[PATCH 5/9] perf, bpf: save bpf_prog_info in a rbtree in perf_env

Song Liu
2019-02-09T01:17:23Z

bpf_prog_info contains information necessary to annotate bpf programs.
This patch saves bpf_prog_info for bpf programs loaded in the system.

perf-record saves bpf_prog_info information as headers to perf.data.
A new header type HEADER_BPF_PROG_INFO is introduced for this data.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
tools/perf/builtin-record.c | 2 +-
tools/perf/builtin-top.c | 2 +-
tools/perf/util/bpf-event.c | 39 ++++++++---
tools/perf/util/bpf-event.h | 15 +++-
tools/perf/util/env.c | 83 ++++++++++++++++++++++
tools/perf/util/env.h | 9 +++
tools/perf/util/header.c | 134 +++++++++++++++++++++++++++++++++++-
tools/perf/util/header.h | 1 +
8 files changed, 271 insertions(+), 14 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 88ea11d57c6f..2355e0a9eda0 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1083,7 +1083,7 @@ static int record__synthesize(struct record *rec, bool tail)
return err;
}

- err = perf_event__synthesize_bpf_events(tool, process_synthesized_event,
+ err = perf_event__synthesize_bpf_events(session, process_synthesized_event,
machine, opts);
if (err < 0)
pr_warning("Couldn't synthesize bpf events.\n");
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 5a486d4de56e..27d8d42e0a4d 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1216,7 +1216,7 @@ static int __cmd_top(struct perf_top *top)

init_process_thread(top);

- ret = perf_event__synthesize_bpf_events(&top->tool, perf_event__process,
+ ret = perf_event__synthesize_bpf_events(top->session, perf_event__process,
&top->session->machines.host,
&top->record_opts);
if (ret < 0)
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index e6dfb95029e5..ead599bc4f4e 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -1,15 +1,13 @@
// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <stdlib.h>
-#include <bpf/bpf.h>
-#include <bpf/btf.h>
-#include <bpf/libbpf.h>
-#include <linux/btf.h>
#include <linux/err.h>
#include "bpf-event.h"
#include "debug.h"
#include "symbol.h"
#include "machine.h"
+#include "env.h"
+#include "session.h"

#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))

@@ -42,7 +40,7 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
* -1 for failures;
* -2 for lack of kernel support.
*/
-static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
+static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
perf_event__handler_t process,
struct machine *machine,
int fd,
@@ -52,17 +50,29 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
struct ksymbol_event *ksymbol_event = &event->ksymbol_event;
struct bpf_event *bpf_event = &event->bpf_event;
struct bpf_prog_info_linear *info_linear;
+ struct perf_tool *tool = session->tool;
+ struct bpf_prog_info_node *info_node;
struct bpf_prog_info *info;
struct btf *btf = NULL;
bool has_btf = false;
+ struct perf_env *env;
u32 sub_prog_cnt, i;
int err = 0;
u64 arrays;

+ /*
+ * for perf-record and perf-report use header.env;
+ * otherwise, use global perf_env.
+ */
+ env = session->data ? &session->header.env : &perf_env;
+
arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
+ arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
+ arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
+ arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;

info_linear = bpf_program__get_prog_info_linear(fd, arrays);
if (IS_ERR_OR_NULL(info_linear)) {
@@ -151,8 +161,8 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
machine, process);
}

- /* Synthesize PERF_RECORD_BPF_EVENT */
if (opts->bpf_event) {
+ /* Synthesize PERF_RECORD_BPF_EVENT */
*bpf_event = (struct bpf_event){
.header = {
.type = PERF_RECORD_BPF_EVENT,
@@ -165,6 +175,19 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
memset((void *)event + event->header.size, 0, machine->id_hdr_size);
event->header.size += machine->id_hdr_size;
+
+ /* save bpf_prog_info to env */
+ info_node = malloc(sizeof(struct bpf_prog_info_node));
+ if (info_node) {
+ info_node->info_linear = info_linear;
+ perf_env__insert_bpf_prog_info(env, info_node);
+ info_linear = NULL;
+ }
+
+ /*
+ * process after saving bpf_prog_info to env, so that
+ * required information is ready for look up
+ */
err = perf_tool__process_synth_event(tool, event,
machine, process);
}
@@ -175,7 +198,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
return err ? -1 : 0;
}

