how to trace a function from the linux kernel module

[daliancat]

hi community,

I am going to use the ebpf to do some trace work against my kernel module, however, I haven't seen much discussion on that and most of the discussion are based on Linux kernel events, functions. I tried to trace a kernel module function, let's say named as my_kernel_func(), I will get the errors like below:
libbpf: kprobe perf_event_open() failed: Cannot assign requested address libbpf: prog 'my_kernel_func': failed to create kprobe 'my_kernel_func+0x0' perf event: Cannot assign requested address libbpf: failed to auto-attach program 'asmSubmitBio': -99 failed to attach BPF programs: Cannot assign requested address

This function is already existed and available for tracing
$sudo bpftrace -l "kprobe:my_kernel_func"
kprobe:my_kernel_func
$ sudo cat /sys/kernel/debug/tracing/available_filter_functions|grep my_kernel_func
my_kernel_func [test_module]
$ cat /proc/kallsyms |grep my_kernel_func
0000000000000000 t asmSubmitBio [test_module]

do I miss anything? how to make it work? thanks for your suggestions

This is how I define the trace function in .bpf.c file:
SEC("kprobe/my_kernel_func")
int BPF_KPROBE(kprobe__my_kernel_func)
{
return inc_stats(S_MY_KERNEL_FUNC);
}