[linux-block.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 "map.h"
#include "symbol.h"
#include "event.h"
#include "thread.h"

#include "tests.h"

#include <linux/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];
	bool decomp = false;
	int ret;

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

	if (!thread__find_map(thread, cpumode, addr, &al) || !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_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;
		}

		decomp = true;
		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 (decomp)
		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;
	struct perf_mmap *md;
	int i, ret;

	for (i = 0; i < evlist->nr_mmaps; i++) {
		md = &evlist->mmap[i];
		if (perf_mmap__read_init(md) < 0)
			continue;

		while ((event = perf_mmap__read_event(md)) != NULL) {
			ret = process_event(machine, evlist, event, state);
			perf_mmap__consume(md);
			if (ret < 0)
				return ret;
		}
		perf_mmap__read_done(md);
	}
	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 const char *do_determine_event(bool excl_kernel)
{
	const char *event = excl_kernel ? "cycles:u" : "cycles";

#ifdef __s390x__
	char cpuid[128], model[16], model_c[16], cpum_cf_v[16];
	unsigned int family;
	int ret, cpum_cf_a;

	if (get_cpuid(cpuid, sizeof(cpuid)))
		goto out_clocks;
	ret = sscanf(cpuid, "%*[^,],%u,%[^,],%[^,],%[^,],%x", &family, model_c,
		     model, cpum_cf_v, &cpum_cf_a);
	if (ret != 5)		 /* Not available */
		goto out_clocks;
	if (excl_kernel && (cpum_cf_a & 4))
		return event;
	if (!excl_kernel && (cpum_cf_a & 2))
		return event;

	/* Fall through: missing authorization */
out_clocks:
	event = excl_kernel ? "cpu-clock:u" : "cpu-clock";

#endif
	return event;
}

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 perf_thread_map *threads = NULL;
	struct perf_cpu_map *cpus = NULL;
	struct perf_evlist *evlist = NULL;
	struct 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();
	machine->env = &perf_env;

	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);
	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);

