Head

GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/main/signal_handlers.cpp	Lines:	39	130	30.0 %
Date:	2021-09-15	Branches:	12	106	11.3 %


/******************************************************************************
 * Top contributors (to current version):
 *   Morgan Deters, Gereon Kremer, Andres Noetzli
 *
 * This file is part of the cvc5 project.
 *
 * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
 * in the top-level source directory and their institutional affiliations.
 * All rights reserved.  See the file COPYING in the top-level source
 * directory for licensing information.
 * ****************************************************************************
 *
 * Implementation of signal handlers.
 *
 * It is important to only call async-signal-safe functions from signal
 * handlers. See: http://man7.org/linux/man-pages/man7/signal-safety.7.html for
 * a list of async-signal-safe POSIX.1 functions.
 */

#include <string.h>

#include <cerrno>
#include <cstdio>
#include <cstdlib>
#include <exception>

#ifndef __WIN32__

#include <signal.h>
#include <sys/resource.h>
#include <unistd.h>

#endif /* __WIN32__ */

#include "base/cvc5config.h"
#include "base/exception.h"
#include "main/command_executor.h"
#include "main/main.h"
#include "util/safe_print.h"

using cvc5::Exception;
using namespace std;

namespace cvc5 {
namespace main {

/**
 * If true, will not spin on segfault even when CVC5_DEBUG is on.
 * Useful for nightly regressions, noninteractive performance runs
 * etc.
 */
bool segvSpin = false;

namespace signal_handlers {

void print_statistics()
{
  if (pExecutor != nullptr)
  {
    pExecutor->printStatisticsSafe(STDERR_FILENO);
  }
}

void timeout_handler()
{
  safe_print(STDERR_FILENO, "cvc5 interrupted by timeout.\n");
  print_statistics();
  abort();
}

#ifndef __WIN32__

#ifdef HAVE_SIGALTSTACK
size_t stackSize;
void* stackBase;
#endif /* HAVE_SIGALTSTACK */

/** Handler for SIGXCPU and SIGALRM, i.e., timeout. */
void timeout_handler(int sig, siginfo_t* info, void*) { timeout_handler(); }

/** Handler for SIGTERM. */
void sigterm_handler(int sig, siginfo_t* info, void*)
{
  safe_print(STDERR_FILENO, "cvc5 interrupted by SIGTERM.\n");
  print_statistics();
  signal(sig, SIG_DFL);
  raise(sig);
}

/** Handler for SIGINT, i.e., when the user hits control C. */
void sigint_handler(int sig, siginfo_t* info, void*)
{
  safe_print(STDERR_FILENO, "cvc5 interrupted by user.\n");
  print_statistics();
  signal(sig, SIG_DFL);
  raise(sig);
}

#ifdef HAVE_SIGALTSTACK
/** Handler for SIGSEGV (segfault). */
void segv_handler(int sig, siginfo_t* info, void* c)
{
  uintptr_t extent = reinterpret_cast<uintptr_t>(stackBase) - stackSize;
  uintptr_t addr = reinterpret_cast<uintptr_t>(info->si_addr);
#ifdef CVC5_DEBUG
  safe_print(STDERR_FILENO, "cvc5 suffered a segfault in DEBUG mode.\n");
  safe_print(STDERR_FILENO, "Offending address is ");
  safe_print(STDERR_FILENO, info->si_addr);
  safe_print(STDERR_FILENO, "\n");
  // cerr << "base is " << (void*)stackBase << endl;
  // cerr << "size is " << stackSize << endl;
  // cerr << "extent is " << (void*)extent << endl;
  if (addr >= extent && addr <= extent + 10 * 1024)
  {
    safe_print(STDERR_FILENO,
               "Looks like this is likely due to stack overflow.\n");
    safe_print(STDERR_FILENO,
               "You might consider increasing the limit with `ulimit -s' or "
               "equivalent.\n");
  }
  else if (addr < 10 * 1024)
  {
    safe_print(STDERR_FILENO, "Looks like a NULL pointer was dereferenced.\n");
  }

