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From: Jiri Olsa <jolsa@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: dwarves@vger.kernel.org, bpf@vger.kernel.org,
	Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andriin@fb.com>, Yonghong Song <yhs@fb.com>,
	Hao Luo <haoluo@google.com>
Subject: [RFC 0/2] btf_encoder: Detect kernel modules
Date: Tue, 24 Nov 2020 17:19:17 +0100	[thread overview]
Message-ID: <20201124161919.2152187-1-jolsa@kernel.org> (raw)

hi,
adding support to detect kernel module and use its
mcount_loc section data as function filter.

It's working on my setup, but I fear there might be
kernel configuration where it could fail.

I'm mostly worried about the assumption that there's
always relocation section '.rela__mcount_loc' for
'__mcount_loc' section in kernel modules.

And because the relocation changes addresses, we need
to be sure we compare relative or relocated addresses.

I still need to double check scripts/recordmcount.c
to be sure about that. 

Any testing feedback would be great.

thanks,
jirka


---
Jiri Olsa (2):
      btf_encoder: Factor filter_functions function
      btf_encoder: Detect kernel module ftrace addresses

 btf_encoder.c | 142 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------------------
 dutil.c       |  16 ++++++++++++++++
 dutil.h       |   2 ++
 3 files changed, 137 insertions(+), 23 deletions(-)


             reply	other threads:[~2020-11-24 16:19 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-24 16:19 Jiri Olsa [this message]
2020-11-24 16:19 ` [PATCH 1/2] btf_encoder: Factor filter_functions function Jiri Olsa
2020-11-27  4:05   ` Andrii Nakryiko
2020-11-27 17:21     ` Jiri Olsa
2020-11-24 16:19 ` [PATCH 2/2] btf_encoder: Detect kernel module ftrace addresses Jiri Olsa
2020-11-27  4:18   ` Andrii Nakryiko
2020-11-27 17:40     ` Jiri Olsa
2020-11-27 20:39       ` Arnaldo Carvalho de Melo

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