tools/testing/selftests/clone3/clone3_clear_sighand.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #define _GNU_SOURCE
   4 #include <errno.h>
   5 #include <sched.h>
   6 #include <signal.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <linux/sched.h>
  12 #include <linux/types.h>
  13 #include <sys/syscall.h>
  14 #include <sys/wait.h>
  15
  16 #include "../kselftest.h"
  17 #include "clone3_selftests.h"
  18
  19 #ifndef CLONE_CLEAR_SIGHAND
  20 #define CLONE_CLEAR_SIGHAND 0x100000000ULL
  21 #endif
  22
  23 static void nop_handler(int signo)
  24 {
  25 }
  26
  27 static int wait_for_pid(pid_t pid)
  28 {
  29         int status, ret;
  30
  31 again:
  32         ret = waitpid(pid, &status, 0);
  33         if (ret == -1) {
  34                 if (errno == EINTR)
  35                         goto again;
  36
  37                 return -1;
  38         }
  39
  40         if (!WIFEXITED(status))
  41                 return -1;
  42
  43         return WEXITSTATUS(status);
  44 }
  45
  46 static void test_clone3_clear_sighand(void)
  47 {
  48         int ret;
  49         pid_t pid;
  50         struct __clone_args args = {};
  51         struct sigaction act;
  52
  53         /*
  54          * Check that CLONE_CLEAR_SIGHAND and CLONE_SIGHAND are mutually
  55          * exclusive.
  56          */
  57         args.flags |= CLONE_CLEAR_SIGHAND | CLONE_SIGHAND;
  58         args.exit_signal = SIGCHLD;
  59         pid = sys_clone3(&args, sizeof(args));
  60         if (pid > 0)
  61                 ksft_exit_fail_msg(
  62                         "clone3(CLONE_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n");
  63
  64         act.sa_handler = nop_handler;
  65         ret = sigemptyset(&act.sa_mask);
  66         if (ret < 0)
  67                 ksft_exit_fail_msg("%s - sigemptyset() failed\n",
  68                                    strerror(errno));
  69
  70         act.sa_flags = 0;
  71
  72         /* Register signal handler for SIGUSR1 */
  73         ret = sigaction(SIGUSR1, &act, NULL);
  74         if (ret < 0)
  75                 ksft_exit_fail_msg(
  76                         "%s - sigaction(SIGUSR1, &act, NULL) failed\n",
  77                         strerror(errno));
  78
  79         /* Register signal handler for SIGUSR2 */
  80         ret = sigaction(SIGUSR2, &act, NULL);
  81         if (ret < 0)
  82                 ksft_exit_fail_msg(
  83                         "%s - sigaction(SIGUSR2, &act, NULL) failed\n",
  84                         strerror(errno));
  85
  86         /* Check that CLONE_CLEAR_SIGHAND works. */
  87         args.flags = CLONE_CLEAR_SIGHAND;
  88         pid = sys_clone3(&args, sizeof(args));
  89         if (pid < 0)
  90                 ksft_exit_fail_msg("%s - clone3(CLONE_CLEAR_SIGHAND) failed\n",
  91                                    strerror(errno));
  92
  93         if (pid == 0) {
  94                 ret = sigaction(SIGUSR1, NULL, &act);
  95                 if (ret < 0)
  96                         exit(EXIT_FAILURE);
  97
  98                 if (act.sa_handler != SIG_DFL)
  99                         exit(EXIT_FAILURE);
 100
 101                 ret = sigaction(SIGUSR2, NULL, &act);
 102                 if (ret < 0)
 103                         exit(EXIT_FAILURE);
 104
 105                 if (act.sa_handler != SIG_DFL)
 106                         exit(EXIT_FAILURE);
 107
 108                 exit(EXIT_SUCCESS);
 109         }
 110
 111         ret = wait_for_pid(pid);
 112         if (ret)
 113                 ksft_exit_fail_msg(
 114                         "Failed to clear signal handler for child process\n");
 115
 116         ksft_test_result_pass("Cleared signal handlers for child process\n");
 117 }
 118
 119 int main(int argc, char **argv)
 120 {
 121         ksft_print_header();
 122         ksft_set_plan(1);
 123         test_clone3_supported();
 124
 125         test_clone3_clear_sighand();
 126
 127         return ksft_exit_pass();
 128 }