[mirror_ubuntu-artful-kernel.git] / tools / perf / tests / code-reading.c

#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 "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"

#include "sane_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];
	int ret;

	pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);

	thread__find_addr_map(thread, 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 &&
	    !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->mg->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;
		}

		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 (dso__needs_decompress(al.map->dso))
		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 perf_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 perf_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 perf_evlist *evlist,
			  struct state *state)
{
	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, state);
			perf_evlist__mmap_consume(evlist, i);
			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)
{
	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);
		}
	}
}

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 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, have_kcore, excl_kernel = false;

	pid = getpid();

	machine = machine__new_host();

	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, 500);
	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 = cpu_map__new(NULL);
	if (!cpus) {
		pr_debug("cpu_map__new failed\n");
		goto out_put;
	}

	while (1) {
		const char *str;

		evlist = perf_evlist__new();
		if (!evlist) {
			pr_debug("perf_evlist__new failed\n");
			goto out_put;
		}

		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, NULL);
		if (ret < 0) {
			pr_debug("parse_events failed\n");
			goto out_put;
		}

		perf_evlist__config(evlist, &opts, NULL);

		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;
				/*
				 * 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.
				 */
				cpu_map__get(cpus);
				thread_map__get(threads);
				perf_evlist__set_maps(evlist, NULL, NULL);
				perf_evlist__delete(evlist);
				evlist = NULL;
				continue;
			}

			if (verbose > 0) {
				char errbuf[512];
				perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
				pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
			}

			goto out_put;
		}
		break;
	}

	ret = perf_evlist__mmap(evlist, UINT_MAX, false);
	if (ret < 0) {
		pr_debug("perf_evlist__mmap failed\n");
		goto out_put;
	}

	perf_evlist__enable(evlist);

	do_something();

	perf_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) {
		perf_evlist__delete(evlist);
	} else {
		cpu_map__put(cpus);
		thread_map__put(threads);
	}
	machine__delete_threads(machine);
	machine__delete(machine);

