rw-r--r-- 1 root root 4096 Dec  7 05:13 /sys/class/i2c-adapter/i2c-1/1-0059/fan1_target
root@sonic:/home/admin#
root@sonic:/home/admin# echo 15000 > /sys/class/i2c-adapter/i2c-1/1-0059/fan1_target
bash: echo: write error: Bad address
root@sonic:/home/admin#

• Read

root@sonic:/home/admin# cat /sys/class/i2c-adapter/i2c-1/1-0059/fan1_target
[ 4000.706618] list_add corruption. prev->next should be next (ffff9ea8ab3fe910), but was ffff9ea8ab3fe918. (prev=ffff9ea8ab3fe918).
[ 4000.846311] kernel BUG at lib/list_debug.c:28!
[ 4000.899547] invalid opcode: 0000 [#1] SMP NOPTI
[ 4000.953772] CPU: 0 PID: 30237 Comm: cat Tainted: G           OE     4.19.0-9-2-amd64 #1 Debian 4.19.118-2+deb10u1
[ 4001.076689] Hardware name: Dell Inc S6000-ACS/S6000 CPU, BIOS 4.6.5 10/12/2015
[ 4001.163124] RIP: 0010:__list_add_valid.cold.0+0x26/0x28
[ 4001.225724] Code: 00 00 00 c3 48 89 d1 48 c7 c7 88 9e 49 a2 48 89 c2 e8 90 7a d0 ff 0f 0b 48 89 c1 4c 89 c6 48 c7 c7 e0 9e 49 a2 e8 7c 7a d0 ff <0f> 0b 48 89 fe 48 89 c2 48 c7 c7 70 9f 49 a2 e8 68 7a d0 ff 0f 0b
[ 4001.450574] RSP: 0018:ffffb25303e13d60 EFLAGS: 00010246
[ 4001.513174] RAX: 0000000000000075 RBX: ffffb25303e13db0 RCX: 0000000000000000
[ 4001.598559] RDX: 0000000000000000 RSI: ffff9ea8f7a166b8 RDI: ffff9ea8f7a166b8
[ 4001.683947] RBP: ffff9ea8ab3fe910 R08: 000000000000036f R09: 0000000000000004
[ 4001.769330] R10: 000000000000072e R11: ffffffffa2bf66ad R12: ffff9ea8ab3fe918
[ 4001.854713] R13: ffff9ea8ab3fe900 R14: ffff9ea8f3d16e00 R15: ffff9ea8ab3fe900
[ 4001.940105] FS:  00007fefe16c8540(0000) GS:ffff9ea8f7a00000(0000) knlGS:0000000000000000
[ 4002.037028] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4002.105768] CR2: 00007fefe1165000 CR3: 0000000174560000 CR4: 00000000000006f0
[ 4002.191163] Call Trace:
[ 4002.220504]  __mutex_add_waiter+0x23/0x50
[ 4002.268555]  __mutex_lock.isra.8+0x1d1/0x4a0
[ 4002.319723]  ? mem_cgroup_try_charge+0x86/0x190
[ 4002.374008]  ? mem_cgroup_throttle_swaprate+0x24/0x14a
[ 4002.435580]  get_target+0x28/0x70 [dni_dps460]
[ 4002.488827]  dev_attr_show+0x1c/0x40
[ 4002.531676]  sysfs_kf_seq_show+0x9b/0x100
[ 4002.579721]  seq_read+0x153/0x410
[ 4002.619454]  vfs_read+0x91/0x140
[ 4002.658137]  ksys_read+0x57/0xd0
[ 4002.696827]  do_syscall_64+0x53/0x110
[ 4002.740712]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 4002.801234] RIP: 0033:0x7fefe15f0461
[ 4002.844079] Code: fe ff ff 50 48 8d 3d fe d0 09 00 e8 e9 03 02 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 99 62 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 41 54 49 89 d4 55 48
[ 4003.068923] RSP: 002b:00007ffc2b194fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 4003.159607] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fefe15f0461
[ 4003.245092] RDX: 0000000000020000 RSI: 00007fefe1166000 RDI: 0000000000000003
[ 4003.330475] RBP: 00007fefe1166000 R08: 00000000ffffffff R09: 0000000000000000
[ 4003.415868] R10: fffffffffffffb9c R11: 0000000000000246 R12: 00007fefe1166000
[ 4003.501350] R13: 0000000000000003 R14: 0000000000000fff R15: 0000000000020000
[ 4003.586734] Modules linked in: nft_chain_route_ipv4(E) xt_TCPMSS(E) dummy(E) xt_hl(E) xt_tcpudp(E) ip6_tables(E) nft_compat(E) optoe(E) emc1403(E) lm75(E) ltc4215(E) max6620(E) jc42(E) dni_dps460(E) at24(E) pmbus_core(E) nft_counter(E) xt_conntrack(E) nf_nat(E) dell_s6000_platform(OE) i2c_mux_gpio(E) i2c_mux(E) nvram(E) nf_conntrack_netlink(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) libcrc32c(E) xfrm_user(E) xfrm_algo(E) intel_powerclamp(E) coretemp(E) evdev(E) bonding(E) kvm(E) linux_knet_cb(OE) linux_bcm_knet(OE) dcdbas(E) psample(OE) linux_user_bde(OE) linux_kernel_bde(OE) irqbypass(E) ie6xx_wdt(E) efi_pstore(E) pcspkr(E) efivars(E) sg(E) button(E) ebt_vlan(E) ebtable_broute(E) bridge(E) stp(E) llc(E) ebtable_nat(E) ebtable_filter(E) ebtables(E) nf_tables(E) nfnetlink(E) efivarfs(E)
[ 4004.432496]  ip_tables(E) x_tables(E) autofs4(E) loop(E) ext4(E) crc16(E) mbcache(E) jbd2(E) crc32c_generic(E) fscrypto(E) ecb(E) crypto_simd(E) cryptd(E) glue_helper(E) aes_x86_64(E) nls_utf8(E) nls_cp437(E) nls_ascii(E) vfat(E) fat(E) overlay(E) squashfs(E) zstd_decompress(E) xxhash(E) sd_mod(E) gpio_sch(E) i2c_isch(E) ohci_pci(E) e1000e(E) lpc_sch(E) ahci(E) mfd_core(E) ehci_pci(E) libahci(E) ohci_hcd(E) i2c_ismt(E) ehci_hcd(E) libata(E) usbcore(E) usb_common(E) scsi_mod(E) thermal(E)
[ 4004.949713] ---[ end trace 207182749fc39df2 ]---
[ 4005.953436] RIP: 0010:__list_add_valid.cold.0+0x26/0x28
[ 4006.016021] Code: 00 00 00 c3 48 89 d1 48 c7 c7 88 9e 49 a2 48 89 c2 e8 90 7a d0 ff 0f 0b 48 89 c1 4c 89 c6 48 c7 c7 e0 9e 49 a2 e8 7c 7a d0 ff <0f> 0b 48 89 fe 48 89 c2 48 c7 c7 70 9f 49 a2 e8 68 7a d0 ff 0f 0b
[ 4006.240880] RSP: 0018:ffffb25303e13d60 EFLAGS: 00010246
[ 4006.303522] RAX: 0000000000000075 RBX: ffffb25303e13db0 RCX: 0000000000000000
[ 4006.388986] RDX: 0000000000000000 RSI: ffff9ea8f7a166b8 RDI: ffff9ea8f7a166b8
[ 4006.474466] RBP: ffff9ea8ab3fe910 R08: 000000000000036f R09: 0000000000000004
[ 4006.559944] R10: 000000000000072e R11: ffffffffa2bf66ad R12: ffff9ea8ab3fe918
[ 4006.645421] R13: ffff9ea8ab3fe900 R14: ffff9ea8f3d16e00 R15: ffff9ea8ab3fe900
[ 4006.730916] FS:  00007fefe16c8540(0000) GS:ffff9ea8f7a00000(0000) knlGS:0000000000000000
[ 4006.827854] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4006.896696] CR2: 00007fefe1165000 CR3: 0000000174560000 CR4: 00000000000006f0
Segmentation fault
root@sonic:/home/admin#

