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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pidfd_poll_test.c (2506B)

      1// SPDX-License-Identifier: GPL-2.0
      2
      3#define _GNU_SOURCE
      4#include <errno.h>
      5#include <linux/types.h>
      6#include <poll.h>
      7#include <signal.h>
      8#include <stdbool.h>
      9#include <stdio.h>
     10#include <stdlib.h>
     11#include <string.h>
     12#include <syscall.h>
     13#include <sys/wait.h>
     14#include <unistd.h>
     15
     16#include "pidfd.h"
     17#include "../kselftest.h"
     18
     19static bool timeout;
     20
     21static void handle_alarm(int sig)
     22{
     23	timeout = true;
     24}
     25
     26int main(int argc, char **argv)
     27{
     28	struct pollfd fds;
     29	int iter, nevents;
     30	int nr_iterations = 10000;
     31
     32	fds.events = POLLIN;
     33
     34	if (argc > 2)
     35		ksft_exit_fail_msg("Unexpected command line argument\n");
     36
     37	if (argc == 2) {
     38		nr_iterations = atoi(argv[1]);
     39		if (nr_iterations <= 0)
     40			ksft_exit_fail_msg("invalid input parameter %s\n",
     41					argv[1]);
     42	}
     43
     44	ksft_print_msg("running pidfd poll test for %d iterations\n",
     45		nr_iterations);
     46
     47	for (iter = 0; iter < nr_iterations; iter++) {
     48		int pidfd;
     49		int child_pid = fork();
     50
     51		if (child_pid < 0) {
     52			if (errno == EAGAIN) {
     53				iter--;
     54				continue;
     55			}
     56			ksft_exit_fail_msg(
     57				"%s - failed to fork a child process\n",
     58				strerror(errno));
     59		}
     60
     61		if (child_pid == 0) {
     62			/* Child process just sleeps for a min and exits */
     63			sleep(60);
     64			exit(EXIT_SUCCESS);
     65		}
     66
     67		/* Parent kills the child and waits for its death */
     68		pidfd = sys_pidfd_open(child_pid, 0);
     69		if (pidfd < 0)
     70			ksft_exit_fail_msg("%s - pidfd_open failed\n",
     71					strerror(errno));
     72
     73		/* Setup 3 sec alarm - plenty of time */
     74		if (signal(SIGALRM, handle_alarm) == SIG_ERR)
     75			ksft_exit_fail_msg("%s - signal failed\n",
     76					strerror(errno));
     77		alarm(3);
     78
     79		/* Send SIGKILL to the child */
     80		if (sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0))
     81			ksft_exit_fail_msg("%s - pidfd_send_signal failed\n",
     82					strerror(errno));
     83
     84		/* Wait for the death notification */
     85		fds.fd = pidfd;
     86		nevents = poll(&fds, 1, -1);
     87
     88		/* Check for error conditions */
     89		if (nevents < 0)
     90			ksft_exit_fail_msg("%s - poll failed\n",
     91					strerror(errno));
     92
     93		if (nevents != 1)
     94			ksft_exit_fail_msg("unexpected poll result: %d\n",
     95					nevents);
     96
     97		if (!(fds.revents & POLLIN))
     98			ksft_exit_fail_msg(
     99				"unexpected event type received: 0x%x\n",
    100				fds.revents);
    101
    102		if (timeout)
    103			ksft_exit_fail_msg(
    104				"death notification wait timeout\n");
    105
    106		close(pidfd);
    107		/* Wait for child to prevent zombies */
    108		if (waitpid(child_pid, NULL, 0) < 0)
    109			ksft_exit_fail_msg("%s - waitpid failed\n",
    110					strerror(errno));
    111
    112	}
    113
    114	ksft_test_result_pass("pidfd poll test: pass\n");
    115	return ksft_exit_pass();
    116}