112 lines
2.6 KiB
C
112 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) 2022 FUJITSU LIMITED. All rights reserved.
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* Author: Yang Xu <xuyang2018.jy@fujitsu.com>
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*/
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/*\
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* [Description]
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*
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* Basic test to test behaviour of PR_GET_TSC and PR_SET_TSC.
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*
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* Set the state of the flag determining whether the timestamp counter can
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* be read by the process.
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*
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* - Pass PR_TSC_ENABLE to arg2 to allow it to be read.
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* - Pass PR_TSC_SIGSEGV to arg2 to generate a SIGSEGV when read.
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*/
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#include <sys/prctl.h>
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#include <string.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include "tst_test.h"
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#include "lapi/prctl.h"
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#define TCASE_ENTRY(tsc_read_stat) { .name = #tsc_read_stat, .read_stat = tsc_read_stat}
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static const char * const tsc_read_stat_names[] = {
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[0] = "[not set]",
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[PR_TSC_ENABLE] = "PR_TSC_ENABLE",
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[PR_TSC_SIGSEGV] = "PR_TSC_SIGSEGV",
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};
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static struct tcase {
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char *name;
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int read_stat;
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} tcases[] = {
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TCASE_ENTRY(PR_TSC_ENABLE),
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TCASE_ENTRY(PR_TSC_SIGSEGV)
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};
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static uint64_t rdtsc(void)
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{
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uint32_t lo = 0, hi = 0;
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#if (defined(__x86_64__) || defined(__i386__))
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/* We cannot use "=A", since this would use %rax on x86_64 */
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__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
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#endif
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return (uint64_t)hi << 32 | lo;
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}
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static int expected_status(int status, int exp_status)
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{
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if (!exp_status && WIFEXITED(status))
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return 0;
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if (exp_status && WIFSIGNALED(status) && WTERMSIG(status) == exp_status)
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return 0;
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return 1;
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}
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static void verify_prctl(unsigned int n)
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{
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struct tcase *tc = &tcases[n];
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unsigned long long time1, time2;
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int tsc_val = 0, pid, status;
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pid = SAFE_FORK();
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if (!pid) {
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TST_EXP_PASS_SILENT(prctl(PR_SET_TSC, tc->read_stat));
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TST_EXP_PASS_SILENT(prctl(PR_GET_TSC, &tsc_val));
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if (tsc_val == tc->read_stat)
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tst_res(TPASS, "current state is %s(%d)",
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tc->name, tc->read_stat);
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else
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tst_res(TFAIL, "current state is %s(%d), expect %s(%d)",
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tsc_read_stat_names[tsc_val],
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tsc_val, tc->name, tc->read_stat);
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time1 = rdtsc();
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time2 = rdtsc();
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if (time2 > time1)
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tst_res(TPASS, "rdtsc works correctly, %lld ->%lld",
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time1, time2);
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else
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tst_res(TFAIL, "rdtsc works incorrectly, %lld ->%lld",
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time1, time2);
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exit(0);
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}
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SAFE_WAITPID(pid, &status, 0);
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if (expected_status(status, tc->read_stat == PR_TSC_SIGSEGV ? SIGSEGV : 0))
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tst_res(TFAIL, "Test %s failed", tc->name);
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else
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tst_res(TPASS, "Test %s succeeded", tc->name);
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}
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static struct tst_test test = {
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.forks_child = 1,
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.test = verify_prctl,
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.tcnt = ARRAY_SIZE(tcases),
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.supported_archs = (const char *const []) {
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"x86",
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"x86_64",
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NULL
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},
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};
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