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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/perf/tests/code-reading.c | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/tests/code-reading.c')
-rw-r--r-- | tools/perf/tests/code-reading.c | 756 |
1 files changed, 756 insertions, 0 deletions
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c new file mode 100644 index 000000000..035c91235 --- /dev/null +++ b/tools/perf/tests/code-reading.c @@ -0,0 +1,756 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <errno.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <inttypes.h> +#include <stdlib.h> +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <sys/param.h> +#include <perf/cpumap.h> +#include <perf/evlist.h> +#include <perf/mmap.h> + +#include "debug.h" +#include "dso.h" +#include "env.h" +#include "parse-events.h" +#include "trace-event.h" +#include "evlist.h" +#include "evsel.h" +#include "thread_map.h" +#include "machine.h" +#include "map.h" +#include "symbol.h" +#include "event.h" +#include "record.h" +#include "util/mmap.h" +#include "util/synthetic-events.h" +#include "thread.h" + +#include "tests.h" + +#include <linux/ctype.h> + +#define BUFSZ 1024 +#define READLEN 128 + +struct state { + u64 done[1024]; + size_t done_cnt; +}; + +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 size_t read_objdump_chunk(const char **line, unsigned char **buf, + size_t *buf_len) +{ + size_t bytes_read = 0; + unsigned char *chunk_start = *buf; + + /* Read bytes */ + while (*buf_len > 0) { + char c1, c2; + + /* Get 2 hex digits */ + c1 = *(*line)++; + if (!isxdigit(c1)) + break; + c2 = *(*line)++; + if (!isxdigit(c2)) + break; + + /* Store byte and advance buf */ + **buf = (hex(c1) << 4) | hex(c2); + (*buf)++; + (*buf_len)--; + bytes_read++; + + /* End of chunk? */ + if (isspace(**line)) + break; + } + + /* + * objdump will display raw insn as LE if code endian + * is LE and bytes_per_chunk > 1. In that case reverse + * the chunk we just read. + * + * see disassemble_bytes() at binutils/objdump.c for details + * how objdump chooses display endian) + */ + if (bytes_read > 1 && !bigendian()) { + unsigned char *chunk_end = chunk_start + bytes_read - 1; + unsigned char tmp; + + while (chunk_start < chunk_end) { + tmp = *chunk_start; + *chunk_start = *chunk_end; + *chunk_end = tmp; + chunk_start++; + chunk_end--; + } + } + + return bytes_read; +} + +static size_t read_objdump_line(const char *line, unsigned char *buf, + size_t buf_len) +{ + const char *p; + size_t ret, bytes_read = 0; + + /* Skip to a colon */ + p = strchr(line, ':'); + if (!p) + return 0; + p++; + + /* Skip initial spaces */ + while (*p) { + if (!isspace(*p)) + break; + p++; + } + + do { + ret = read_objdump_chunk(&p, &buf, &buf_len); + bytes_read += ret; + p++; + } while (ret > 0); + + /* return number of successfully read bytes */ + return bytes_read; +} + +static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) +{ + char *line = NULL; + size_t line_len, off_last = 0; + ssize_t ret; + int err = 0; + u64 addr, last_addr = start_addr; + + while (off_last < *len) { + size_t off, read_bytes, written_bytes; + unsigned char tmp[BUFSZ]; + + ret = getline(&line, &line_len, f); + if (feof(f)) + break; + if (ret < 0) { + pr_debug("getline failed\n"); + err = -1; + break; + } + + /* read objdump data into temporary buffer */ + read_bytes = read_objdump_line(line, tmp, sizeof(tmp)); + if (!read_bytes) + continue; + + if (sscanf(line, "%"PRIx64, &addr) != 1) + continue; + if (addr < last_addr) { + pr_debug("addr going backwards, read beyond section?