-int perf_event__synthesize_bpf_events(struct perf_tool *tool,
+int perf_event__synthesize_bpf_events(struct perf_session *session,
perf_event__handler_t process,
struct machine *machine,
struct record_opts *opts)
@@ -209,7 +232,7 @@ int perf_event__synthesize_bpf_events(struct perf_tool *tool,
continue;
}

- err = perf_event__synthesize_one_bpf_prog(tool, process,
+ err = perf_event__synthesize_one_bpf_prog(session, process,
machine, fd,
event, opts);
close(fd);
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index 7890067e1a37..11e6730b6105 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -3,19 +3,28 @@
#define __PERF_BPF_EVENT_H

#include <linux/compiler.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
+#include <linux/btf.h>
+#include <linux/rbtree.h>
#include "event.h"

struct machine;
union perf_event;
struct perf_sample;
-struct perf_tool;
struct record_opts;

+struct bpf_prog_info_node {
+ struct bpf_prog_info_linear *info_linear;
+ struct rb_node rb_node;
+};
+
#ifdef HAVE_LIBBPF_SUPPORT
int machine__process_bpf_event(struct machine *machine, union perf_event *event,
struct perf_sample *sample);

-int perf_event__synthesize_bpf_events(struct perf_tool *tool,
+int perf_event__synthesize_bpf_events(struct perf_session *session,
perf_event__handler_t process,
struct machine *machine,
struct record_opts *opts);
@@ -27,7 +36,7 @@ static inline int machine__process_bpf_event(struct machine *machine __maybe_unu
return 0;
}

-static inline int perf_event__synthesize_bpf_events(struct perf_tool *tool __maybe_unused,
+static inline int perf_event__synthesize_bpf_events(struct perf_session *session __maybe_unused,
perf_event__handler_t process __maybe_unused,
struct machine *machine __maybe_unused,
struct record_opts *opts __maybe_unused)
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 4c23779e271a..665b6fe3c7b2 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -8,10 +8,86 @@

struct perf_env perf_env;

+void perf_env__insert_bpf_prog_info(struct perf_env *env,
+ struct bpf_prog_info_node *info_node)
+{
+ __u32 prog_id = info_node->info_linear->info.id;
+ struct bpf_prog_info_node *node;
+ struct rb_node *parent = NULL;
+ struct rb_node **p;
+
+ down_write(&env->bpf_info_lock);
+ p = &env->bpf_prog_infos.rb_node;
+
+ while (*p != NULL) {
+ parent = *p;
+ node = rb_entry(parent, struct bpf_prog_info_node, rb_node);
+ if (prog_id < node->info_linear->info.id) {
+ p = &(*p)->rb_left;
+ } else if (prog_id > node->info_linear->info.id) {
+ p = &(*p)->rb_right;
+ } else {
+ pr_debug("duplicated bpf prog info %u\n", prog_id);
+ up_write(&env->bpf_info_lock);
+ return;
+ }
+ }
+
+ rb_link_node(&info_node->rb_node, parent, p);
+ rb_insert_color(&info_node->rb_node, &env->bpf_prog_infos);
+ up_write(&env->bpf_info_lock);
+}
+
+struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
+ __u32 prog_id)
+{
+ struct bpf_prog_info_node *node = NULL;
+ struct rb_node *n;
+
+ down_read(&env->bpf_info_lock);
+ n = env->bpf_prog_infos.rb_node;
+
+ while (n) {
+ node = rb_entry(n, struct bpf_prog_info_node, rb_node);
+ if (prog_id < node->info_linear->info.id)
+ n = n->rb_left;
+ else if (prog_id > node->info_linear->info.id)
+ n = n->rb_right;
+ else
+ break;
+ }
+
+ up_read(&env->bpf_info_lock);
+ return node;
+}
+
+/* purge data in bpf_prog_infos tree */
+static void purge_bpf_info(struct perf_env *env)
+{
+ struct rb_root *root;
+ struct rb_node *next;
+
+ down_write(&env->bpf_info_lock);
+
+ root = &env->bpf_prog_infos;
+ next = rb_first(root);
+
+ while (next) {
+ struct bpf_prog_info_node *node;
+
+ node = rb_entry(next, struct bpf_prog_info_node, rb_node);
+ next = rb_next(&node->rb_node);
+ rb_erase_init(&node->rb_node, root);
+ free(node);
+ }
+ up_write(&env->bpf_info_lock);
+}
+
void perf_env__exit(struct perf_env *env)
{
int i;