	return err;
}

int test__code_reading(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;
	};
}
Commit	Line	Data
a43783ae	1	#include <errno.h>
877a7a11	2	#include <linux/kernel.h>
d944c4ee	3	#include <linux/types.h>
fd20e811	4	#include <inttypes.h>
b55ae0a9 AH	5	#include <stdlib.h>
	6	#include <unistd.h>
	7	#include <stdio.h>
b55ae0a9	8	#include <string.h>
391e4206	9	#include <sys/param.h>
b55ae0a9 AH	10
	11	#include "parse-events.h"
	12	#include "evlist.h"
	13	#include "evsel.h"
	14	#include "thread_map.h"
	15	#include "cpumap.h"
	16	#include "machine.h"
	17	#include "event.h"
	18	#include "thread.h"
	19
	20	#include "tests.h"
	21
3d689ed6 ACM	22	#include "sane_ctype.h"
3d689ed6 ACM	23
b55ae0a9 AH	24	#define BUFSZ 1024
	25	#define READLEN 128
	26
7a77bc2c AH	27	struct state {
	28	u64 done[1024];
	29	size_t done_cnt;
	30	};
	31
b55ae0a9 AH	32	static unsigned int hex(char c)
	33	{
	34	if (c >= '0' && c <= '9')
	35	return c - '0';
	36	if (c >= 'a' && c <= 'f')
	37	return c - 'a' + 10;
	38	return c - 'A' + 10;
	39	}
	40
b2d0dbf0 JS	41	static size_t read_objdump_chunk(const char line, unsigned char buf,
b2d0dbf0 JS	42	size_t *buf_len)
b55ae0a9	43	{
b2d0dbf0 JS	44	size_t bytes_read = 0;
b2d0dbf0 JS	45	unsigned char chunk_start = buf;
b55ae0a9 AH	46
b55ae0a9 AH	47	/* Read bytes */
b2d0dbf0	48	while (*buf_len > 0) {
b55ae0a9 AH	49	char c1, c2;
b55ae0a9 AH	50
b55ae0a9	51	/* Get 2 hex digits */
b2d0dbf0 JS	52	c1 = (line)++;
b2d0dbf0 JS	53	if (!isxdigit(c1))
b55ae0a9	54	break;
b2d0dbf0 JS	55	c2 = (line)++;
b2d0dbf0 JS	56	if (!isxdigit(c2))
b55ae0a9	57	break;
b2d0dbf0 JS	58
	59	/* Store byte and advance buf */
	60	**buf = (hex(c1) << 4) \| hex(c2);
	61	(*buf)++;
	62	(*buf_len)--;
	63	bytes_read++;
	64
	65	/* End of chunk? */
	66	if (isspace(**line))
b55ae0a9	67	break;
b55ae0a9	68	}
b2d0dbf0 JS	69
	70	/*
	71	* objdump will display raw insn as LE if code endian
	72	* is LE and bytes_per_chunk > 1. In that case reverse
	73	* the chunk we just read.
	74	*
	75	* see disassemble_bytes() at binutils/objdump.c for details
	76	* how objdump chooses display endian)
	77	*/
	78	if (bytes_read > 1 && !bigendian()) {
	79	unsigned char *chunk_end = chunk_start + bytes_read - 1;
	80	unsigned char tmp;
	81
	82	while (chunk_start < chunk_end) {
	83	tmp = *chunk_start;
	84	chunk_start = chunk_end;
	85	*chunk_end = tmp;
	86	chunk_start++;
	87	chunk_end--;
	88	}
	89	}
	90
	91	return bytes_read;
	92	}
	93
	94	static size_t read_objdump_line(const char line, unsigned char buf,
	95	size_t buf_len)
	96	{
	97	const char *p;
	98	size_t ret, bytes_read = 0;
	99
	100	/* Skip to a colon */
	101	p = strchr(line, ':');
	102	if (!p)
	103	return 0;
	104	p++;
	105
	106	/* Skip initial spaces */
	107	while (*p) {
	108	if (!isspace(*p))
	109	break;
	110	p++;
	111	}
	112
	113	do {
	114	ret = read_objdump_chunk(&p, &buf, &buf_len);
	115	bytes_read += ret;
	116	p++;
	117	} while (ret > 0);
	118
729a7ed1	119	/* return number of successfully read bytes */
b2d0dbf0	120	return bytes_read;
b55ae0a9 AH	121	}
b55ae0a9 AH	122
729a7ed1	123	static int read_objdump_output(FILE f, void buf, size_t *len, u64 start_addr)
b55ae0a9 AH	124	{
b55ae0a9 AH	125	char *line = NULL;
729a7ed1	126	size_t line_len, off_last = 0;
