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

// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <inttypes.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <sys/param.h>

#include "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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
a43783ae	2	#include <errno.h>
877a7a11	3	#include <linux/kernel.h>
d944c4ee	4	#include <linux/types.h>
fd20e811	5	#include <inttypes.h>
b55ae0a9 AH	6	#include <stdlib.h>
	7	#include <unistd.h>
	8	#include <stdio.h>
b55ae0a9	9	#include <string.h>
391e4206	10	#include <sys/param.h>
b55ae0a9 AH	11
	12	#include "parse-events.h"
	13	#include "evlist.h"
	14	#include "evsel.h"
	15	#include "thread_map.h"
	16	#include "cpumap.h"
	17	#include "machine.h"
	18	#include "event.h"
	19	#include "thread.h"
	20
	21	#include "tests.h"
	22
3d689ed6 ACM	23	#include "sane_ctype.h"
3d689ed6 ACM	24
b55ae0a9 AH	25	#define BUFSZ 1024
	26	#define READLEN 128
	27
7a77bc2c AH	28	struct state {
	29	u64 done[1024];
	30	size_t done_cnt;
	31	};
	32
b55ae0a9 AH	33	static unsigned int hex(char c)
	34	{
	35	if (c >= '0' && c <= '9')
	36	return c - '0';
	37	if (c >= 'a' && c <= 'f')
	38	return c - 'a' + 10;
	39	return c - 'A' + 10;
	40	}
	41
b2d0dbf0 JS	42	static size_t read_objdump_chunk(const char line, unsigned char buf,
b2d0dbf0 JS	43	size_t *buf_len)
b55ae0a9	44	{
b2d0dbf0 JS	45	size_t bytes_read = 0;
b2d0dbf0 JS	46	unsigned char chunk_start = buf;
b55ae0a9 AH	47
b55ae0a9 AH	48	/* Read bytes */
b2d0dbf0	49	while (*buf_len > 0) {
b55ae0a9 AH	50	char c1, c2;
b55ae0a9 AH	51
b55ae0a9	52	/* Get 2 hex digits */
b2d0dbf0 JS	53	c1 = (line)++;
b2d0dbf0 JS	54	if (!isxdigit(c1))
b55ae0a9	55	break;
b2d0dbf0 JS	56	c2 = (line)++;
b2d0dbf0 JS	57	if (!isxdigit(c2))
b55ae0a9	58	break;
b2d0dbf0 JS	59
	60	/* Store byte and advance buf */
	61	**buf = (hex(c1) << 4) \| hex(c2);
	62	(*buf)++;
	63	(*buf_len)--;
	64	bytes_read++;
	65
	66	/* End of chunk? */
	67	if (isspace(**line))
b55ae0a9	68	break;
b55ae0a9	69	}
b2d0dbf0 JS	70
	71	/*
	72	* objdump will display raw insn as LE if code endian
	73	* is LE and bytes_per_chunk > 1. In that case reverse
	74	* the chunk we just read.
	75	*
	76	* see disassemble_bytes() at binutils/objdump.c for details
	77	* how objdump chooses display endian)
	78	*/
	79	if (bytes_read > 1 && !bigendian()) {
	80	unsigned char *chunk_end = chunk_start + bytes_read - 1;
	81	unsigned char tmp;
	82
	83	while (chunk_start < chunk_end) {
	84	tmp = *chunk_start;
	85	chunk_start = chunk_end;
	86	*chunk_end = tmp;
	87	chunk_start++;
	88	chunk_end--;
	89	}
	90	}
	91
	92	return bytes_read;
	93	}
	94
	95	static size_t read_objdump_line(const char line, unsigned char buf,
	96	size_t buf_len)
	97	{
	98	const char *p;
	99	size_t ret, bytes_read = 0;
	100
	101	/* Skip to a colon */
	102	p = strchr(line, ':');
	103	if (!p)
	104	return 0;
	105	p++;
	106
	107	/* Skip initial spaces */
	108	while (*p) {
	109	if (!isspace(*p))
	110	break;
	111	p++;
	112	}
	113
	114	do {
	115	ret = read_objdump_chunk(&p, &buf, &buf_len);
	116	bytes_read += ret;
	117	p++;
	118	} while (ret > 0);
	119
