stdlib/tst-makecontext3.c

   1 /* Copyright (C) 2001-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <ucontext.h>
  23 #include <unistd.h>
  24
  25 static ucontext_t ctx[3];
  26
  27 static int was_in_f1;
  28 static int was_in_f2;
  29
  30 static char st2[32768];
  31
  32 static volatile int flag;
  33
  34 static void
  35 f1 (int a00, int a01, int a02, int a03, int a04, int a05, int a06, int a07,
  36     int a08, int a09, int a10, int a11, int a12, int a13, int a14, int a15,
  37     int a16, int a17, int a18, int a19, int a20, int a21, int a22, int a23,
  38     int a24, int a25, int a26, int a27, int a28, int a29, int a30, int a31,
  39     int a32)
  40 {
  41   printf ("start f1(a00=%08x,a01=%08x,a02=%08x,a03=%08x,\n"
  42           "         a04=%08x,a05=%08x,a06=%08x,a07=%08x,\n"
  43           "         a08=%08x,a09=%08x,a10=%08x,a11=%08x,\n"
  44           "         a12=%08x,a13=%08x,a14=%08x,a15=%08x,\n"
  45           "         a16=%08x,a17=%08x,a18=%08x,a19=%08x,\n"
  46           "         a20=%08x,a21=%08x,a22=%08x,a23=%08x,\n"
  47           "         a24=%08x,a25=%08x,a26=%08x,a27=%08x,\n"
  48           "         a28=%08x,a29=%08x,a30=%08x,a31=%08x,\n"
  49           "         a32=%08x) [%d]\n",
  50           a00, a01, a02, a03, a04, a05, a06, a07,
  51           a08, a09, a10, a11, a12, a13, a14, a15,
  52           a16, a17, a18, a19, a20, a21, a22, a23,
  53           a24, a25, a26, a27, a28, a29, a30, a31,
  54           a32, flag);
  55
  56   if (a00 != (0x00000001 << flag) || a01 != (0x00000004 << flag)
  57       || a02 != (0x00000012 << flag) || a03 != (0x00000048 << flag)
  58       || a04 != (0x00000123 << flag) || a05 != (0x0000048d << flag)
  59       || a06 != (0x00001234 << flag) || a07 != (0x000048d1 << flag)
  60       || a08 != (0x00012345 << flag) || a09 != (0x00048d15 << flag)
  61       || a10 != (0x00123456 << flag) || a11 != (0x0048d159 << flag)
  62       || a12 != (0x01234567 << flag) || a13 != (0x048d159e << flag)
  63       || a14 != (0x12345678 << flag) || a15 != (0x48d159e2 << flag)
  64       || a16 != (0x23456789 << flag) || a17 != (0x8d159e26 << flag)
  65       || a18 != (0x3456789a << flag) || a19 != (0xd159e26a << flag)
  66       || a20 != (0x456789ab << flag) || a21 != (0x159e26af << flag)
  67       || a22 != (0x56789abc << flag) || a23 != (0x59e26af3 << flag)
  68       || a24 != (0x6789abcd << flag) || a25 != (0x9e26af37 << flag)
  69       || a26 != (0x789abcde << flag) || a27 != (0xe26af37b << flag)
  70       || a28 != (0x89abcdef << flag) || a29 != (0x26af37bc << flag)
  71       || a30 != (0x9abcdef0 << flag) || a31 != (0x6af37bc3 << flag)
  72       || a32 != (0xabcdef0f << flag))
  73     {
  74       puts ("arg mismatch");
  75       exit (-1);
  76     }
  77
  78   if (flag && swapcontext (&ctx[1], &ctx[2]) != 0)
  79     {
  80       printf ("%s: swapcontext: %m\n", __FUNCTION__);
  81       exit (1);
  82     }
  83   printf ("finish f1 [%d]\n", flag);
  84   flag++;
  85   was_in_f1++;
  86 }
  87
  88 static void
  89 f2 (void)
  90 {
  91   puts ("start f2");
  92   if (swapcontext (&ctx[2], &ctx[1]) != 0)
  93     {
  94       printf ("%s: swapcontext: %m\n", __FUNCTION__);
  95       exit (1);
  96     }
  97   puts ("finish f2");
  98   was_in_f2 = 1;
  99 }
 100
 101 volatile int global;
 102
 103
 104 static int back_in_main;