		str = do_determine_event(excl_kernel);
		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);
	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"
1101f69a	18	#include "map.h"
daecf9e0	19	#include "symbol.h"
b55ae0a9 AH	20	#include "event.h"
	21	#include "thread.h"
	22
	23	#include "tests.h"
	24
3052ba56	25	#include <linux/ctype.h>
3d689ed6	26
b55ae0a9 AH	27	#define BUFSZ 1024
	28	#define READLEN 128
	29
7a77bc2c AH	30	struct state {
	31	u64 done[1024];
	32	size_t done_cnt;
	33	};
	34
b55ae0a9 AH	35	static unsigned int hex(char c)
	36	{
	37	if (c >= '0' && c <= '9')
	38	return c - '0';
	39	if (c >= 'a' && c <= 'f')
	40	return c - 'a' + 10;
	41	return c - 'A' + 10;
	42	}
	43
b2d0dbf0 JS	44	static size_t read_objdump_chunk(const char line, unsigned char buf,
b2d0dbf0 JS	45	size_t *buf_len)
b55ae0a9	46	{
b2d0dbf0 JS	47	size_t bytes_read = 0;
b2d0dbf0 JS	48	unsigned char chunk_start = buf;
b55ae0a9 AH	49
b55ae0a9 AH	50	/* Read bytes */
b2d0dbf0	51	while (*buf_len > 0) {
b55ae0a9 AH	52	char c1, c2;
b55ae0a9 AH	53
b55ae0a9	54	/* Get 2 hex digits */
b2d0dbf0 JS	55	c1 = (line)++;
b2d0dbf0 JS	56	if (!isxdigit(c1))
b55ae0a9	57	break;
b2d0dbf0 JS	58	c2 = (line)++;
b2d0dbf0 JS	59	if (!isxdigit(c2))
b55ae0a9	60	break;
b2d0dbf0 JS	61
	62	/* Store byte and advance buf */
	63	**buf = (hex(c1) << 4) \| hex(c2);
	64	(*buf)++;
	65	(*buf_len)--;
	66	bytes_read++;
	67
	68	/* End of chunk? */
	69	if (isspace(**line))
b55ae0a9	70	break;
b55ae0a9	71	}
b2d0dbf0 JS	72
	73	/*
	74	* objdump will display raw insn as LE if code endian
	75	* is LE and bytes_per_chunk > 1. In that case reverse
	76	* the chunk we just read.
	77	*
	78	* see disassemble_bytes() at binutils/objdump.c for details
	79	* how objdump chooses display endian)
	80	*/
	81	if (bytes_read > 1 && !bigendian()) {
	82	unsigned char *chunk_end = chunk_start + bytes_read - 1;
	83	unsigned char tmp;
	84
	85	while (chunk_start < chunk_end) {
	86	tmp = *chunk_start;
	87	chunk_start = chunk_end;
	88	*chunk_end = tmp;
	89	chunk_start++;
	90	chunk_end--;
	91	}
	92	}
	93
	94	return bytes_read;
	95	}
	96
	97	static size_t read_objdump_line(const char line, unsigned char buf,
	98	size_t buf_len)
	99	{
	100	const char *p;
	101	size_t ret, bytes_read = 0;
	102
	103	/* Skip to a colon */
	104	p = strchr(line, ':');
	105	if (!p)
	106	return 0;
	107	p++;
	108
	109	/* Skip initial spaces */
	110	while (*p) {
	111	if (!isspace(*p))
	112	break;
	113	p++;
	114	}
	115
	116	do {
	117	ret = read_objdump_chunk(&p, &buf, &buf_len);
	118	bytes_read += ret;
	119	p++;
	120	} while (ret > 0);
	121
729a7ed1	122	/* return number of successfully read bytes */
b2d0dbf0	123	return bytes_read;
b55ae0a9 AH	124	}
b55ae0a9 AH	125
729a7ed1	126	static int read_objdump_output(FILE f, void buf, size_t *len, u64 start_addr)
b55ae0a9 AH	127	{
b55ae0a9 AH	128	char *line = NULL;
729a7ed1	129	size_t line_len, off_last = 0;
b55ae0a9 AH	130	ssize_t ret;
b55ae0a9 AH	131	int err = 0;
edfdb7ea	132	u64 addr, last_addr = start_addr;
729a7ed1 JS	133
	134	while (off_last < *len) {
	135	size_t off, read_bytes, written_bytes;
	136	unsigned char tmp[BUFSZ];
b55ae0a9	137
b55ae0a9 AH	138	ret = getline(&line, &line_len, f);
	139	if (feof(f))
	140	break;
	141	if (ret < 0) {
	142	pr_debug("getline failed\n");
	143	err = -1;
	144	break;
	145	}
729a7ed1 JS	146
729a7ed1 JS	147	/* read objdump data into temporary buffer */
