1  /* This test needs to use setrlimit to set the stack size, so it can
       2     only run on Unix.  */
       3  /* { dg-do run { target { i?86-*-linux* i?86-*-gnu* x86_64-*-linux* } } } */
       4  /* { dg-require-effective-target cet } */
       5  /* { dg-require-effective-target split_stack } */
       6  /* { dg-options "-fsplit-stack -fcf-protection" } */
       7  
       8  #include <stdlib.h>
       9  #include <string.h>
      10  #include <sys/types.h>
      11  #include <sys/resource.h>
      12  
      13  /* Use a noinline function to ensure that the buffer is not removed
      14     from the stack.  */
      15  static void use_buffer (char *buf, size_t) __attribute__ ((noinline));
      16  static void
      17  use_buffer (char *buf, size_t c)
      18  {
      19    size_t i;
      20  
      21    for (i = 0; i < c; ++i)
      22      buf[i] = (char) i;
      23  }
      24  
      25  /* Each recursive call uses 10 * i bytes.  We call it 1000 times,
      26     using a total of 5,000,000 bytes.  If -fsplit-stack is not working,
      27     that will overflow our stack limit.  */
      28  
      29  static void
      30  down1 (int i)
      31  {
      32    char buf[10 * i];
      33  
      34    if (i > 0)
      35      {
      36        use_buffer (buf, 10 * i);
      37        down1 (i - 1);
      38      }
      39  }
      40  
      41  /* Same thing, using alloca.  */
      42  
      43  static void
      44  down2 (int i)
      45  {
      46    char *buf = alloca (10 * i);
      47  
      48    if (i > 0)
      49      {
      50        use_buffer (buf, 10 * i);
      51        down2 (i - 1);
      52      }
      53  }
      54  
      55  int
      56  main (void)
      57  {
      58    struct rlimit r;
      59  
      60    /* We set a stack limit because we are usually invoked via make, and
      61       make sets the stack limit to be as large as possible.  */
      62    r.rlim_cur = 8192 * 1024;
      63    r.rlim_max = 8192 * 1024;
      64    if (setrlimit (RLIMIT_STACK, &r) != 0)
      65      abort ();
      66    down1 (1000);
      67    down2 (1000);
      68    return 0;
      69  }