b55ae0a9 AH	127	ssize_t ret;
b55ae0a9 AH	128	int err = 0;
edfdb7ea	129	u64 addr, last_addr = start_addr;
729a7ed1 JS	130
	131	while (off_last < *len) {
	132	size_t off, read_bytes, written_bytes;
	133	unsigned char tmp[BUFSZ];
b55ae0a9	134
b55ae0a9 AH	135	ret = getline(&line, &line_len, f);
	136	if (feof(f))
	137	break;
	138	if (ret < 0) {
	139	pr_debug("getline failed\n");
	140	err = -1;
	141	break;
	142	}
729a7ed1 JS	143
729a7ed1 JS	144	/* read objdump data into temporary buffer */
b2d0dbf0	145	read_bytes = read_objdump_line(line, tmp, sizeof(tmp));
729a7ed1 JS	146	if (!read_bytes)
	147	continue;
	148
	149	if (sscanf(line, "%"PRIx64, &addr) != 1)
	150	continue;
edfdb7ea JS	151	if (addr < last_addr) {
	152	pr_debug("addr going backwards, read beyond section?\n");
	153	break;
	154	}
	155	last_addr = addr;
729a7ed1 JS	156
	157	/* copy it from temporary buffer to 'buf' according
	158	* to address on current objdump line */
	159	off = addr - start_addr;
	160	if (off >= *len)
	161	break;
	162	written_bytes = MIN(read_bytes, *len - off);
	163	memcpy(buf + off, tmp, written_bytes);
	164	off_last = off + written_bytes;
b55ae0a9 AH	165	}
b55ae0a9 AH	166
729a7ed1 JS	167	/* len returns number of bytes that could not be read */
	168	*len -= off_last;
	169
b55ae0a9 AH	170	free(line);
	171
	172	return err;
	173	}
	174
	175	static int read_via_objdump(const char filename, u64 addr, void buf,
	176	size_t len)
	177	{
	178	char cmd[PATH_MAX * 2];
	179	const char *fmt;
	180	FILE *f;
	181	int ret;
	182
06f679c1	183	fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
b55ae0a9 AH	184	ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
	185	filename);
	186	if (ret <= 0 \|\| (size_t)ret >= sizeof(cmd))
	187	return -1;
	188
	189	pr_debug("Objdump command is: %s\n", cmd);
	190
7a77bc2c AH	191	/* Ignore objdump errors */
	192	strcat(cmd, " 2>/dev/null");
	193
b55ae0a9 AH	194	f = popen(cmd, "r");
	195	if (!f) {
	196	pr_debug("popen failed\n");
	197	return -1;
	198	}
	199
729a7ed1	200	ret = read_objdump_output(f, buf, &len, addr);
b55ae0a9	201	if (len) {
b2d0dbf0	202	pr_debug("objdump read too few bytes: %zd\n", len);
b55ae0a9 AH	203	if (!ret)
	204	ret = len;
	205	}
	206
	207	pclose(f);
	208
	209	return ret;
	210	}
	211
fd405cf6 JS	212	static void dump_buf(unsigned char *buf, size_t len)
	213	{
	214	size_t i;
	215
	216	for (i = 0; i < len; i++) {
	217	pr_debug("0x%02x ", buf[i]);
	218	if (i % 16 == 15)
	219	pr_debug("\n");
	220	}
	221	pr_debug("\n");
	222	}
	223
b55ae0a9	224	static int read_object_code(u64 addr, size_t len, u8 cpumode,
29f9e521	225	struct thread thread, struct state state)
b55ae0a9 AH	226	{
	227	struct addr_location al;
	228	unsigned char buf1[BUFSZ];
	229	unsigned char buf2[BUFSZ];
	230	size_t ret_len;
	231	u64 objdump_addr;
94df1040 NK	232	const char *objdump_name;
94df1040 NK	233	char decomp_name[KMOD_DECOMP_LEN];
b55ae0a9 AH	234	int ret;
	235
	236	pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
	237
bb871a9c	238	thread__find_addr_map(thread, cpumode, MAP__FUNCTION, addr, &al);
b55ae0a9 AH	239	if (!al.map \|\| !al.map->dso) {
	240	pr_debug("thread__find_addr_map failed\n");
	241	return -1;
	242	}
	243
	244	pr_debug("File is: %s\n", al.map->dso->long_name);
