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From: Yaniv Agman <yanivagman@gmail.com>
To: bpf <bpf@vger.kernel.org>
Subject: libbpf: Loading kprobes fail on some distros
Date: Sun, 11 Oct 2020 22:28:30 +0300	[thread overview]
Message-ID: <CAMy7=ZWoL7w97aR5_02OEjKEkJT8R7OEzpL5Zp8Cycm=yZSLJQ@mail.gmail.com> (raw)

Trying to load kprobes on ubuntu 4.15.0, I get the following error:
libbpf: load bpf program failed: Invalid argument

The same kprobes load successfully using bcc

After some digging, I found that the issue was with the kernel version
given to the bpf syscall. While libbpf calculated the value 265984 for
the kern_version argument, bcc used 266002.
It turns out that some distros (e.g. ubuntu, debian) change the patch
number of the kernel version, as detailed in:
https://github.com/ajor/bpftrace/issues/8

I didn't find a proper API in libbpf to load kprobes in such cases -
is there any?

             reply	other threads:[~2020-10-11 19:28 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-11 19:28 Yaniv Agman [this message]
2020-10-12 17:01 ` libbpf: Loading kprobes fail on some distros Andrii Nakryiko
2020-10-12 21:20   ` Yaniv Agman
2020-10-12 22:10     ` Andrii Nakryiko

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