[Crash-utility] [BUG?] failed to execute bt -a for arm64

Hi All, I try to use `bt -a' for arm64 platform, then Segmentation fault happened. My crash is built from source code hosted on github. And my kernel version is 4.4.35. I tried to use gdb to examine this problem, Some information is shown as below: (gdb) bt #0 arm64_is_kernel_exception_frame (bt=bt@entry=0x7ffeba6577e0, stkptr=stkptr@entry=18446743803091823872) at arm64.c:1504 #1 0x00000000004fbda8 in arm64_back_trace_cmd (bt=0x7ffeba6577e0) at arm64.c:2259 #2 0x00000000004d415c in back_trace (bt=bt@entry=0x7ffeba6577e0) at kernel.c:3063 #3 0x00000000004dee87 in cmd_bt () at kernel.c:2701 [...] (gdb) p/x stkptr $14 = 0xffffffc0fded2d00 (gdb) p/x bt->stackbase $15 = 0xffffff8008dcc000 As it is, (stkptr - bt->stackbase) is too large. It lead bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(stkptr))] index out of bounds. This stack belongs to swapper/0. I'm not sure whether it is a BUG. Could anyone give me some advise to solve this problem? Thank you!