[PATCH v4 04/16] perf tools: Enable BPF object configure syntax

Wang Nan
2015-12-08T02:27:16Z

This patch adds the final step for BPF map configuration. A new syntax
is appended into parser so user can config BPF objects through '/' '/'
enclosed config terms.

After this patch, following syntax is available:

# perf record -e bpf_file.c/maps:mymap:value=123/ ...

It would takes effect after appling following commits.

Test result:

# cat ./test_bpf_map_1.c
/************************ BEGIN **************************/
#define SEC(NAME) __attribute__((section(NAME), used))
enum bpf_map_type {
BPF_MAP_TYPE_ARRAY = 2,
};
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
};
static void *(*map_lookup_elem)(struct bpf_map_def *, void *) =
(void *)1;
static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
(void *)6;
struct bpf_map_def SEC("maps") channel = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 1,
};
SEC("func=sys_nanosleep")
int func(void *ctx)
{
int key = 0;
char fmt[] = "%d\n";
int *pval = map_lookup_elem(&channel, &key);
if (!pval)
return 0;
bpf_trace_printk(fmt, sizeof(fmt), *pval);
return 0;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
/************************* END ***************************/

- Normal case:
# ./perf record -e './test_bpf_map_1.c/maps:channel.value=10/' usleep 10
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.012 MB perf.data ]

- Error case:

# ./perf record -e './test_bpf_map_1.c/maps:channel.value/' usleep 10
event syntax error: '..ps:channel:value/'
\___ Config value not set (lost '=')
Hint: Valid config term:
maps:[<arraymap>]:value=[value]
(add -v to see detail)
Run 'perf list' for a list of valid events

Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list available events

# ./perf record -e './test_bpf_map_1.c/xmaps:channel.value=10/' usleep 10
event syntax error: '..pf_map_1.c/xmaps:channel.value=10/'
\___ Invalid object config option
[SNIP]

# ./perf record -e './test_bpf_map_1.c/maps:xchannel.value=10/' usleep 10
event syntax error: '..p_1.c/maps:xchannel.value=10/'
\___ Target map not exist
[SNIP]

# ./perf record -e './test_bpf_map_1.c/maps:channel.xvalue=10/' usleep 10
event syntax error: '..ps:channel.xvalue=10/'
\___ Invalid object maps config option
[SNIP]

# ./perf record -e './test_bpf_map_1.c/maps:channel.value=x10/' usleep 10
event syntax error: '..nnel.value=x10/'
\___ Incorrect value type for map
[SNIP]

Change BPF_MAP_TYPE_ARRAY = 2 tp BPF_MAP_TYPE_ARRAY = 1:

# ./perf record -e './test_bpf_map_1.c/maps:channel.value=10/' usleep 10
event syntax error: '..ps:channel.value=10/'
\___ Can't use this config term to this type of map

Hint: Valid config term:
maps:[<arraymap>].value=[value]
(add -v to see detail)

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: He Kuang <hekuang@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
---
tools/perf/util/parse-events.c | 56 +++++++++++++++++++++++++++++++++++++++---
tools/perf/util/parse-events.h | 3 ++-
tools/perf/util/parse-events.l | 2 +-
tools/perf/util/parse-events.y | 23 ++++++++++++++---
4 files changed, 75 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 6fc8cd7..95775fe 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -628,17 +628,64 @@ errout:
return err;
}

