[mirror_ubuntu-focal-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) {
		if (cpumode == PERF_RECORD_MISC_HYPERVISOR) {
			pr_debug("Hypervisor address can not be resolved - skipping\n");
			return 0;
		}

		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(struct test *test __maybe_unused, int subtest __maybe_unused)
{
	int ret;

	ret = do_test_code_reading(false);
	if (!ret)
		ret = do_test_code_reading(true);

	switch (ret) {
	case TEST_CODE_READING_OK:
		return 0;
	case TEST_CODE_READING_NO_VMLINUX:
		pr_debug("no vmlinux\n");
		return 0;
	case TEST_CODE_READING_NO_KCORE:
		pr_debug("no kcore\n");
		return 0;
	case TEST_CODE_READING_NO_ACCESS:
		pr_debug("no access\n");
		return 0;
	case TEST_CODE_READING_NO_KERNEL_OBJ:
		pr_debug("no kernel obj\n");
		return 0;
	default:
		return -1;
	};
}
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	239	if (!al.map \|\| !al.map->dso) {
9a805d86 RB	240	if (cpumode == PERF_RECORD_MISC_HYPERVISOR) {
	241	pr_debug("Hypervisor address can not be resolved - skipping\n");
	242	return 0;
	243	}
	244
b55ae0a9 AH	245	pr_debug("thread__find_addr_map failed\n");
	246	return -1;
	247	}
	248
	249	pr_debug("File is: %s\n", al.map->dso->long_name);
	250
7a77bc2c AH	251	if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
7a77bc2c AH	252	!dso__is_kcore(al.map->dso)) {
b55ae0a9 AH	253	pr_debug("Unexpected kernel address - skipping\n");
	254	return 0;
	255	}
	256
	257	pr_debug("On file address is: %#"PRIx64"\n", al.addr);
	258
	259	if (len > BUFSZ)
	260	len = BUFSZ;
	261
	262	/* Do not go off the map */
	263	if (addr + len > al.map->end)
	264	len = al.map->end - addr;
	265
	266	/* Read the object code using perf */
29f9e521 ACM	267	ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
29f9e521 ACM	268	al.addr, buf1, len);
b55ae0a9 AH	269	if (ret_len != len) {
	270	pr_debug("dso__data_read_offset failed\n");
	271	return -1;
	272	}
	273
	274	/*
	275	* Converting addresses for use by objdump requires more information.
	276	* map__load() does that. See map__rip_2objdump() for details.
	277	*/
be39db9f	278	if (map__load(al.map))
b55ae0a9 AH	279	return -1;
b55ae0a9 AH	280
7a77bc2c AH	281	/* objdump struggles with kcore - try each map only once */
	282	if (dso__is_kcore(al.map->dso)) {
	283	size_t d;
	284
	285	for (d = 0; d < state->done_cnt; d++) {
	286	if (state->done[d] == al.map->start) {
	287	pr_debug("kcore map tested already");
	288	pr_debug(" - skipping\n");
	289	return 0;
	290	}
	291	}
	292	if (state->done_cnt >= ARRAY_SIZE(state->done)) {
	293	pr_debug("Too many kcore maps - skipping\n");
	294	return 0;
	295	}
	296	state->done[state->done_cnt++] = al.map->start;
	297	}
	298
94df1040 NK	299	objdump_name = al.map->dso->long_name;
	300	if (dso__needs_decompress(al.map->dso)) {
	301	if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
	302	decomp_name,
	303	sizeof(decomp_name)) < 0) {
	304	pr_debug("decompression failed\n");
	305	return -1;
	306	}
	307
	308	objdump_name = decomp_name;
	309	}
	310
b55ae0a9 AH	311	/* Read the object code using objdump */
b55ae0a9 AH	312	objdump_addr = map__rip_2objdump(al.map, al.addr);
94df1040 NK	313	ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
	314
	315	if (dso__needs_decompress(al.map->dso))
	316	unlink(objdump_name);
	317
b55ae0a9 AH	318	if (ret > 0) {
	319	/*
	320	* The kernel maps are inaccurate - assume objdump is right in
	321	* that case.
	322	*/
	323	if (cpumode == PERF_RECORD_MISC_KERNEL \|\|
	324	cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
	325	len -= ret;
7a77bc2c	326	if (len) {
b55ae0a9	327	pr_debug("Reducing len to %zu\n", len);
7a77bc2c AH	328	} else if (dso__is_kcore(al.map->dso)) {
	329	/*
	330	* objdump cannot handle very large segments
	331	* that may be found in kcore.
