From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 10/17] perf bpf: Add bpf_map dumper Date: Wed, 20 Feb 2019 22:25:42 -0300 Message-ID: <20190221012549.4069-11-acme@kernel.org> References: <20190221012549.4069-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190221012549.4069-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Yonghong Song List-Id: linux-perf-users.vger.kernel.org From: Arnaldo Carvalho de Melo At some point I'll suggest moving this to libbpf, for now I'll experiment with ways to dump BPF maps set by events in 'perf trace', starting with a very basic dumper for the current very limited needs of the augmented_raw_syscalls code: dumping booleans. Having functions that apply to the map keys and values and do table lookup in things like syscall id to string tables should come next. Cc: Adrian Hunter Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Jiri Olsa Cc: Martin KaFai Lau Cc: Namhyung Kim Cc: Yonghong Song Link: https://lkml.kernel.org/n/tip-lz14w0esqyt1333aon05jpwc@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/Build | 1 + tools/perf/util/bpf_map.c | 72 +++++++++++++++++++++++++++++++++++++++ tools/perf/util/bpf_map.h | 22 ++++++++++++ 3 files changed, 95 insertions(+) create mode 100644 tools/perf/util/bpf_map.c create mode 100644 tools/perf/util/bpf_map.h diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 3008d49fa587..8dd3102301ea 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -115,6 +115,7 @@ perf-y += branch.o perf-y += mem2node.o perf-$(CONFIG_LIBBPF) += bpf-loader.o +perf-$(CONFIG_LIBBPF) += bpf_map.o perf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o perf-$(CONFIG_LIBELF) += symbol-elf.o perf-$(CONFIG_LIBELF) += probe-file.o diff --git a/tools/perf/util/bpf_map.c b/tools/perf/util/bpf_map.c new file mode 100644 index 000000000000..eb853ca67cf4 --- /dev/null +++ b/tools/perf/util/bpf_map.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +#include "util/bpf_map.h" +#include +#include +#include +#include +#include +#include +#include + +static bool bpf_map_def__is_per_cpu(const struct bpf_map_def *def) +{ + return def->type == BPF_MAP_TYPE_PERCPU_HASH || + def->type == BPF_MAP_TYPE_PERCPU_ARRAY || + def->type == BPF_MAP_TYPE_LRU_PERCPU_HASH || + def->type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE; +} + +static void *bpf_map_def__alloc_value(const struct bpf_map_def *def) +{ + if (bpf_map_def__is_per_cpu(def)) + return malloc(round_up(def->value_size, 8) * sysconf(_SC_NPROCESSORS_CONF)); + + return malloc(def->value_size); +} + +int bpf_map__fprintf(struct bpf_map *map, FILE *fp) +{ + const struct bpf_map_def *def = bpf_map__def(map); + void *prev_key = NULL, *key, *value; + int fd = bpf_map__fd(map), err; + int printed = 0; + + if (fd < 0) + return fd; + + if (IS_ERR(def)) + return PTR_ERR(def); + + err = -ENOMEM; + key = malloc(def->key_size); + if (key == NULL) + goto out; + + value = bpf_map_def__alloc_value(def); + if (value == NULL) + goto out_free_key; + + while ((err = bpf_map_get_next_key(fd, prev_key, key) == 0)) { + int intkey = *(int *)key; + + if (!bpf_map_lookup_elem(fd, key, value)) { + bool boolval = *(bool *)value; + if (boolval) + printed += fprintf(fp, "[%d] = %d,\n", intkey, boolval); + } else { + printed += fprintf(fp, "[%d] = ERROR,\n", intkey); + } + + prev_key = key; + } + + if (err == ENOENT) + err = printed; + + free(value); +out_free_key: + free(key); +out: + return err; +} diff --git a/tools/perf/util/bpf_map.h b/tools/perf/util/bpf_map.h new file mode 100644 index 000000000000..d6abd5e47af8 --- /dev/null +++ b/tools/perf/util/bpf_map.h @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +#ifndef __PERF_BPF_MAP_H +#define __PERF_BPF_MAP_H 1 + +#include +#include +struct bpf_map; + +#ifdef HAVE_LIBBPF_SUPPORT + +int bpf_map__fprintf(struct bpf_map *map, FILE *fp); + +#else + +static inline int bpf_map__fprintf(struct bpf_map *map __maybe_unused, FILE *fp __maybe_unused) +{ + return 0; +} + +#endif // HAVE_LIBBPF_SUPPORT + +#endif // __PERF_BPF_MAP_H -- 2.19.1