gdb/testsuite/gdb.base/morestack.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2011-2019 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Based on the gcc testcase `gcc/testsuite/gcc.dg/split-1.c'.  This test
  19    needs to use setrlimit to set the stack size, so it can only run on Unix.
  20    */
  21
  22 #include <stdlib.h>
  23 #include <sys/types.h>
  24 #include <sys/resource.h>
  25 #include <stdio.h>
  26 #include <sys/mman.h>
  27
  28 /* Use a noinline function to ensure that the buffer is not removed
  29    from the stack.  */
  30 static void use_buffer (char *buf) __attribute__ ((noinline));
  31 static void
  32 use_buffer (char *buf)
  33 {
  34   buf[0] = '\0';
  35 }
  36
  37 static volatile int marker_var;
  38
  39 static void
  40 marker_miss (void)
  41 {
  42   marker_var = 0;
  43 }
  44
  45 static void
  46 marker_hit (void)
  47 {
  48   marker_var = 0;
  49 }
  50
  51 void *reserved;
  52 #define RESERVED_SIZE 0x1000000
  53
  54 /* Each recursive call uses 10,000 bytes.  We call it 1000 times,
  55    using a total of 10,000,000 bytes.  If -fsplit-stack is not
  56    working, that will overflow our stack limit.  */
  57
  58 static void
  59 down (int i)
  60 {
  61   char buf[10000];
  62   static void *last;
  63
  64   if (last && last < (void *) buf)
  65     {
  66       printf ("%d: %p < %p\n", i, last, buf);
  67       marker_hit ();
  68     }
  69   last = buf;
  70
  71   if (i == 500)
  72     {
  73       if (munmap (reserved, RESERVED_SIZE) != 0)
  74         abort ();
  75       reserved = NULL;
  76     }
  77
  78   if (i > 0)
  79     {
  80       use_buffer (buf);
  81       down (i - 1);
  82     }
  83   else
  84     marker_miss ();
  85 }
  86
  87 int
  88 main (void)
  89 {
  90   struct rlimit r;
  91
  92   reserved = mmap (NULL, RESERVED_SIZE, PROT_READ | PROT_WRITE,
  93                    MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
  94   if (reserved == MAP_FAILED)
  95     abort ();
  96
  97   /* We set a stack limit because we are usually invoked via make, and
  98      make sets the stack limit to be as large as possible.  */
  99   r.rlim_cur = 8192 * 1024;
 100   r.rlim_max = 8192 * 1024;
 101   if (setrlimit (RLIMIT_STACK, &r) != 0)
 102     abort ();
 103   down (1000);
 104   return 0;
 105 }