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Wed, 2 Oct 2024 18:09:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8FEFC4CECF; Wed, 2 Oct 2024 18:09:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727892600; bh=ePjQez0zpwMreMUAuz+KvIM2b9Vii7HFddbSYrTFhpc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wi4ubqCtkGXIKFj8UkgIyBOAnxzZZ4rGMyF8fzGhCZlvRlhRcuVtq1zaxLxBO7D2B YIa0YE0VwzDvdvCx2E3L6+tfbVRSvYbgESP5vjC6VnYWMjTuDxAfbUFiOmyX+qE/yJ SpcOCRE2lFI1WeyjcJstBSx4pl1hcNBlwZyNKXuaoMXHRs/k4ITT1ouVY4jjtQ/3fY veNrgPyqOU7aoSqrAeVzyW2FUSVOZPt26DGJo/mQSzl5cYlwtPURE15RSR1BKw5goE SIhtC9kgrdwp+knOGWJ90EpG+dEiimHqjCMj+zAIgpL5ofo2WV3gGqVJFdiz48pyJA yr1h7z8v5Uj3w== From: Namhyung Kim To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , LKML , bpf@vger.kernel.org, Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, Arnaldo Carvalho de Melo , Kees Cook Subject: [PATCH v4 bpf-next 3/3] selftests/bpf: Add a test for kmem_cache_iter Date: Wed, 2 Oct 2024 11:09:56 -0700 Message-ID: <20241002180956.1781008-4-namhyung@kernel.org> X-Mailer: git-send-email 2.46.1.824.gd892dcdcdd-goog In-Reply-To: <20241002180956.1781008-1-namhyung@kernel.org> References: <20241002180956.1781008-1-namhyung@kernel.org> MIME-Version: 1.0 X-Stat-Signature: 6r8spdqmy48eqqnxrxfzh647ez78rnmx X-Rspamd-Queue-Id: C602DA0011 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1727892601-157220 X-HE-Meta: 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 1eZm7YFa MuOW2Ar5ZjGAg4tNUxCXYBG0I99Xk9aeqVZjFW7v7B+5KOlmcRje68ylJmUxMTdDwna8CJm4JNO2QY5bCUawjmUoU8glqMhpTmK7FamNYnVf5FvH3BhR3CQBGsBqRSYzYz6vxkprBR4cTNxmlZRK6rQQYqCmTr/1hJLiHMgttCKlg45UUz3rGLtNaW+5AUurUhAhsBUwu4KWQBlCyz6koeDc955zF/c63zf6ksxRvdk+VBTL+CycpKrqvo06yJN9K3hIJuE6kPAXjX1+uJ+LQa/T2tw0YP/F82C/umvcqIbwPP3hIKT4ar03VjIeuI7EFPHSTT1WnsvNL6fmrVDCAiMP1aAbGFAJtq0dIgbOFZ1FxxOlhUXdZcrPCEnY8j1m/hBxIRgkuwhsU048= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: The test traverses all slab caches using the kmem_cache_iter and check if current task's pointer is from "task_struct" slab cache. Signed-off-by: Namhyung Kim --- .../bpf/prog_tests/kmem_cache_iter.c | 64 ++++++++++++++++++ tools/testing/selftests/bpf/progs/bpf_iter.h | 7 ++ .../selftests/bpf/progs/kmem_cache_iter.c | 66 +++++++++++++++++++ 3 files changed, 137 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c create mode 100644 tools/testing/selftests/bpf/progs/kmem_cache_iter.c diff --git a/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c b/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c new file mode 100644 index 0000000000000000..3965e2924ac82d91 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Google */ + +#include +#include +#include +#include "kmem_cache_iter.skel.h" + +static void test_kmem_cache_iter_check_task(struct kmem_cache_iter *skel) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts, + .flags = 0, /* run it with the current task */ + ); + int prog_fd = bpf_program__fd(skel->progs.check_task_struct); + + /* get task_struct and check it if's from a slab cache */ + bpf_prog_test_run_opts(prog_fd, &opts); + + /* the BPF program should set 'found' variable */ + ASSERT_EQ(skel->bss->found, 1, "found task_struct"); +} + +void test_kmem_cache_iter(void) +{ + DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); + struct kmem_cache_iter *skel = NULL; + union bpf_iter_link_info linfo = {}; + struct bpf_link *link; + char buf[1024]; + int iter_fd; + + skel = kmem_cache_iter__open_and_load(); + if (!ASSERT_OK_PTR(skel, "kmem_cache_iter__open_and_load")) + return; + + opts.link_info = &linfo; + opts.link_info_len = sizeof(linfo); + + link = bpf_program__attach_iter(skel->progs.slab_info_collector, &opts); + if (!ASSERT_OK_PTR(link, "attach_iter")) + goto destroy; + + iter_fd = bpf_iter_create(bpf_link__fd(link)); + if (!ASSERT_GE(iter_fd, 0, "iter_create")) + goto free_link; + + memset(buf, 0, sizeof(buf)); + while (read(iter_fd, buf, sizeof(buf) > 0)) { + /* read out all contents */ + printf("%s", buf); + } + + /* next reads should return 0 */ + ASSERT_EQ(read(iter_fd, buf, sizeof(buf)), 0, "read"); + + test_kmem_cache_iter_check_task(skel); + + close(iter_fd); + +free_link: + bpf_link__destroy(link); +destroy: + kmem_cache_iter__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/bpf_iter.h b/tools/testing/selftests/bpf/progs/bpf_iter.h index c41ee80533ca219a..3305dc3a74b32481 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter.h +++ b/tools/testing/selftests/bpf/progs/bpf_iter.h @@ -24,6 +24,7 @@ #define BTF_F_PTR_RAW BTF_F_PTR_RAW___not_used #define BTF_F_ZERO BTF_F_ZERO___not_used #define bpf_iter__ksym bpf_iter__ksym___not_used +#define bpf_iter__kmem_cache bpf_iter__kmem_cache___not_used #include "vmlinux.h" #undef bpf_iter_meta #undef bpf_iter__bpf_map @@ -48,6 +49,7 @@ #undef BTF_F_PTR_RAW #undef BTF_F_ZERO #undef bpf_iter__ksym +#undef bpf_iter__kmem_cache struct bpf_iter_meta { struct seq_file *seq; @@ -165,3 +167,8 @@ struct bpf_iter__ksym { struct bpf_iter_meta *meta; struct kallsym_iter *ksym; }; + +struct bpf_iter__kmem_cache { + struct bpf_iter_meta *meta; + struct kmem_cache *s; +} __attribute__((preserve_access_index)); diff --git a/tools/testing/selftests/bpf/progs/kmem_cache_iter.c b/tools/testing/selftests/bpf/progs/kmem_cache_iter.c new file mode 100644 index 0000000000000000..3f6ec15a1bf6344c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/kmem_cache_iter.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Google */ + +#include "bpf_iter.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +#define SLAB_NAME_MAX 256 + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(key_size, sizeof(void *)); + __uint(value_size, SLAB_NAME_MAX); + __uint(max_entries, 1024); +} slab_hash SEC(".maps"); + +extern struct kmem_cache *bpf_get_kmem_cache(__u64 addr) __ksym; + +/* result, will be checked by userspace */ +int found; + +SEC("iter/kmem_cache") +int slab_info_collector(struct bpf_iter__kmem_cache *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct kmem_cache *s = ctx->s; + + if (s) { + char name[SLAB_NAME_MAX]; + + /* + * To make sure if the slab_iter implements the seq interface + * properly and it's also useful for debugging. + */ + BPF_SEQ_PRINTF(seq, "%s: %u\n", s->name, s->object_size); + + bpf_probe_read_kernel_str(name, sizeof(name), s->name); + bpf_map_update_elem(&slab_hash, &s, name, BPF_NOEXIST); + } + + return 0; +} + +SEC("raw_tp/bpf_test_finish") +int BPF_PROG(check_task_struct) +{ + __u64 curr = bpf_get_current_task(); + struct kmem_cache *s; + char *name; + + s = bpf_get_kmem_cache(curr); + if (s == NULL) { + found = -1; + return 0; + } + + name = bpf_map_lookup_elem(&slab_hash, &s); + if (name && !bpf_strncmp(name, 11, "task_struct")) + found = 1; + else + found = -2; + + return 0; +}