\n"); + break; + } + last_addr = addr; + + /* copy it from temporary buffer to 'buf' according + * to address on current objdump line */ + off = addr - start_addr; + if (off >= *len) + break; + written_bytes = MIN(read_bytes, *len - off); + memcpy(buf + off, tmp, written_bytes); + off_last = off + written_bytes; + } + + /* len returns number of bytes that could not be read */ + *len -= off_last; + + 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 -z -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); + + /* Ignore objdump errors */ + strcat(cmd, " 2>/dev/null"); + + f = popen(cmd, "r"); + if (!f) { + pr_debug("popen failed\n"); + return -1; + } + + ret = read_objdump_output(f, buf, &len, addr); + if (len) { + pr_debug("objdump read too few bytes: %zd\n", len); + if (!ret) + ret = len; + } + + pclose(f); + + return ret; +} + +static void dump_buf(unsigned char *buf, size_t len) +{ + size_t i; + + for (i = 0; i < len; i++) { + pr_debug("0x%02x ", buf[i]); + if (i % 16 == 15) + pr_debug("\n"); + } + pr_debug("\n"); +} + +static int read_object_code(u64 addr, size_t len, u8 cpumode, + struct thread *thread, struct state *state) +{ + struct addr_location al; + unsigned char buf1[BUFSZ]; + unsigned char buf2[BUFSZ]; + size_t ret_len; + u64 objdump_addr; + const char *objdump_name; + char decomp_name[KMOD_DECOMP_LEN]; + bool decomp = false; + int ret; + + pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr); + + if (!thread__find_map(thread, cpumode, addr, &al) || !al.map->dso) { + if (cpumode == PERF_RECORD_MISC_HYPERVISOR) { + pr_debug("Hypervisor address can not be resolved - skipping\n"); + return 0; + } + + pr_debug("thread__find_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 && + !dso__is_kcore(al.map->dso)) { + 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, thread->maps->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)) + return -1; + + /* objdump struggles with kcore - try each map only once */ + if (dso__is_kcore(al.map->dso)) { + size_t d; + + for (d = 0; d < state->done_cnt; d++) { + if (state->done[d] == al.map->start) { + pr_debug("kcore map tested already"); + pr_debug(" - skipping\n"); + return 0; + } + } + if (state->done_cnt >= ARRAY_SIZE(state->done)) { + pr_debug("Too many kcore maps - skipping\n"); + return 0; + } + state->done[state->done_cnt++] = al.map->start; + } + + objdump_name = al.map->dso->long_name; + if (dso__needs_decompress(al.map->dso)) { + if (dso__decompress_kmodule_path(al.map->dso, objdump_name, + decomp_name, + sizeof(decomp_name)) < 0) { + pr_debug("decompression failed\n"); + return -1; + } + + decomp = true; + objdump_name = decomp_name; + } + + /* Read the object code using objdump */ + objdump_addr = map__rip_2objdump(al.map, al.addr); + ret = read_via_objdump(objdump_name, objdump_addr, buf2, len); + + if (decomp) + unlink(objdump_name); + + 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 if (dso__is_kcore(al.map->dso)) { + /* + * objdump cannot handle very large segments + * that may be found in kcore. + */ + pr_debug("objdump failed for kcore"); + pr_debug(" - skipping\n"); + return 0; + } 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"); + pr_debug("buf1 (dso):\n"); + dump_buf(buf1, len); + pr_debug("buf2 (objdump):\n"); + dump_buf(buf2, len); + return -1; + } + pr_debug("Bytes read match those read by objdump\n"); + + return 0; +} + +static int process_sample_event(struct machine *machine, + struct evlist *evlist, + union perf_event *event, struct state *state) +{ + struct perf_sample sample; + struct