Head

GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/main/signal_handlers.cpp	Lines:	39	131	29.8 %
Date:	2021-08-17	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)
  {
    totalTime.reset();
    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		totalTime.reset();
61		pExecutor->printStatisticsSafe(STDERR_FILENO);
62		}
63		}
64
65		void timeout_handler()
66		{
67		safe_print(STDERR_FILENO, "cvc5 interrupted by timeout.\n");
68		print_statistics();
69		abort();
70		}
71
72		#ifndef __WIN32__
73
74		#ifdef HAVE_SIGALTSTACK
75		size_t stackSize;
76		void* stackBase;
77		#endif /* HAVE_SIGALTSTACK */
78
79		/** Handler for SIGXCPU and SIGALRM, i.e., timeout. */
80		void timeout_handler(int sig, siginfo_t* info, void*) { timeout_handler(); }
81
82		/** Handler for SIGTERM. */
83		void sigterm_handler(int sig, siginfo_t* info, void*)
84		{
85		safe_print(STDERR_FILENO, "cvc5 interrupted by SIGTERM.\n");
86		print_statistics();
87		signal(sig, SIG_DFL);
88		raise(sig);
89		}
90
91		/** Handler for SIGINT, i.e., when the user hits control C. */
92		void sigint_handler(int sig, siginfo_t* info, void*)
93		{
94		safe_print(STDERR_FILENO, "cvc5 interrupted by user.\n");
95		print_statistics();
96		signal(sig, SIG_DFL);
97		raise(sig);
98		}
99
100		#ifdef HAVE_SIGALTSTACK
101		/** Handler for SIGSEGV (segfault). */
102		void segv_handler(int sig, siginfo_t* info, void* c)
103		{
104		uintptr_t extent = reinterpret_cast<uintptr_t>(stackBase) - stackSize;
105		uintptr_t addr = reinterpret_cast<uintptr_t>(info->si_addr);
106		#ifdef CVC5_DEBUG
107		safe_print(STDERR_FILENO, "cvc5 suffered a segfault in DEBUG mode.\n");
108		safe_print(STDERR_FILENO, "Offending address is ");
109		safe_print(STDERR_FILENO, info->si_addr);
110		safe_print(STDERR_FILENO, "\n");
111		// cerr << "base is " << (void*)stackBase << endl;
112		// cerr << "size is " << stackSize << endl;
113		// cerr << "extent is " << (void*)extent << endl;
114		if (addr >= extent && addr <= extent + 10 * 1024)
115		{
116		safe_print(STDERR_FILENO,
117		"Looks like this is likely due to stack overflow.\n");
118		safe_print(STDERR_FILENO,
119		"You might consider increasing the limit with `ulimit -s' or "
120		"equivalent.\n");
121		}
122		else if (addr < 10 * 1024)
123		{
124		safe_print(STDERR_FILENO, "Looks like a NULL pointer was dereferenced.\n");
125		}
126
127		if (!segvSpin)
128		{
129		print_statistics();
130		signal(sig, SIG_DFL);
131		raise(sig);
132		}
133		else
134		{
135		safe_print(STDERR_FILENO,
136		"Spinning so that a debugger can be connected.\n");
137		safe_print(STDERR_FILENO, "Try: gdb ");
138		safe_print(STDERR_FILENO, progName);
139		safe_print(STDERR_FILENO, " ");
140		safe_print<int64_t>(STDERR_FILENO, getpid());
141		safe_print(STDERR_FILENO, "\n");
142		safe_print(STDERR_FILENO, " or: gdb --pid=");
143		safe_print<int64_t>(STDERR_FILENO, getpid());
144		safe_print(STDERR_FILENO, " ");
145		safe_print(STDERR_FILENO, progName);
