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-rw-r--r--stdlib/tst-sigcontext.c312
1 files changed, 312 insertions, 0 deletions
diff --git a/stdlib/tst-sigcontext.c b/stdlib/tst-sigcontext.c
new file mode 100644
index 0000000000..45b1a06a28
--- /dev/null
+++ b/stdlib/tst-sigcontext.c
@@ -0,0 +1,312 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Maciej W. Rozycki <macro@codesourcery.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
+   02110-1301, USA.  */
+
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <ucontext.h>
+#include <unistd.h>
+
+static volatile ucontext_t ctx[3];
+static volatile int flags[3];
+static volatile int oflag;
+static volatile int flag;
+
+static volatile int sig_errno_set;
+static volatile int sig_errno;
+static volatile int sig_ready;
+
+static int was_in_f1;
+static int was_in_f2;
+
+static char st2[32768];
+
+static long long int max;
+static volatile long long int count;
+
+/* These have to be run with the caller's frame.  */
+static inline int sig_getcontext (int) __attribute__ ((always_inline));
+static inline int sig_swapcontext (int, int) __attribute__ ((always_inline));
+
+static void
+sig_gethandler (int signo, siginfo_t *info, void *context)
+{
+  ucontext_t *ucp = context;
+
+  if (! sig_ready)
+    {
+      alarm (1);
+      return;
+    }
+
+  ctx[flag] = *ucp;
+  flags[flag] = 1;
+
+  sig_errno_set = 1;
+  sig_errno = 0;
+}
+
+static void
+sig_swaphandler (int signo, siginfo_t *info, void *context)
+{
+  ucontext_t *oucp = context;
+  ucontext_t *ucp = (ucontext_t *) (ctx + flag);
+
+  if (! sig_ready)
+    {
+      alarm (1);
+      return;
+    }
+
+  ctx[oflag] = *oucp;
+  flags[oflag] = 1;
+
+  sig_errno_set = 1;
+  sig_errno = setcontext (ucp);
+}
+
+static int
+sig_getcontext (int uci)
+{
+  struct sigaction sa;
+
+  sigemptyset (&sa.sa_mask);
+  sa.sa_flags = SA_SIGINFO;
+  sa.sa_sigaction = sig_gethandler;
+  if (sigaction (SIGALRM, &sa, NULL) < 0)
+    {
+      printf ("%s: sigaction ALRM failed: %m\n", __FUNCTION__);
+      exit (1);
+    }
+
+  flag = uci;
+  sig_errno_set = 0;
+  sig_ready = 0;
+  alarm (1);
+
+  /* Need to get the signal in this frame.  */
+  sig_ready = 1;
+  for (count = max; count > 0; count--)
+    if (sig_errno_set)
+      break;
+
+  if (! sig_errno_set)
+    {
+      printf ("%s: ALRM signal not received\n", __FUNCTION__);
+      exit (1);
+    }
+
+  return 0;
+}
+
+static int
+sig_swapcontext (int ouci, int uci)
+{
+  struct sigaction sa;
+
+  sigemptyset (&sa.sa_mask);
+  sa.sa_flags = SA_SIGINFO;
+  sa.sa_sigaction = sig_swaphandler;
+  if (sigaction (SIGALRM, &sa, NULL) < 0)
+    {
+      printf ("%s: sigaction ALRM failed: %m\n", __FUNCTION__);
+      exit (1);
+    }
+
+  flag = uci;
+  oflag = ouci;
+  sig_errno_set = 0;
+  sig_ready = 0;
+  alarm (1);
+
+  /* Need to get the signal in this frame.  */
+  sig_ready = 1;
+  for (count = max; count > 0; count--)
+    if (sig_errno_set)
+      break;
+
+  if (! sig_errno_set)
+    {
+      printf ("%s: ALRM signal not received\n", __FUNCTION__);
+      exit (1);
+    }
+
+  return sig_errno;
+}
+
+
+static void
+f1 (int a0, int a1, int a2, int a3)
+{