+ purge_bpf_info(env);
zfree(&env->hostname);
zfree(&env->os_release);
zfree(&env->version);
@@ -38,6 +114,12 @@ void perf_env__exit(struct perf_env *env)
zfree(&env->memory_nodes);
}

+static void init_bpf_rb_trees(struct perf_env *env)
+{
+ env->bpf_prog_infos = RB_ROOT;
+ init_rwsem(&env->bpf_info_lock);
+}
+
int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
{
int i;
@@ -59,6 +141,7 @@ int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])

env->nr_cmdline = argc;

+ init_bpf_rb_trees(env);
return 0;
out_free:
zfree(&env->cmdline_argv);
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index d01b8355f4ca..5894a177b7cf 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -3,7 +3,10 @@
#define __PERF_ENV_H

#include <linux/types.h>
+#include <linux/rbtree.h>
#include "cpumap.h"
+#include "rwsem.h"
+#include "bpf-event.h"

struct cpu_topology_map {
int socket_id;
@@ -64,6 +67,8 @@ struct perf_env {
struct memory_node *memory_nodes;
unsigned long long memory_bsize;
u64 clockid_res_ns;
+ struct rw_semaphore bpf_info_lock;
+ struct rb_root bpf_prog_infos;
};

extern struct perf_env perf_env;
@@ -80,4 +85,8 @@ const char *perf_env__arch(struct perf_env *env);
const char *perf_env__raw_arch(struct perf_env *env);
int perf_env__nr_cpus_avail(struct perf_env *env);

+void perf_env__insert_bpf_prog_info(struct perf_env *env,
+ struct bpf_prog_info_node *info_node);
+struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
+ __u32 prog_id);
#endif /* __PERF_ENV_H */
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index dec6d218c31c..2ae76a9d06f6 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1080,6 +1080,51 @@ static int write_clockid(struct feat_fd *ff,
sizeof(ff->ph->env.clockid_res_ns));
}

+static int write_bpf_prog_info(struct feat_fd *ff,
+ struct perf_evlist *evlist __maybe_unused)
+{
+ struct perf_env *env = &ff->ph->env;
+ struct rb_root *root;
+ struct rb_node *next;
+ u32 count = 0;
+ int ret;
+
+ down_read(&env->bpf_info_lock);
+
+ root = &env->bpf_prog_infos;
+ next = rb_first(root);
+ while (next) {
+ ++count;
+ next = rb_next(next);
+ }
+
+ ret = do_write(ff, &count, sizeof(count));
+
+ if (ret < 0)
+ goto out;
+
+ next = rb_first(root);
+ while (next) {
+ struct bpf_prog_info_node *node;
+ size_t len;
+
+ node = rb_entry(next, struct bpf_prog_info_node, rb_node);
+ next = rb_next(&node->rb_node);
+ len = sizeof(struct bpf_prog_info_linear) +
+ node->info_linear->data_len;
+
+ /* before writing to file, translate address to offset */
+ bpf_program__bpil_addr_to_offs(node->info_linear);
+ ret = do_write(ff, node->info_linear, len);
+ bpf_program__bpil_offs_to_addr(node->info_linear);
+ if (ret < 0)
+ goto out;
+ }
+out:
+ up_read(&env->bpf_info_lock);
+ return ret;
+}
+
static int cpu_cache_level__sort(const void *a, const void *b)
{
struct cpu_cache_level *cache_a = (struct cpu_cache_level *)a;
@@ -1560,6 +1605,29 @@ static void print_clockid(struct feat_fd *ff, FILE *fp)
ff->ph->env.clockid_res_ns * 1000);
}

