Hello, I found some confusing things during the usage of analysing the stack data. Summury: with the same demo named oops.ko and the same architecure(x86_64), there are two different stack layout the demo make a crash with hungtask. 1) kernel version [root@localhost ~]# uname -r 3.10.0-693.el7.x86_64 gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) crash version: [root@localhost ~]# crash --version crash 7.1.9-2.el7 [root@localhost ~]# gdb -v GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-100.el7\ bt -f pid 1--the callback address for create_oops function 2--the rbp register value for stack frame 5, point to the address ffff8800a637fd69. this layout in accordance with the x86_64 stack principle 2) kernel version [root@kylinv10 ~]# uname -r 4.19.90-24.4.v2101.ky10.x86_64 gcc version: [root@kylinv10 ~]# gcc --version gcc (GCC) 7.3.0 [root@kylinv10 ~]# gdb -v GNU gdb (GDB) EulerOS 9.2-1.ky10 crash version: [root@kylinv10 ~]# crash --version crash 7.2.9-2.p02.ky10 bt -f pid 1/2/3--there should be the value for the next stack frame's(in higher address) rbp register value, should be the valid address in this stack. but, they are invalid address "0000000000000001" "ffff8adb5424ccc0" and "ffffffffc096b000" I don't know the reason.4.19kernel, has this kernel param value like: kernel.randomize_va_space=0 thank you. -- Jane