	332	*/
	333	pr_debug("objdump failed for kcore");
	334	pr_debug(" - skipping\n");
	335	return 0;
	336	} else {
b55ae0a9	337	return -1;
7a77bc2c	338	}
b55ae0a9 AH	339	}
	340	}
	341	if (ret < 0) {
	342	pr_debug("read_via_objdump failed\n");
	343	return -1;
	344	}
	345
	346	/* The results should be identical */
	347	if (memcmp(buf1, buf2, len)) {
	348	pr_debug("Bytes read differ from those read by objdump\n");
fd405cf6 JS	349	pr_debug("buf1 (dso):\n");
	350	dump_buf(buf1, len);
	351	pr_debug("buf2 (objdump):\n");
	352	dump_buf(buf2, len);
b55ae0a9 AH	353	return -1;
	354	}
	355	pr_debug("Bytes read match those read by objdump\n");
	356
	357	return 0;
	358	}
	359
	360	static int process_sample_event(struct machine *machine,
	361	struct perf_evlist *evlist,
7a77bc2c	362	union perf_event event, struct state state)
b55ae0a9 AH	363	{
	364	struct perf_sample sample;
	365	struct thread *thread;
b91fc39f	366	int ret;
b55ae0a9 AH	367
	368	if (perf_evlist__parse_sample(evlist, event, &sample)) {
	369	pr_debug("perf_evlist__parse_sample failed\n");
	370	return -1;
	371	}
	372
13ce34df	373	thread = machine__findnew_thread(machine, sample.pid, sample.tid);
b55ae0a9 AH	374	if (!thread) {
	375	pr_debug("machine__findnew_thread failed\n");
	376	return -1;
	377	}
	378
473398a2	379	ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
b91fc39f ACM	380	thread__put(thread);
b91fc39f ACM	381	return ret;
b55ae0a9 AH	382	}
	383
	384	static int process_event(struct machine machine, struct perf_evlist evlist,
7a77bc2c	385	union perf_event event, struct state state)
b55ae0a9 AH	386	{
b55ae0a9 AH	387	if (event->header.type == PERF_RECORD_SAMPLE)
7a77bc2c	388	return process_sample_event(machine, evlist, event, state);
b55ae0a9	389
48095b72 AH	390	if (event->header.type == PERF_RECORD_THROTTLE \|\|
	391	event->header.type == PERF_RECORD_UNTHROTTLE)
	392	return 0;
	393
	394	if (event->header.type < PERF_RECORD_MAX) {
	395	int ret;
	396
	397	ret = machine__process_event(machine, event, NULL);
	398	if (ret < 0)
	399	pr_debug("machine__process_event failed, event type %u\n",
	400	event->header.type);
	401	return ret;
	402	}
b55ae0a9 AH	403
	404	return 0;
	405	}
	406
7a77bc2c AH	407	static int process_events(struct machine machine, struct perf_evlist evlist,
7a77bc2c AH	408	struct state *state)
b55ae0a9 AH	409	{
	410	union perf_event *event;
	411	int i, ret;
	412
	413	for (i = 0; i < evlist->nr_mmaps; i++) {
	414	while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
7a77bc2c	415	ret = process_event(machine, evlist, event, state);
8e50d384	416	perf_evlist__mmap_consume(evlist, i);
b55ae0a9 AH	417	if (ret < 0)
	418	return ret;
	419	}
	420	}
	421	return 0;
	422	}
	423
	424	static int comp(const void a, const void b)
	425	{
	426	return (int )a - (int )b;
	427	}
	428
	429	static void do_sort_something(void)
	430	{
309b5185	431	int buf[40960], i;
b55ae0a9	432
309b5185 DA	433	for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
309b5185 DA	434	buf[i] = ARRAY_SIZE(buf) - i - 1;
b55ae0a9	435
309b5185	436	qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
b55ae0a9	437
309b5185	438	for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
b55ae0a9 AH	439	if (buf[i] != i) {
	440	pr_debug("qsort failed\n");
	441	break;
	442	}
	443	}
	444	}
	445
	446	static void sort_something(void)
	447	{
	448	int i;
	449
	450	for (i = 0; i < 10; i++)
	451	do_sort_something();
	452	}
	453
	454	static void syscall_something(void)
	455	{
	456	int pipefd[2];
	457	int i;
	458
	459	for (i = 0; i < 1000; i++) {
	460	if (pipe(pipefd) < 0) {
	461	pr_debug("pipe failed\n");
	462	break;
	463	}
	464	close(pipefd[1]);
	465	close(pipefd[0]);
	466	}
	467	}
	468
	469	static void fs_something(void)
	470	{
	471	const char *test_file_name = "temp-perf-code-reading-test-file--";
	472	FILE *f;
	473	int i;
	474
	475	for (i = 0; i < 1000; i++) {
	476	f = fopen(test_file_name, "w+");
	477	if (f) {
	478	fclose(f);
	479	unlink(test_file_name);
	480	}
	481	}