Describe the results you expected:

Read and write operations to succeed.

Additional information you deem important (e.g. issue happens only occasionally):

Show version

root@sonic:/home/admin# show version

SONiC Software Version: SONiC.master.513-af357f3e
Distribution: Debian 10.7
Kernel: 4.19.0-9-2-amd64
Build commit: af357f3e
Build date: Sun Dec  6 09:14:25 UTC 2020
Built by: johnar@jenkins-worker-8

Platform: x86_64-dell_s6000_s1220-r0
HwSKU: Force10-S6000
ASIC: broadcom
ASIC Count: 1
Serial Number: HFV9VS1
Uptime: 06:45:03 up  1:32,  1 user,  load average: 7.01, 8.90, 9.37

Docker images:
REPOSITORY                    TAG                   IMAGE ID            SIZE
docker-snmp                   latest                8daa11cbf19b        484MB
docker-snmp                   master.513-af357f3e   8daa11cbf19b        484MB
docker-teamd                  latest                e442c7202130        491MB
docker-teamd                  master.513-af357f3e   e442c7202130        491MB
docker-sonic-mgmt-framework   latest                2a3949717681        606MB
docker-sonic-mgmt-framework   master.513-af357f3e   2a3949717681        606MB
docker-router-advertiser      latest                2ded3ce86035        448MB
docker-router-advertiser      master.513-af357f3e   2ded3ce86035        448MB
docker-platform-monitor       latest                59987ecb8c7e        572MB
docker-platform-monitor       master.513-af357f3e   59987ecb8c7e        572MB
docker-lldp                   latest                079b876a59a1        488MB
docker-lldp                   master.513-af357f3e   079b876a59a1        488MB
docker-dhcp-relay             latest                c62a5faa21f1        455MB
docker-dhcp-relay             master.513-af357f3e   c62a5faa21f1        455MB
docker-database               latest                035f87ff4fcc        448MB
docker-database               master.513-af357f3e   035f87ff4fcc        448MB
docker-orchagent              latest                433129065bf0        505MB
docker-orchagent              master.513-af357f3e   433129065bf0        505MB
docker-nat                    latest                cc2ed184bfb5        494MB
docker-nat                    master.513-af357f3e   cc2ed184bfb5        494MB
docker-sonic-telemetry        latest                cc5bacd84995        517MB
docker-sonic-telemetry        master.513-af357f3e   cc5bacd84995        517MB
docker-fpm-frr                latest                c13f136a82d1        507MB
docker-fpm-frr                master.513-af357f3e   c13f136a82d1        507MB
docker-sflow                  latest                28b7bad1411c        492MB
docker-sflow                  master.513-af357f3e   28b7bad1411c        492MB
docker-syncd-brcm             latest                a3c3d4b1837b        542MB
docker-syncd-brcm             master.513-af357f3e   a3c3d4b1837b        542MB

root@sonic:/home/admin#

Show techsupport: sonic_dump_sonic_20201207_062850.tar.gz

[anshuv-mfst]

Dell team to take this issue forward.