729a7ed1	120	/* return number of successfully read bytes */
b2d0dbf0	121	return bytes_read;
b55ae0a9 AH	122	}
b55ae0a9 AH	123
729a7ed1	124	static int read_objdump_output(FILE f, void buf, size_t *len, u64 start_addr)
b55ae0a9 AH	125	{
b55ae0a9 AH	126	char *line = NULL;
729a7ed1	127	size_t line_len, off_last = 0;
b55ae0a9 AH	128	ssize_t ret;
b55ae0a9 AH	129	int err = 0;
edfdb7ea	130	u64 addr, last_addr = start_addr;
729a7ed1 JS	131
	132	while (off_last < *len) {
	133	size_t off, read_bytes, written_bytes;
	134	unsigned char tmp[BUFSZ];
b55ae0a9	135
b55ae0a9 AH	136	ret = getline(&line, &line_len, f);
	137	if (feof(f))
	138	break;
	139	if (ret < 0) {
	140	pr_debug("getline failed\n");
	141	err = -1;
	142	break;
	143	}
729a7ed1 JS	144
729a7ed1 JS	145	/* read objdump data into temporary buffer */
b2d0dbf0	146	read_bytes = read_objdump_line(line, tmp, sizeof(tmp));
729a7ed1 JS	147	if (!read_bytes)
	148	continue;
	149
	150	if (sscanf(line, "%"PRIx64, &addr) != 1)
	151	continue;
edfdb7ea JS	152	if (addr < last_addr) {
	153	pr_debug("addr going backwards, read beyond section?\n");
	154	break;
	155	}
	156	last_addr = addr;
729a7ed1 JS	157
	158	/* copy it from temporary buffer to 'buf' according
	159	* to address on current objdump line */
	160	off = addr - start_addr;
	161	if (off >= *len)
	162	break;
	163	written_bytes = MIN(read_bytes, *len - off);
	164	memcpy(buf + off, tmp, written_bytes);
	165	off_last = off + written_bytes;
b55ae0a9 AH	166	}
b55ae0a9 AH	167
729a7ed1 JS	168	/* len returns number of bytes that could not be read */
	169	*len -= off_last;
	170
b55ae0a9 AH	171	free(line);
	172
	173	return err;
	174	}
	175
	176	static int read_via_objdump(const char filename, u64 addr, void buf,
	177	size_t len)
	178	{
	179	char cmd[PATH_MAX * 2];
	180	const char *fmt;
	181	FILE *f;
	182	int ret;
	183
06f679c1	184	fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
b55ae0a9 AH	185	ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
	186	filename);
	187	if (ret <= 0 \|\| (size_t)ret >= sizeof(cmd))
	188	return -1;
	189
	190	pr_debug("Objdump command is: %s\n", cmd);
	191
7a77bc2c AH	192	/* Ignore objdump errors */
	193	strcat(cmd, " 2>/dev/null");
	194
b55ae0a9 AH	195	f = popen(cmd, "r");
	196	if (!f) {
	197	pr_debug("popen failed\n");
	198	return -1;
	199	}
	200
729a7ed1	201	ret = read_objdump_output(f, buf, &len, addr);
b55ae0a9	202	if (len) {
b2d0dbf0	203	pr_debug("objdump read too few bytes: %zd\n", len);
b55ae0a9 AH	204	if (!ret)
	205	ret = len;
	206	}
	207
	208	pclose(f);
	209
	210	return ret;
	211	}
	212
fd405cf6 JS	213	static void dump_buf(unsigned char *buf, size_t len)
	214	{
	215	size_t i;
	216
	217	for (i = 0; i < len; i++) {
	218	pr_debug("0x%02x ", buf[i]);
	219	if (i % 16 == 15)
	220	pr_debug("\n");
	221	}
	222	pr_debug("\n");
	223	}
	224
b55ae0a9	225	static int read_object_code(u64 addr, size_t len, u8 cpumode,
29f9e521	226	struct thread thread, struct state state)
b55ae0a9 AH	227	{
	228	struct addr_location al;
	229	unsigned char buf1[BUFSZ];
	230	unsigned char buf2[BUFSZ];
	231	size_t ret_len;
	232	u64 objdump_addr;
94df1040 NK	233	const char *objdump_name;
