[RFC PATCH 2/2] perf script: Print bpf-output events in 'perf script'
From: Wang Nan
Date: Wed Feb 24 2016 - 06:22:12 EST
This patch allows 'perf script' output messages from BPF program.
For example, use test_bpf_output_3.c at the end of this commit
message,
# ./perf record -e bpf-output/no-inherit,name=evt/ \
-e ./test_bpf_output_3.c/map:channel.event=evt/ \
usleep 100000
# ./perf script
usleep 4882 21384.532523: evt: ffffffff810e97d1 sys_nanosleep ([kernel.kallsyms])
BPF output: 0000: 52 61 69 73 65 20 61 20 Raise a
0008: 42 50 46 20 65 76 65 6e BPF even
0010: 74 21 00 00 t!..
BPF string: "Raise a BPF event!"
usleep 4882 21384.632606: evt: ffffffff8105c609 kretprobe_trampoline_holder ([kernel.kallsyms
BPF output: 0000: 52 61 69 73 65 20 61 20 Raise a
0008: 42 50 46 20 65 76 65 6e BPF even
0010: 74 21 00 00 t!..
BPF string: "Raise a BPF event!"
Two samples from BPF output are printed by both binary and string
format.
If BPF program output something unprintable, string format is
suppressed.
/************************ BEGIN **************************/
#include <uapi/linux/bpf.h>
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
};
#define SEC(NAME) __attribute__((section(NAME), used))
static u64 (*ktime_get_ns)(void) =
(void *)BPF_FUNC_ktime_get_ns;
static int (*trace_printk)(const char *fmt, int fmt_size, ...) =
(void *)BPF_FUNC_trace_printk;
static int (*get_smp_processor_id)(void) =
(void *)BPF_FUNC_get_smp_processor_id;
static int (*perf_event_output)(void *, struct bpf_map_def *, int, void *, unsigned long) =
(void *)BPF_FUNC_perf_event_output;
struct bpf_map_def SEC("maps") channel = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
.max_entries = __NR_CPUS__,
};
static inline int __attribute__((always_inline))
func(void *ctx, int type)
{
char output_str[] = "Raise a BPF event!";
perf_event_output(ctx, &channel, get_smp_processor_id(),
&output_str, sizeof(output_str));
return 0;
}
SEC("func_begin=sys_nanosleep")
int func_begin(void *ctx) {return func(ctx, 1);}
SEC("func_end=sys_nanosleep%return")
int func_end(void *ctx) { return func(ctx, 2);}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
/************************* END ***************************/
Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
tools/perf/builtin-script.c | 93 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 88 insertions(+), 5 deletions(-)
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index f4caf48..e52f55c 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -60,6 +60,7 @@ enum perf_output_field {
PERF_OUTPUT_BRSTACKSYM = 1U << 16,
PERF_OUTPUT_DATA_SRC = 1U << 17,
PERF_OUTPUT_WEIGHT = 1U << 18,
+ PERF_OUTPUT_BPF_OUTPUT = 1U << 19,
};
struct output_option {
@@ -85,6 +86,7 @@ struct output_option {
{.str = "brstacksym", .field = PERF_OUTPUT_BRSTACKSYM},
{.str = "data_src", .field = PERF_OUTPUT_DATA_SRC},
{.str = "weight", .field = PERF_OUTPUT_WEIGHT},
+ {.str = "bpf-output", .field = PERF_OUTPUT_BPF_OUTPUT},
};
/* default set to maintain compatibility with current format */
@@ -105,7 +107,7 @@ static struct {
PERF_OUTPUT_SYM | PERF_OUTPUT_DSO |
PERF_OUTPUT_PERIOD,
- .invalid_fields = PERF_OUTPUT_TRACE,
