From patchwork Tue Jul 23 05:14:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 13739320 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 100A718D for ; Tue, 23 Jul 2024 05:15:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721711728; cv=none; b=GluzEE10/UNyNWA59iVLdP9jCZkUuFLwI0gUzYyK6WIjd19mOR4nGoy7Al4Gec8y5j8Dl1GkhYJKnlWiMX/ZMK7L2HNgI4VTiBiqoWVuQbPSwpbxOWtnpStpDbrQszdVXgEQMjvgTbeB7I0HaR6cF69KNj0pvLOF6Tizd7JX/a4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721711728; c=relaxed/simple; bh=qongxs3Cg31ginS50mBJ1KazckHoBhiYnW03F/8cWog=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=BbC6bUMwyLuciZr031e1ahoekjIAqB9RNUIKotjryvjG/VU5kN2mJxBM8d/N7fChyJ1t2ViMILEEkh3K/rPRHp/0oX3LghtDzZFYKAek31eGcLx06xd9PkPUOtSSpV/LbP93SjKajERG+rTIFrd4tU+vXaoD0rlGsulvT8hGY4k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gUxqT2Zy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gUxqT2Zy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FF15C4AF09; Tue, 23 Jul 2024 05:15:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721711727; bh=qongxs3Cg31ginS50mBJ1KazckHoBhiYnW03F/8cWog=; h=From:To:Cc:Subject:Date:From; b=gUxqT2Zyap8WDz/7XY9YouSMZNI7872q9XrRVOPCsUjEN3oC+DcLLEcouGxerIkmL CsTlhQ69ObvWLZ0iuDiuQkNzn5uyk0xfOGJIpw+BByXjxxKNYy65cHxam1mN9B25GI hxfhoC7k1w2pDfggeQf07kkvsrXJLh/WBT8QoIkTJidMcPJad8Yx52yvL90eUgV7ae zQaVzfqrONBrAZkox/TXqZ5ssmxQengvwD+dpj6yBYwEhb+RH3RvZC6+qSkYtC9ar6 rbjGsr4mU6YdmhG/vMk/TpxeU/8Fagx7HsZ54tvsIACfJlWEfEiZwk/lzGvw2Vgudc QiccLV0LdfPkQ== From: Song Liu To: bpf@vger.kernel.org Cc: kernel-team@meta.com, andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, Song Liu Subject: [PATCH bpf-next] selftests/bpf: Add a test for mmap-able map in map Date: Mon, 22 Jul 2024 22:14:55 -0700 Message-ID: <20240723051455.1589192-1-song@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net Regular BPF hash map is not mmap-able from user space. However, map-in-map with outer map of type BPF_MAP_TYPE_HASH_OF_MAPS and mmap-able array as inner map can perform similar operations as a mmap-able hash map. This can be used by applications that benefit from fast accesses to some local data. Add a selftest to show this use case. Signed-off-by: Song Liu --- .../bpf/prog_tests/test_mmap_inner_array.c | 57 ++++++++++++++++++ .../selftests/bpf/progs/mmap_inner_array.c | 59 +++++++++++++++++++ 2 files changed, 116 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/test_mmap_inner_array.c create mode 100644 tools/testing/selftests/bpf/progs/mmap_inner_array.c diff --git a/tools/testing/selftests/bpf/prog_tests/test_mmap_inner_array.c b/tools/testing/selftests/bpf/prog_tests/test_mmap_inner_array.c new file mode 100644 index 000000000000..ce745776ed18 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_mmap_inner_array.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#include +#include +#include "mmap_inner_array.skel.h" + +void test_mmap_inner_array(void) +{ + const long page_size = sysconf(_SC_PAGE_SIZE); + struct mmap_inner_array *skel; + int inner_array_fd, err; + void *tmp; + __u64 *val; + + skel = mmap_inner_array__open_and_load(); + + if (!ASSERT_OK_PTR(skel, "open_and_load")) + return; + + inner_array_fd = bpf_map__fd(skel->maps.inner_array); + tmp = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, inner_array_fd, 0); + if (!ASSERT_OK_PTR(tmp, "inner array mmap")) + goto out; + val = (void *)tmp; + + err = mmap_inner_array__attach(skel); + if (!ASSERT_OK(err, "attach")) + goto out_unmap; + + skel->bss->pid = getpid(); + usleep(1); + + /* pid is set, pid_match == true and outer_map_match == false */ + ASSERT_TRUE(skel->bss->pid_match, "pid match 1"); + ASSERT_FALSE(skel->bss->outer_map_match, "outer map match 1"); + ASSERT_FALSE(skel->bss->done, "done 1"); + ASSERT_EQ(*val, 0, "value match 1"); + + err = bpf_map__update_elem(skel->maps.outer_map, + &skel->bss->pid, sizeof(skel->bss->pid), + &inner_array_fd, sizeof(inner_array_fd), + BPF_ANY); + if (!ASSERT_OK(err, "update elem")) + goto out_unmap; + usleep(1); + + /* outer map key is set, outer_map_match == true */ + ASSERT_TRUE(skel->bss->pid_match, "pid match 2"); + ASSERT_TRUE(skel->bss->outer_map_match, "outer map match 2"); + ASSERT_TRUE(skel->bss->done, "done 2"); + ASSERT_EQ(*val, skel->data->match_value, "value match 2"); + +out_unmap: + munmap(tmp, page_size); +out: + mmap_inner_array__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/mmap_inner_array.c b/tools/testing/selftests/bpf/progs/mmap_inner_array.c new file mode 100644 index 000000000000..db8ca2aa4347 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/mmap_inner_array.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ + +#include "vmlinux.h" +#include +#include + +#include "bpf_misc.h" +#include "bpf_experimental.h" + +char _license[] SEC("license") = "GPL"; + +struct inner_array_type { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(map_flags, BPF_F_MMAPABLE); + __type(key, __u32); + __type(value, __u64); + __uint(max_entries, 1); +} inner_array SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS); + __uint(key_size, 4); + __uint(value_size, 4); + __uint(max_entries, 1); + __array(values, struct inner_array_type); +} outer_map SEC(".maps"); + +int pid = 0; +__u64 match_value = 0x13572468; +bool done = false; +bool pid_match = false; +bool outer_map_match = false; + +SEC("fentry/" SYS_PREFIX "sys_nanosleep") +int add_to_list_in_inner_array(void *ctx) +{ + __u32 curr_pid, zero = 0; + struct bpf_map *map; + __u64 *value; + + curr_pid = (u32)bpf_get_current_pid_tgid(); + if (done || curr_pid != pid) + return 0; + + pid_match = true; + map = bpf_map_lookup_elem(&outer_map, &curr_pid); + if (!map) + return 0; + + outer_map_match = true; + value = bpf_map_lookup_elem(map, &zero); + if (!value) + return 0; + + *value = match_value; + done = true; + return 0; +}