perf tests: Add test for reading object code

Using the information in mmap events, perf tools can read object code
associated with sampled addresses.  A test is added that compares bytes
read by perf with the same bytes read using objdump.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
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/r/1375875537-4509-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter 2013-08-07 14:38:45 +03:00 committed by Arnaldo Carvalho de Melo
parent 3445432b7b
commit b55ae0a976
4 changed files with 515 additions and 0 deletions

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@ -392,6 +392,7 @@ LIB_OBJS += $(OUTPUT)tests/sw-clock.o
ifeq ($(ARCH),x86)
LIB_OBJS += $(OUTPUT)tests/perf-time-to-tsc.o
endif
LIB_OBJS += $(OUTPUT)tests/code-reading.o
BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
BUILTIN_OBJS += $(OUTPUT)builtin-bench.o

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@ -99,6 +99,10 @@ static struct test {
.func = test__perf_time_to_tsc,
},
#endif
{
.desc = "Test object code reading",
.func = test__code_reading,
},
{
.func = NULL,
},

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@ -0,0 +1,509 @@
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <inttypes.h>
#include <ctype.h>
#include <string.h>
#include "parse-events.h"
#include "evlist.h"
#include "evsel.h"
#include "thread_map.h"
#include "cpumap.h"
#include "machine.h"
#include "event.h"
#include "thread.h"
#include "tests.h"
#define BUFSZ 1024
#define READLEN 128
static unsigned int hex(char c)
{
if (c >= '0' && c <= '9')
return c - '0';
if (c >= 'a' && c <= 'f')
return c - 'a' + 10;
return c - 'A' + 10;
}
static void read_objdump_line(const char *line, size_t line_len, void **buf,
size_t *len)
{
const char *p;
size_t i;
/* Skip to a colon */
p = strchr(line, ':');
if (!p)
return;
i = p + 1 - line;
/* Read bytes */
while (*len) {
char c1, c2;
/* Skip spaces */
for (; i < line_len; i++) {
if (!isspace(line[i]))
break;
}
/* Get 2 hex digits */
if (i >= line_len || !isxdigit(line[i]))
break;
c1 = line[i++];
if (i >= line_len || !isxdigit(line[i]))
break;
c2 = line[i++];
/* Followed by a space */
if (i < line_len && line[i] && !isspace(line[i]))
break;
/* Store byte */
*(unsigned char *)*buf = (hex(c1) << 4) | hex(c2);
*buf += 1;
*len -= 1;
}
}
static int read_objdump_output(FILE *f, void **buf, size_t *len)
{
char *line = NULL;
size_t line_len;
ssize_t ret;
int err = 0;
while (1) {
ret = getline(&line, &line_len, f);
if (feof(f))
break;
if (ret < 0) {
pr_debug("getline failed\n");
err = -1;
break;
}
read_objdump_line(line, ret, buf, len);
}
free(line);
return err;
}
static int read_via_objdump(const char *filename, u64 addr, void *buf,
size_t len)
{
char cmd[PATH_MAX * 2];
const char *fmt;
FILE *f;
int ret;
fmt = "%s -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
filename);
if (ret <= 0 || (size_t)ret >= sizeof(cmd))
return -1;
pr_debug("Objdump command is: %s\n", cmd);
f = popen(cmd, "r");
if (!f) {
pr_debug("popen failed\n");
return -1;
}
ret = read_objdump_output(f, &buf, &len);
if (len) {
pr_debug("objdump read too few bytes\n");
if (!ret)
ret = len;
}
pclose(f);
return ret;
}
static int read_object_code(u64 addr, size_t len, u8 cpumode,
struct thread *thread, struct machine *machine)
{
struct addr_location al;
unsigned char buf1[BUFSZ];
unsigned char buf2[BUFSZ];
size_t ret_len;
u64 objdump_addr;
int ret;
pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION, addr,
&al);
if (!al.map || !al.map->dso) {
pr_debug("thread__find_addr_map failed\n");