thread *thread; + int ret; + + 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, sample.tid); + if (!thread) { + pr_debug("machine__findnew_thread failed\n"); + return -1; + } + + ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state); + thread__put(thread); + return ret; +} + +static int process_event(struct machine *machine, struct evlist *evlist, + union perf_event *event, struct state *state) +{ + if (event->header.type == PERF_RECORD_SAMPLE) + return process_sample_event(machine, evlist, event, state); + + if (event->header.type == PERF_RECORD_THROTTLE || + event->header.type == PERF_RECORD_UNTHROTTLE) + return 0; + + if (event->header.type < PERF_RECORD_MAX) { + int ret; + + ret = machine__process_event(machine, event, NULL); + if (ret < 0) + pr_debug("machine__process_event failed, event type %u\n", + event->header.type); + return ret; + } + + return 0; +} + +static int process_events(struct machine *machine, struct evlist *evlist, + struct state *state) +{ + union perf_event *event; + struct mmap *md; + int i, ret; + + for (i = 0; i < evlist->core.nr_mmaps; i++) { + md = &evlist->mmap[i]; + if (perf_mmap__read_init(&md->core) < 0) + continue; + + while ((event = perf_mmap__read_event(&md->core)) != NULL) { + ret = process_event(machine, evlist, event, state); + perf_mmap__consume(&md->core); + if (ret < 0) + return ret; + } + perf_mmap__read_done(&md->core); + } + return 0; +} + +static int comp(const void *a, const void *b) +{ + return *(int *)a - *(int *)b; +} + +static void do_sort_something(void) +{ + int buf[40960], i; + + for (i = 0; i < (int)ARRAY_SIZE(buf); i++) + buf[i] = ARRAY_SIZE(buf) - i - 1; + + qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp); + + for (i = 0; i < (int)ARRAY_SIZE(buf); 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); + } + } +} + +#ifdef __s390x__ +#include "header.h" // for get_cpuid() +#endif + +static const char *do_determine_event(bool excl_kernel) +{ + const char *event = excl_kernel ? "cycles:u" : "cycles"; + +#ifdef __s390x__ + char cpuid[128], model[16], model_c[16], cpum_cf_v[16]; + unsigned int family; + int ret, cpum_cf_a; + + if (get_cpuid(cpuid, sizeof(cpuid))) + goto out_clocks; + ret = sscanf(cpuid, "%*[^,],%u,%[^,],%[^,],%[^,],%x", &family, model_c, + model, cpum_cf_v, &cpum_cf_a); + if (ret != 5) /* Not available */ + goto out_clocks; + if (excl_kernel && (cpum_cf_a & 4)) + return event; + if (!excl_kernel && (cpum_cf_a & 2)) + return event; + + /* Fall through: missing authorization */ +out_clocks: + event = excl_kernel ? "cpu-clock:u" : "cpu-clock"; + +#endif + return event; +} + +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_KCORE, + TEST_CODE_READING_NO_ACCESS, + TEST_CODE_READING_NO_KERNEL_OBJ, +}; + +static int do_test_code_reading(bool try_kcore) +{ + struct machine *machine; + struct thread *thread; + struct record_opts opts = { + .mmap_pages = UINT_MAX, + .user_freq = UINT_MAX, + .user_interval = ULLONG_MAX, + .freq = 500, + .target = { + .uses_mmap = true, + }, + }; + struct state state = { + .done_cnt = 0, + }; + struct perf_thread_map *threads = NULL; + struct perf_cpu_map *cpus = NULL; + struct evlist *evlist = NULL; + struct evsel *evsel = NULL; + int err = -1, ret; + pid_t pid; + struct map *map; + bool have_vmlinux, have_kcore, excl_kernel = false; + + pid = getpid(); + + machine = machine__new_host(); + machine->env = &perf_env; + + ret = machine__create_kernel_maps(machine); + if (ret < 0) { + pr_debug("machine__create_kernel_maps failed\n"); + goto out_err; + } + + /* Force the use of kallsyms