Hi!
> +/*
> + * Copyright (c) International Business Machines Corp., 2002
> + * Copyright (C) 2014 Linux Test Project, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
> + * the GNU General Public License for more details.
> + */
> +/*
> + * ALGORITHM
> + * Set up a profiling buffer, turn profiling on, set a timer for
> + * cpu time, spin the pc and wait for timer to go off.
> + * The profiling buffer should contain some info, highly concentrated.
> + * We just do a "looks reasonable" check.
> + */
> +
> +#include <stdio.h>
> +#include <signal.h>
> +#include <unistd.h>
> +#include <errno.h>
> +#include <sys/types.h>
> +#include "test.h"
> +#include "safe_macros.h"
> +#include "usctest.h"
> +
> +#define PROFIL_TIME 5
> +
> +/* should be large enough to hold data for test_profil() .text
> + * on x86_64 this is ~600 bytes, so 16k should enough for all arches */
> +#define PROFIL_BUFLEN (16*1024)
> +#define PROFIL_BUFSZ (16*1024*sizeof(short))
> +
> +char *TCID = "profil01";
> +int TST_TOTAL = 1;
> +
> +#ifndef __UCLIBC__
We can add profil to FILTER_OUT_DIRS for UCLINUX into the
kernel/syscalls/Makefile and drop these ifdefs completly.
> +static volatile sig_atomic_t profil_done;
> +
> +static void alrm_handler(int sig)
> +{
> + (void) sig;
> + profil_done = 1;
> +}
> +
> +static void test_profil(void)
> +{
> + unsigned short buf[PROFIL_BUFSZ] = { 0 };
^
PROFIL_BUFLEN ?
> + size_t offset = (size_t) &test_profil, count = 0;
> + int ret, i, data[8];
> +
> + /* make data depend on runtime value, so gcc can't make assumptions */
> + memset(data, getpid(), sizeof(data));
> +
> + /* reset for test looping */
> + profil_done = 0;
> +
> + /* profil_count in glibc calculates offset as
> + * i = (pc - pc_offset - (void *) 0) / 2
> + * i = i * pc_scale / 65536
> + * set scale to 2*65536 to have 1:1 mapping for $pc */
> + ret = profil(buf, PROFIL_BUFSZ, offset, 2*65536);
^ ^
sizeof(buf) ? why 2* ?
> + if (ret)
> + tst_brkm(TBROK, NULL, "profil returned: %d\n", ret);
> +
> + signal(SIGALRM, alrm_handler);
> + alarm(PROFIL_TIME);
> +
> + while (!profil_done) {
> + if (data[0])
> + data[0] = -data[7];
> + else
> + data[1] = data[0] / 2;
> + if (data[2])
> + data[2] = data[1] * 2;
> + else
> + data[3] = data[2] + data[0];
> + if (data[4])
> + data[4] = data[3] - data[1];
> + else
> + data[5] = data[4] * data[2];
> + if (data[6])
> + data[6] = data[5] + data[3];
> + else
> + data[7] = data[6] - data[4];
> + }
> +
> + for (i = 0; i < PROFIL_BUFLEN; i++)
> + if (buf[i]) {
> + tst_resm(TINFO, "buf[0x%04x]=%d", i, buf[i]);
> + count += buf[i];
> + }
> +
> + if (count > 0) {
> + tst_resm(TPASS, "profil recorded some data");
> + } else {
> + /* don't let gcc optimize data away, use it */
> + tst_resm(TINFO, "data[7]: %d", data[7]);
It may be more future proof to mark the data as volatile
instead of assuming something about the compiler.
--
Cyril Hrubis
chru...@suse.cz
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