[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_line(const char *line, size_t line_len, void *buf,
			      size_t len)
{
	const char *p;
	size_t i, j = 0;

	/* Skip to a colon */
	p = strchr(line, ':');
	if (!p)
		return 0;
	i = p + 1 - line;

	/* Read bytes */
	while (j < 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;
		j++;
	}
	/* return number of successfully read bytes */
	return j;
}

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