[deliverable/linux.git] / tools / perf / tests / code-reading.c

#include <linux/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.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

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;
	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, NULL))
		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;
	}

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