b2d0dbf0	148	read_bytes = read_objdump_line(line, tmp, sizeof(tmp));
729a7ed1 JS	149	if (!read_bytes)
	150	continue;
	151
	152	if (sscanf(line, "%"PRIx64, &addr) != 1)
	153	continue;
edfdb7ea JS	154	if (addr < last_addr) {
	155	pr_debug("addr going backwards, read beyond section?\n");
	156	break;
	157	}
	158	last_addr = addr;
729a7ed1 JS	159
	160	/* copy it from temporary buffer to 'buf' according
	161	* to address on current objdump line */
	162	off = addr - start_addr;
	163	if (off >= *len)
	164	break;
	165	written_bytes = MIN(read_bytes, *len - off);
	166	memcpy(buf + off, tmp, written_bytes);
	167	off_last = off + written_bytes;
b55ae0a9 AH	168	}
b55ae0a9 AH	169
729a7ed1 JS	170	/* len returns number of bytes that could not be read */
	171	*len -= off_last;
	172
b55ae0a9 AH	173	free(line);
	174
	175	return err;
	176	}
	177
	178	static int read_via_objdump(const char filename, u64 addr, void buf,
	179	size_t len)
	180	{
	181	char cmd[PATH_MAX * 2];
	182	const char *fmt;
	183	FILE *f;
	184	int ret;
	185
06f679c1	186	fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
b55ae0a9 AH	187	ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
	188	filename);
	189	if (ret <= 0 \|\| (size_t)ret >= sizeof(cmd))
	190	return -1;
	191
	192	pr_debug("Objdump command is: %s\n", cmd);
	193
7a77bc2c AH	194	/* Ignore objdump errors */
	195	strcat(cmd, " 2>/dev/null");
	196
b55ae0a9 AH	197	f = popen(cmd, "r");
	198	if (!f) {
	199	pr_debug("popen failed\n");
	200	return -1;
	201	}
	202
729a7ed1	203	ret = read_objdump_output(f, buf, &len, addr);
b55ae0a9	204	if (len) {
b2d0dbf0	205	pr_debug("objdump read too few bytes: %zd\n", len);
b55ae0a9 AH	206	if (!ret)
	207	ret = len;
	208	}
	209
	210	pclose(f);
	211
	212	return ret;
	213	}
	214
fd405cf6 JS	215	static void dump_buf(unsigned char *buf, size_t len)
	216	{
	217	size_t i;
	218
	219	for (i = 0; i < len; i++) {
	220	pr_debug("0x%02x ", buf[i]);
	221	if (i % 16 == 15)
	222	pr_debug("\n");
	223	}
	224	pr_debug("\n");
	225	}
	226
b55ae0a9	227	static int read_object_code(u64 addr, size_t len, u8 cpumode,
29f9e521	228	struct thread thread, struct state state)
b55ae0a9 AH	229	{
	230	struct addr_location al;
	231	unsigned char buf1[BUFSZ];
	232	unsigned char buf2[BUFSZ];
	233	size_t ret_len;
	234	u64 objdump_addr;
94df1040 NK	235	const char *objdump_name;
94df1040 NK	236	char decomp_name[KMOD_DECOMP_LEN];
bcd4287e	237	bool decomp = false;
b55ae0a9 AH	238	int ret;
	239
	240	pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
	241
71a84b5a	242	if (!thread__find_map(thread, cpumode, addr, &al) \|\| !al.map->dso) {
9a805d86 RB	243	if (cpumode == PERF_RECORD_MISC_HYPERVISOR) {
	244	pr_debug("Hypervisor address can not be resolved - skipping\n");
	245	return 0;
	246	}
	247
f07a2d32	248	pr_debug("thread__find_map failed\n");
b55ae0a9 AH	249	return -1;
	250	}
	251
	252	pr_debug("File is: %s\n", al.map->dso->long_name);
	253
7a77bc2c AH	254	if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
7a77bc2c AH	255	!dso__is_kcore(al.map->dso)) {
b55ae0a9 AH	256	pr_debug("Unexpected kernel address - skipping\n");
	257	return 0;
	258	}
	259
	260	pr_debug("On file address is: %#"PRIx64"\n", al.addr);
	261
	262	if (len > BUFSZ)
	263	len = BUFSZ;
	264
	265	/* Do not go off the map */
	266	if (addr + len > al.map->end)
	267	len = al.map->end - addr;
	268
	269	/* Read the object code using perf */
29f9e521 ACM	270	ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