	482	}
	483
	484	static void do_something(void)
	485	{
	486	fs_something();
	487
	488	sort_something();
	489
	490	syscall_something();
	491	}
	492
	493	enum {
	494	TEST_CODE_READING_OK,
	495	TEST_CODE_READING_NO_VMLINUX,
7a77bc2c	496	TEST_CODE_READING_NO_KCORE,
b55ae0a9	497	TEST_CODE_READING_NO_ACCESS,
7a77bc2c	498	TEST_CODE_READING_NO_KERNEL_OBJ,
b55ae0a9 AH	499	};
b55ae0a9 AH	500
7a77bc2c	501	static int do_test_code_reading(bool try_kcore)
b55ae0a9	502	{
b55ae0a9 AH	503	struct machine *machine;
b55ae0a9 AH	504	struct thread *thread;
b4006796	505	struct record_opts opts = {
b55ae0a9 AH	506	.mmap_pages = UINT_MAX,
	507	.user_freq = UINT_MAX,
	508	.user_interval = ULLONG_MAX,
5243ba76	509	.freq = 500,
b55ae0a9 AH	510	.target = {
	511	.uses_mmap = true,
	512	},
	513	};
7a77bc2c AH	514	struct state state = {
	515	.done_cnt = 0,
	516	};
b55ae0a9 AH	517	struct thread_map *threads = NULL;
	518	struct cpu_map *cpus = NULL;
	519	struct perf_evlist *evlist = NULL;
	520	struct perf_evsel *evsel = NULL;
	521	int err = -1, ret;
	522	pid_t pid;
	523	struct map *map;
7a77bc2c	524	bool have_vmlinux, have_kcore, excl_kernel = false;
b55ae0a9 AH	525
	526	pid = getpid();
	527
0fd4008e	528	machine = machine__new_host();
b55ae0a9 AH	529
	530	ret = machine__create_kernel_maps(machine);
	531	if (ret < 0) {
	532	pr_debug("machine__create_kernel_maps failed\n");
	533	goto out_err;
	534	}
	535
7a77bc2c AH	536	/* Force the use of kallsyms instead of vmlinux to try kcore */
	537	if (try_kcore)
	538	symbol_conf.kallsyms_name = "/proc/kallsyms";
	539
b55ae0a9	540	/* Load kernel map */
a5e813c6	541	map = machine__kernel_map(machine);
be39db9f	542	ret = map__load(map);
b55ae0a9 AH	543	if (ret < 0) {
	544	pr_debug("map__load failed\n");
	545	goto out_err;
	546	}
7a77bc2c AH	547	have_vmlinux = dso__is_vmlinux(map->dso);
	548	have_kcore = dso__is_kcore(map->dso);
	549
	550	/* 2nd time through we just try kcore */
	551	if (try_kcore && !have_kcore)
	552	return TEST_CODE_READING_NO_KCORE;
	553
	554	/* No point getting kernel events if there is no kernel object */
	555	if (!have_vmlinux && !have_kcore)
b55ae0a9 AH	556	excl_kernel = true;
	557
	558	threads = thread_map__new_by_tid(pid);
	559	if (!threads) {
	560	pr_debug("thread_map__new_by_tid failed\n");
	561	goto out_err;
	562	}
	563
	564	ret = perf_event__synthesize_thread_map(NULL, threads,
9d9cad76	565	perf_event__process, machine, false, 500);
b55ae0a9 AH	566	if (ret < 0) {
	567	pr_debug("perf_event__synthesize_thread_map failed\n");
	568	goto out_err;
	569	}
	570
314add6b	571	thread = machine__findnew_thread(machine, pid, pid);
b55ae0a9 AH	572	if (!thread) {
b55ae0a9 AH	573	pr_debug("machine__findnew_thread failed\n");
b91fc39f	574	goto out_put;
b55ae0a9 AH	575	}
	576
	577	cpus = cpu_map__new(NULL);
	578	if (!cpus) {
	579	pr_debug("cpu_map__new failed\n");
b91fc39f	580	goto out_put;
b55ae0a9 AH	581	}
	582
	583	while (1) {
	584	const char *str;
	585
	586	evlist = perf_evlist__new();
	587	if (!evlist) {
	588	pr_debug("perf_evlist__new failed\n");
b91fc39f	589	goto out_put;
b55ae0a9 AH	590	}
	591
	592	perf_evlist__set_maps(evlist, cpus, threads);
	593
	594	if (excl_kernel)
	595	str = "cycles:u";
	596	else
	597	str = "cycles";
	598	pr_debug("Parsing event '%s'\n", str);
b39b8393	599	ret = parse_events(evlist, str, NULL);
b55ae0a9 AH	600	if (ret < 0) {
b55ae0a9 AH	601	pr_debug("parse_events failed\n");
b91fc39f	602	goto out_put;
b55ae0a9 AH	603	}
b55ae0a9 AH	604
e68ae9cf	605	perf_evlist__config(evlist, &opts, NULL);
b55ae0a9 AH	606
	607	evsel = perf_evlist__first(evlist);
	608
	609	evsel->attr.comm = 1;
	610	evsel->attr.disabled = 1;
	611	evsel->attr.enable_on_exec = 0;
	612
	613	ret = perf_evlist__open(evlist);
	614	if (ret < 0) {
	615	if (!excl_kernel) {
	616	excl_kernel = true;
7320b1b3 JO	617	/*
	618	* Both cpus and threads are now owned by evlist
	619	* and will be freed by following perf_evlist__set_maps
	620	* call. Getting refference to keep them alive.