return -1;
}
pr_debug("File is: %s\n", al.map->dso->long_name);
if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS) {
pr_debug("Unexpected kernel address - skipping\n");
return 0;
}
pr_debug("On file address is: %#"PRIx64"\n", al.addr);
if (len > BUFSZ)
len = BUFSZ;
/* Do not go off the map */
if (addr + len > al.map->end)
len = al.map->end - addr;
/* Read the object code using perf */
ret_len = dso__data_read_offset(al.map->dso, machine, al.addr, buf1,
len);
if (ret_len != len) {
pr_debug("dso__data_read_offset failed\n");
return -1;
}
/*
* Converting addresses for use by objdump requires more information.
* map__load() does that. See map__rip_2objdump() for details.
*/
if (map__load(al.map, NULL))
return -1;
/* Read the object code using objdump */
objdump_addr = map__rip_2objdump(al.map, al.addr);
ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
if (ret > 0) {
/*
* The kernel maps are inaccurate - assume objdump is right in
* that case.
*/
if (cpumode == PERF_RECORD_MISC_KERNEL ||
cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
len -= ret;
if (len)
pr_debug("Reducing len to %zu\n", len);
else
return -1;
}
}
if (ret < 0) {
pr_debug("read_via_objdump failed\n");
return -1;
}
/* The results should be identical */
if (memcmp(buf1, buf2, len)) {
pr_debug("Bytes read differ from those read by objdump\n");
return -1;
}
pr_debug("Bytes read match those read by objdump\n");
return 0;
}
static int process_sample_event(struct machine *machine,
struct perf_evlist *evlist,
union perf_event *event)
{
struct perf_sample sample;
struct thread *thread;
u8 cpumode;
if (perf_evlist__parse_sample(evlist, event, &sample)) {
pr_debug("perf_evlist__parse_sample failed\n");
return -1;
}
thread = machine__findnew_thread(machine, sample.pid);
if (!thread) {
pr_debug("machine__findnew_thread failed\n");
return -1;
}
cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
return read_object_code(sample.ip, READLEN, cpumode, thread, machine);
}
static int process_event(struct machine *machine, struct perf_evlist *evlist,
union perf_event *event)
{
if (event->header.type == PERF_RECORD_SAMPLE)
return process_sample_event(machine, evlist, event);
if (event->header.type < PERF_RECORD_MAX)
return machine__process_event(machine, event);
return 0;
}
static int process_events(struct machine *machine, struct perf_evlist *evlist)
{
union perf_event *event;
int i, ret;
for (i = 0; i < evlist->nr_mmaps; i++) {
while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
ret = process_event(machine, evlist, event);
if (ret < 0)
return ret;
}
}
return 0;
}
static int comp(const void *a, const void *b)
{
return *(int *)a - *(int *)b;
}
static void do_sort_something(void)
{
size_t sz = 40960;
int buf[sz], i;
for (i = 0; i < (int)sz; i++)
buf[i] = sz - i - 1;
qsort(buf, sz, sizeof(int), comp);
for (i = 0; i < (int)sz; i++) {
if (buf[i] != i) {
pr_debug("qsort failed\n");
break;
}
}
}
static void sort_something(void)
{
int i;
for (i = 0; i < 10; i++)
do_sort_something();
}
static void syscall_something(void)
{
int pipefd[2];
int i;
for (i = 0; i < 1000; i++) {
if (pipe(pipefd) < 0) {
pr_debug("pipe failed\n");
break;
}
close(pipefd[1]);
close(pipefd[0]);
}
}
static void fs_something(void)
{
const char *test_file_name = "temp-perf-code-reading-test-file--";
FILE *f;
int i;
for (i = 0; i < 1000; i++) {
f = fopen(test_file_name, "w+");
if (f) {
fclose(f);
unlink(test_file_name);
}
}
}
static void do_something(void)
{
fs_something();
sort_something();
syscall_something();
}
enum {
TEST_CODE_READING_OK,