29f9e521 ACM	271	al.addr, buf1, len);
b55ae0a9 AH	272	if (ret_len != len) {
	273	pr_debug("dso__data_read_offset failed\n");
	274	return -1;
	275	}
	276
	277	/*
	278	* Converting addresses for use by objdump requires more information.
	279	* map__load() does that. See map__rip_2objdump() for details.
	280	*/
be39db9f	281	if (map__load(al.map))
b55ae0a9 AH	282	return -1;
b55ae0a9 AH	283
7a77bc2c AH	284	/* objdump struggles with kcore - try each map only once */
	285	if (dso__is_kcore(al.map->dso)) {
	286	size_t d;
	287
	288	for (d = 0; d < state->done_cnt; d++) {
	289	if (state->done[d] == al.map->start) {
	290	pr_debug("kcore map tested already");
	291	pr_debug(" - skipping\n");
	292	return 0;
	293	}
	294	}
	295	if (state->done_cnt >= ARRAY_SIZE(state->done)) {
	296	pr_debug("Too many kcore maps - skipping\n");
	297	return 0;
	298	}
	299	state->done[state->done_cnt++] = al.map->start;
	300	}
	301
94df1040 NK	302	objdump_name = al.map->dso->long_name;
	303	if (dso__needs_decompress(al.map->dso)) {
	304	if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
	305	decomp_name,
	306	sizeof(decomp_name)) < 0) {
	307	pr_debug("decompression failed\n");
	308	return -1;
	309	}
	310
bcd4287e	311	decomp = true;
94df1040 NK	312	objdump_name = decomp_name;
	313	}
	314
b55ae0a9 AH	315	/* Read the object code using objdump */
b55ae0a9 AH	316	objdump_addr = map__rip_2objdump(al.map, al.addr);
94df1040 NK	317	ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
94df1040 NK	318
bcd4287e	319	if (decomp)
94df1040 NK	320	unlink(objdump_name);
94df1040 NK	321
b55ae0a9 AH	322	if (ret > 0) {
	323	/*
	324	* The kernel maps are inaccurate - assume objdump is right in
	325	* that case.
	326	*/
	327	if (cpumode == PERF_RECORD_MISC_KERNEL \|\|
	328	cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
	329	len -= ret;
7a77bc2c	330	if (len) {
b55ae0a9	331	pr_debug("Reducing len to %zu\n", len);
7a77bc2c AH	332	} else if (dso__is_kcore(al.map->dso)) {
	333	/*
	334	* objdump cannot handle very large segments
	335	* that may be found in kcore.
	336	*/
	337	pr_debug("objdump failed for kcore");
	338	pr_debug(" - skipping\n");
	339	return 0;
	340	} else {
b55ae0a9	341	return -1;
7a77bc2c	342	}
b55ae0a9 AH	343	}
	344	}
	345	if (ret < 0) {
	346	pr_debug("read_via_objdump failed\n");
	347	return -1;
	348	}
	349
	350	/* The results should be identical */
	351	if (memcmp(buf1, buf2, len)) {
	352	pr_debug("Bytes read differ from those read by objdump\n");
fd405cf6 JS	353	pr_debug("buf1 (dso):\n");
	354	dump_buf(buf1, len);
	355	pr_debug("buf2 (objdump):\n");
	356	dump_buf(buf2, len);
b55ae0a9 AH	357	return -1;
	358	}
	359	pr_debug("Bytes read match those read by objdump\n");
	360
	361	return 0;
	362	}
	363
	364	static int process_sample_event(struct machine *machine,
	365	struct perf_evlist *evlist,
7a77bc2c	366	union perf_event event, struct state state)
b55ae0a9 AH	367	{
	368	struct perf_sample sample;
	369	struct thread *thread;
b91fc39f	370	int ret;
b55ae0a9 AH	371
	372	if (perf_evlist__parse_sample(evlist, event, &sample)) {
	373	pr_debug("perf_evlist__parse_sample failed\n");
	374	return -1;
	375	}
	376
13ce34df	377	thread = machine__findnew_thread(machine, sample.pid, sample.tid);
b55ae0a9 AH	378	if (!thread) {
	379	pr_debug("machine__findnew_thread failed\n");
	380	return -1;
	381	}
	382
