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Message-ID: <tip-lz14w0esqyt1333aon05jpwc@git.kernel.org>
Date: Wed, 27 Feb 2019 23:43:19 -0800
From: tip-bot for Arnaldo Carvalho de Melo <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: tglx@...utronix.de, yhs@...com, daniel@...earbox.net,
jolsa@...nel.org, mingo@...nel.org, ast@...nel.org,
linux-kernel@...r.kernel.org, adrian.hunter@...el.com,
hpa@...or.com, namhyung@...nel.org, kafai@...com, acme@...hat.com
Subject: [tip:perf/core] perf bpf: Add bpf_map dumper
Commit-ID: d19f856479feef7c1383f02b87688563a0ef7a14
Gitweb: https://git.kernel.org/tip/d19f856479feef7c1383f02b87688563a0ef7a14
Author: Arnaldo Carvalho de Melo <acme@...hat.com>
AuthorDate: Tue, 19 Feb 2019 16:11:56 -0300
Committer: Arnaldo Carvalho de Melo <acme@...hat.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.hunter@...el.com>
Cc: Alexei Starovoitov <ast@...nel.org>
Cc: Daniel Borkmann <daniel@...earbox.net>
Cc: Jiri Olsa <jolsa@...nel.org>
Cc: Martin KaFai Lau <kafai@...com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Yonghong Song <yhs@...com>
Link: https://lkml.kernel.org/n/tip-lz14w0esqyt1333aon05jpwc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.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
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