tools/testing/selftests/proc/thread-self.c

   1 /*
   2  * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 // Test that /proc/thread-self gives correct TGID/PID.
  17 #undef NDEBUG
  18 #include <assert.h>
  19 #include <sched.h>
  20 #include <stdio.h>
  21 #include <unistd.h>
  22 #include <sys/mman.h>
  23 #include <sys/wait.h>
  24
  25 #include "proc.h"
  26
  27 int f(void *arg)
  28 {
  29         char buf1[64], buf2[64];
  30         pid_t pid, tid;
  31         ssize_t rv;
  32
  33         pid = sys_getpid();
  34         tid = sys_gettid();
  35         snprintf(buf1, sizeof(buf1), "%u/task/%u", pid, tid);
  36
  37         rv = readlink("/proc/thread-self", buf2, sizeof(buf2));
  38         assert(rv == strlen(buf1));
  39         buf2[rv] = '\0';
  40         assert(streq(buf1, buf2));
  41
  42         if (arg)
  43                 exit(0);
  44         return 0;
  45 }
  46
  47 int main(void)
  48 {
  49         const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
  50         pid_t pid;
  51         void *stack;
  52
  53         /* main thread */
  54         f((void *)0);
  55
  56         stack = mmap(NULL, 2 * PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  57         assert(stack != MAP_FAILED);
  58         /* side thread */
  59         pid = clone(f, stack + PAGE_SIZE, CLONE_THREAD|CLONE_SIGHAND|CLONE_VM, (void *)1);
  60         assert(pid > 0);
  61         pause();
  62
  63         return 0;
  64 }