	621	*/
	622	cpu_map__get(cpus);
	623	thread_map__get(threads);
ae450a7d	624	perf_evlist__set_maps(evlist, NULL, NULL);
b55ae0a9 AH	625	perf_evlist__delete(evlist);
	626	evlist = NULL;
	627	continue;
	628	}
6880bbf9	629
bb963e16	630	if (verbose > 0) {
6880bbf9 ACM	631	char errbuf[512];
	632	perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
	633	pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
	634	}
	635
b91fc39f	636	goto out_put;
b55ae0a9 AH	637	}
	638	break;
	639	}
	640
	641	ret = perf_evlist__mmap(evlist, UINT_MAX, false);
	642	if (ret < 0) {
	643	pr_debug("perf_evlist__mmap failed\n");
b91fc39f	644	goto out_put;
b55ae0a9 AH	645	}
	646
	647	perf_evlist__enable(evlist);
	648
	649	do_something();
	650
	651	perf_evlist__disable(evlist);
	652
7a77bc2c	653	ret = process_events(machine, evlist, &state);
b55ae0a9	654	if (ret < 0)
b91fc39f	655	goto out_put;
b55ae0a9	656
7a77bc2c AH	657	if (!have_vmlinux && !have_kcore && !try_kcore)
	658	err = TEST_CODE_READING_NO_KERNEL_OBJ;
	659	else if (!have_vmlinux && !try_kcore)
b55ae0a9 AH	660	err = TEST_CODE_READING_NO_VMLINUX;
	661	else if (excl_kernel)
	662	err = TEST_CODE_READING_NO_ACCESS;
	663	else
	664	err = TEST_CODE_READING_OK;
b91fc39f ACM	665	out_put:
b91fc39f ACM	666	thread__put(thread);
b55ae0a9	667	out_err:
b91fc39f	668
b55ae0a9	669	if (evlist) {
b55ae0a9	670	perf_evlist__delete(evlist);
03ad9747	671	} else {
f30a79b0	672	cpu_map__put(cpus);
186fbb74	673	thread_map__put(threads);
03ad9747	674	}
b55ae0a9	675	machine__delete_threads(machine);
0fd4008e	676	machine__delete(machine);
b55ae0a9 AH	677
	678	return err;
	679	}
	680
81f17c90	681	int test__code_reading(struct test *test __maybe_unused, int subtest __maybe_unused)
b55ae0a9 AH	682	{
	683	int ret;
	684
7a77bc2c AH	685	ret = do_test_code_reading(false);
	686	if (!ret)
	687	ret = do_test_code_reading(true);
b55ae0a9 AH	688
	689	switch (ret) {
	690	case TEST_CODE_READING_OK:
	691	return 0;
	692	case TEST_CODE_READING_NO_VMLINUX:
597bdeb4	693	pr_debug("no vmlinux\n");
b55ae0a9	694	return 0;
7a77bc2c	695	case TEST_CODE_READING_NO_KCORE:
597bdeb4	696	pr_debug("no kcore\n");
7a77bc2c	697	return 0;
b55ae0a9	698	case TEST_CODE_READING_NO_ACCESS:
597bdeb4	699	pr_debug("no access\n");
b55ae0a9	700	return 0;
7a77bc2c	701	case TEST_CODE_READING_NO_KERNEL_OBJ:
597bdeb4	702	pr_debug("no kernel obj\n");
7a77bc2c	703	return 0;
b55ae0a9 AH	704	default:
	705	return -1;
	706	};
	707	}