473398a2	383	ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
b91fc39f ACM	384	thread__put(thread);
b91fc39f ACM	385	return ret;
b55ae0a9 AH	386	}
	387
	388	static int process_event(struct machine machine, struct perf_evlist evlist,
7a77bc2c	389	union perf_event event, struct state state)
b55ae0a9 AH	390	{
b55ae0a9 AH	391	if (event->header.type == PERF_RECORD_SAMPLE)
7a77bc2c	392	return process_sample_event(machine, evlist, event, state);
b55ae0a9	393
48095b72 AH	394	if (event->header.type == PERF_RECORD_THROTTLE \|\|
	395	event->header.type == PERF_RECORD_UNTHROTTLE)
	396	return 0;
	397
	398	if (event->header.type < PERF_RECORD_MAX) {
	399	int ret;
	400
	401	ret = machine__process_event(machine, event, NULL);
	402	if (ret < 0)
	403	pr_debug("machine__process_event failed, event type %u\n",
	404	event->header.type);
	405	return ret;
	406	}
b55ae0a9 AH	407
	408	return 0;
	409	}
	410
7a77bc2c AH	411	static int process_events(struct machine machine, struct perf_evlist evlist,
7a77bc2c AH	412	struct state *state)
b55ae0a9 AH	413	{
b55ae0a9 AH	414	union perf_event *event;
00fc2460	415	struct perf_mmap *md;
b55ae0a9 AH	416	int i, ret;
	417
	418	for (i = 0; i < evlist->nr_mmaps; i++) {
00fc2460	419	md = &evlist->mmap[i];
b9bae2c8	420	if (perf_mmap__read_init(md) < 0)
00fc2460 KL	421	continue;
00fc2460 KL	422
0019dc87	423	while ((event = perf_mmap__read_event(md)) != NULL) {
7a77bc2c	424	ret = process_event(machine, evlist, event, state);
d6ace3df	425	perf_mmap__consume(md);
b55ae0a9 AH	426	if (ret < 0)
	427	return ret;
	428	}
00fc2460	429	perf_mmap__read_done(md);
b55ae0a9 AH	430	}
	431	return 0;
	432	}
	433
	434	static int comp(const void a, const void b)
	435	{
	436	return (int )a - (int )b;
	437	}
	438
	439	static void do_sort_something(void)
	440	{
309b5185	441	int buf[40960], i;
b55ae0a9	442
309b5185 DA	443	for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
309b5185 DA	444	buf[i] = ARRAY_SIZE(buf) - i - 1;
b55ae0a9	445
309b5185	446	qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
b55ae0a9	447
309b5185	448	for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
b55ae0a9 AH	449	if (buf[i] != i) {
	450	pr_debug("qsort failed\n");
	451	break;
	452	}
	453	}
	454	}
	455
	456	static void sort_something(void)
	457	{
	458	int i;
	459
	460	for (i = 0; i < 10; i++)
	461	do_sort_something();
	462	}
	463
	464	static void syscall_something(void)
	465	{
	466	int pipefd[2];
	467	int i;
	468
	469	for (i = 0; i < 1000; i++) {
	470	if (pipe(pipefd) < 0) {
	471	pr_debug("pipe failed\n");
	472	break;
	473	}
	474	close(pipefd[1]);
	475	close(pipefd[0]);
	476	}
	477	}
	478
	479	static void fs_something(void)
	480	{
	481	const char *test_file_name = "temp-perf-code-reading-test-file--";
	482	FILE *f;
	483	int i;
	484
	485	for (i = 0; i < 1000; i++) {
	486	f = fopen(test_file_name, "w+");
	487	if (f) {
	488	fclose(f);
	489	unlink(test_file_name);
	490	}
	491	}
	492	}
	493
b3be39c5 TR	494	static const char *do_determine_event(bool excl_kernel)
	495	{
	496	const char *event = excl_kernel ? "cycles:u" : "cycles";
	497
	498	#ifdef __s390x__
	499	char cpuid[128], model[16], model_c[16], cpum_cf_v[16];
	500	unsigned int family;
	501	int ret, cpum_cf_a;
	502
	503	if (get_cpuid(cpuid, sizeof(cpuid)))
	504	goto out_clocks;
	505	ret = sscanf(cpuid, "%*[^,],%u,%[^,],%[^,],%[^,],%x", &family, model_c,
	506	model, cpum_cf_v, &cpum_cf_a);
	507	if (ret != 5) /* Not available */