94df1040 NK	234	char decomp_name[KMOD_DECOMP_LEN];
b55ae0a9 AH	235	int ret;
	236
	237	pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
	238
bb871a9c	239	thread__find_addr_map(thread, cpumode, MAP__FUNCTION, addr, &al);
b55ae0a9	240	if (!al.map \|\| !al.map->dso) {
9a805d86 RB	241	if (cpumode == PERF_RECORD_MISC_HYPERVISOR) {
	242	pr_debug("Hypervisor address can not be resolved - skipping\n");
	243	return 0;
	244	}
	245
b55ae0a9 AH	246	pr_debug("thread__find_addr_map failed\n");
	247	return -1;
	248	}
	249
	250	pr_debug("File is: %s\n", al.map->dso->long_name);
	251
7a77bc2c AH	252	if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
7a77bc2c AH	253	!dso__is_kcore(al.map->dso)) {
b55ae0a9 AH	254	pr_debug("Unexpected kernel address - skipping\n");
	255	return 0;
	256	}
	257
	258	pr_debug("On file address is: %#"PRIx64"\n", al.addr);
	259
	260	if (len > BUFSZ)
	261	len = BUFSZ;
	262
	263	/* Do not go off the map */
	264	if (addr + len > al.map->end)
	265	len = al.map->end - addr;
	266
	267	/* Read the object code using perf */
29f9e521 ACM	268	ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
29f9e521 ACM	269	al.addr, buf1, len);
b55ae0a9 AH	270	if (ret_len != len) {
	271	pr_debug("dso__data_read_offset failed\n");
	272	return -1;
	273	}
	274
	275	/*
	276	* Converting addresses for use by objdump requires more information.
	277	* map__load() does that. See map__rip_2objdump() for details.
	278	*/
be39db9f	279	if (map__load(al.map))
b55ae0a9 AH	280	return -1;
b55ae0a9 AH	281
7a77bc2c AH	282	/* objdump struggles with kcore - try each map only once */
	283	if (dso__is_kcore(al.map->dso)) {
	284	size_t d;
	285
	286	for (d = 0; d < state->done_cnt; d++) {
	287	if (state->done[d] == al.map->start) {
	288	pr_debug("kcore map tested already");
	289	pr_debug(" - skipping\n");
	290	return 0;
	291	}
	292	}
	293	if (state->done_cnt >= ARRAY_SIZE(state->done)) {
	294	pr_debug("Too many kcore maps - skipping\n");
	295	return 0;
	296	}
	297	state->done[state->done_cnt++] = al.map->start;
	298	}
	299
94df1040 NK	300	objdump_name = al.map->dso->long_name;
	301	if (dso__needs_decompress(al.map->dso)) {
	302	if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
	303	decomp_name,
	304	sizeof(decomp_name)) < 0) {
	305	pr_debug("decompression failed\n");
	306	return -1;
	307	}
	308
	309	objdump_name = decomp_name;
	310	}
	311
b55ae0a9 AH	312	/* Read the object code using objdump */
b55ae0a9 AH	313	objdump_addr = map__rip_2objdump(al.map, al.addr);
94df1040 NK	314	ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
	315
	316	if (dso__needs_decompress(al.map->dso))
	317	unlink(objdump_name);
	318
b55ae0a9 AH	319	if (ret > 0) {
	320	/*
	321	* The kernel maps are inaccurate - assume objdump is right in
	322	* that case.
	323	*/
	324	if (cpumode == PERF_RECORD_MISC_KERNEL \|\|
	325	cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
	326	len -= ret;
7a77bc2c	327	if (len) {
b55ae0a9	328	pr_debug("Reducing len to %zu\n", len);
7a77bc2c AH	329	} else if (dso__is_kcore(al.map->dso)) {
	330	/*
	331	* objdump cannot handle very large segments
	332	* that may be found in kcore.
