nptl/tst-context1.c

   1 /* Copyright (C) 2003-2024 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 <error.h>
  20 #include <limits.h>
  21 #include <pthread.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <ucontext.h>
  25 #include <support/support.h>
  26
  27 #define N       4
  28 #if __WORDSIZE == 64
  29 #define GUARD_PATTERN 0xdeadbeafdeadbeaf
  30 #else
  31 #define GUARD_PATTERN 0xdeadbeaf
  32 #endif
  33
  34 typedef struct {
  35        ucontext_t uctx;
  36        unsigned long    guard[3];
  37    } tst_context_t;
  38
  39 static char *stacks[N];
  40 static size_t stack_size;
  41 static tst_context_t ctx[N][2];
  42 static volatile int failures;
  43
  44
  45 static void
  46 fct (long int n)
  47 {
  48   char on_stack[1];
  49
  50   /* Just to use the thread local descriptor.  */
  51   printf ("%ld: in %s now, on_stack = %p\n", n, __FUNCTION__, on_stack);
  52   errno = 0;
  53
  54   if (ctx[n][1].uctx.uc_link != &ctx[n][0].uctx)
  55     {
  56       printf ("context[%ld][1] uc_link damaged, = %p\n", n,
  57               ctx[n][1].uctx.uc_link);
  58       exit (1);
  59     }
  60
  61   if ((ctx[n][0].guard[0] != GUARD_PATTERN)
  62   ||  (ctx[n][0].guard[1] != GUARD_PATTERN)
  63   ||  (ctx[n][0].guard[2] != GUARD_PATTERN))
  64     {
  65       printf ("%ld: %s context[0] overflow detected!\n", n, __FUNCTION__);
  66       ++failures;
  67     }
  68
  69   if ((ctx[n][1].guard[0] != GUARD_PATTERN)
  70   ||  (ctx[n][1].guard[1] != GUARD_PATTERN)
  71   ||  (ctx[n][1].guard[2] != GUARD_PATTERN))
  72     {
  73       printf ("%ld: %s context[1] overflow detected!\n", n, __FUNCTION__);
  74       ++failures;
  75     }
  76
  77   if (n < 0 || n >= N)
  78     {
  79       printf ("%ld out of range\n", n);
  80       exit (1);
  81     }
  82
  83   if (on_stack < stacks[n] || on_stack >= stacks[n] + stack_size)
  84     {
  85       printf ("%ld: on_stack not on appropriate stack\n", n);
  86       exit (1);
  87     }
  88 }
  89
  90
  91 static void *
  92 tf (void *arg)
  93 {
  94   int n = (int) (long int) arg;
  95
  96   ctx[n][0].guard[0] = GUARD_PATTERN;
  97   ctx[n][0].guard[1] = GUARD_PATTERN;
  98   ctx[n][0].guard[2] = GUARD_PATTERN;
  99
 100   ctx[n][1].guard[0] = GUARD_PATTERN;
 101   ctx[n][1].guard[1] = GUARD_PATTERN;
 102   ctx[n][1].guard[2] = GUARD_PATTERN;
 103
 104   if (getcontext (&ctx[n][1].uctx) != 0)
 105     {
 106       printf ("%d: cannot get context: %m\n", n);
 107       exit (1);
 108     }
 109
 110   printf ("%d: %s: before makecontext\n", n, __FUNCTION__);
 111
 112   ctx[n][1].uctx.uc_stack.ss_sp = stacks[n];
 113   ctx[n][1].uctx.uc_stack.ss_size = stack_size;
 114   ctx[n][1].uctx.uc_link = &ctx[n][0].uctx;
 115   makecontext (&ctx[n][1].uctx, (void (*) (void)) fct, 1, (long int) n);
 116
 117   printf ("%d: %s: before swapcontext\n", n, __FUNCTION__);
 118
 119   if (swapcontext (&ctx[n][0].uctx, &ctx[n][1].uctx) != 0)
 120     {
 121       ++failures;
 122       printf ("%d: %s: swapcontext failed\n", n, __FUNCTION__);
 123     }
 124   else
 125     printf ("%d: back in %s\n", n, __FUNCTION__);
 126
 127   return NULL;
 128 }
 129
 130
 131 static volatile int global;
 132
 133
 134 static int
 135 do_test (void)
 136 {
 137   int n;
 138   pthread_t th[N];
 139   ucontext_t mctx;
 140
 141   stack_size = 2 * PTHREAD_STACK_MIN;
 142   for (int i = 0; i < N; i++)
 143     stacks[i] = xmalloc (stack_size);
 144
 145   puts ("making contexts");
 146   if (getcontext (&mctx) != 0)
 147     {
 148       if (errno == ENOSYS)
 149         {
 150           puts ("context handling not supported");
 151           exit (0);
 152         }
 153
 154       printf ("%s: getcontext: %m\n", __FUNCTION__);
 155       exit (1);
 156     }
 157
 158   /* Play some tricks with this context.  */
 159   if (++global == 1)
 160     if (setcontext (&mctx) != 0)
 161       {
 162         puts ("setcontext failed");
 163         exit (1);
 164       }
 165   if (global != 2)
 166     {
 167       puts ("global not incremented twice");
 168       exit (1);
 169     }
 170   puts ("global OK");
 171
 172   pthread_attr_t at;
 173
 174   if (pthread_attr_init (&at) != 0)
 175     {
 176       puts ("attr_init failed");
 177       return 1;
 178     }
 179
 180   if (pthread_attr_setstacksize (&at, 1 * 1024 * 1024) != 0)
 181     {
 182       puts ("attr_setstacksize failed");
 183       return 1;
 184     }
 185
 186   for (n = 0; n < N; ++n)
 187     if (pthread_create (&th[n], &at, tf, (void *) (long int) n) != 0)
 188       {
 189         puts ("create failed");
 190         exit (1);
 191       }
 192
 193   if (pthread_attr_destroy (&at) != 0)
 194     {
 195       puts ("attr_destroy failed");
 196       return 1;
 197     }
 198
 199   for (n = 0; n < N; ++n)
 200     if (pthread_join (th[n], NULL) != 0)
 201       {
 202         puts ("join failed");
 203         exit (1);
 204       }
 205
 206   for (int i = 0; i < N; i++)
 207     free (stacks[i]);
 208
 209   return failures;
 210 }
 211
 212 #define TEST_FUNCTION do_test ()
 213 #include "../test-skeleton.c"