	508	goto out_clocks;
	509	if (excl_kernel && (cpum_cf_a & 4))
	510	return event;
	511	if (!excl_kernel && (cpum_cf_a & 2))
	512	return event;
	513
	514	/* Fall through: missing authorization */
	515	out_clocks:
	516	event = excl_kernel ? "cpu-clock:u" : "cpu-clock";
	517
	518	#endif
	519	return event;
	520	}
	521
b55ae0a9 AH	522	static void do_something(void)
	523	{
	524	fs_something();
	525
	526	sort_something();
	527
	528	syscall_something();
	529	}
	530
	531	enum {
	532	TEST_CODE_READING_OK,
	533	TEST_CODE_READING_NO_VMLINUX,
7a77bc2c	534	TEST_CODE_READING_NO_KCORE,
b55ae0a9	535	TEST_CODE_READING_NO_ACCESS,
7a77bc2c	536	TEST_CODE_READING_NO_KERNEL_OBJ,
b55ae0a9 AH	537	};
b55ae0a9 AH	538
7a77bc2c	539	static int do_test_code_reading(bool try_kcore)
b55ae0a9	540	{
b55ae0a9 AH	541	struct machine *machine;
b55ae0a9 AH	542	struct thread *thread;
b4006796	543	struct record_opts opts = {
b55ae0a9 AH	544	.mmap_pages = UINT_MAX,
	545	.user_freq = UINT_MAX,
	546	.user_interval = ULLONG_MAX,
5243ba76	547	.freq = 500,
b55ae0a9 AH	548	.target = {
	549	.uses_mmap = true,
	550	},
	551	};
7a77bc2c AH	552	struct state state = {
	553	.done_cnt = 0,
	554	};
9749b90e	555	struct perf_thread_map *threads = NULL;
f854839b	556	struct perf_cpu_map *cpus = NULL;
b55ae0a9	557	struct perf_evlist *evlist = NULL;
32dcd021	558	struct evsel *evsel = NULL;
b55ae0a9 AH	559	int err = -1, ret;
	560	pid_t pid;
	561	struct map *map;
7a77bc2c	562	bool have_vmlinux, have_kcore, excl_kernel = false;
b55ae0a9 AH	563
	564	pid = getpid();
	565
0fd4008e	566	machine = machine__new_host();
f6c66d73	567	machine->env = &perf_env;
b55ae0a9 AH	568
	569	ret = machine__create_kernel_maps(machine);
	570	if (ret < 0) {
	571	pr_debug("machine__create_kernel_maps failed\n");
	572	goto out_err;
	573	}
	574
7a77bc2c AH	575	/* Force the use of kallsyms instead of vmlinux to try kcore */
	576	if (try_kcore)
	577	symbol_conf.kallsyms_name = "/proc/kallsyms";
	578
b55ae0a9	579	/* Load kernel map */
a5e813c6	580	map = machine__kernel_map(machine);
be39db9f	581	ret = map__load(map);
b55ae0a9 AH	582	if (ret < 0) {
	583	pr_debug("map__load failed\n");
	584	goto out_err;
	585	}
7a77bc2c AH	586	have_vmlinux = dso__is_vmlinux(map->dso);
	587	have_kcore = dso__is_kcore(map->dso);
	588
	589	/* 2nd time through we just try kcore */
	590	if (try_kcore && !have_kcore)
	591	return TEST_CODE_READING_NO_KCORE;
	592
	593	/* No point getting kernel events if there is no kernel object */
	594	if (!have_vmlinux && !have_kcore)
b55ae0a9 AH	595	excl_kernel = true;
	596
	597	threads = thread_map__new_by_tid(pid);
	598	if (!threads) {
	599	pr_debug("thread_map__new_by_tid failed\n");
	600	goto out_err;
	601	}
	602
	603	ret = perf_event__synthesize_thread_map(NULL, threads,
3fcb10e4	604	perf_event__process, machine, false);
b55ae0a9 AH	605	if (ret < 0) {
	606	pr_debug("perf_event__synthesize_thread_map failed\n");
	607	goto out_err;
	608	}
	609
314add6b	610	thread = machine__findnew_thread(machine, pid, pid);
b55ae0a9 AH	611	if (!thread) {
b55ae0a9 AH	612	pr_debug("machine__findnew_thread failed\n");
b91fc39f	613	goto out_put;
b55ae0a9 AH	614	}
	615
	616	cpus = cpu_map__new(NULL);
	617	if (!cpus) {
	618	pr_debug("cpu_map__new failed\n");
b91fc39f	619	goto out_put;
b55ae0a9 AH	620	}
	621
	622	while (1) {
	623	const char *str;
	624
	625	evlist = perf_evlist__new();
	626	if (!evlist) {
