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#include "lapi/abisize.h"
31#include "config.h"
32
33char *TCID = "profil01";
34
35#if HAVE_PROFIL
36
37#define PROFIL_TIME 5
38
39/* Should be large enough to hold data for test_profil() .text,
40 * on x86_64 this is ~600 bytes, so 16k should enough for all arches.
41 * We will monitor 16k on each side around current pc value,
42 * just in case compiler put call to get_pc() below "data shuffling" code */
43#define PROFIL_BUFLEN (32*1024)
44
45int TST_TOTAL = 1;
46
47static volatile sig_atomic_t profil_done;
48
49static void alrm_handler(int sig)
50{
51	(void) sig;
52	profil_done = 1;
53}
54
55static void __attribute__ ((noinline)) *get_pc(void)
56{
57#if defined(__s390__) && defined(TST_ABI32)
58	/* taken from glibc,
59	 *   sysdeps/unix/sysv/linux/s390/s390-32/profil-counter.h
60	 * 31-bit s390 pointers don't use the 32th bit, however integers do,
61	 * so wrap the value around at 31 bits */
62	return (void *)
63		((unsigned long) __builtin_return_address(0) & 0x7fffffffUL);
64#else
65	return __builtin_return_address(0);
66#endif
67}
68
69static void test_profil(void)
70{
71	unsigned short buf[PROFIL_BUFLEN] = { 0 };
72	volatile int data[8] = { 0 };
73	size_t offset = (size_t) get_pc() - PROFIL_BUFLEN/2, count = 0;
74	int ret, i;
75
76	/* reset for test looping */
77	profil_done = 0;
78
79	/* profil_count in glibc calculates offset as
80	 *   i = (pc - pc_offset - (void *) 0) / 2
81	 *   i = i * pc_scale / 65536
82	 * set scale to 2*65536 to have 1:1 mapping for $pc */
83	ret = profil(buf, sizeof(buf), offset, 2*65536);
84	if (ret)
85		tst_brkm(TBROK, NULL, "profil returned: %d", ret);
86
87	signal(SIGALRM, alrm_handler);
88	alarm(PROFIL_TIME);
89
90	while (!profil_done) {
91		if (data[0])
92			data[0] = -data[7];
93		else
94			data[1] = data[0] / 2;
95		if (data[2])
96			data[2] = data[1] * 2;
97		else
98			data[3] = data[2] + data[0];
99		if (data[4])
100			data[4] = data[3] - data[1];
101		else
102			data[5] = data[4] * data[2];
103		if (data[6])
104			data[6] = data[5] + data[3];
105		else
106			data[7] = data[6] - data[4];
107	}
108
109	for (i = 0; i < PROFIL_BUFLEN; i++)
110		if (buf[i]) {
111			tst_resm(TINFO, "buf[0x%04x]=%d", i, buf[i]);
112			count += buf[i];
113		}
114
115	if (count > 0)
116		tst_resm(TPASS, "profil recorded some data");
117	else
118		tst_resm(TFAIL, "profil failed to record anything");
119}
120
121int main(int ac, char *av[])
122{
123	int lc;
124
125	tst_parse_opts(ac, av, NULL, NULL);
126
127	for (lc = 0; TEST_LOOPING(lc); lc++)
128		test_profil();
129
130	tst_exit();
131}
132#else /* systems without profil() */
133int main(void)
134{
135        tst_brkm(TCONF, NULL, "system doesn't have profil() support");
136}
137#endif
138