logo
down
shadow

Causing segfault in program doesn't get caught by signal handler


Causing segfault in program doesn't get caught by signal handler

By : user2955615
Date : November 22 2020, 10:40 AM
seems to work fine So the explanation of this is that RTEMS does not handle signals the way that I thought it does.
There are some POSIX signals which are really exceptions at the hardware level. for eg. SIGSEGV, SIGBUS, and SIGFPE. The exact semantics of what is possible when this occurs is defined by POSIX but the magic starts with an architecture and BSP specific handler. Since the general rule is to avoid these faults in embedded systems, the default action is often something like a kernal stack trace, or other BSP specific code.
code :


Share : facebook icon twitter icon
Causing segfault in system call to return to user signal handler?

Causing segfault in system call to return to user signal handler?


By : Sumanta Soren
Date : March 29 2020, 07:55 AM
hope this fix your issue No there is no way to have syscalls like write make a SIGSEGV when the buffer is wrong. Return EFAULT is part of the semantics of that write(2) syscall.
You might do LD_PRELOAD things if only concerned by libc.so ; you could also use ptrace to catch syscalls à la strace.
boost::asio signal_set handler only executes after first signal is caught and ignores consecutive signals of the same ty

boost::asio signal_set handler only executes after first signal is caught and ignores consecutive signals of the same ty


By : user2331618
Date : March 29 2020, 07:55 AM
With these it helps When your first event is handled, you don't post any new work on the service object, so it exits.
This means that then (after the ioservice exited) the tight loop is started. This may not be what you expected.
code :
#include <boost/asio.hpp>
#include <boost/asio/signal_set.hpp>
#include <boost/bind.hpp>
#include <boost/atomic.hpp>
#include <iostream>

void handler(boost::asio::signal_set& this_, boost::system::error_code error, int signal_number) {
    if (!error) {
        static boost::atomic_bool first(true);
        if(first) {
            // do something like writing data to a file
            std::cout << " A signal(SIGINT) occurred." << std::endl;
            first = false;

            this_.async_wait(boost::bind(handler, boost::ref(this_), _1, _2));
        }
        else {
            std::cout << " A second signal(SIGINT) occurred, exiting...." << std::endl;
            exit(1);
        }
    }
}

int main() {
    // Construct a signal set registered for process termination.
    boost::asio::io_service io;
    boost::asio::signal_set signals(io, SIGINT);

    // Start an asynchronous wait for one of the signals to occur.
    signals.async_wait(boost::bind(handler, boost::ref(signals), _1, _2));
    io.run();
    return 2;
}
signals.async_wait(boost::bind(handler, boost::ref(signals), _1, _2));

boost::thread(boost::bind(&boost::asio::io_service::run, boost::ref(io))).detach();

while (true)
{
    std::cout << "Some work on the main thread...\n";
    boost::this_thread::sleep_for(boost::chrono::seconds(1));
}
Some work on the main thread...
Some work on the main thread...
Some work on the main thread...
^CSome work on the main thread...
 A signal(SIGINT) occurred.
Some work on the main thread...
Some work on the main thread...
^CSome work on the main thread...
 A second signal(SIGINT) occurred, exiting....
Custom SIGINT signal handler - Program still terminates even after signal is caught

Custom SIGINT signal handler - Program still terminates even after signal is caught


By : dynaDE
Date : March 29 2020, 07:55 AM
wish helps you I am playing with the signal.h and unistd.h libraries, and I am having some issues. In the code below, when I send the SIGINT signal to my running program by calling CTRL-C, the signal is caught. However, when pressing CTRL-C again, the program terminates. As I understand it, the print statement "Received signal 2" should be printed every time I press CTRL-C. , Don't use signal, use sigaction:
Scrapinghub Getting Error caught on signal handler: <bound method ? on Yield

Scrapinghub Getting Error caught on signal handler: <bound method ? on Yield


By : Luke Xavier Scriffin
Date : March 29 2020, 07:55 AM
it should still fix some issue I have a scrapy script that works locally, but when I deploy it to Scrapinghub, it's giving all errors. Upon debugging, the error is coming from Yielding the item. , Yeah, right here:
code :
item["media"][media_index] = {}
Get line number of segfault using signal handler