	245
7a77bc2c AH	246	if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
7a77bc2c AH	247	!dso__is_kcore(al.map->dso)) {
b55ae0a9 AH	248	pr_debug("Unexpected kernel address - skipping\n");
	249	return 0;
	250	}
	251
	252	pr_debug("On file address is: %#"PRIx64"\n", al.addr);
	253
	254	if (len > BUFSZ)
	255	len = BUFSZ;
	256
	257	/* Do not go off the map */
	258	if (addr + len > al.map->end)
	259	len = al.map->end - addr;
	260
	261	/* Read the object code using perf */
29f9e521 ACM	262	ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
29f9e521 ACM	263	al.addr, buf1, len);
b55ae0a9 AH	264	if (ret_len != len) {
	265	pr_debug("dso__data_read_offset failed\n");
	266	return -1;
	267	}
	268
	269	/*
	270	* Converting addresses for use by objdump requires more information.
	271	* map__load() does that. See map__rip_2objdump() for details.
	272	*/
be39db9f	273	if (map__load(al.map))
b55ae0a9 AH	274	return -1;
b55ae0a9 AH	275
7a77bc2c AH	276	/* objdump struggles with kcore - try each map only once */
	277	if (dso__is_kcore(al.map->dso)) {
	278	size_t d;
	279
	280	for (d = 0; d < state->done_cnt; d++) {
	281	if (state->done[d] == al.map->start) {
	282	pr_debug("kcore map tested already");
	283	pr_debug(" - skipping\n");
	284	return 0;
	285	}
	286	}
	287	if (state->done_cnt >= ARRAY_SIZE(state->done)) {
	288	pr_debug("Too many kcore maps - skipping\n");
	289	return 0;
	290	}
	291	state->done[state->done_cnt++] = al.map->start;
	292	}
	293
94df1040 NK	294	objdump_name = al.map->dso->long_name;
	295	if (dso__needs_decompress(al.map->dso)) {
	296	if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
	297	decomp_name,
	298	sizeof(decomp_name)) < 0) {
	299	pr_debug("decompression failed\n");
	300	return -1;
	301	}
	302
	303	objdump_name = decomp_name;
	304	}
	305
b55ae0a9 AH	306	/* Read the object code using objdump */
b55ae0a9 AH	307	objdump_addr = map__rip_2objdump(al.map, al.addr);
94df1040 NK	308	ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
	309
	310	if (dso__needs_decompress(al.map->dso))
	311	unlink(objdump_name);
	312
b55ae0a9 AH	313	if (ret > 0) {
	314	/*
	315	* The kernel maps are inaccurate - assume objdump is right in
	316	* that case.
	317	*/
	318	if (cpumode == PERF_RECORD_MISC_KERNEL \|\|
	319	cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
	320	len -= ret;
7a77bc2c	321	if (len) {
b55ae0a9	322	pr_debug("Reducing len to %zu\n", len);
7a77bc2c AH	323	} else if (dso__is_kcore(al.map->dso)) {
	324	/*
	325	* objdump cannot handle very large segments
	326	* that may be found in kcore.
	327	*/
	328	pr_debug("objdump failed for kcore");
	329	pr_debug(" - skipping\n");
	330	return 0;
	331	} else {
b55ae0a9	332	return -1;
7a77bc2c	333	}
b55ae0a9 AH	334	}
	335	}
	336	if (ret < 0) {
	337	pr_debug("read_via_objdump failed\n");
	338	return -1;
	339	}
	340
	341	/* The results should be identical */
	342	if (memcmp(buf1, buf2, len)) {
	343	pr_debug("Bytes read differ from those read by objdump\n");
fd405cf6 JS	344	pr_debug("buf1 (dso):\n");
	345	dump_buf(buf1, len);
	346	pr_debug("buf2 (objdump):\n");
	347	dump_buf(buf2, len);
b55ae0a9 AH	348	return -1;
	349	}
	350	pr_debug("Bytes read match those read by objdump\n");
	351
	352	return 0;
