Unable to handle kernel paging request at virtual address on RISCV kernel when running ubuntu_ftrace_smoke_test

[Po-Hsu Lin]

Issue found on Focal RISCV 5.4.0-27

When running the ubuntu_ftrace_smoke_test test, the following error message could be found in dmesg:
[ 1491.973122] Unable to handle kernel paging request at virtual address fffffff888eea090
[ 1491.973278] Unable to handle kernel paging request at virtual address fffffff888eea090
[ 1491.973346] Unable to handle kernel paging request at virtual address fffffff888eea090
[ 1491.973421] Unable to handle kernel paging request at virtual address fffffff888eea090
[ 1491.973485] Unable to handle kernel paging request at virtual address fffffff888eea090
[ 1491.973545] Unable to handle kernel paging request at virtual address fffffff888eea090
[ 1491.973865] Oops [#1]
[ 1491.973927] Unable to handle kernel paging request at virtual address fffffff888eea090
[ 1491.981391] Modules linked in: aufs ofpart redboot cmdlinepart cfi_cmdset_0001 cfi_probe cfi_util gen_probe physmap map_funcs chipreg mtd uio_pdrv_genirq uio sch_fq_codel drm drm_panel_orientation_quirks ip_tables x_tables autofs4 virtio_blk virtio_net net_failover failover
[ 1491.984773] CPU: 3 PID: 25 Comm: migration/3 Not tainted 5.4.0-27-generic #31-Ubuntu
[ 1491.985795] sepc: ffffffe0000b8c56 ra : ffffffe00015cc12 sp : ffffffe078035d60
[ 1491.987039] gp : ffffffe000d53840 tp : ffffffe078022280 t0 : 0000000000000000
[ 1491.987967] t1 : fffffffff4e53a0c t2 : 0000000000000018 s0 : ffffffe078035d70
[ 1491.988996] s1 : ffffffe0719b1bec a0 : 0000000000000000 a1 : 0000000000000000
[ 1491.989877] a2 : ffffffe000d691cc a3 : 0000000000000004 a4 : 0000002ad7faa680
[ 1491.990775] a5 : fffffff888eea088 a6 : 000000037f010229 a7 : 0000000000000000
[ 1491.991635] s2 : 0000000000000003 s3 : ffffffffffffffff s4 : ffffffe000d54408
[ 1491.992550] s5 : 0000000000000001 s6 : 0000000000000003 s7 : 0000000000000003
[ 1491.993473] s8 : 0000000000000002 s9 : 0000000000000004 s10: 0000000000000000
[ 1491.994437] s11: ffffffe0719b1bc8 t3 : 0000000000000014 t4 : 0000000000000013
[ 1491.995360] t5 : 0000000000000004 t6 : 0000000000000000
[ 1491.996109] sstatus: 0000000000000100 sbadaddr: fffffff888eea090 scause: 000000000000000d
[ 1491.997470] Oops [#2]
[ 1491.997909] Modules linked in: aufs ofpart redboot cmdlinepart cfi_cmdset_0001 cfi_probe cfi_util gen_probe physmap map_funcs chipreg mtd uio_pdrv_genirq uio sch_fq_codel drm drm_panel_orientation_quirks ip_tables x_tables autofs4 virtio_blk virtio_net net_failover failover
[ 1492.000565] CPU: 2 PID: 20 Comm: migration/2 Tainted: G D 5.4.0-27-generic #31-Ubuntu
[ 1492.001501] sepc: ffffffe0000b8c56 ra : ffffffe00015cc12 sp : ffffffe07802bd60
[ 1492.002287] gp : ffffffe000d53840 tp : ffffffe078027300 t0 : 0000000000000000
[ 1492.003091] t1 : fffffffff47d3a0c t2 : 0000000000000018 s0 : ffffffe07802bd70
[ 1492.003983] s1 : ffffffe0719b1bec a0 : 0000000000000000 a1 : 0000000000000000
[ 1492.004764] a2 : ffffffe000d691cc a3 : 0000000000000003 a4 : 0000002ad7faa680
[ 1492.005612] a5 : fffffff888eea088 a6 : 000000037f010229 a7 : 0000000000000000
[ 1492.006433] s2 : 0000000000000003 s3 : ffffffffffffffff s4 : ffffffe000d54408
[ 1492.006746] ---[ end trace 7c8d93ec2f9285a9 ]---

The test will hang:
Running '/home/ubuntu/autotest/client/tests/ubuntu_ftrace_smoke_test/ubuntu_ftrace_smoke_test.sh'
PASSED (CONFIG_FUNCTION_TRACER=y in /boot/config-5.4.0-27-generic)
PASSED (CONFIG_FUNCTION_GRAPH_TRACER=y in /boot/config-5.4.0-27-generic)
PASSED (CONFIG_STACK_TRACER=y in /boot/config-5.4.0-27-generic)
PASSED (CONFIG_DYNAMIC_FTRACE=y in /boot/config-5.4.0-27-generic)
PASSED all expected /sys/kernel/debug/tracing files exist
PASSED (function_graph in /sys/kernel/debug/tracing/available_tracers)
PASSED (function in /sys/kernel/debug/tracing/available_tracers)
PASSED (nop in /sys/kernel/debug/tracing/available_tracers)
(looks like it has stopped here)