+static int
+parse_events_config_bpf(struct parse_events_evlist *data,
+ struct bpf_object *obj,
+ struct list_head *head_config)
+{
+ struct parse_events_term *term;
+ int error_pos;
+
+ if (!head_config || list_empty(head_config))
+ return 0;
+
+ list_for_each_entry(term, head_config, list) {
+ char errbuf[BUFSIZ];
+ int err;
+
+ if (term->type_term != PARSE_EVENTS__TERM_TYPE_USER) {
+ snprintf(errbuf, sizeof(errbuf),
+ "Invalid config term for BPF object");
+ errbuf[BUFSIZ - 1] = '\0';
+
+ data->error->idx = term->err_term;
+ data->error->str = strdup(errbuf);
+ return -EINVAL;
+ }
+
+ err = bpf__config_obj(obj, term, NULL, &error_pos);
+ if (err) {
+ bpf__strerror_config_obj(obj, term, NULL,
+ &error_pos, err, errbuf,
+ sizeof(errbuf));
+ data->error->help = strdup(
+"Hint:\tValid config term:\n"
+" \tmaps:[<arraymap>].value=[value]\n"
+" \t(add -v to see detail)");
+ data->error->str = strdup(errbuf);
+ if (err == -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUE)
+ data->error->idx = term->err_val;
+ else
+ data->error->idx = term->err_term + error_pos;
+ return err;
+ }
+ }
+ return 0;
+
+}
+
int parse_events_load_bpf(struct parse_events_evlist *data,
struct list_head *list,
char *bpf_file_name,
- bool source)
+ bool source,
+ struct list_head *head_config)
{
struct bpf_object *obj;
+ int err;

obj = bpf__prepare_load(bpf_file_name, source);
if (IS_ERR(obj)) {
char errbuf[BUFSIZ];
- int err;

err = PTR_ERR(obj);

@@ -656,7 +703,10 @@ int parse_events_load_bpf(struct parse_events_evlist *data,
return err;
}

- return parse_events_load_bpf_obj(data, list, obj);
+ err = parse_events_load_bpf_obj(data, list, obj);
+ if (err)
+ return err;
+ return parse_events_config_bpf(data, obj, head_config);
}

static int
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index f1a6db1..84694f3 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -126,7 +126,8 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
int parse_events_load_bpf(struct parse_events_evlist *data,
struct list_head *list,
char *bpf_file_name,
- bool source);
+ bool source,
+ struct list_head *head_config);
/* Provide this function for perf test */
struct bpf_object;
int parse_events_load_bpf_obj(struct parse_events_evlist *data,
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 58c5831..4387728 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -122,7 +122,7 @@ num_dec [0-9]+
num_hex 0x[a-fA-F0-9]+
num_raw_hex [a-fA-F0-9]+
name [a-zA-Z_*?][a-zA-Z0-9_*?.]*
-name_minus [a-zA-Z_*?][a-zA-Z0-9\-_*?.]*
+name_minus [a-zA-Z_*?][a-zA-Z0-9\-_*?.:]*
/* If you add a modifier you need to update check_modifier() */
modifier_event [ukhpPGHSDI]+
modifier_bp [rwx]{1,3}
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index ad37996..8992d16 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -64,6 +64,7 @@ static inc_group_count(struct list_head *list,
%type <str> PE_PMU_EVENT_PRE PE_PMU_EVENT_SUF PE_KERNEL_PMU_EVENT
%type <num> value_sym
%type event_config
+%type event_bpf_config
%type <term> event_term
%type event_pmu
%type event_legacy_symbol
@@ -455,27 +456,41 @@ PE_RAW
}

event_bpf_file:
-PE_BPF_OBJECT
+PE_BPF_OBJECT event_bpf_config
{
struct parse_events_evlist *data = _data;
struct parse_events_error *error = data->error;
struct list_head *list;

ALLOC_LIST(list);
- ABORT_ON(parse_events_load_bpf(data, list, $1, false));
+ ABORT_ON(parse_events_load_bpf(data, list, $1, false, $2));
+ if ($2)
+ parse_events__free_terms($2);
$$ = list;
}
|
-PE_BPF_SOURCE
+PE_BPF_SOURCE event_bpf_config
{
struct parse_events_evlist *data = _data;
struct list_head *list;

ALLOC_LIST(list);
- ABORT_ON(parse_events_load_bpf(data, list, $1, true));
+ ABORT_ON(parse_events_load_bpf(data, list, $1, true, $2));
+ if ($2)
+ parse_events__free_terms($2);
$$ = list;
}

+event_bpf_config:
+'/' event_config '/'
+{
+ $$ = $2;
+}
+|
+{
+ $$ = NULL;
+}
+
start_terms: event_config
{
struct parse_events_terms *data = _data;
--
1.8.3.4