linux/tools/perf/builtin-trace.c
Arnaldo Carvalho de Melo fc551f8d44 perf trace: Check if sample raw_data field is set
Sometimes we're segfaulting because we were expecting that the
perf_sample.raw_data field was set as requested, but in some cases
that needs further investigation, that field can be NULL, leading
to segfaults.

Make the tool more robust by checking that before calling any per event
handlers that may try to use that field.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-g1fmodl6ys4lq8honbj1igoi@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-10-21 23:07:36 -02:00

349 lines
8.7 KiB
C

#include "builtin.h"
#include "util/evlist.h"
#include "util/parse-options.h"
#include "util/thread_map.h"
#include "event-parse.h"
#include <libaudit.h>
#include <stdlib.h>
static struct syscall_fmt {
const char *name;
const char *alias;
bool errmsg;
bool timeout;
} syscall_fmts[] = {
{ .name = "arch_prctl", .errmsg = true, .alias = "prctl", },
{ .name = "fstat", .errmsg = true, .alias = "newfstat", },
{ .name = "fstatat", .errmsg = true, .alias = "newfstatat", },
{ .name = "futex", .errmsg = true, },
{ .name = "poll", .errmsg = true, .timeout = true, },
{ .name = "ppoll", .errmsg = true, .timeout = true, },
{ .name = "read", .errmsg = true, },
{ .name = "recvfrom", .errmsg = true, },
{ .name = "select", .errmsg = true, .timeout = true, },
{ .name = "stat", .errmsg = true, .alias = "newstat", },
};
static int syscall_fmt__cmp(const void *name, const void *fmtp)
{
const struct syscall_fmt *fmt = fmtp;
return strcmp(name, fmt->name);
}
static struct syscall_fmt *syscall_fmt__find(const char *name)
{
const int nmemb = ARRAY_SIZE(syscall_fmts);
return bsearch(name, syscall_fmts, nmemb, sizeof(struct syscall_fmt), syscall_fmt__cmp);
}
struct syscall {
struct event_format *tp_format;
const char *name;
struct syscall_fmt *fmt;
};
struct trace {
int audit_machine;
struct {
int max;
struct syscall *table;
} syscalls;
struct perf_record_opts opts;
};
static int trace__read_syscall_info(struct trace *trace, int id)
{
char tp_name[128];
struct syscall *sc;
const char *name = audit_syscall_to_name(id, trace->audit_machine);
if (name == NULL)
return -1;
if (id > trace->syscalls.max) {
struct syscall *nsyscalls = realloc(trace->syscalls.table, (id + 1) * sizeof(*sc));
if (nsyscalls == NULL)
return -1;
if (trace->syscalls.max != -1) {
memset(nsyscalls + trace->syscalls.max + 1, 0,
(id - trace->syscalls.max) * sizeof(*sc));
} else {
memset(nsyscalls, 0, (id + 1) * sizeof(*sc));
}
trace->syscalls.table = nsyscalls;
trace->syscalls.max = id;
}
sc = trace->syscalls.table + id;
sc->name = name;
sc->fmt = syscall_fmt__find(sc->name);
snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name);
sc->tp_format = event_format__new("syscalls", tp_name);
if (sc->tp_format == NULL && sc->fmt && sc->fmt->alias) {
snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->fmt->alias);
sc->tp_format = event_format__new("syscalls", tp_name);
}
return sc->tp_format != NULL ? 0 : -1;
}
static size_t syscall__fprintf_args(struct syscall *sc, unsigned long *args, FILE *fp)
{
int i = 0;
size_t printed = 0;
if (sc->tp_format != NULL) {
struct format_field *field;
for (field = sc->tp_format->format.fields->next; field; field = field->next) {
printed += fprintf(fp, "%s%s: %ld", printed ? ", " : "",
field->name, args[i++]);
}
} else {
while (i < 6) {
printed += fprintf(fp, "%sarg%d: %ld", printed ? ", " : "", i, args[i]);
++i;
}
}
return printed;
}
typedef int (*tracepoint_handler)(struct trace *trace, struct perf_evsel *evsel,
struct perf_sample *sample);
static struct syscall *trace__syscall_info(struct trace *trace,
struct perf_evsel *evsel,
struct perf_sample *sample)
{
int id = perf_evsel__intval(evsel, sample, "id");
if (id < 0) {
printf("Invalid syscall %d id, skipping...\n", id);
return NULL;
}
if ((id > trace->syscalls.max || trace->syscalls.table[id].name == NULL) &&
trace__read_syscall_info(trace, id))
goto out_cant_read;
if ((id > trace->syscalls.max || trace->syscalls.table[id].name == NULL))
goto out_cant_read;
return &trace->syscalls.table[id];
out_cant_read:
printf("Problems reading syscall %d information\n", id);
return NULL;
}
static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
struct perf_sample *sample)
{
void *args;
struct syscall *sc = trace__syscall_info(trace, evsel, sample);
if (sc == NULL)
return -1;
args = perf_evsel__rawptr(evsel, sample, "args");