	333	*/
	334	pr_debug("objdump failed for kcore");
	335	pr_debug(" - skipping\n");
	336	return 0;
	337	} else {
b55ae0a9	338	return -1;
7a77bc2c	339	}
b55ae0a9 AH	340	}
	341	}
	342	if (ret < 0) {
	343	pr_debug("read_via_objdump failed\n");
	344	return -1;
	345	}
	346
	347	/* The results should be identical */
	348	if (memcmp(buf1, buf2, len)) {
	349	pr_debug("Bytes read differ from those read by objdump\n");
fd405cf6 JS	350	pr_debug("buf1 (dso):\n");
	351	dump_buf(buf1, len);
	352	pr_debug("buf2 (objdump):\n");
	353	dump_buf(buf2, len);
b55ae0a9 AH	354	return -1;
	355	}
	356	pr_debug("Bytes read match those read by objdump\n");
	357
	358	return 0;
	359	}
	360
	361	static int process_sample_event(struct machine *machine,
	362	struct perf_evlist *evlist,
7a77bc2c	363	union perf_event event, struct state state)
b55ae0a9 AH	364	{
	365	struct perf_sample sample;
	366	struct thread *thread;
b91fc39f	367	int ret;
b55ae0a9 AH	368
	369	if (perf_evlist__parse_sample(evlist, event, &sample)) {
	370	pr_debug("perf_evlist__parse_sample failed\n");
	371	return -1;
	372	}
	373
13ce34df	374	thread = machine__findnew_thread(machine, sample.pid, sample.tid);
b55ae0a9 AH	375	if (!thread) {
	376	pr_debug("machine__findnew_thread failed\n");
	377	return -1;
	378	}
	379
473398a2	380	ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
b91fc39f ACM	381	thread__put(thread);
b91fc39f ACM	382	return ret;
b55ae0a9 AH	383	}
	384
	385	static int process_event(struct machine machine, struct perf_evlist evlist,
7a77bc2c	386	union perf_event event, struct state state)
b55ae0a9 AH	387	{
b55ae0a9 AH	388	if (event->header.type == PERF_RECORD_SAMPLE)
7a77bc2c	389	return process_sample_event(machine, evlist, event, state);
b55ae0a9	390
48095b72 AH	391	if (event->header.type == PERF_RECORD_THROTTLE \|\|
	392	event->header.type == PERF_RECORD_UNTHROTTLE)
	393	return 0;
	394
	395	if (event->header.type < PERF_RECORD_MAX) {
	396	int ret;
	397
	398	ret = machine__process_event(machine, event, NULL);
	399	if (ret < 0)
	400	pr_debug("machine__process_event failed, event type %u\n",
	401	event->header.type);
	402	return ret;
	403	}
b55ae0a9 AH	404
	405	return 0;
	406	}
	407
7a77bc2c AH	408	static int process_events(struct machine machine, struct perf_evlist evlist,
7a77bc2c AH	409	struct state *state)
b55ae0a9 AH	410	{
	411	union perf_event *event;
	412	int i, ret;
	413
	414	for (i = 0; i < evlist->nr_mmaps; i++) {
	415	while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
7a77bc2c	416	ret = process_event(machine, evlist, event, state);
8e50d384	417	perf_evlist__mmap_consume(evlist, i);
b55ae0a9 AH	418	if (ret < 0)
	419	return ret;
	420	}
	421	}
	422	return 0;
	423	}
	424
	425	static int comp(const void a, const void b)
	426	{
	427	return (int )a - (int )b;
	428	}
	429
	430	static void do_sort_something(void)
	431	{
309b5185	432	int buf[40960], i;
b55ae0a9	433
309b5185 DA	434	for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
309b5185 DA	435	buf[i] = ARRAY_SIZE(buf) - i - 1;
b55ae0a9	436
309b5185	437	qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
b55ae0a9	438
309b5185	439	for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
b55ae0a9 AH	440	if (buf[i] != i) {
	441	pr_debug("qsort failed\n");
	442	break;
	443	}
	444	}
	445	}
	446
	447	static void sort_something(void)
	448	{
	449	int i;
	450
	451	for (i = 0; i < 10; i++)
	452	do_sort_something();
	453	}
	454
	455	static void syscall_something(void)
	456	{
	457	int pipefd[2];
	458	int i;
	459
	460	for (i = 0; i < 1000; i++) {
	461	if (pipe(pipefd) < 0) {
	462	pr_debug("pipe failed\n");
	463	break;
	464	}
	465	close(pipefd[1]);
	466	close(pipefd[0]);
	467	}
	468	}
	469
	470	static void fs_something(void)
	471	{
	472	const char *test_file_name = "temp-perf-code-reading-test-file--";
	473	FILE *f;
	474	int i;
	475
	476	for (i = 0; i < 1000; i++) {
	477	f = fopen(test_file_name, "w+");
	478	if (f) {
	479	fclose(f);
	480	unlink(test_file_name);
	481	}
	482	}
