Commit-ID: d19f856479feef7c1383f02b87688563a0ef7a14 Gitweb: https://git.kernel.org/tip/d19f856479feef7c1383f02b87688563a0ef7a14 Author: Arnaldo Carvalho de Melo <a...@redhat.com> AuthorDate: Tue, 19 Feb 2019 16:11:56 -0300 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Tue, 19 Feb 2019 16:11:56 -0300
perf bpf: Add bpf_map dumper 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 <adrian.hun...@intel.com> Cc: Alexei Starovoitov <a...@kernel.org> Cc: Daniel Borkmann <dan...@iogearbox.net> Cc: Jiri Olsa <jo...@kernel.org> Cc: Martin KaFai Lau <ka...@fb.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Yonghong Song <y...@fb.com> Link: https://lkml.kernel.org/n/tip-lz14w0esqyt1333aon05j...@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/Build | 1 + tools/perf/util/bpf_map.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/bpf_map.h | 22 +++++++++++++++ 3 files changed, 95 insertions(+) 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 <bpf/bpf.h> +#include <bpf/libbpf.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <stdbool.h> +#include <stdlib.h> +#include <unistd.h> + +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 <stdio.h> +#include <linux/compiler.h> +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