  if (!segvSpin)
  {
    print_statistics();
    signal(sig, SIG_DFL);
    raise(sig);
  }
  else
  {
    safe_print(STDERR_FILENO,
               "Spinning so that a debugger can be connected.\n");
    safe_print(STDERR_FILENO, "Try:  gdb ");
    safe_print(STDERR_FILENO, progName);
    safe_print(STDERR_FILENO, " ");
    safe_print<int64_t>(STDERR_FILENO, getpid());
    safe_print(STDERR_FILENO, "\n");
    safe_print(STDERR_FILENO, " or:  gdb --pid=");
    safe_print<int64_t>(STDERR_FILENO, getpid());
    safe_print(STDERR_FILENO, " ");
    safe_print(STDERR_FILENO, progName);
    safe_print(STDERR_FILENO, "\n");
    for (;;)
    {
      sleep(60);
    }
  }
#else  /* CVC5_DEBUG */
  safe_print(STDERR_FILENO, "cvc5 suffered a segfault.\n");
  safe_print(STDERR_FILENO, "Offending address is ");
  safe_print(STDERR_FILENO, info->si_addr);
  safe_print(STDERR_FILENO, "\n");
  if (addr >= extent && addr <= extent + 10 * 1024)
  {
    safe_print(STDERR_FILENO,
               "Looks like this is likely due to stack overflow.\n");
    safe_print(STDERR_FILENO,
               "You might consider increasing the limit with `ulimit -s' or "
               "equivalent.\n");
  }
  else if (addr < 10 * 1024)
  {
    safe_print(STDERR_FILENO, "Looks like a NULL pointer was dereferenced.\n");
  }
  print_statistics();
  signal(sig, SIG_DFL);
  raise(sig);
#endif /* CVC5_DEBUG */
}
#endif /* HAVE_SIGALTSTACK */

/** Handler for SIGILL (illegal instruction). */
void ill_handler(int sig, siginfo_t* info, void*)
{
#ifdef CVC5_DEBUG
  safe_print(STDERR_FILENO,
             "cvc5 executed an illegal instruction in DEBUG mode.\n");
  if (!segvSpin)
  {
    print_statistics();
    signal(sig, SIG_DFL);
    raise(sig);
  }
  else
  {
    safe_print(STDERR_FILENO,
               "Spinning so that a debugger can be connected.\n");
    safe_print(STDERR_FILENO, "Try:  gdb ");
    safe_print(STDERR_FILENO, progName);
    safe_print(STDERR_FILENO, " ");
    safe_print<int64_t>(STDERR_FILENO, getpid());
    safe_print(STDERR_FILENO, "\n");
    safe_print(STDERR_FILENO, " or:  gdb --pid=");
    safe_print<int64_t>(STDERR_FILENO, getpid());
    safe_print(STDERR_FILENO, " ");
    safe_print(STDERR_FILENO, progName);
    safe_print(STDERR_FILENO, "\n");
    for (;;)
    {
      sleep(60);
    }
  }
#else  /* CVC5_DEBUG */
  safe_print(STDERR_FILENO, "cvc5 executed an illegal instruction.\n");
  print_statistics();
  signal(sig, SIG_DFL);
  raise(sig);
#endif /* CVC5_DEBUG */
}

#endif /* __WIN32__ */

static terminate_handler default_terminator;

void cvc5terminate()
{
  set_terminate(default_terminator);
#ifdef CVC5_DEBUG
  LastExceptionBuffer* current = LastExceptionBuffer::getCurrent();
  LastExceptionBuffer::setCurrent(NULL);
  delete current;

  safe_print(STDERR_FILENO,
             "\n"
             "cvc5 was terminated by the C++ runtime.\n"
             "Perhaps an exception was thrown during stack unwinding.  "
             "(Don't do that.)\n");
  print_statistics();
  default_terminator();
#else  /* CVC5_DEBUG */
  safe_print(STDERR_FILENO,
             "cvc5 was terminated by the C++ runtime.\n"
             "Perhaps an exception was thrown during stack unwinding.\n");
  print_statistics();
  default_terminator();
#endif /* CVC5_DEBUG */
}

void install()
{
#ifdef CVC5_DEBUG
  LastExceptionBuffer::setCurrent(new LastExceptionBuffer());
#endif