	483	}
	484
	485	static void do_something(void)
	486	{
	487	fs_something();
	488
	489	sort_something();
	490
	491	syscall_something();
	492	}
	493
	494	enum {
	495	TEST_CODE_READING_OK,
	496	TEST_CODE_READING_NO_VMLINUX,
7a77bc2c	497	TEST_CODE_READING_NO_KCORE,
b55ae0a9	498	TEST_CODE_READING_NO_ACCESS,
7a77bc2c	499	TEST_CODE_READING_NO_KERNEL_OBJ,
b55ae0a9 AH	500	};
b55ae0a9 AH	501
7a77bc2c	502	static int do_test_code_reading(bool try_kcore)
b55ae0a9	503	{
b55ae0a9 AH	504	struct machine *machine;
b55ae0a9 AH	505	struct thread *thread;
b4006796	506	struct record_opts opts = {
b55ae0a9 AH	507	.mmap_pages = UINT_MAX,
	508	.user_freq = UINT_MAX,
	509	.user_interval = ULLONG_MAX,
5243ba76	510	.freq = 500,
b55ae0a9 AH	511	.target = {
	512	.uses_mmap = true,
	513	},
	514	};
7a77bc2c AH	515	struct state state = {
	516	.done_cnt = 0,
	517	};
b55ae0a9 AH	518	struct thread_map *threads = NULL;
	519	struct cpu_map *cpus = NULL;
	520	struct perf_evlist *evlist = NULL;
	521	struct perf_evsel *evsel = NULL;
	522	int err = -1, ret;
	523	pid_t pid;
	524	struct map *map;
7a77bc2c	525	bool have_vmlinux, have_kcore, excl_kernel = false;
b55ae0a9 AH	526
	527	pid = getpid();
	528
0fd4008e	529	machine = machine__new_host();
b55ae0a9 AH	530
	531	ret = machine__create_kernel_maps(machine);
	532	if (ret < 0) {
	533	pr_debug("machine__create_kernel_maps failed\n");
	534	goto out_err;
	535	}
	536
7a77bc2c AH	537	/* Force the use of kallsyms instead of vmlinux to try kcore */
	538	if (try_kcore)
	539	symbol_conf.kallsyms_name = "/proc/kallsyms";
	540
b55ae0a9	541	/* Load kernel map */
a5e813c6	542	map = machine__kernel_map(machine);
be39db9f	543	ret = map__load(map);
b55ae0a9 AH	544	if (ret < 0) {
	545	pr_debug("map__load failed\n");
	546	goto out_err;
	547	}
7a77bc2c AH	548	have_vmlinux = dso__is_vmlinux(map->dso);
	549	have_kcore = dso__is_kcore(map->dso);
	550
	551	/* 2nd time through we just try kcore */
	552	if (try_kcore && !have_kcore)
	553	return TEST_CODE_READING_NO_KCORE;
	554
	555	/* No point getting kernel events if there is no kernel object */
	556	if (!have_vmlinux && !have_kcore)
b55ae0a9 AH	557	excl_kernel = true;
	558
	559	threads = thread_map__new_by_tid(pid);
	560	if (!threads) {
	561	pr_debug("thread_map__new_by_tid failed\n");
	562	goto out_err;
	563	}
	564
	565	ret = perf_event__synthesize_thread_map(NULL, threads,
9d9cad76	566	perf_event__process, machine, false, 500);
b55ae0a9 AH	567	if (ret < 0) {
	568	pr_debug("perf_event__synthesize_thread_map failed\n");
	569	goto out_err;
	570	}
	571
314add6b	572	thread = machine__findnew_thread(machine, pid, pid);
b55ae0a9 AH	573	if (!thread) {
b55ae0a9 AH	574	pr_debug("machine__findnew_thread failed\n");
b91fc39f	575	goto out_put;
b55ae0a9 AH	576	}
	577
	578	cpus = cpu_map__new(NULL);
	579	if (!cpus) {
	580	pr_debug("cpu_map__new failed\n");
b91fc39f	581	goto out_put;
b55ae0a9 AH	582	}
	583
	584	while (1) {
	585	const char *str;
	586
	587	evlist = perf_evlist__new();
	588	if (!evlist) {
	589	pr_debug("perf_evlist__new failed\n");
b91fc39f	590	goto out_put;
b55ae0a9 AH	591	}
	592
	593	perf_evlist__set_maps(evlist, cpus, threads);
	594
	595	if (excl_kernel)
	596	str = "cycles:u";
	597	else
	598	str = "cycles";
	599	pr_debug("Parsing event '%s'\n", str);
b39b8393	600	ret = parse_events(evlist, str, NULL);
b55ae0a9 AH	601	if (ret < 0) {
b55ae0a9 AH	602	pr_debug("parse_events failed\n");
b91fc39f	603	goto out_put;
b55ae0a9 AH	604	}
b55ae0a9 AH	605
e68ae9cf	606	perf_evlist__config(evlist, &opts, NULL);
b55ae0a9 AH	607
	608	evsel = perf_evlist__first(evlist);
	609
	610	evsel->attr.comm = 1;
	611	evsel->attr.disabled = 1;
	612	evsel->attr.enable_on_exec = 0;
	613
	614	ret = perf_evlist__open(evlist);
	615	if (ret < 0) {
	616	if (!excl_kernel) {
	617	excl_kernel = true;
7320b1b3 JO	618	/*
	619	* Both cpus and threads are now owned by evlist
	620	* and will be freed by following perf_evlist__set_maps
	621	* call. Getting refference to keep them alive.