Get line number of segfault using signal handler


By : Cyril Parks
Date : March 29 2020, 07:55 AM
Hope this helps That sounds like a horrible debugging environment, but if it's really infeasible to get GDB running, you could try the following (assuming Linux):
Register a handler for SIGSEGV, SIGBUS, or whatever you think the fatal signal is using sigaction(), and pass sa.sa_flags = SA_SIGINFO. Use the sa_sigaction rather than sa_handler member of struct sigaction to register the handler. The handler will receive a void *context argument. Assuming X86_64 (you will have to figure out what the corresponding index is for the instruction pointer on other architectures), you can get the address where the signal was triggered via ((ucontext_t*)context)->uc_mcontext.gregs[REG_RIP]. Once you have the address, run e.g. addr2line -Cfip -e
to get the function and line number. (If you're cross-compiling, you need to use the addr2line from the toolchain, which will probably have some prefix, e.g. arm-linux-androideabi-addr2line.)
Related Posts Related Posts :
  • C++: How to overload pow for user type?
  • C++ using arrays as multidimensional despite initalising it as 1D with pointer
  • How negate std::is_integral for use in tag dispatch?
  • Retrieve serial number from USB memory (Windows environment c++)
  • g++ error: invalid preprocessing directive #INCLUDE
  • C++ What is the std::for_each() function parameter type?
  • C++: Read individual lines from text file, sort words alphabetically
  • Saving 'this' address into a variable
  • c++ command line arguments in ubuntu terminal
  • Convert "Cartesian coordinates" to "polar coordinates with respect to user specified origin"
  • In what order are local scoped objects destructed?
  • How to use SDL_MapRGB with SDL 2.0
  • how compiler and interpreter work in case of array declaration
  • GSL integration behaves strange
  • Cropping an image with OpenCV and C
  • Find the last line in text file and select the first 10 char and print to a new file?
  • Created many CCSprits but when triggering ccTouchBegan gives the last one allways
  • seekp and seekg don't work with fstream
  • Taking input in Sublime Text 3
  • ld: -bind_at_load and -bitcode_bundle (Xcode setting ENABLE_BITCODE=YES) cannot be used together
  • C++ storing #define as std::string would give size as zero compile time
  • How to use static linking with OpenSSL in C/C++
  • What is the difference between a trap, an error, a failure and program abortion?
  • Dynamic members allocation in qt
  • How to reduce object file size when compiling for VxWorks 5.5.1?
  • Printing char by integer qualifier
  • How to write code to be executed before main() gets control?
  • Blocking socket - waitForReadyRead()
  • std::string related errors and handling them, c++
  • VM interpreter - weighting performance benefits and drawbacks of larger instruction set / dispatch loop
  • C / C++ SHIFT / OFFSET / MOVE a Bitmap to the LEFT or RIGHT?
  • Printing numbers column by column
  • How do you change your app icon in visual studio 2013?
  • Fast Screen Transfer
  • c++ Read text file and input the numbers into a 2D array
  • Why are my C++ pointers suddenly diverging?
  • Is there a macro-based adapter to make a functor from a class?
  • CRTP and multilevel inheritance
  • How to implement timer for each object in c++?
  • Stuck when testing custom list class in c++
  • Using each member of class within one function to calculate average
  • check whether if two squares are intersecting with each other
  • Glm Quaternion lookat function
  • Is there guarantee heap allocated block address will not change(implicitly)?
  • Cosine Calculation without cmath library
  • Manually deleting a pointer returned by function
  • Avoid output interleaving
  • C++ error : Expected an identifier
  • Segmentation fault when I call operator new in linux mint
  • Recursively Solving A Sudoku Puzzle Using Backtracking Theoretically
  • lambda closure type and default argument in function template
  • How to ensure the function return consistent floating point values in C/C++?
  • What does throw do when not in used with try and catch?
  • The Unpredictablilty of the Order of Evaluation of Subexpressions
  • cannot convert const wchar_t to 'const_char' for argument 2 in MessageBOX etc etc
  • Size of a empty Class & Derived Virtual Class
  • unformatted i/o to and from memory
  • Storing an std::thread object as a class member
  • Remove duplicate string in an array
  • How to use copy_if() polymorphically?
  • shadow
    Privacy Policy - Terms - Contact Us © ourworld-yourmove.org