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From: Pramukh Naduthota <pnaduthota@google.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
	haoluo@google.com, jolsa@kernel.org,
	Pramukh Naduthota <pnaduthota@google.com>
Subject: [PATCH bpf 0/2] Fix pinning devmaps
Date: Tue, 27 Sep 2022 18:23:43 +0000	[thread overview]
Message-ID: <20220927182345.149171-1-pnaduthota@google.com> (raw)

Fix devmap pinning and reloading. The kernel adds BPF_F_RDONLY_PROG to all
devmaps when created, but libbpf checks that user flags match pinned map
flags when using LIBBPF_PIN_BY_NAME, so reusing pinned devmaps doesn't
work, failing with an error like:

    libbpf: couldn't reuse pinned map at '/sys/fs/bpf/dev_map': parameter mismatch

Work around this by ignoring RDONLY_PROG in the compat check in libbpf.

Pramukh Naduthota (2):
  Ignore RDONLY_PROG for devmaps in libbpf to allow re-loading of pinned
    devmaps
  Add selftests for devmap pinning

 tools/lib/bpf/libbpf.c                        |  8 +++++++-
 .../testing/selftests/bpf/prog_tests/devmap.c | 21 +++++++++++++++++++
 .../selftests/bpf/progs/test_pinned_devmap.c  | 17 ++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/devmap.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_pinned_devmap.c

-- 
2.30.2


             reply	other threads:[~2022-09-27 18:24 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-27 18:23 Pramukh Naduthota [this message]
2022-09-27 18:23 ` [PATCH bpf 1/2] Ignore RDONLY_PROG for devmaps in libbpf to allow re-loading of pinned devmaps Pramukh Naduthota
2022-09-28  0:39   ` Martin KaFai Lau
2022-09-30 21:03     ` Andrii Nakryiko
2022-10-14 20:32       ` Pramukh Naduthota
2022-09-27 18:23 ` [PATCH bpf 2/2] Add selftests for devmap pinning Pramukh Naduthota
2022-09-27 20:30   ` Pramukh Naduthota
2022-09-30 21:05   ` Andrii Nakryiko

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