Commit-ID: b55ae0a976f2927ea8f15a85c43bbe6d25a68a41 Gitweb: http://git.kernel.org/tip/b55ae0a976f2927ea8f15a85c43bbe6d25a68a41 Author: Adrian Hunter <adrian.hun...@intel.com> AuthorDate: Wed, 7 Aug 2013 14:38:45 +0300 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Wed, 7 Aug 2013 17:35:30 -0300
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.hun...@intel.com> Cc: David Ahern <dsah...@gmail.com> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Jiri Olsa <jo...@redhat.com> Cc: Mike Galbraith <efa...@gmx.de> Cc: Namhyung Kim <namhy...@gmail.com> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stephane Eranian <eran...@google.com> Link: http://lkml.kernel.org/r/1375875537-4509-2-git-send-email-adrian.hun...@intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/Makefile | 1 + tools/perf/tests/builtin-test.c | 4 + tools/perf/tests/code-reading.c | 509 ++++++++++++++++++++++++++++++++++++++++ tools/perf/tests/tests.h | 1 + 4 files changed, 515 insertions(+) diff --git a/tools/perf/Makefile b/tools/perf/Makefile index bfd12d0..e0d3d9f 100644 --- a/tools/perf/Makefile +++ b/tools/perf/Makefile @@ -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 diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index b7b4049..f5af192 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -100,6 +100,10 @@ static struct test { }, #endif { + .desc = "Test object code reading", + .func = test__code_reading, + }, + { .func = NULL, }, }; diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c new file mode 100644 index 0000000..28bee62 --- /dev/null +++ b/tools/perf/tests/code-reading.c @@ -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; + }; +} diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index d22202a..c748f53 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -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 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