#ifndef __WIN32__
  struct rlimit limit;
  if (getrlimit(RLIMIT_STACK, &limit))
  {
    throw Exception(string("getrlimit() failure: ") + strerror(errno));
  }
  if (limit.rlim_cur != limit.rlim_max)
  {
    limit.rlim_cur = limit.rlim_max;
    if (setrlimit(RLIMIT_STACK, &limit))
    {
      throw Exception(string("setrlimit() failure: ") + strerror(errno));
    }
    if (getrlimit(RLIMIT_STACK, &limit))
    {
      throw Exception(string("getrlimit() failure: ") + strerror(errno));
    }
  }

  struct sigaction act1;
  act1.sa_sigaction = sigint_handler;
  act1.sa_flags = SA_SIGINFO;
  sigemptyset(&act1.sa_mask);
  if (sigaction(SIGINT, &act1, NULL))
  {
    throw Exception(string("sigaction(SIGINT) failure: ") + strerror(errno));
  }

  struct sigaction act2;
  act2.sa_sigaction = timeout_handler;
  act2.sa_flags = SA_SIGINFO;
  sigemptyset(&act2.sa_mask);
  if (sigaction(SIGXCPU, &act2, NULL))
  {
    throw Exception(string("sigaction(SIGXCPU) failure: ") + strerror(errno));
  }

  struct sigaction act3;
  act3.sa_sigaction = ill_handler;
  act3.sa_flags = SA_SIGINFO;
  sigemptyset(&act3.sa_mask);
  if (sigaction(SIGILL, &act3, NULL))
  {
    throw Exception(string("sigaction(SIGILL) failure: ") + strerror(errno));
  }

#ifdef HAVE_SIGALTSTACK
  stack_t ss;
  ss.ss_sp = (char*)malloc(SIGSTKSZ);
  if (ss.ss_sp == NULL)
  {
    throw Exception("Can't malloc() space for a signal stack");
  }
  ss.ss_size = SIGSTKSZ;
  ss.ss_flags = 0;
  if (sigaltstack(&ss, NULL) == -1)
  {
    throw Exception(string("sigaltstack() failure: ") + strerror(errno));
  }

  stackSize = limit.rlim_cur;
  stackBase = ss.ss_sp;

  struct sigaction act4;
  act4.sa_sigaction = segv_handler;
  act4.sa_flags = SA_SIGINFO | SA_ONSTACK;
  sigemptyset(&act4.sa_mask);
  if (sigaction(SIGSEGV, &act4, NULL))
  {
    throw Exception(string("sigaction(SIGSEGV) failure: ") + strerror(errno));
  }
#endif /* HAVE_SIGALTSTACK */

  struct sigaction act5;
  act5.sa_sigaction = sigterm_handler;
  act5.sa_flags = SA_SIGINFO;
  sigemptyset(&act5.sa_mask);
  if (sigaction(SIGTERM, &act5, NULL))
  {
    throw Exception(string("sigaction(SIGTERM) failure: ") + strerror(errno));
  }

#endif /* __WIN32__ */

  default_terminator = set_terminate(cvc5terminate);
}

void cleanup() noexcept
{
#ifndef __WIN32__
#ifdef HAVE_SIGALTSTACK
  free(stackBase);
  stackBase = nullptr;
  stackSize = 0;
#endif /* HAVE_SIGALTSTACK */
#endif /* __WIN32__ */
}

}  // namespace signal_handlers
}  // namespace main
}  // namespace cvc5


Generated by: GCOVR (Version 3.2)