146		safe_print(STDERR_FILENO, "\n");
147		for (;;)
148		{
149		sleep(60);
150		}
151		}
152		#else /* CVC5_DEBUG */
153		safe_print(STDERR_FILENO, "cvc5 suffered a segfault.\n");
154		safe_print(STDERR_FILENO, "Offending address is ");
155		safe_print(STDERR_FILENO, info->si_addr);
156		safe_print(STDERR_FILENO, "\n");
157		if (addr >= extent && addr <= extent + 10 * 1024)
158		{
159		safe_print(STDERR_FILENO,
160		"Looks like this is likely due to stack overflow.\n");
161		safe_print(STDERR_FILENO,
162		"You might consider increasing the limit with `ulimit -s' or "
163		"equivalent.\n");
164		}
165		else if (addr < 10 * 1024)
166		{
167		safe_print(STDERR_FILENO, "Looks like a NULL pointer was dereferenced.\n");
168		}
169		print_statistics();
170		signal(sig, SIG_DFL);
171		raise(sig);
172		#endif /* CVC5_DEBUG */
173		}
174		#endif /* HAVE_SIGALTSTACK */
175
176		/** Handler for SIGILL (illegal instruction). */
177		void ill_handler(int sig, siginfo_t* info, void*)
178		{
179		#ifdef CVC5_DEBUG
180		safe_print(STDERR_FILENO,
181		"cvc5 executed an illegal instruction in DEBUG mode.\n");
182		if (!segvSpin)
183		{
184		print_statistics();
185		signal(sig, SIG_DFL);
186		raise(sig);
187		}
188		else
189		{
190		safe_print(STDERR_FILENO,
191		"Spinning so that a debugger can be connected.\n");
192		safe_print(STDERR_FILENO, "Try: gdb ");
193		safe_print(STDERR_FILENO, progName);
194		safe_print(STDERR_FILENO, " ");
195		safe_print<int64_t>(STDERR_FILENO, getpid());
196		safe_print(STDERR_FILENO, "\n");
197		safe_print(STDERR_FILENO, " or: gdb --pid=");
198		safe_print<int64_t>(STDERR_FILENO, getpid());
199		safe_print(STDERR_FILENO, " ");
200		safe_print(STDERR_FILENO, progName);
201		safe_print(STDERR_FILENO, "\n");
202		for (;;)
203		{
204		sleep(60);
205		}
206		}
207		#else /* CVC5_DEBUG */
208		safe_print(STDERR_FILENO, "cvc5 executed an illegal instruction.\n");
209		print_statistics();
210		signal(sig, SIG_DFL);
211		raise(sig);
212		#endif /* CVC5_DEBUG */
213		}
214
215		#endif /* __WIN32__ */
216
217		static terminate_handler default_terminator;
218
219		void cvc5terminate()
220		{
221		set_terminate(default_terminator);
222		#ifdef CVC5_DEBUG
223		LastExceptionBuffer* current = LastExceptionBuffer::getCurrent();
224		LastExceptionBuffer::setCurrent(NULL);
225		delete current;
226
227		safe_print(STDERR_FILENO,
228		"\n"
229		"cvc5 was terminated by the C++ runtime.\n"
230		"Perhaps an exception was thrown during stack unwinding. "
231		"(Don't do that.)\n");
232		print_statistics();
233		default_terminator();
234		#else /* CVC5_DEBUG */
235		safe_print(STDERR_FILENO,
236		"cvc5 was terminated by the C++ runtime.\n"
237		"Perhaps an exception was thrown during stack unwinding.\n");
238		print_statistics();
239		default_terminator();
240		#endif /* CVC5_DEBUG */
241		}
242
243	8739	void install()
244		{
245		#ifdef CVC5_DEBUG
246	8739	LastExceptionBuffer::setCurrent(new LastExceptionBuffer());