+  int status;
+
+  printf ("start f1(a0=%x,a1=%x,a2=%x,a3=%x)\n", a0, a1, a2, a3);
+
+  if (a0 != 1 || a1 != 2 || a2 != 3 || a3 != -4)
+    {
+      puts ("arg mismatch");
+      exit (-1);
+    }
+
+  status = sig_swapcontext (1, 2);
+  if (status != 0)
+    {
+      printf ("%s: swapping contexts failed: %s\n",
+	      __FUNCTION__, strerror (status));
+      exit (1);
+    }
+  puts ("finish f1");
+  was_in_f1 = 1;
+}
+
+static void
+f2 (void)
+{
+  int status;
+
+  puts ("start f2");
+
+  status = sig_swapcontext (2, 1);
+  if (status != 0)
+    {
+      printf ("%s: swapping contexts failed: %s\n",
+	      __FUNCTION__, strerror (status));
+      exit (1);
+    }
+  puts ("finish f2");
+  was_in_f2 = 1;
+}
+
+
+static int back_in_main;
+
+static void
+check_called (void)
+{
+  if (back_in_main == 0)
+    {
+      printf ("%s: program did not reach main again", __FUNCTION__);
+      _exit (1);
+    }
+}
+
+
+volatile int global;
+
+int
+main (void)
+{
+  char st1[32768];
+  time_t t0, t1;
+  int status;
+
+  atexit (check_called);
+
+  puts ("calibrating delay loop");
+  for (max = 0x10000; max < LLONG_MAX / 2; max *= 2)
+    {
+      t0 = time (NULL);
+      for (count = max; count > 0; count--);
+      t1 = time (NULL);
+      if (difftime (t1, t0) > 10.0)
+	break;
+    }
+
+  puts ("making contexts");
+
+  sig_getcontext (1);
+  if (! flags[1])
+    {
+      printf ("%s: context not retrieved\n", __FUNCTION__);
+      exit (1);
+    }
+
+  /* Play some tricks with this context.  */
+  if (++global == 1)
+    if (setcontext ((ucontext_t *) &ctx[1]) != 0)
+      {
+	if (errno == ENOSYS)
+	  {
+	    back_in_main = 1;
+	    exit (0);
+	  }
+	printf ("%s: setcontext: %m\n", __FUNCTION__);
+	exit (1);
+      }
+  if (global != 2)
+    {
+      printf ("%s: 'global' not incremented twice\n", __FUNCTION__);
+      exit (1);
+    }
+
+  ctx[1].uc_stack.ss_sp = st1;
+  ctx[1].uc_stack.ss_size = sizeof st1;
+  ctx[1].uc_link = (ucontext_t *) &ctx[0];
+  {
+    ucontext_t tempctx = ctx[1];
+    makecontext ((ucontext_t *) &ctx[1], (void (*) (void)) f1, 4, 1, 2, 3, -4);
+
+    /* Without this check, a stub makecontext can make us spin forever.  */
+    if (memcmp (&tempctx, (void *) &ctx[1], sizeof ctx[1]) == 0)
+      {
+        puts ("makecontext was a no-op, presuming not implemented");
+        return 0;
+      }
+  }
+
+  sig_getcontext (2);
+  if (! flags[2])
+    {
+      printf ("%s: second context not retrieved\n", __FUNCTION__);
+      exit (1);
+    }
+
+  ctx[2].uc_stack.ss_sp = st2;
+  ctx[2].uc_stack.ss_size = sizeof st2;
+  ctx[2].uc_link = (ucontext_t *) &ctx[1];
+  makecontext ((ucontext_t *) &ctx[2], f2, 0);
+
+  puts ("swapping contexts");
+  status = sig_swapcontext (0, 2);
+  if (status != 0)
+    {
+      printf ("%s: swapping contexts failed: %s\n",
+	      __FUNCTION__, strerror (status));
+      exit (1);
+    }
+  puts ("back at main program");
+  back_in_main = 1;
+
+  if (was_in_f1 == 0)
+    {
+      puts ("didn't reach f1");
+      exit (1);
+    }
+  if (was_in_f2 == 0)
+    {
+      puts ("didn't reach f2");
+      exit (1);
+    }
+
+  puts ("test succeeded");
+  return 0;
+}