	627	pr_debug("perf_evlist__new failed\n");
b91fc39f	628	goto out_put;
b55ae0a9 AH	629	}
	630
	631	perf_evlist__set_maps(evlist, cpus, threads);
	632
b3be39c5	633	str = do_determine_event(excl_kernel);
b55ae0a9	634	pr_debug("Parsing event '%s'\n", str);
b39b8393	635	ret = parse_events(evlist, str, NULL);
b55ae0a9 AH	636	if (ret < 0) {
b55ae0a9 AH	637	pr_debug("parse_events failed\n");
b91fc39f	638	goto out_put;
b55ae0a9 AH	639	}
b55ae0a9 AH	640
e68ae9cf	641	perf_evlist__config(evlist, &opts, NULL);
b55ae0a9 AH	642
	643	evsel = perf_evlist__first(evlist);
	644
	645	evsel->attr.comm = 1;
	646	evsel->attr.disabled = 1;
	647	evsel->attr.enable_on_exec = 0;
	648
	649	ret = perf_evlist__open(evlist);
	650	if (ret < 0) {
	651	if (!excl_kernel) {
	652	excl_kernel = true;
7320b1b3 JO	653	/*
	654	* Both cpus and threads are now owned by evlist
	655	* and will be freed by following perf_evlist__set_maps
	656	* call. Getting refference to keep them alive.
	657	*/
	658	cpu_map__get(cpus);
	659	thread_map__get(threads);
ae450a7d	660	perf_evlist__set_maps(evlist, NULL, NULL);
b55ae0a9 AH	661	perf_evlist__delete(evlist);
	662	evlist = NULL;
	663	continue;
	664	}
6880bbf9	665
bb963e16	666	if (verbose > 0) {
6880bbf9 ACM	667	char errbuf[512];
	668	perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
	669	pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
	670	}
	671
b91fc39f	672	goto out_put;
b55ae0a9 AH	673	}
	674	break;
	675	}
	676
f74b9d3a	677	ret = perf_evlist__mmap(evlist, UINT_MAX);
b55ae0a9 AH	678	if (ret < 0) {
b55ae0a9 AH	679	pr_debug("perf_evlist__mmap failed\n");
b91fc39f	680	goto out_put;
b55ae0a9 AH	681	}
	682
	683	perf_evlist__enable(evlist);
	684
	685	do_something();
	686
	687	perf_evlist__disable(evlist);
	688
7a77bc2c	689	ret = process_events(machine, evlist, &state);
b55ae0a9	690	if (ret < 0)
b91fc39f	691	goto out_put;
b55ae0a9	692
7a77bc2c AH	693	if (!have_vmlinux && !have_kcore && !try_kcore)
	694	err = TEST_CODE_READING_NO_KERNEL_OBJ;
	695	else if (!have_vmlinux && !try_kcore)
b55ae0a9 AH	696	err = TEST_CODE_READING_NO_VMLINUX;
	697	else if (excl_kernel)
	698	err = TEST_CODE_READING_NO_ACCESS;
	699	else
	700	err = TEST_CODE_READING_OK;
b91fc39f ACM	701	out_put:
b91fc39f ACM	702	thread__put(thread);
b55ae0a9	703	out_err:
b91fc39f	704
b55ae0a9	705	if (evlist) {
b55ae0a9	706	perf_evlist__delete(evlist);
03ad9747	707	} else {
f30a79b0	708	cpu_map__put(cpus);
186fbb74	709	thread_map__put(threads);
03ad9747	710	}
b55ae0a9	711	machine__delete_threads(machine);
0fd4008e	712	machine__delete(machine);
b55ae0a9 AH	713
	714	return err;
	715	}
	716
81f17c90	717	int test__code_reading(struct test *test __maybe_unused, int subtest __maybe_unused)
b55ae0a9 AH	718	{
	719	int ret;
	720
7a77bc2c AH	721	ret = do_test_code_reading(false);
	722	if (!ret)
	723	ret = do_test_code_reading(true);
b55ae0a9 AH	724
	725	switch (ret) {
	726	case TEST_CODE_READING_OK:
	727	return 0;
	728	case TEST_CODE_READING_NO_VMLINUX:
597bdeb4	729	pr_debug("no vmlinux\n");
b55ae0a9	730	return 0;
7a77bc2c	731	case TEST_CODE_READING_NO_KCORE:
597bdeb4	732	pr_debug("no kcore\n");
7a77bc2c	733	return 0;
b55ae0a9	734	case TEST_CODE_READING_NO_ACCESS:
597bdeb4	735	pr_debug("no access\n");
b55ae0a9	736	return 0;
7a77bc2c	737	case TEST_CODE_READING_NO_KERNEL_OBJ:
597bdeb4	738	pr_debug("no kernel obj\n");
7a77bc2c	739	return 0;
b55ae0a9 AH	740	default:
	741	return -1;
	742	};
	743	}