247		#endif
248
249		#ifndef __WIN32__
250		struct rlimit limit;
251	8739	if (getrlimit(RLIMIT_STACK, &limit))
252		{
253		throw Exception(string("getrlimit() failure: ") + strerror(errno));
254		}
255	8739	if (limit.rlim_cur != limit.rlim_max)
256		{
257		limit.rlim_cur = limit.rlim_max;
258		if (setrlimit(RLIMIT_STACK, &limit))
259		{
260		throw Exception(string("setrlimit() failure: ") + strerror(errno));
261		}
262		if (getrlimit(RLIMIT_STACK, &limit))
263		{
264		throw Exception(string("getrlimit() failure: ") + strerror(errno));
265		}
266		}
267
268		struct sigaction act1;
269	8739	act1.sa_sigaction = sigint_handler;
270	8739	act1.sa_flags = SA_SIGINFO;
271	8739	sigemptyset(&act1.sa_mask);
272	8739	if (sigaction(SIGINT, &act1, NULL))
273		{
274		throw Exception(string("sigaction(SIGINT) failure: ") + strerror(errno));
275		}
276
277		struct sigaction act2;
278	8739	act2.sa_sigaction = timeout_handler;
279	8739	act2.sa_flags = SA_SIGINFO;
280	8739	sigemptyset(&act2.sa_mask);
281	8739	if (sigaction(SIGXCPU, &act2, NULL))
282		{
283		throw Exception(string("sigaction(SIGXCPU) failure: ") + strerror(errno));
284		}
285
286		struct sigaction act3;
287	8739	act3.sa_sigaction = ill_handler;
288	8739	act3.sa_flags = SA_SIGINFO;
289	8739	sigemptyset(&act3.sa_mask);
290	8739	if (sigaction(SIGILL, &act3, NULL))
291		{
292		throw Exception(string("sigaction(SIGILL) failure: ") + strerror(errno));
293		}
294
295		#ifdef HAVE_SIGALTSTACK
296		stack_t ss;
297	8739	ss.ss_sp = (char*)malloc(SIGSTKSZ);
298	8739	if (ss.ss_sp == NULL)
299		{
300		throw Exception("Can't malloc() space for a signal stack");
301		}
302	8739	ss.ss_size = SIGSTKSZ;
303	8739	ss.ss_flags = 0;
304	8739	if (sigaltstack(&ss, NULL) == -1)
305		{
306		throw Exception(string("sigaltstack() failure: ") + strerror(errno));
307		}
308
309	8739	stackSize = limit.rlim_cur;
310	8739	stackBase = ss.ss_sp;
311
312		struct sigaction act4;
313	8739	act4.sa_sigaction = segv_handler;
314	8739	act4.sa_flags = SA_SIGINFO \| SA_ONSTACK;
315	8739	sigemptyset(&act4.sa_mask);
316	8739	if (sigaction(SIGSEGV, &act4, NULL))
317		{
318		throw Exception(string("sigaction(SIGSEGV) failure: ") + strerror(errno));
319		}
320		#endif /* HAVE_SIGALTSTACK */
321
322		struct sigaction act5;
323	8739	act5.sa_sigaction = sigterm_handler;
324	8739	act5.sa_flags = SA_SIGINFO;
325	8739	sigemptyset(&act5.sa_mask);
326	8739	if (sigaction(SIGTERM, &act5, NULL))
327		{
328		throw Exception(string("sigaction(SIGTERM) failure: ") + strerror(errno));
329		}
330
331		#endif /* __WIN32__ */
332
333	8739	default_terminator = set_terminate(cvc5terminate);
334	8739	}
335
336	6110	void cleanup() noexcept
337		{
338		#ifndef __WIN32__
339		#ifdef HAVE_SIGALTSTACK
340	6110	free(stackBase);
341	6110	stackBase = nullptr;
342	6110	stackSize = 0;
343		#endif /* HAVE_SIGALTSTACK */
344		#endif /* __WIN32__ */
345	6110	}
346
347		} // namespace signal_handlers
348		} // namespace main
349	9349	} // namespace cvc5