+static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp)
+{
+ struct perf_env *env = &ff->ph->env;
+ struct rb_root *root;
+ struct rb_node *next;
+
+ down_read(&env->bpf_info_lock);
+
+ root = &env->bpf_prog_infos;
+ next = rb_first(root);
+
+ while (next) {
+ struct bpf_prog_info_node *node;
+
+ node = rb_entry(next, struct bpf_prog_info_node, rb_node);
+ next = rb_next(&node->rb_node);
+ fprintf(fp, "# bpf_prog_info of id %u\n",
+ node->info_linear->info.id);
+ }
+
+ up_read(&env->bpf_info_lock);
+}
+
static void free_event_desc(struct perf_evsel *events)
{
struct perf_evsel *evsel;
@@ -2592,6 +2660,69 @@ static int process_clockid(struct feat_fd *ff,
return 0;
}

+static int process_bpf_prog_info(struct feat_fd *ff,
+ void *data __maybe_unused)
+{
+ struct bpf_prog_info_linear *info_linear;
+ struct bpf_prog_info_node *info_node;
+ struct perf_env *env = &ff->ph->env;
+ u32 count, i;
+ int err = -1;
+
+ if (do_read_u32(ff, &count))
+ return -1;
+
+ down_write(&env->bpf_info_lock);
+
+ for (i = 0; i < count; ++i) {
+ u32 info_len, data_len;
+
+ info_linear = NULL;
+ info_node = NULL;
+ if (do_read_u32(ff, &info_len))
+ goto out;
+ if (do_read_u32(ff, &data_len))
+ goto out;
+
+ if (info_len > sizeof(struct bpf_prog_info)) {
+ pr_warning("detected invalid bpf_prog_info\n");
+ goto out;
+ }
+
+ info_linear = malloc(sizeof(struct bpf_prog_info_linear) +
+ data_len);
+ if (!info_linear)
+ goto out;
+ info_linear->info_len = sizeof(struct bpf_prog_info);
+ info_linear->data_len = data_len;
+ if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
+ goto out;
+ if (__do_read(ff, &info_linear->info, info_len))
+ goto out;
+ if (info_len < sizeof(struct bpf_prog_info))
+ memset(((void *)(&info_linear->info)) + info_len, 0,
+ sizeof(struct bpf_prog_info) - info_len);
+
+ if (__do_read(ff, info_linear->data, data_len))
+ goto out;
+ info_node = malloc(sizeof(struct bpf_prog_info_node));
+ if (!info_node)
+ goto out;
+
+ /* after reading from file, translate offset to address */
+ bpf_program__bpil_offs_to_addr(info_linear);
+ info_node->info_linear = info_linear;
+ perf_env__insert_bpf_prog_info(env, info_node);
+ }
+
+ return 0;
+out:
+ free(info_linear);
+ free(info_node);
+ up_write(&env->bpf_info_lock);
+ return err;
+}
+
struct feature_ops {
int (*write)(struct feat_fd *ff, struct perf_evlist *evlist);
void (*print)(struct feat_fd *ff, FILE *fp);
@@ -2651,7 +2782,8 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
FEAT_OPN(CACHE, cache, true),
FEAT_OPR(SAMPLE_TIME, sample_time, false),
FEAT_OPR(MEM_TOPOLOGY, mem_topology, true),
- FEAT_OPR(CLOCKID, clockid, false)
+ FEAT_OPR(CLOCKID, clockid, false),
+ FEAT_OPR(BPF_PROG_INFO, bpf_prog_info, false)
};

struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 0d553ddca0a3..0785c91b4c3a 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -39,6 +39,7 @@ enum {
HEADER_SAMPLE_TIME,
HEADER_MEM_TOPOLOGY,
HEADER_CLOCKID,
+ HEADER_BPF_PROG_INFO,
HEADER_LAST_FEATURE,
HEADER_FEAT_BITS = 256,
};
--
2.17.1