memcheck/tests/linux/getregset.c

   1 /* -*- mode: C; c-basic-offset: 3; -*- */
   2
   3 #include <assert.h>
   4 #include <elf.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <unistd.h>
   9
  10 #include <sys/ptrace.h>
  11 #include <sys/types.h>
  12 #include <sys/uio.h>
  13 #include <sys/user.h>
  14 #include <sys/wait.h>
  15
  16 static int
  17 err_out(const char *msg)
  18 {
  19    perror(msg);
  20    return 1;
  21 }
  22
  23 static int
  24 non_empty(const char *buf, size_t len)
  25 {
  26    size_t i;
  27    int c = 0;
  28    volatile const char *p = buf;
  29
  30    for (i = 0; i != len; i++)
  31       c |= p[i];
  32    return c;
  33 }
  34
  35 static int
  36 do_child(void)
  37 {
  38    if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) == -1)
  39       return err_out("ptrace traceme");
  40    raise(SIGUSR1);
  41    return 0;
  42 }
  43
  44 int
  45 main(void)
  46 {
  47    char buf[1024];
  48    struct iovec iov;
  49    pid_t cpid, pid;
  50    int status;
  51
  52    cpid = fork();
  53    if (cpid == -1)
  54       return err_out("fork");
  55    if (cpid == 0)
  56       return do_child();
  57
  58    pid = wait(&status);
  59    if (pid == -1)
  60       return err_out("wait");
  61
  62    /* Intentionally provide an uninitialized buffer to ptrace. */
  63    iov.iov_len = sizeof(buf);
  64    iov.iov_base = buf;
  65    if (ptrace(0x4204, cpid, NT_PRSTATUS, &iov) == -1)
  66       return err_out("ptrace getregset");
  67
  68    assert(iov.iov_base == buf);
  69    assert(iov.iov_len > 0 && iov.iov_len < sizeof(buf));
  70
  71    /* We're assuming here that NT_PRSTATUS never contains
  72       all-zeros. */
  73    assert(non_empty(buf, iov.iov_len));
  74    puts("OK");
  75    return 0;
  76 }