+ .invalid_fields = PERF_OUTPUT_TRACE | PERF_OUTPUT_BPF_OUTPUT,
},
[PERF_TYPE_SOFTWARE] = {
@@ -115,7 +117,7 @@ static struct {
PERF_OUTPUT_CPU | PERF_OUTPUT_TIME |
PERF_OUTPUT_EVNAME | PERF_OUTPUT_IP |
PERF_OUTPUT_SYM | PERF_OUTPUT_DSO |
- PERF_OUTPUT_PERIOD,
+ PERF_OUTPUT_PERIOD | PERF_OUTPUT_BPF_OUTPUT,
.invalid_fields = PERF_OUTPUT_TRACE,
},
@@ -125,7 +127,7 @@ static struct {
.fields = PERF_OUTPUT_COMM | PERF_OUTPUT_TID |
PERF_OUTPUT_CPU | PERF_OUTPUT_TIME |
- PERF_OUTPUT_EVNAME | PERF_OUTPUT_TRACE,
+ PERF_OUTPUT_EVNAME | PERF_OUTPUT_TRACE
},
[PERF_TYPE_RAW] = {
@@ -138,7 +140,7 @@ static struct {
PERF_OUTPUT_PERIOD | PERF_OUTPUT_ADDR |
PERF_OUTPUT_DATA_SRC | PERF_OUTPUT_WEIGHT,
- .invalid_fields = PERF_OUTPUT_TRACE,
+ .invalid_fields = PERF_OUTPUT_TRACE | PERF_OUTPUT_BPF_OUTPUT,
},
[PERF_TYPE_BREAKPOINT] = {
@@ -150,7 +152,7 @@ static struct {
PERF_OUTPUT_SYM | PERF_OUTPUT_DSO |
PERF_OUTPUT_PERIOD,
- .invalid_fields = PERF_OUTPUT_TRACE,
+ .invalid_fields = PERF_OUTPUT_TRACE | PERF_OUTPUT_BPF_OUTPUT,
},
};
@@ -623,6 +625,84 @@ static void print_sample_flags(u32 flags)
printf(" %-4s ", str);
}
+struct printer_data {
+ int line_no;
+ bool hit_nul;
+ bool is_printable;
+};
+
+static void
+print_sample_bpf_output_printer(enum binary_printer_ops op,
+ unsigned int val,
+ void *extra)
+{
+ unsigned char ch = (unsigned char)val;
+ struct printer_data *printer_data = extra;
+
+ switch (op) {
+ case BINARY_PRINT_DATA_BEGIN:
+ printf("\n");
+ break;
+ case BINARY_PRINT_LINE_BEGIN:
+ printf("%17s", !printer_data->line_no ? "BPF output:" :
+ " ");
+ break;
+ case BINARY_PRINT_ADDR:
+ printf(" %04x:", val);
+ break;
+ case BINARY_PRINT_NUM_DATA:
+ printf(" %02x", val);
+ break;
+ case BINARY_PRINT_NUM_PAD:
+ printf(" ");
+ break;
+ case BINARY_PRINT_SEP:
+ printf(" ");
+ break;
+ case BINARY_PRINT_CHAR_DATA:
+ if (printer_data->hit_nul && ch)
+ printer_data->is_printable = false;
+
+ if (!isprint(ch)) {
+ printf("%c", '.');
+
+ if (!printer_data->is_printable)
+ break;
+
+ if (ch == '\0')
+ printer_data->hit_nul = true;
+ else
+ printer_data->is_printable = false;
+ } else {
+ printf("%c", ch);
+ }
+ break;
+ case BINARY_PRINT_CHAR_PAD:
+ printf(" ");
+ break;
+ case BINARY_PRINT_LINE_END:
+ printf("\n");
+ printer_data->line_no++;
+ break;
+ case BINARY_PRINT_DATA_END:
+ default:
+ break;
+ }
+}
+
+static void print_sample_bpf_output(struct perf_sample *sample)
+{
+ unsigned int nr_bytes = sample->raw_size;
+ struct printer_data printer_data = {0, false, true};
+
+ print_binary(sample->raw_data, nr_bytes, 8,
+ print_sample_bpf_output_printer, &printer_data);
+
+ if (printer_data.is_printable && printer_data.hit_nul)
+ printf("%17s \"%s\"\n", "BPF string:",
+ (char *)(sample->raw_data));
+}
+
struct perf_script {
struct perf_tool tool;
struct perf_session *session;
@@ -713,6 +793,9 @@ static void process_event(struct perf_script *script, union perf_event *event,
else if (PRINT_FIELD(BRSTACKSYM))
print_sample_brstacksym(event, sample, thread, attr);
+ if (perf_evsel__is_bpf_output(evsel) && PRINT_FIELD(BPF_OUTPUT))
+ print_sample_bpf_output(sample);
+
printf("\n");
}
--
1.8.3.4