Re: [Crash-utility] [PATCH 1/2] Revert "Fix segfault in arm64_is_kernel_exception_frame() when corrupt stack pointer address is given"
Thank you for pointing out this issue, HATAYAMA.
Anyway, I did not reproduce the above issue. Seems it can not always be reproduced.
# ./crash /home/vmlinux /var/crash/127.0.0.1-2023-06-09-05\:20\:38/vmcore -s
WARNING: cpu 2: invalid NT_PRSTATUS note (n_type != NT_PRSTATUS)
WARNING: cpu 1: cannot find NT_PRSTATUS note
WARNING: cpu 2: cannot find NT_PRSTATUS note
crash> ps insmod
PID PPID CPU TASK ST %MEM VSZ RSS COMM
1684 1683 0 ffff06738f1cdd00 ZO 0.0 0 0 insmod
crash> bt 1684
PID: 1684 TASK: ffff06738f1cdd00 CPU: 0 COMMAND: "insmod"
(no stack)
crash>
The problematic case is the active tasks running in user mode at the
moment of kernel panic. In most cases, it's enough to prepare some
programs that running in infinite loop just like:
# while : ; do continue ; done &
[3] 3295
Just in case, note that this issue is different from the one of
corrupt mapping of NT_PRSTATUS notes. You don't need to use the
reproduction steps I shared. It's enough to prepare the above busy
loop process in advance, make the kernel panic and then use bt command
for the busy loop process.
Thanks.
HATAYAMA, Daisuke