Just in case someone is looking for setting environment variable from source code, here is how you do it: use std::env; fn main() { // this method needs to be inside main() method env::set_var(“RUST_BACKTRACE”, “1”); } The benefit of this approach — in contrast to manually setting the env variable from PowerShell– is that you … Read more
env SEGFAULT_SIGNALS=”abrt segv” LD_PRELOAD=/lib/libSegFault.so someapp Note that the actual path to the preload library may differ. On my machine, I’d use env SEGFAULT_SIGNALS=”abrt segv” LD_PRELOAD=/lib/x86_64-linux-gnu/libSegFault.so some-64bit-app or env SEGFAULT_SIGNALS=”abrt segv” LD_PRELOAD=/lib/i386-linux-gnu/libSegFault.so some-32bit-app depending whether the application I was running was compiled 64-bit or 32-bit. (You can use file to check.) The source tells us there … Read more
Rust uses the backtrace crate to print the backtrace in case of panics (has been merged in PR #60852). A simple example can be found in the crate documentation use backtrace::Backtrace; fn main() { let bt = Backtrace::new(); // do_some_work(); println!(“{:?}”, bt); } which gives for example stack backtrace: 0: playground::main::h6849180917e9510b (0x55baf1676201) at src/main.rs:4 1: … Read more
In order to to get stacktrace of code which caused SIGSEGV instead of stacktrace of the signal handler, you have to get ARM registers from ucontext_t and use them for unwinding. But it is hard to do with _Unwind_Backtrace(). Thus, if you use libc++ (LLVM STL) and compile for 32-bit ARM, better try precompiled libunwind, … Read more
‘?’ means that the information about this stack entry is probably not reliable. The stack output mechanism (see the implementation of dump_trace() function) was unable to prove that the address it has found is a valid return address in the call stack. ‘?’ itself is output by printk_stack_address(). The stack entry may be valid or … Read more
This should generate a readable string: error_log(print_r(debug_backtrace(), true)); Additionally, debug_print_backtrace() prints the back trace as string and its output can be captured with regular output buffer functions: ob_start(); debug_print_backtrace(); error_log(ob_get_clean());
Alright, now I got it. : ) The problem was in the SYMBOL_INFO structure. It needs to be allocated on the heap, reserving space for the symbol name, and initialized properly. Here’s the final code: void printStack( void ); void printStack( void ) { unsigned int i; void * stack[ 100 ]; unsigned short frames; … Read more
Xdebug prints a backtrace table on errors, and you don’t have to write any PHP code to implement it. Downside is you have to install it as a PHP extension.
The symbols are taken from the dynamic symbol table; you need the -rdynamic option to gcc, which makes it pass a flag to the linker which ensures that all symbols are placed in the table. (See the Link Options page of the GCC manual, and / or the Backtraces page of the glibc manual.)
Generally, the backtrace is used to get the stack of the current thread, but if there is a necessity to get the stack trace of all the threads, use the following command. thread apply all bt