	353	}
	354
	355	static int process_sample_event(struct machine *machine,
	356	struct perf_evlist *evlist,
7a77bc2c	357	union perf_event event, struct state state)
b55ae0a9 AH	358	{
	359	struct perf_sample sample;
	360	struct thread *thread;
b91fc39f	361	int ret;
b55ae0a9 AH	362
	363	if (perf_evlist__parse_sample(evlist, event, &sample)) {
	364	pr_debug("perf_evlist__parse_sample failed\n");
	365	return -1;
	366	}
	367
13ce34df	368	thread = machine__findnew_thread(machine, sample.pid, sample.tid);
b55ae0a9 AH	369	if (!thread) {
	370	pr_debug("machine__findnew_thread failed\n");
	371	return -1;
	372	}
	373
473398a2	374	ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
b91fc39f ACM	375	thread__put(thread);
b91fc39f ACM	376	return ret;
b55ae0a9 AH	377	}
	378
	379	static int process_event(struct machine machine, struct perf_evlist evlist,
7a77bc2c	380	union perf_event event, struct state state)
b55ae0a9 AH	381	{
b55ae0a9 AH	382	if (event->header.type == PERF_RECORD_SAMPLE)
7a77bc2c	383	return process_sample_event(machine, evlist, event, state);
b55ae0a9	384
48095b72 AH	385	if (event->header.type == PERF_RECORD_THROTTLE \|\|
	386	event->header.type == PERF_RECORD_UNTHROTTLE)
	387	return 0;
	388
	389	if (event->header.type < PERF_RECORD_MAX) {
	390	int ret;
	391
	392	ret = machine__process_event(machine, event, NULL);
	393	if (ret < 0)
	394	pr_debug("machine__process_event failed, event type %u\n",
	395	event->header.type);
	396	return ret;
	397	}
b55ae0a9 AH	398
	399	return 0;
	400	}
	401
7a77bc2c AH	402	static int process_events(struct machine machine, struct perf_evlist evlist,
7a77bc2c AH	403	struct state *state)
b55ae0a9 AH	404	{
	405	union perf_event *event;
	406	int i, ret;
	407
	408	for (i = 0; i < evlist->nr_mmaps; i++) {
	409	while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
7a77bc2c	410	ret = process_event(machine, evlist, event, state);
8e50d384	411	perf_evlist__mmap_consume(evlist, i);
b55ae0a9 AH	412	if (ret < 0)
	413	return ret;
	414	}
	415	}
	416	return 0;
	417	}
	418
	419	static int comp(const void a, const void b)
	420	{
	421	return (int )a - (int )b;
	422	}
	423
	424	static void do_sort_something(void)
	425	{
309b5185	426	int buf[40960], i;
b55ae0a9	427
309b5185 DA	428	for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
309b5185 DA	429	buf[i] = ARRAY_SIZE(buf) - i - 1;
b55ae0a9	430
309b5185	431	qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
b55ae0a9	432
309b5185	433	for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
b55ae0a9 AH	434	if (buf[i] != i) {
	435	pr_debug("qsort failed\n");
	436	break;
	437	}
	438	}
	439	}
	440
	441	static void sort_something(void)
	442	{
	443	int i;
	444
	445	for (i = 0; i < 10; i++)
	446	do_sort_something();
	447	}
	448
	449	static void syscall_something(void)
	450	{
	451	int pipefd[2];
	452	int i;
	453
	454	for (i = 0; i < 1000; i++) {
	455	if (pipe(pipefd) < 0) {
	456	pr_debug("pipe failed\n");
	457	break;
	458	}
	459	close(pipefd[1]);
	460	close(pipefd[0]);
	461	}
	462	}
	463
	464	static void fs_something(void)
	465	{
	466	const char *test_file_name = "temp-perf-code-reading-test-file--";
	467	FILE *f;
	468	int i;
	469
	470	for (i = 0; i < 1000; i++) {
	471	f = fopen(test_file_name, "w+");
