tsan8.go

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  // This program failed when run under the C/C++ ThreadSanitizer.  The TSAN
     8  // sigaction function interceptor returned SIG_DFL instead of the Go runtime's
     9  // handler in registerSegvForwarder.
    10  
    11  /*
    12  #cgo CFLAGS: -fsanitize=thread
    13  #cgo LDFLAGS: -fsanitize=thread
    14  
    15  #include <signal.h>
    16  #include <stdio.h>
    17  #include <stdlib.h>
    18  #include <string.h>
    19  
    20  struct sigaction prev_sa;
    21  
    22  void forwardSignal(int signo, siginfo_t *info, void *context) {
    23  	// One of sa_sigaction and/or sa_handler
    24  	if ((prev_sa.sa_flags&SA_SIGINFO) != 0) {
    25  		prev_sa.sa_sigaction(signo, info, context);
    26  		return;
    27  	}
    28  	if (prev_sa.sa_handler != SIG_IGN && prev_sa.sa_handler != SIG_DFL) {
    29  		prev_sa.sa_handler(signo);
    30  		return;
    31  	}
    32  
    33  	fprintf(stderr, "No Go handler to forward to!\n");
    34  	abort();
    35  }
    36  
    37  void registerSegvFowarder() {
    38  	struct sigaction sa;
    39  	memset(&sa, 0, sizeof(sa));
    40  	sigemptyset(&sa.sa_mask);
    41  	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
    42  	sa.sa_sigaction = forwardSignal;
    43  
    44  	if (sigaction(SIGSEGV, &sa, &prev_sa) != 0) {
    45  		perror("failed to register SEGV forwarder");
    46  		exit(EXIT_FAILURE);
    47  	}
    48  }
    49  */
    50  import "C"
    51  
    52  func main() {
    53  	C.registerSegvFowarder()
    54  
    55  	defer func() {
    56  		recover()
    57  	}()
    58  	var nilp *int
    59  	*nilp = 42
    60  }
    61
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