[Po-Hsu Lin (cypressyew)]

The system will end up with kernel-panic:
 1499.266021] Oops - illegal instruction [#28]
[ 1499.266801] Modules linked in: aufs ofpart redboot cmdlinepart cfi_cmdset_0001 cfi_probe cfi_util gen_probe physmap map_funcs chipreg mtd uio_pdrv_genirq uio sch_fq_codel drm drm_panel_orientation_quirks ip_tables x_tables autofs4 virtio_blk virtio_net net_failover failover
[ 1499.270735] CPU: 3 PID: 3775 Comm: systemd-udevd Tainted: G D 5.4.0-27-generic #31-Ubuntu
[ 1499.272408] sepc: ffffffe000256970 ra : ffffffe000256ee6 sp : ffffffe073601e00
[ 1499.273691] gp : ffffffe000d53840 tp : ffffffe05ca61700 t0 : ffffffe073601d38
[ 1499.274983] t1 : ffffffe0008c7d82 t2 : ffffffe073601db0 s0 : ffffffe073601e70
[ 1499.275990] s1 : 0000000000000000 a0 : 0000000000000002 a1 : ffffffe0008c7d82
[ 1499.277251] a2 : ffffffe073601db0 a3 : 0000000000000002 a4 : 0000000000000002
[ 1499.278400] a5 : 0000000000000000 a6 : ffffffe000c7eec0 a7 : 0000000000000000
[ 1499.279488] s2 : 0000000000000002 s3 : 0000000000000002 s4 : ffffffe073601e78
[ 1499.280675] s5 : ffffffe073601e78 s6 : 0000000000000000 s7 : 0000000000000001
[ 1499.281837] s8 : 0000002abea97770 s9 : 0000003fff8c1770 s10: 0000002ad9353560
[ 1499.282918] s11: 0000002abeab6010 t3 : f000000000000000 t4 : 0000000000000008
[ 1499.284036] t5 : ffffffe000d535b8 t6 : 0000000000000005
[ 1499.285012] sstatus: 0000000000000120 sbadaddr: 0000000000000000 scause: 0000000000000002
[ 1499.286341] Oops - illegal instruction [#29]
[ 1499.287219] Modules linked in: aufs ofpart redboot cmdlinepart cfi_cmdset_0001 cfi_probe cfi_util gen_probe physmap map_funcs chipreg mtd uio_pdrv_genirq uio sch_fq_codel drm drm_panel_orientation_quirks ip_tables x_tables autofs4 virtio_blk virtio_net net_failover
[ 1499.287505] ---[ end trace 7c8d93ec2f9285c4 ]---
[ 1499.287538] failover
[ 1499.292118] CPU: 6 PID: 1 Comm: systemd Tainted: G D 5.4.0-27-generic #31-Ubuntu
[ 1499.293650] sepc: ffffffe000256970 ra : ffffffe000256ee6 sp : ffffffe077fbbe00
[ 1499.295033] gp : ffffffe000d53840 tp : ffffffe077fca280 t0 : ffffffe076c97e18
[ 1499.296250] t1 : ffffffe07fd5fd60 t2 : ffffffe077fbbe00 s0 : ffffffe077fbbe70
[ 1499.297503] s1 : 0000000000000000 a0 : 0000000000000003 a1 : 00000000ff000000
[ 1499.298654] a2 : 0000000000000ceb a3 : 00ff000000000000 a4 : ffffffe07fd5fd68
[ 1499.299908] a5 : 000000000000ff00 a6 : 000000ff00000000 a7 : ffffffe000dadb18
[ 1499.301330] s2 : 0000000000000003 s3 : 0000000000000003 s4 : ffffffe077fbbe78
[ 1499.302589] s5 : ffffffe077fbbe78 s6 : 0000003fbf0528a8 s7 : 0000003fffa8a3a8
[ 1499.303737] s8 : 0000003fffa8a298 s9 : 0000003fffa8a398 s10: 0000002ac6e5ef98
[ 1499.305041] s11: 0000002ae671c560 t3 : 0000000000ff0000 t4 : 0000000000000cea
[ 1499.306270] t5 : 0000000000000002 t6 : 000000007fcaa000
[ 1499.307233] sstatus: 0000000000000120 sbadaddr: 0000000000000000 scause: 0000000000000002
[ 1499.309376] ---[ end trace 7c8d93ec2f9285c5 ]---
[ 1499.310276] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[ 1499.311797] SMP: stopping secondary CPUs
[ 1499.313925] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---