cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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signal.c (2109B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright 2016, Cyril Bur, IBM Corp.
      4 *
      5 * Sending one self a signal should always get delivered.
      6 */
      7
      8#include <signal.h>
      9#include <stdio.h>
     10#include <stdlib.h>
     11#include <string.h>
     12#include <sys/types.h>
     13#include <sys/wait.h>
     14#include <unistd.h>
     15
     16#include <altivec.h>
     17
     18#include "utils.h"
     19
     20#define MAX_ATTEMPT 500000
     21#define TIMEOUT 5
     22
     23extern long signal_self(pid_t pid, int sig);
     24
     25static sig_atomic_t signaled;
     26static sig_atomic_t fail;
     27
     28static void signal_handler(int sig)
     29{
     30	if (sig == SIGUSR1)
     31		signaled = 1;
     32	else
     33		fail = 1;
     34}
     35
     36static int test_signal()
     37{
     38	int i;
     39	struct sigaction act;
     40	pid_t ppid = getpid();
     41	pid_t pid;
     42
     43	act.sa_handler = signal_handler;
     44	act.sa_flags = 0;
     45	sigemptyset(&act.sa_mask);
     46	if (sigaction(SIGUSR1, &act, NULL) < 0) {
     47		perror("sigaction SIGUSR1");
     48		exit(1);
     49	}
     50	if (sigaction(SIGALRM, &act, NULL) < 0) {
     51		perror("sigaction SIGALRM");
     52		exit(1);
     53	}
     54
     55	/* Don't do this for MAX_ATTEMPT, its simply too long */
     56	for(i  = 0; i < 1000; i++) {
     57		pid = fork();
     58		if (pid == -1) {
     59			perror("fork");
     60			exit(1);
     61		}
     62		if (pid == 0) {
     63			signal_self(ppid, SIGUSR1);
     64			exit(1);
     65		} else {
     66			alarm(0); /* Disable any pending */
     67			alarm(2);
     68			while (!signaled && !fail)
     69				asm volatile("": : :"memory");
     70			if (!signaled) {
     71				fprintf(stderr, "Didn't get signal from child\n");
     72				FAIL_IF(1); /* For the line number */
     73			}
     74			/* Otherwise we'll loop too fast and fork() will eventually fail */
     75			waitpid(pid, NULL, 0);
     76		}
     77	}
     78
     79	for (i = 0; i < MAX_ATTEMPT; i++) {
     80		long rc;
     81
     82		alarm(0); /* Disable any pending */
     83		signaled = 0;
     84		alarm(TIMEOUT);
     85		rc = signal_self(ppid, SIGUSR1);
     86		if (rc) {
     87			fprintf(stderr, "(%d) Fail reason: %d rc=0x%lx",
     88					i, fail, rc);
     89			FAIL_IF(1); /* For the line number */
     90		}
     91		while (!signaled && !fail)
     92			asm volatile("": : :"memory");
     93		if (!signaled) {
     94			fprintf(stderr, "(%d) Fail reason: %d rc=0x%lx",
     95					i, fail, rc);
     96			FAIL_IF(1); /* For the line number */
     97		}
     98	}
     99
    100	return 0;
    101}
    102
    103int main(void)
    104{
    105	test_harness_set_timeout(300);
    106	return test_harness(test_signal, "signal");
    107}