Re: Notification when an eBPF map is modified


Raffaele Sommese
 

bpf tracepoints have been removed from recent linux so the you need to
use kprobe to trace update/delete.

typical map_update_elem and map_delete_elem first argument is
'struct bpf_map *map', you can get name and id from there:
Hello again :)
It seems that there is 2 function that can be traced inside the
kernel, one is map_update_elem, and it is the syscall, the other one
is the BPF helper.
I have successful attach my ebpf code to the first one, but it doesn't
have as parameter struct bpf_map *map (it have a union bpf_attr).
If I attach my program to the bpf_map_update_elem (that I think is the
function name of BPF helper), I don't receive any event.
I'm using the last version of bcc and of kernel.
I try also with kprobe program of perf kernel suite with the same results.
I was looking for this helper BPF_CALL_4 (bpf_map_update_elem, struct
bpf_map *, map, void *, key, void *, value, u64, flags)
Thank you again for the support,
Raffaele
--
________________________________
Raffaele Sommese
Mail:raffysommy@...
About me:https://about.me/r4ffy
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GPG key ID: 0x830b1428cf91db2a on http://pgp.mit.edu:11371/

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