TEST_CODE_READING_NO_VMLINUX,
TEST_CODE_READING_NO_ACCESS,
};
static int do_test_code_reading(void)
{
struct machines machines;
struct machine *machine;
struct thread *thread;
struct perf_record_opts opts = {
.mmap_pages = UINT_MAX,
.user_freq = UINT_MAX,
.user_interval = ULLONG_MAX,
.freq = 4000,
.target = {
.uses_mmap = true,
},
};
struct thread_map *threads = NULL;
struct cpu_map *cpus = NULL;
struct perf_evlist *evlist = NULL;
struct perf_evsel *evsel = NULL;
int err = -1, ret;
pid_t pid;
struct map *map;
bool have_vmlinux, excl_kernel = false;
pid = getpid();
machines__init(&machines);
machine = &machines.host;
ret = machine__create_kernel_maps(machine);
if (ret < 0) {
pr_debug("machine__create_kernel_maps failed\n");
goto out_err;
}
/* Load kernel map */
map = machine->vmlinux_maps[MAP__FUNCTION];
ret = map__load(map, NULL);
if (ret < 0) {
pr_debug("map__load failed\n");
goto out_err;
}
have_vmlinux = map->dso->symtab_type == DSO_BINARY_TYPE__VMLINUX;
/* No point getting kernel events if there is no vmlinux */
if (!have_vmlinux)
excl_kernel = true;
threads = thread_map__new_by_tid(pid);
if (!threads) {
pr_debug("thread_map__new_by_tid failed\n");
goto out_err;
}
ret = perf_event__synthesize_thread_map(NULL, threads,
perf_event__process, machine);
if (ret < 0) {
pr_debug("perf_event__synthesize_thread_map failed\n");
goto out_err;
}
thread = machine__findnew_thread(machine, pid);
if (!thread) {
pr_debug("machine__findnew_thread failed\n");
goto out_err;
}
cpus = cpu_map__new(NULL);
if (!cpus) {
pr_debug("cpu_map__new failed\n");
goto out_err;
}
while (1) {
const char *str;
evlist = perf_evlist__new();
if (!evlist) {
pr_debug("perf_evlist__new failed\n");
goto out_err;
}
perf_evlist__set_maps(evlist, cpus, threads);
if (excl_kernel)
str = "cycles:u";
else
str = "cycles";
pr_debug("Parsing event '%s'\n", str);
ret = parse_events(evlist, str);
if (ret < 0) {
pr_debug("parse_events failed\n");
goto out_err;
}
perf_evlist__config(evlist, &opts);
evsel = perf_evlist__first(evlist);
evsel->attr.comm = 1;
evsel->attr.disabled = 1;
evsel->attr.enable_on_exec = 0;
ret = perf_evlist__open(evlist);
if (ret < 0) {
if (!excl_kernel) {
excl_kernel = true;
perf_evlist__delete(evlist);
evlist = NULL;
continue;
}
pr_debug("perf_evlist__open failed\n");
goto out_err;
}
break;
}
ret = perf_evlist__mmap(evlist, UINT_MAX, false);
if (ret < 0) {
pr_debug("perf_evlist__mmap failed\n");
goto out_err;
}
perf_evlist__enable(evlist);
do_something();
perf_evlist__disable(evlist);
ret = process_events(machine, evlist);
if (ret < 0)
goto out_err;
if (!have_vmlinux)
err = TEST_CODE_READING_NO_VMLINUX;
else if (excl_kernel)
err = TEST_CODE_READING_NO_ACCESS;
else
err = TEST_CODE_READING_OK;
out_err:
if (evlist) {
perf_evlist__munmap(evlist);
perf_evlist__close(evlist);
perf_evlist__delete(evlist);
}
if (cpus)
cpu_map__delete(cpus);
if (threads)
thread_map__delete(threads);
machines__destroy_kernel_maps(&machines);
machine__delete_threads(machine);
machines__exit(&machines);
return err;
}
int test__code_reading(void)
{
int ret;
ret = do_test_code_reading();
switch (ret) {
case TEST_CODE_READING_OK:
return 0;
case TEST_CODE_READING_NO_VMLINUX:
fprintf(stderr, " (no vmlinux)");
return 0;
case TEST_CODE_READING_NO_ACCESS:
fprintf(stderr, " (no access)");
return 0;
default:
return -1;
};
}

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@ -36,5 +36,6 @@ int test__bp_signal_overflow(void);
int test__task_exit(void);
int test__sw_clock_freq(void);
int test__perf_time_to_tsc(void);
int test__code_reading(void);
#endif /* TESTS_H */