1/*
2 *   Copyright (c) International Business Machines  Corp., 2002
3 *   Copyright (C) 2014 Linux Test Project, Inc.
4 *
5 *   This program is free software;  you can redistribute it and/or modify
6 *   it under the terms of the GNU General Public License as published by
7 *   the Free Software Foundation; either version 2 of the License, or
8 *   (at your option) any later version.
9 *
10 *   This program is distributed in the hope that it will be useful,
11 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13 *   the GNU General Public License for more details.
14 */
15/*
16 * ALGORITHM
17 *	Set up a profiling buffer, turn profiling on, set a timer for
18 *	cpu time, spin the pc and wait for timer to go off.
19 *	The profiling buffer should contain some info, highly concentrated.
20 *	We just do a "looks reasonable" check.
21 */
22
23#include <stdio.h>
24#include <signal.h>
25#include <unistd.h>
26#include <errno.h>
27#include <sys/types.h>
28#include "test.h"
29#include "safe_macros.h"
30
31#define PROFIL_TIME 5
32
33/* Should be large enough to hold data for test_profil() .text,
34 * on x86_64 this is ~600 bytes, so 16k should enough for all arches.
35 * We will monitor 16k on each side around current pc value,
36 * just in case compiler put call to get_pc() below "data shuffling" code */
37#define PROFIL_BUFLEN (32*1024)
38
39char *TCID = "profil01";
40int TST_TOTAL = 1;
41
42static volatile sig_atomic_t profil_done;
43
44static void alrm_handler(int sig)
45{
46	(void) sig;
47	profil_done = 1;
48}
49
50static void __attribute__ ((noinline)) *get_pc(void)
51{
52#if defined(__s390__) && __WORDSIZE == 32
53	/* taken from glibc,
54	 *   sysdeps/unix/sysv/linux/s390/s390-32/profil-counter.h
55	 * 31-bit s390 pointers don't use the 32th bit, however integers do,
56	 * so wrap the value around at 31 bits */
57	return (void *)
58		((unsigned long) __builtin_return_address(0) & 0x7fffffffUL);
59#else
60	return __builtin_return_address(0);
61#endif
62}
63
64static void test_profil(void)
65{
66	unsigned short buf[PROFIL_BUFLEN] = { 0 };
67	volatile int data[8] = { 0 };
68	size_t offset = (size_t) get_pc() - PROFIL_BUFLEN/2, count = 0;
69	int ret, i;
70
71	/* reset for test looping */
72	profil_done = 0;
73
74	/* profil_count in glibc calculates offset as
75	 *   i = (pc - pc_offset - (void *) 0) / 2
76	 *   i = i * pc_scale / 65536
77	 * set scale to 2*65536 to have 1:1 mapping for $pc */
78	ret = profil(buf, sizeof(buf), offset, 2*65536);
79	if (ret)
80		tst_brkm(TBROK, NULL, "profil returned: %d\n", ret);
81
82	signal(SIGALRM, alrm_handler);
83	alarm(PROFIL_TIME);
84
85	while (!profil_done) {
86		if (data[0])
87			data[0] = -data[7];
88		else
89			data[1] = data[0] / 2;
90		if (data[2])
91			data[2] = data[1] * 2;
92		else
93			data[3] = data[2] + data[0];
94		if (data[4])
95			data[4] = data[3] - data[1];
96		else
97			data[5] = data[4] * data[2];
98		if (data[6])
99			data[6] = data[5] + data[3];
100		else
101			data[7] = data[6] - data[4];
102	}
103
104	for (i = 0; i < PROFIL_BUFLEN; i++)
105		if (buf[i]) {
106			tst_resm(TINFO, "buf[0x%04x]=%d", i, buf[i]);
107			count += buf[i];
108		}
109
110	if (count > 0)
111		tst_resm(TPASS, "profil recorded some data");
112	else
113		tst_resm(TFAIL, "profil failed to record anything");
114}
115
116int main(int ac, char *av[])
117{
118	int lc;
119
120	tst_parse_opts(ac, av, NULL, NULL);
121
122	for (lc = 0; TEST_LOOPING(lc); lc++)
123		test_profil();
124
125	tst_exit();
126}
127