Line	Exec	Source
1		/******************************************************************************
2		* Top contributors (to current version):
3		* Morgan Deters, Gereon Kremer, Andres Noetzli
4		*
5		* This file is part of the cvc5 project.
6		*
7		* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
8		* in the top-level source directory and their institutional affiliations.
9		* All rights reserved. See the file COPYING in the top-level source
10		* directory for licensing information.
11		* ****************************************************************************
12		*
13		* Implementation of signal handlers.
14		*
15		* It is important to only call async-signal-safe functions from signal
16		* handlers. See: http://man7.org/linux/man-pages/man7/signal-safety.7.html for
17		* a list of async-signal-safe POSIX.1 functions.
18		*/
19
20		#include <string.h>
21
22		#include <cerrno>
23		#include <cstdio>
24		#include <cstdlib>
25		#include <exception>
26
27		#ifndef __WIN32__
28
29		#include <signal.h>
30		#include <sys/resource.h>
31		#include <unistd.h>
32
33		#endif /* __WIN32__ */
34
35		#include "base/cvc5config.h"
36		#include "base/exception.h"
37		#include "main/command_executor.h"
38		#include "main/main.h"
39		#include "util/safe_print.h"
40
41		using cvc5::Exception;
42		using namespace std;
43
44		namespace cvc5 {
45		namespace main {
46
47		/**
48		* If true, will not spin on segfault even when CVC5_DEBUG is on.
49		* Useful for nightly regressions, noninteractive performance runs
50		* etc.
51		*/
52		bool segvSpin = false;
53
54		namespace signal_handlers {
55
56		void print_statistics()
57		{
58		if (pExecutor != nullptr)
59		{
60		pExecutor->printStatisticsSafe(STDERR_FILENO);
61		}
62		}
63
64		void timeout_handler()
65		{
66		safe_print(STDERR_FILENO, "cvc5 interrupted by timeout.\n");
67		print_statistics();
68		abort();
69		}
70
71		#ifndef __WIN32__
72
73		#ifdef HAVE_SIGALTSTACK
74		size_t stackSize;
75		void* stackBase;
76		#endif /* HAVE_SIGALTSTACK */
77
78		/** Handler for SIGXCPU and SIGALRM, i.e., timeout. */
79		void timeout_handler(int sig, siginfo_t* info, void*) { timeout_handler(); }
80
81		/** Handler for SIGTERM. */
82		void sigterm_handler(int sig, siginfo_t* info, void*)
83		{
84		safe_print(STDERR_FILENO, "cvc5 interrupted by SIGTERM.\n");
85		print_statistics();
86		signal(sig, SIG_DFL);
87		raise(sig);
88		}
89
90		/** Handler for SIGINT, i.e., when the user hits control C. */
91		void sigint_handler(int sig, siginfo_t* info, void*)
92		{
93		safe_print(STDERR_FILENO, "cvc5 interrupted by user.\n");
94		print_statistics();
95		signal(sig, SIG_DFL);
96		raise(sig);
97		}
98
99		#ifdef HAVE_SIGALTSTACK
100		/** Handler for SIGSEGV (segfault). */
101		void segv_handler(int sig, siginfo_t* info, void* c)
102		{
103		uintptr_t extent = reinterpret_cast<uintptr_t>(stackBase) - stackSize;
104		uintptr_t addr = reinterpret_cast<uintptr_t>(info->si_addr);
105		#ifdef CVC5_DEBUG
106		safe_print(STDERR_FILENO, "cvc5 suffered a segfault in DEBUG mode.\n");
107		safe_print(STDERR_FILENO, "Offending address is ");
108		safe_print(STDERR_FILENO, info->si_addr);
109		safe_print(STDERR_FILENO, "\n");
110		// cerr << "base is " << (void*)stackBase << endl;
111		// cerr << "size is " << stackSize << endl;
112		// cerr << "extent is " << (void*)extent << endl;
113		if (addr >= extent && addr <= extent + 10 * 1024)
114		{
115		safe_print(STDERR_FILENO,
