Re: [BUG] Failed to obtain stack trace via bpf_get_stackid on ARM64 architecture

On Wed, 24 Sep 2025 14:25:36 +0800
Feng Yang [off-list ref] wrote:

By the way, during my testing, I also noticed that when executing bpf_get_stackid via kprobes or tracepoints, 
the command bpftrace -e 'kprobe:bpf_get_stackid {printf("bpf_get_stackid\n");}' produces no output. 

I think this is because the bpf_get_stackid is a kind of recursive
event from kprobes. Kprobe handler can not be reentered.

However, it does output something when bpf_get_stackid is invoked via uprobes. 
This phenomenon also occurs on the x86 architecture, could this be a bug as well?

Maybe if bpf_get_stackid() is kicked from uprobes, it is not recursive
call from kprobes, so it works.

So it is expected behavior, not a bug. Sorry for confusion.


Thank you,

Thanks.

-- 
Masami Hiramatsu (Google) [off-list ref]