	472	if (f) {
	473	fclose(f);
	474	unlink(test_file_name);
	475	}
	476	}
	477	}
	478
	479	static void do_something(void)
	480	{
	481	fs_something();
	482
	483	sort_something();
	484
	485	syscall_something();
	486	}
	487
	488	enum {
	489	TEST_CODE_READING_OK,
	490	TEST_CODE_READING_NO_VMLINUX,
7a77bc2c	491	TEST_CODE_READING_NO_KCORE,
b55ae0a9	492	TEST_CODE_READING_NO_ACCESS,
7a77bc2c	493	TEST_CODE_READING_NO_KERNEL_OBJ,
b55ae0a9 AH	494	};
b55ae0a9 AH	495
7a77bc2c	496	static int do_test_code_reading(bool try_kcore)
b55ae0a9	497	{
b55ae0a9 AH	498	struct machine *machine;
b55ae0a9 AH	499	struct thread *thread;
b4006796	500	struct record_opts opts = {
b55ae0a9 AH	501	.mmap_pages = UINT_MAX,
	502	.user_freq = UINT_MAX,
	503	.user_interval = ULLONG_MAX,
5243ba76	504	.freq = 500,
b55ae0a9 AH	505	.target = {
	506	.uses_mmap = true,
	507	},
	508	};
7a77bc2c AH	509	struct state state = {
	510	.done_cnt = 0,
	511	};
b55ae0a9 AH	512	struct thread_map *threads = NULL;
	513	struct cpu_map *cpus = NULL;
	514	struct perf_evlist *evlist = NULL;
	515	struct perf_evsel *evsel = NULL;
	516	int err = -1, ret;
	517	pid_t pid;
	518	struct map *map;
7a77bc2c	519	bool have_vmlinux, have_kcore, excl_kernel = false;
b55ae0a9 AH	520
	521	pid = getpid();
	522
0fd4008e	523	machine = machine__new_host();
b55ae0a9 AH	524
	525	ret = machine__create_kernel_maps(machine);
	526	if (ret < 0) {
	527	pr_debug("machine__create_kernel_maps failed\n");
	528	goto out_err;
	529	}
	530
7a77bc2c AH	531	/* Force the use of kallsyms instead of vmlinux to try kcore */
	532	if (try_kcore)
	533	symbol_conf.kallsyms_name = "/proc/kallsyms";
	534
b55ae0a9	535	/* Load kernel map */
a5e813c6	536	map = machine__kernel_map(machine);
be39db9f	537	ret = map__load(map);
b55ae0a9 AH	538	if (ret < 0) {
	539	pr_debug("map__load failed\n");
	540	goto out_err;
	541	}
7a77bc2c AH	542	have_vmlinux = dso__is_vmlinux(map->dso);
	543	have_kcore = dso__is_kcore(map->dso);
	544
	545	/* 2nd time through we just try kcore */
	546	if (try_kcore && !have_kcore)
	547	return TEST_CODE_READING_NO_KCORE;
	548
	549	/* No point getting kernel events if there is no kernel object */
	550	if (!have_vmlinux && !have_kcore)
b55ae0a9 AH	551	excl_kernel = true;
	552
	553	threads = thread_map__new_by_tid(pid);
	554	if (!threads) {
	555	pr_debug("thread_map__new_by_tid failed\n");
	556	goto out_err;
	557	}
	558
	559	ret = perf_event__synthesize_thread_map(NULL, threads,
9d9cad76	560	perf_event__process, machine, false, 500);
b55ae0a9 AH	561	if (ret < 0) {
	562	pr_debug("perf_event__synthesize_thread_map failed\n");
	563	goto out_err;
	564	}
	565
314add6b	566	thread = machine__findnew_thread(machine, pid, pid);
b55ae0a9 AH	567	if (!thread) {
b55ae0a9 AH	568	pr_debug("machine__findnew_thread failed\n");
b91fc39f	569	goto out_put;
b55ae0a9 AH	570	}
	571
	572	cpus = cpu_map__new(NULL);
	573	if (!cpus) {
	574	pr_debug("cpu_map__new failed\n");
b91fc39f	575	goto out_put;
b55ae0a9 AH	576	}
	577
	578	while (1) {
	579	const char *str;
	580
	581	evlist = perf_evlist__new();
	582	if (!evlist) {
	583	pr_debug("perf_evlist__new failed\n");
b91fc39f	584	goto out_put;
b55ae0a9 AH	585	}
	586
	587	perf_evlist__set_maps(evlist, cpus, threads);
	588
