arm64: Support overflow stack panic

[yangh]

Overflow stack supported since kernel 4.14 in commit 872d8327ce8,
without this patch, bt command trigger a SIGSEGV fault due the SP
pointed to the overflow stack which not yet loaded by crash.

Before:

  KERNEL: ../vmlinux
DUMPFILE: la_guestdump.gcore
    CPUS: 8
    DATE: Tue Jul 13 19:59:44 CST 2021
  UPTIME: 00:00:42

LOAD AVERAGE: 3.99, 1.13, 0.39
TASKS: 1925
NODENAME: localhost
RELEASE: 4.14.156+
VERSION: #1 SMP PREEMPT Tue Jul 13 10:37:23 UTC 2021
MACHINE: aarch64 (unknown Mhz)
MEMORY: 8.7 GB
PANIC: "Kernel panic - not syncing: kernel stack overflow"
PID: 1969
COMMAND: "irq/139-0-0024"
TASK: ffffffcc1a230000 [THREAD_INFO: ffffffcc1a230000]
CPU: 0
STATE: TASK_RUNNING (PANIC)

crash-7.3.0> bt
PID: 1969 TASK: ffffffcc1a230000 CPU: 0 COMMAND: "irq/139-0-0024"
Segmentation fault (core dumped)

After:

crash> bt
PID: 1969 TASK: ffffffcc1a230000 CPU: 0 COMMAND: "irq/139-0-0024"
#0 [ffffffcc7fd5cf50] __delay at ffffff8008c80774
#1 [ffffffcc7fd5cf60] __const_udelay at ffffff8008c80864
#2 [ffffffcc7fd5cf80] msm_trigger_wdog_bite at ffffff80084e9430
#3 [ffffffcc7fd5cfa0] do_vm_restart at ffffff80087bc974
#4 [ffffffcc7fd5cfc0] machine_restart at ffffff80080856fc
#5 [ffffffcc7fd5cfd0] emergency_restart at ffffff80080d49bc
#6 [ffffffcc7fd5d140] panic at ffffff80080af4c0
#7 [ffffffcc7fd5d150] nmi_panic at ffffff80080af150
#8 [ffffffcc7fd5d190] handle_bad_stack at ffffff800808b0b8
#9 [ffffffcc7fd5d2d0] __bad_stack at ffffff800808285c
--- ---
#10 [ffffff801187bc60] el1_error_invalid at ffffff8008082e7c
#11 [ffffff801187bcc0] cyttsp6_mt_attention at ffffff8000e8498c [cyttsp6]
#12 [ffffff801187bd20] call_atten_cb at ffffff8000e82030 [cyttsp6]
#13 [ffffff801187bdc0] cyttsp6_irq at ffffff8000e81e34 [cyttsp6]
#14 [ffffff801187bdf0] irq_thread_fn at ffffff8008128dd8
#15 [ffffff801187be50] irq_thread at ffffff8008128ca4
#16 [ffffff801187beb0] kthread at ffffff80080d2fc4
crash>

Signed-off-by: Hong YANG [email protected]

[k-hagio]

Thanks for the patch.
Could you please subscribe and send it to the crash-utility mailing list? We usually review patches there.

Please see Contribution Guidelines -> Submitting Patches.

[yangh]

Thanks, I'll sent to the mail list later.