	622	*/
	623	cpu_map__get(cpus);
	624	thread_map__get(threads);
ae450a7d	625	perf_evlist__set_maps(evlist, NULL, NULL);
b55ae0a9 AH	626	perf_evlist__delete(evlist);
	627	evlist = NULL;
	628	continue;
	629	}
6880bbf9	630
bb963e16	631	if (verbose > 0) {
6880bbf9 ACM	632	char errbuf[512];
	633	perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
	634	pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
	635	}
	636
b91fc39f	637	goto out_put;
b55ae0a9 AH	638	}
	639	break;
	640	}
	641
	642	ret = perf_evlist__mmap(evlist, UINT_MAX, false);
	643	if (ret < 0) {
	644	pr_debug("perf_evlist__mmap failed\n");
b91fc39f	645	goto out_put;
b55ae0a9 AH	646	}
	647
	648	perf_evlist__enable(evlist);
	649
	650	do_something();
	651
	652	perf_evlist__disable(evlist);
	653
7a77bc2c	654	ret = process_events(machine, evlist, &state);
b55ae0a9	655	if (ret < 0)
b91fc39f	656	goto out_put;
b55ae0a9	657
7a77bc2c AH	658	if (!have_vmlinux && !have_kcore && !try_kcore)
	659	err = TEST_CODE_READING_NO_KERNEL_OBJ;
	660	else if (!have_vmlinux && !try_kcore)
b55ae0a9 AH	661	err = TEST_CODE_READING_NO_VMLINUX;
	662	else if (excl_kernel)
	663	err = TEST_CODE_READING_NO_ACCESS;
	664	else
	665	err = TEST_CODE_READING_OK;
b91fc39f ACM	666	out_put:
b91fc39f ACM	667	thread__put(thread);
b55ae0a9	668	out_err:
b91fc39f	669
b55ae0a9	670	if (evlist) {
b55ae0a9	671	perf_evlist__delete(evlist);
03ad9747	672	} else {
f30a79b0	673	cpu_map__put(cpus);
186fbb74	674	thread_map__put(threads);
03ad9747	675	}
b55ae0a9	676	machine__delete_threads(machine);
0fd4008e	677	machine__delete(machine);
b55ae0a9 AH	678
	679	return err;
	680	}
	681
81f17c90	682	int test__code_reading(struct test *test __maybe_unused, int subtest __maybe_unused)
b55ae0a9 AH	683	{
	684	int ret;
	685
7a77bc2c AH	686	ret = do_test_code_reading(false);
	687	if (!ret)
	688	ret = do_test_code_reading(true);
b55ae0a9 AH	689
	690	switch (ret) {
	691	case TEST_CODE_READING_OK:
	692	return 0;
	693	case TEST_CODE_READING_NO_VMLINUX:
597bdeb4	694	pr_debug("no vmlinux\n");
b55ae0a9	695	return 0;
7a77bc2c	696	case TEST_CODE_READING_NO_KCORE:
597bdeb4	697	pr_debug("no kcore\n");
7a77bc2c	698	return 0;
b55ae0a9	699	case TEST_CODE_READING_NO_ACCESS:
597bdeb4	700	pr_debug("no access\n");
b55ae0a9	701	return 0;
7a77bc2c	702	case TEST_CODE_READING_NO_KERNEL_OBJ:
597bdeb4	703	pr_debug("no kernel obj\n");
7a77bc2c	704	return 0;
b55ae0a9 AH	705	default:
	706	return -1;
	707	};
	708	}