116		"Looks like this is likely due to stack overflow.\n");
117		safe_print(STDERR_FILENO,
118		"You might consider increasing the limit with `ulimit -s' or "
119		"equivalent.\n");
120		}
121		else if (addr < 10 * 1024)
122		{
123		safe_print(STDERR_FILENO, "Looks like a NULL pointer was dereferenced.\n");
124		}
125
126		if (!segvSpin)
127		{
128		print_statistics();
129		signal(sig, SIG_DFL);
130		raise(sig);
131		}
132		else
133		{
134		safe_print(STDERR_FILENO,
135		"Spinning so that a debugger can be connected.\n");
136		safe_print(STDERR_FILENO, "Try: gdb ");
137		safe_print(STDERR_FILENO, progName);
138		safe_print(STDERR_FILENO, " ");
139		safe_print<int64_t>(STDERR_FILENO, getpid());
140		safe_print(STDERR_FILENO, "\n");
141		safe_print(STDERR_FILENO, " or: gdb --pid=");
142		safe_print<int64_t>(STDERR_FILENO, getpid());
143		safe_print(STDERR_FILENO, " ");
144		safe_print(STDERR_FILENO, progName);
145		safe_print(STDERR_FILENO, "\n");
146		for (;;)
147		{
148		sleep(60);
149		}
150		}
151		#else /* CVC5_DEBUG */
152		safe_print(STDERR_FILENO, "cvc5 suffered a segfault.\n");
153		safe_print(STDERR_FILENO, "Offending address is ");
154		safe_print(STDERR_FILENO, info->si_addr);
155		safe_print(STDERR_FILENO, "\n");
156		if (addr >= extent && addr <= extent + 10 * 1024)
157		{
158		safe_print(STDERR_FILENO,
159		"Looks like this is likely due to stack overflow.\n");
160		safe_print(STDERR_FILENO,
161		"You might consider increasing the limit with `ulimit -s' or "
162		"equivalent.\n");
163		}
164		else if (addr < 10 * 1024)
165		{
166		safe_print(STDERR_FILENO, "Looks like a NULL pointer was dereferenced.\n");
167		}
168		print_statistics();
169		signal(sig, SIG_DFL);
170		raise(sig);
171		#endif /* CVC5_DEBUG */
172		}
173		#endif /* HAVE_SIGALTSTACK */
174
175		/** Handler for SIGILL (illegal instruction). */
176		void ill_handler(int sig, siginfo_t* info, void*)
177		{
178		#ifdef CVC5_DEBUG
179		safe_print(STDERR_FILENO,
180		"cvc5 executed an illegal instruction in DEBUG mode.\n");
181		if (!segvSpin)
182		{
183		print_statistics();
184		signal(sig, SIG_DFL);
185		raise(sig);
186		}
187		else
188		{
189		safe_print(STDERR_FILENO,
190		"Spinning so that a debugger can be connected.\n");
191		safe_print(STDERR_FILENO, "Try: gdb ");
192		safe_print(STDERR_FILENO, progName);
193		safe_print(STDERR_FILENO, " ");
194		safe_print<int64_t>(STDERR_FILENO, getpid());
195		safe_print(STDERR_FILENO, "\n");
196		safe_print(STDERR_FILENO, " or: gdb --pid=");
197		safe_print<int64_t>(STDERR_FILENO, getpid());
198		safe_print(STDERR_FILENO, " ");
199		safe_print(STDERR_FILENO, progName);
200		safe_print(STDERR_FILENO, "\n");
201		for (;;)
202		{
203		sleep(60);
204		}
205		}
206		#else /* CVC5_DEBUG */
207		safe_print(STDERR_FILENO, "cvc5 executed an illegal instruction.\n");
208		print_statistics();
209		signal(sig, SIG_DFL);
210		raise(sig);
211		#endif /* CVC5_DEBUG */
212		}
213
214		#endif /* __WIN32__ */
215
216		static terminate_handler default_terminator;
217
218		void cvc5terminate()
219		{
220		set_terminate(default_terminator);
221		#ifdef CVC5_DEBUG
222		LastExceptionBuffer* current = LastExceptionBuffer::getCurrent();
223		LastExceptionBuffer::setCurrent(NULL);
224		delete current;
225
226		safe_print(STDERR_FILENO,
227		"\n"
228		"cvc5 was terminated by the C++ runtime.\n"
229		"Perhaps an exception was thrown during stack unwinding. "