 105
 106
 107 static void
 108 check_called (void)
 109 {
 110   if (back_in_main == 0)
 111     {
 112       puts ("program did not reach main again");
 113       _exit (1);
 114     }
 115 }
 116
 117
 118 int
 119 main (void)
 120 {
 121   atexit (check_called);
 122
 123   char st1[32768];
 124
 125   puts ("making contexts");
 126   if (getcontext (&ctx[0]) != 0)
 127     {
 128       if (errno == ENOSYS)
 129         {
 130           back_in_main = 1;
 131           exit (0);
 132         }
 133
 134       printf ("%s: getcontext: %m\n", __FUNCTION__);
 135       exit (1);
 136     }
 137
 138   if (getcontext (&ctx[1]) != 0)
 139     {
 140       printf ("%s: getcontext: %m\n", __FUNCTION__);
 141       exit (1);
 142     }
 143
 144   ctx[1].uc_stack.ss_sp = st1;
 145   ctx[1].uc_stack.ss_size = sizeof st1;
 146   ctx[1].uc_link = &ctx[0];
 147   errno = 0;
 148   makecontext (&ctx[1], (void (*) (void)) f1, 33,
 149                0x00000001 << flag, 0x00000004 << flag,
 150                0x00000012 << flag, 0x00000048 << flag,
 151                0x00000123 << flag, 0x0000048d << flag,
 152                0x00001234 << flag, 0x000048d1 << flag,
 153                0x00012345 << flag, 0x00048d15 << flag,
 154                0x00123456 << flag, 0x0048d159 << flag,
 155                0x01234567 << flag, 0x048d159e << flag,
 156                0x12345678 << flag, 0x48d159e2 << flag,
 157                0x23456789 << flag, 0x8d159e26 << flag,
 158                0x3456789a << flag, 0xd159e26a << flag,
 159                0x456789ab << flag, 0x159e26af << flag,
 160                0x56789abc << flag, 0x59e26af3 << flag,
 161                0x6789abcd << flag, 0x9e26af37 << flag,
 162                0x789abcde << flag, 0xe26af37b << flag,
 163                0x89abcdef << flag, 0x26af37bc << flag,
 164                0x9abcdef0 << flag, 0x6af37bc3 << flag,
 165                0xabcdef0f << flag);
 166
 167   /* Without this check, a stub makecontext can make us spin forever.  */
 168   if (errno == ENOSYS)
 169     {
 170       puts ("makecontext not implemented");
 171       back_in_main = 1;
 172       return 0;
 173     }
 174
 175   /* Play some tricks with this context.  */
 176   if (++global == 1)
 177     if (setcontext (&ctx[1]) != 0)
 178       {
 179         printf ("%s: setcontext: %m\n", __FUNCTION__);
 180         exit (1);
 181       }
 182   if (global != 2)
 183     {
 184       printf ("%s: 'global' not incremented twice\n", __FUNCTION__);
 185       exit (1);
 186     }
 187
 188   if (getcontext (&ctx[2]) != 0)
 189     {
 190       printf ("%s: second getcontext: %m\n", __FUNCTION__);
 191       exit (1);
 192     }
 193   ctx[2].uc_stack.ss_sp = st2;
 194   ctx[2].uc_stack.ss_size = sizeof st2;
 195   ctx[2].uc_link = &ctx[1];
 196   makecontext (&ctx[2], f2, 0);
 197
 198   puts ("swapping contexts");
 199   if (swapcontext (&ctx[0], &ctx[2]) != 0)
 200     {
 201       printf ("%s: swapcontext: %m\n", __FUNCTION__);
 202       exit (1);
 203     }
 204   puts ("back at main program");
 205   back_in_main = 1;
 206
 207   if (was_in_f1 < 2)
 208     {
 209       puts ("didn't reach f1 twice");
 210       exit (1);
 211     }
 212   if (was_in_f2 == 0)
 213     {
 214       puts ("didn't reach f2");
 215       exit (1);
 216     }
 217
 218   puts ("test succeeded");
 219   return 0;
 220 }