instead of vmlinux to try kcore */ + if (try_kcore) + symbol_conf.kallsyms_name = "/proc/kallsyms"; + + /* Load kernel map */ + map = machine__kernel_map(machine); + ret = map__load(map); + if (ret < 0) { + pr_debug("map__load failed\n"); + goto out_err; + } + have_vmlinux = dso__is_vmlinux(map->dso); + have_kcore = dso__is_kcore(map->dso); + + /* 2nd time through we just try kcore */ + if (try_kcore && !have_kcore) + return TEST_CODE_READING_NO_KCORE; + + /* No point getting kernel events if there is no kernel object */ + if (!have_vmlinux && !have_kcore) + 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, false); + if (ret < 0) { + pr_debug("perf_event__synthesize_thread_map failed\n"); + goto out_err; + } + + thread = machine__findnew_thread(machine, pid, pid); + if (!thread) { + pr_debug("machine__findnew_thread failed\n"); + goto out_put; + } + + cpus = perf_cpu_map__new(NULL); + if (!cpus) { + pr_debug("perf_cpu_map__new failed\n"); + goto out_put; + } + + while (1) { + const char *str; + + evlist = evlist__new(); + if (!evlist) { + pr_debug("perf_evlist__new failed\n"); + goto out_put; + } + + perf_evlist__set_maps(&evlist->core, cpus, threads); + + str = do_determine_event(excl_kernel); + pr_debug("Parsing event '%s'\n", str); + ret = parse_events(evlist, str, NULL); + if (ret < 0) { + pr_debug("parse_events failed\n"); + goto out_put; + } + + perf_evlist__config(evlist, &opts, NULL); + + evsel = evlist__first(evlist); + + evsel->core.attr.comm = 1; + evsel->core.attr.disabled = 1; + evsel->core.attr.enable_on_exec = 0; + + ret = evlist__open(evlist); + if (ret < 0) { + if (!excl_kernel) { + excl_kernel = true; + /* + * Both cpus and threads are now owned by evlist + * and will be freed by following perf_evlist__set_maps + * call. Getting refference to keep them alive. + */ + perf_cpu_map__get(cpus); + perf_thread_map__get(threads); + perf_evlist__set_maps(&evlist->core, NULL, NULL); + evlist__delete(evlist); + evlist = NULL; + continue; + } + + if (verbose > 0) { + char errbuf[512]; + evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf)); + pr_debug("perf_evlist__open() failed!\n%s\n", errbuf); + } + + goto out_put; + } + break; + } + + ret = evlist__mmap(evlist, UINT_MAX); + if (ret < 0) { + pr_debug("evlist__mmap failed\n"); + goto out_put; + } + + evlist__enable(evlist); + + do_something(); + + evlist__disable(evlist); + + ret = process_events(machine, evlist, &state); + if (ret < 0) + goto out_put; + + if (!have_vmlinux && !have_kcore && !try_kcore) + err = TEST_CODE_READING_NO_KERNEL_OBJ; + else if (!have_vmlinux && !try_kcore) + err = TEST_CODE_READING_NO_VMLINUX; + else if (excl_kernel) + err = TEST_CODE_READING_NO_ACCESS; + else + err = TEST_CODE_READING_OK; +out_put: + thread__put(thread); +out_err: + + if (evlist) { + evlist__delete(evlist); + } else { + perf_cpu_map__put(cpus); + perf_thread_map__put(threads); + } + machine__delete_threads(machine); + machine__delete(machine); + + return err; +} + +int test__code_reading(struct test *test __maybe_unused, int subtest __maybe_unused) +{ + int ret; + + ret = do_test_code_reading(false); + if (!ret) + ret = do_test_code_reading(true); + + switch (ret) { + case TEST_CODE_READING_OK: + return 0; + case TEST_CODE_READING_NO_VMLINUX: + pr_debug("no vmlinux\n"); + return 0; + case TEST_CODE_READING_NO_KCORE: + pr_debug("no kcore\n"); + return 0; + case TEST_CODE_READING_NO_ACCESS: + pr_debug("no access\n"); + return 0; + case TEST_CODE_READING_NO_KERNEL_OBJ: + pr_debug("no kernel obj\n"); + return 0; + default: + return -1; + }; +} |