230		"(Don't do that.)\n");
231		print_statistics();
232		default_terminator();
233		#else /* CVC5_DEBUG */
234		safe_print(STDERR_FILENO,
235		"cvc5 was terminated by the C++ runtime.\n"
236		"Perhaps an exception was thrown during stack unwinding.\n");
237		print_statistics();
238		default_terminator();
239		#endif /* CVC5_DEBUG */
240		}
241
242	8800	void install()
243		{
244		#ifdef CVC5_DEBUG
245	8800	LastExceptionBuffer::setCurrent(new LastExceptionBuffer());
246		#endif
247
248		#ifndef __WIN32__
249		struct rlimit limit;
250	8800	if (getrlimit(RLIMIT_STACK, &limit))
251		{
252		throw Exception(string("getrlimit() failure: ") + strerror(errno));
253		}
254	8800	if (limit.rlim_cur != limit.rlim_max)
255		{
256		limit.rlim_cur = limit.rlim_max;
257		if (setrlimit(RLIMIT_STACK, &limit))
258		{
259		throw Exception(string("setrlimit() failure: ") + strerror(errno));
260		}
261		if (getrlimit(RLIMIT_STACK, &limit))
262		{
263		throw Exception(string("getrlimit() failure: ") + strerror(errno));
264		}
265		}
266
267		struct sigaction act1;
268	8800	act1.sa_sigaction = sigint_handler;
269	8800	act1.sa_flags = SA_SIGINFO;
270	8800	sigemptyset(&act1.sa_mask);
271	8800	if (sigaction(SIGINT, &act1, NULL))
272		{
273		throw Exception(string("sigaction(SIGINT) failure: ") + strerror(errno));
274		}
275
276		struct sigaction act2;
277	8800	act2.sa_sigaction = timeout_handler;
278	8800	act2.sa_flags = SA_SIGINFO;
279	8800	sigemptyset(&act2.sa_mask);
280	8800	if (sigaction(SIGXCPU, &act2, NULL))
281		{
282		throw Exception(string("sigaction(SIGXCPU) failure: ") + strerror(errno));
283		}
284
285		struct sigaction act3;
286	8800	act3.sa_sigaction = ill_handler;
287	8800	act3.sa_flags = SA_SIGINFO;
288	8800	sigemptyset(&act3.sa_mask);
289	8800	if (sigaction(SIGILL, &act3, NULL))
290		{
291		throw Exception(string("sigaction(SIGILL) failure: ") + strerror(errno));
292		}
293
294		#ifdef HAVE_SIGALTSTACK
295		stack_t ss;
296	8800	ss.ss_sp = (char*)malloc(SIGSTKSZ);
297	8800	if (ss.ss_sp == NULL)
298		{
299		throw Exception("Can't malloc() space for a signal stack");
300		}
301	8800	ss.ss_size = SIGSTKSZ;
302	8800	ss.ss_flags = 0;
303	8800	if (sigaltstack(&ss, NULL) == -1)
304		{
305		throw Exception(string("sigaltstack() failure: ") + strerror(errno));
306		}
307
308	8800	stackSize = limit.rlim_cur;
309	8800	stackBase = ss.ss_sp;
310
311		struct sigaction act4;
312	8800	act4.sa_sigaction = segv_handler;
313	8800	act4.sa_flags = SA_SIGINFO \| SA_ONSTACK;
314	8800	sigemptyset(&act4.sa_mask);
315	8800	if (sigaction(SIGSEGV, &act4, NULL))
316		{
317		throw Exception(string("sigaction(SIGSEGV) failure: ") + strerror(errno));
318		}
319		#endif /* HAVE_SIGALTSTACK */
320
321		struct sigaction act5;
322	8800	act5.sa_sigaction = sigterm_handler;
323	8800	act5.sa_flags = SA_SIGINFO;
324	8800	sigemptyset(&act5.sa_mask);
325	8800	if (sigaction(SIGTERM, &act5, NULL))
326		{
327		throw Exception(string("sigaction(SIGTERM) failure: ") + strerror(errno));
328		}
329
330		#endif /* __WIN32__ */
331
332	8800	default_terminator = set_terminate(cvc5terminate);
333	8800	}
334
335	6153	void cleanup() noexcept
336		{
337		#ifndef __WIN32__
338		#ifdef HAVE_SIGALTSTACK
339	6153	free(stackBase);
340	6153	stackBase = nullptr;
341	6153	stackSize = 0;
342		#endif /* HAVE_SIGALTSTACK */
343		#endif /* __WIN32__ */
344	6153	}
345
346		} // namespace signal_handlers
347		} // namespace main
348	9416	} // namespace cvc5