	589	if (excl_kernel)
	590	str = "cycles:u";
	591	else
	592	str = "cycles";
	593	pr_debug("Parsing event '%s'\n", str);
b39b8393	594	ret = parse_events(evlist, str, NULL);
b55ae0a9 AH	595	if (ret < 0) {
b55ae0a9 AH	596	pr_debug("parse_events failed\n");
b91fc39f	597	goto out_put;
b55ae0a9 AH	598	}
b55ae0a9 AH	599
e68ae9cf	600	perf_evlist__config(evlist, &opts, NULL);
b55ae0a9 AH	601
	602	evsel = perf_evlist__first(evlist);
	603
	604	evsel->attr.comm = 1;
	605	evsel->attr.disabled = 1;
	606	evsel->attr.enable_on_exec = 0;
	607
	608	ret = perf_evlist__open(evlist);
	609	if (ret < 0) {
	610	if (!excl_kernel) {
	611	excl_kernel = true;
7320b1b3 JO	612	/*
	613	* Both cpus and threads are now owned by evlist
	614	* and will be freed by following perf_evlist__set_maps
	615	* call. Getting refference to keep them alive.
	616	*/
	617	cpu_map__get(cpus);
	618	thread_map__get(threads);
ae450a7d	619	perf_evlist__set_maps(evlist, NULL, NULL);
b55ae0a9 AH	620	perf_evlist__delete(evlist);
	621	evlist = NULL;
	622	continue;
	623	}
6880bbf9	624
bb963e16	625	if (verbose > 0) {
6880bbf9 ACM	626	char errbuf[512];
	627	perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
	628	pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
	629	}
	630
b91fc39f	631	goto out_put;
b55ae0a9 AH	632	}
	633	break;
	634	}
	635
	636	ret = perf_evlist__mmap(evlist, UINT_MAX, false);
	637	if (ret < 0) {
	638	pr_debug("perf_evlist__mmap failed\n");
b91fc39f	639	goto out_put;
b55ae0a9 AH	640	}
	641
	642	perf_evlist__enable(evlist);
	643
	644	do_something();
	645
	646	perf_evlist__disable(evlist);
	647
7a77bc2c	648	ret = process_events(machine, evlist, &state);
b55ae0a9	649	if (ret < 0)
b91fc39f	650	goto out_put;
b55ae0a9	651
7a77bc2c AH	652	if (!have_vmlinux && !have_kcore && !try_kcore)
	653	err = TEST_CODE_READING_NO_KERNEL_OBJ;
	654	else if (!have_vmlinux && !try_kcore)
b55ae0a9 AH	655	err = TEST_CODE_READING_NO_VMLINUX;
	656	else if (excl_kernel)
	657	err = TEST_CODE_READING_NO_ACCESS;
	658	else
	659	err = TEST_CODE_READING_OK;
b91fc39f ACM	660	out_put:
b91fc39f ACM	661	thread__put(thread);
b55ae0a9	662	out_err:
b91fc39f	663
b55ae0a9	664	if (evlist) {
b55ae0a9	665	perf_evlist__delete(evlist);
03ad9747	666	} else {
f30a79b0	667	cpu_map__put(cpus);
186fbb74	668	thread_map__put(threads);
03ad9747	669	}
b55ae0a9	670	machine__delete_threads(machine);
0fd4008e	671	machine__delete(machine);
b55ae0a9 AH	672
	673	return err;
	674	}
	675
721a1f53	676	int test__code_reading(int subtest __maybe_unused)
b55ae0a9 AH	677	{
	678	int ret;
	679
7a77bc2c AH	680	ret = do_test_code_reading(false);
	681	if (!ret)
	682	ret = do_test_code_reading(true);
b55ae0a9 AH	683
	684	switch (ret) {
	685	case TEST_CODE_READING_OK:
	686	return 0;
	687	case TEST_CODE_READING_NO_VMLINUX:
597bdeb4	688	pr_debug("no vmlinux\n");
b55ae0a9	689	return 0;
7a77bc2c	690	case TEST_CODE_READING_NO_KCORE:
597bdeb4	691	pr_debug("no kcore\n");
7a77bc2c	692	return 0;
b55ae0a9	693	case TEST_CODE_READING_NO_ACCESS:
597bdeb4	694	pr_debug("no access\n");
b55ae0a9	695	return 0;
7a77bc2c	696	case TEST_CODE_READING_NO_KERNEL_OBJ:
597bdeb4	697	pr_debug("no kernel obj\n");
7a77bc2c	698	return 0;
b55ae0a9 AH	699	default:
	700	return -1;
	701	};
	702	}