if (args == NULL) {
printf("Problems reading syscall arguments\n");
return -1;
}
printf("%s(", sc->name);
syscall__fprintf_args(sc, args, stdout);
return 0;
}
static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
struct perf_sample *sample)
{
int ret;
struct syscall *sc = trace__syscall_info(trace, evsel, sample);
if (sc == NULL)
return -1;
ret = perf_evsel__intval(evsel, sample, "ret");
if (ret < 0 && sc->fmt && sc->fmt->errmsg) {
char bf[256];
const char *emsg = strerror_r(-ret, bf, sizeof(bf)),
*e = audit_errno_to_name(-ret);
printf(") = -1 %s %s", e, emsg);
} else if (ret == 0 && sc->fmt && sc->fmt->timeout)
printf(") = 0 Timeout");
else
printf(") = %d", ret);
putchar('\n');
return 0;
}
static int trace__run(struct trace *trace)
{
struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);
struct perf_evsel *evsel;
int err = -1, i, nr_events = 0, before;
if (evlist == NULL) {
printf("Not enough memory to run!\n");
goto out;
}
if (perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_enter", trace__sys_enter) ||
perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_exit", trace__sys_exit)) {
printf("Couldn't read the raw_syscalls tracepoints information!\n");
goto out_delete_evlist;
}
err = perf_evlist__create_maps(evlist, &trace->opts.target);
if (err < 0) {
printf("Problems parsing the target to trace, check your options!\n");
goto out_delete_evlist;
}
perf_evlist__config_attrs(evlist, &trace->opts);
err = perf_evlist__open(evlist);
if (err < 0) {
printf("Couldn't create the events: %s\n", strerror(errno));
goto out_delete_evlist;
}
err = perf_evlist__mmap(evlist, UINT_MAX, false);
if (err < 0) {
printf("Couldn't mmap the events: %s\n", strerror(errno));
goto out_delete_evlist;
}
perf_evlist__enable(evlist);
again:
before = nr_events;
for (i = 0; i < evlist->nr_mmaps; i++) {
union perf_event *event;
while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
const u32 type = event->header.type;
tracepoint_handler handler;
struct perf_sample sample;
++nr_events;
switch (type) {
case PERF_RECORD_SAMPLE:
break;
case PERF_RECORD_LOST:
printf("LOST %" PRIu64 " events!\n", event->lost.lost);
continue;
default:
printf("Unexpected %s event, skipping...\n",
perf_event__name(type));
continue;
}
err = perf_evlist__parse_sample(evlist, event, &sample);
if (err) {
printf("Can't parse sample, err = %d, skipping...\n", err);
continue;
}
evsel = perf_evlist__id2evsel(evlist, sample.id);
if (evsel == NULL) {
printf("Unknown tp ID %" PRIu64 ", skipping...\n", sample.id);
continue;
}
if (evlist->threads->map[0] == -1 || evlist->threads->nr > 1)
printf("%d ", sample.tid);
if (sample.raw_data == NULL) {
printf("%s sample with no payload for tid: %d, cpu %d, raw_size=%d, skipping...\n",
perf_evsel__name(evsel), sample.tid,
sample.cpu, sample.raw_size);
continue;
}
handler = evsel->handler.func;
handler(trace, evsel, &sample);
}
}
if (nr_events == before)
poll(evlist->pollfd, evlist->nr_fds, -1);
goto again;
out_delete_evlist:
perf_evlist__delete(evlist);
out:
return err;
}
int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
{
const char * const trace_usage[] = {
"perf trace [<options>]",
NULL
};
struct trace trace = {
.audit_machine = audit_detect_machine(),
.syscalls = {
. max = -1,
},
.opts = {
.target = {
.uid = UINT_MAX,
.uses_mmap = true,
},
.user_freq = UINT_MAX,
.user_interval = ULLONG_MAX,
.no_delay = true,
.mmap_pages = 1024,
},
};
const struct option trace_options[] = {
OPT_STRING('p', "pid", &trace.opts.target.pid, "pid",
"trace events on existing process id"),
OPT_STRING(0, "tid", &trace.opts.target.tid, "tid",
"trace events on existing thread id"),
OPT_BOOLEAN(0, "all-cpus", &trace.opts.target.system_wide,
"system-wide collection from all CPUs"),
OPT_STRING(0, "cpu", &trace.opts.target.cpu_list, "cpu",
"list of cpus to monitor"),
OPT_BOOLEAN(0, "no-inherit", &trace.opts.no_inherit,
"child tasks do not inherit counters"),
OPT_UINTEGER(0, "mmap-pages", &trace.opts.mmap_pages,
"number of mmap data pages"),
OPT_STRING(0, "uid", &trace.opts.target.uid_str, "user",
"user to profile"),
OPT_END()
};
int err;
argc = parse_options(argc, argv, trace_options, trace_usage, 0);
if (argc)
usage_with_options(trace_usage, trace_options);
err = perf_target__parse_uid(&trace.opts.target);
if (err) {
char bf[BUFSIZ];
perf_target__strerror(&trace.opts.target, err, bf, sizeof(bf));
printf("%s", bf);
return err;
}
return trace__run(&trace);
}