libbpf: failed to add legacy kprobe event for 'vfs_open+0x0': No such file or directory

[Ephemeraler]

I execute 'cat /proc/kallsyms | grep vfs_open', it can be found in system. Why I get this error msg.

[chenhengqi]

Do you have tracefs/debugfs mounted ?

[Ephemeraler]

Do you have tracefs/debugfs mounted ? @chenhengqi I guess this problem is related to the system configuration, such as CONFIG_KPROBES*. In my system, I find only CONFIG_HAVE_KPROBES=y. But I am not sure which Config about Kprobe is causing this problem.

[chenhengqi]

Try cat /proc/mounts | grep debug.

[Ephemeraler]

Try cat /proc/mounts | grep debug.

@chenhengqi yes, the system has mountted tracefs and debugfs. I can use tracepoint on BPF, I will recompile kernel to modify config in order to find cause. Maybe CONFIG_KPROBES need to set.

[yonghong-song]

Yes, CONFIG_KPROBES is necessary for kprobe support.

[irenge]

Please close the issue once resolved :)