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perf script: Print bpf-output events in 'perf script'

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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@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1456312845-111583-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Wang Nan 2016-02-24 11:20:45 +00:00 committed by Arnaldo Carvalho de Melo
parent c339b1a90e
commit 30372f04c9
1 changed files with 88 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

93
tools/perf/builtin-script.c
View file

@ -61,6 +61,7 @@ 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 {
@ -86,6 +87,7 @@ 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 */
@ -106,7 +108,7 @@ 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] = {
@ -116,7 +118,7 @@ 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,
},
@ -126,7 +128,7 @@ 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] = {
@ -139,7 +141,7 @@ 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] = {
@ -151,7 +153,7 @@ 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,
},
};
@ -624,6 +626,84 @@ 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;
@ -731,6 +811,9 @@ 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");
}