stdlib/tst-setcontext2.c

   1 /* Testcase checks, if setcontext(), swapcontext() restores signal-mask
   2    and if pending signals are delivered after those calls.
   3    Copyright (C) 2015-2023 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <sys/types.h>
  23 #include <signal.h>
  24 #include <ucontext.h>
  25 #include <unistd.h>
  26
  27 volatile int global;
  28 volatile sig_atomic_t handlerCalled;
  29
  30 static void
  31 check (const char *funcName)
  32 {
  33   sigset_t set;
  34
  35   /* check if SIGUSR2 is unblocked after setcontext-call.  */
  36   sigprocmask (SIG_BLOCK, NULL, &set);
  37
  38   if (sigismember (&set, SIGUSR2) != 0)
  39     {
  40       printf ("FAIL: SIGUSR2 is blocked after %s.\n", funcName);
  41       exit (1);
  42     }
  43
  44   if (sigismember (&set, SIGUSR1) != 1)
  45     {
  46       printf ("FAIL: SIGUSR1 is not blocked after %s.\n", funcName);
  47       exit (1);
  48     }
  49 }
  50
  51 static void
  52 signalmask (int how, int signum)
  53 {
  54   sigset_t set;
  55   sigemptyset (&set);
  56   sigaddset (&set, signum);
  57   if (sigprocmask (how, &set, NULL) != 0)
  58     {
  59       printf ("FAIL: sigprocmaks (%d, %d, NULL): %m\n", how, signum);
  60       exit (1);
  61     }
  62 }
  63
  64 static void
  65 signalpending (int signum, const char *msg)
  66 {
  67   sigset_t set;
  68   sigemptyset (&set);
  69   if (sigpending (&set) != 0)
  70     {
  71       printf ("FAIL: sigpending: %m\n");
  72       exit (1);
  73     }
  74   if (sigismember (&set, SIGUSR2) != 1)
  75     {
  76       printf ("FAIL: Signal %d is not pending %s\n", signum, msg);
  77       exit (1);
  78     }
  79 }
  80
  81 static void
  82 handler (int __attribute__ ((unused)) signum)
  83 {
  84   handlerCalled ++;
  85 }
  86
  87 static int
  88 do_test (void)
  89 {
  90   ucontext_t ctx, oldctx;
  91   struct sigaction action;
  92   pid_t pid;
  93
  94   pid = getpid ();
  95
  96   /* unblock SIGUSR2 */
  97   signalmask (SIG_UNBLOCK, SIGUSR2);
  98
  99   /* block SIGUSR1 */
 100   signalmask (SIG_BLOCK, SIGUSR1);
 101
 102   /* register handler for SIGUSR2  */
 103   action.sa_flags = 0;
 104   action.sa_handler = handler;
 105   sigemptyset (&action.sa_mask);
 106   sigaction (SIGUSR2, &action, NULL);
 107
 108   if (getcontext (&ctx) != 0)
 109     {
 110       printf ("FAIL: getcontext: %m\n");
 111       exit (1);
 112     }
 113
 114   global++;
 115
 116   if (global == 1)
 117     {
 118       puts ("after getcontext");
 119
 120       /* block SIGUSR2  */
 121       signalmask (SIG_BLOCK, SIGUSR2);
 122
 123       /* send SIGUSR2 to me  */
 124       handlerCalled = 0;
 125       kill (pid, SIGUSR2);
 126
 127       /* was SIGUSR2 handler called?  */
 128       if (handlerCalled != 0)
 129         {
 130           puts ("FAIL: signal handler was called, but signal was blocked.");
 131           exit (1);
 132         }
 133
 134       /* is SIGUSR2 pending?  */
 135       signalpending (SIGUSR2, "before setcontext");
 136
 137       /* SIGUSR2 will be unblocked by setcontext-call.  */
 138       if (setcontext (&ctx) != 0)
 139         {
 140           printf ("FAIL: setcontext: %m\n");
 141           exit (1);
 142         }
 143     }
 144   else if (global == 2)
 145     {
 146       puts ("after setcontext");
 147
 148       /* check SIGUSR1/2  */
 149       check ("setcontext");
 150
 151       /* was SIGUSR2 handler called? */
 152       if (handlerCalled != 1)
 153         {
 154           puts ("FAIL: signal handler was not called after setcontext.");
 155           exit (1);
 156         }
 157
 158       /* block SIGUSR2 */
 159       signalmask (SIG_BLOCK, SIGUSR2);
 160
 161       /* send SIGUSR2 to me  */
 162       handlerCalled = 0;
 163       kill (pid, SIGUSR2);
 164
 165       /* was SIGUSR2 handler called?  */
 166       if (handlerCalled != 0)
 167         {
 168           puts ("FAIL: signal handler was called, but signal was blocked.");
 169           exit (1);
 170         }
 171
 172       /* is SIGUSR2 pending?  */
 173       signalpending (SIGUSR2, "before swapcontext");
 174
 175       if (swapcontext (&oldctx, &ctx) != 0)
 176         {
 177           printf ("FAIL: swapcontext: %m\n");
 178           exit (1);
 179         }
 180
 181       puts ("after returned from swapcontext");
 182
 183       if (global != 3)
 184         {
 185           puts ("FAIL: returned from swapcontext without ctx-context called.");
 186           exit (1);
 187         }
 188
 189       puts ("test succeeded");
 190       return 0;
 191     }
 192   else if ( global != 3 )
 193     {
 194       puts ("FAIL: 'global' not incremented three times");
 195       exit (1);
 196     }
 197
 198   puts ("after swapcontext");
 199   /* check SIGUSR1/2  */
 200   check ("swapcontext");
 201
 202   /* was SIGUSR2 handler called? */
 203   if (handlerCalled != 1)
 204     {
 205       puts ("FAIL: signal handler was not called after swapcontext.");
 206       exit (1);
 207     }
 208
 209   /* check sigmask in old context of swapcontext-call  */
 210   if (sigismember (&oldctx.uc_sigmask, SIGUSR2) != 1)
 211     {
 212       puts ("FAIL: SIGUSR2 is not blocked in oldctx.uc_sigmask.");
 213       exit (1);
 214     }
 215
 216   if (sigismember (&oldctx.uc_sigmask, SIGUSR1) != 1)
 217     {
 218       puts ("FAIL: SIGUSR1 is not blocked in oldctx.uc_sigmaks.");
 219       exit (1);
 220     }
 221
 222   /* change to old context, which was gathered by swapcontext() call.  */
 223   setcontext (&oldctx);
 224
 225   puts ("FAIL: returned from setcontext (&oldctx)");
 226   exit (1);
 227 }
 228
 229 #define TEST_FUNCTION do_test ()
 230 #include "../test-skeleton.c"