Questions tagged [gdb]
The gdb tag has no usage guidance.
0
votes
0answers
11 views
Find applications accessing certain memory address / trace memory access
Is there some way on Linux or Unix systems to determine if a distinct physical or virtual memory address has been accessed? I know the address or list of addresses but want to know if and what ...
0
votes
0answers
14 views
SIGSEGV on dlopen with gdb
I'm currently building a shared library. The goal is to inject this lib in a process.
Unfortunaly when I inject this lib in the process I get a SIGESGV about ostream.
Here is a MWE to reproduce the ...
0
votes
1answer
23 views
Get backtrace from core dump using gdb via shell script(non interactive)
I have core dump file and gdb.
I can do
gdb <executable> <core_file>
(gdb)bt
This will give me backtrace but I want to do this using a shell script and in non-interactive mode. ...
1
vote
1answer
72 views
How to enable TUI for gdb on Debian 9?
When debugging it is often helpful to loot at assembly, but on Debian 9 when I try layout asm I get:
Undefined command: "layout". Try "help".
According to some internet research it seems like I ...
0
votes
0answers
36 views
Debugging android kernel goldifish emulator under Mac OS Mojave
I need to debug android kernel goldfish under MacOS Mojave.
So i cloned android-goldfish-3.18 and android-aosp-9.0.0_r22.
I built aosp under macos while the kernel under debian.
Obviously I built ...
0
votes
0answers
47 views
Qemu-user : get memory maps while debugging remotely
I am trying to get the memory map of a process I am debugging remotely (peda pull request link), the process is ran with qemu-user, for example:
qemu-arm -L /usr/arm-linux-gnueabihf/ -g 1234 ./ch47
...
0
votes
3answers
20 views
gdb-customize command, how to test whether a variable is set?
I'm debuging with gdb and need to define some helper commands. Basically I want my customized command to operate differently depending on the number of args given.
So I have to test whether $arg* is ...
5
votes
2answers
358 views
Safest way to force close a file descriptor
Sometimes you need to unmount a filesystem or detach a loop device but it is busy because of open file descriptors, perhaps because of a smb server process.
To force the unmount, you can kill the ...
0
votes
1answer
51 views
tracking segfault upon invocation of perl script (mytop tool and similar)
on my gentoo machine, mytop 1.9.1 quits upon invocation with the following output:
# mytop
Useless use of private variable in void context at /usr/bin/mytop line 1001.
"my" variable $data masks ...
0
votes
0answers
10 views
Thread scheduling behavior between steps of GDB compared to non-stepped execution
The GDB manual states that when using all-stop mode for debugging a multithreaded application, it is not possible to advance every thread in lock-step by exactly one statement. This makes sense since ...
4
votes
1answer
115 views
How to prevent a process from writing to the systemd journal?
I am using a third party .NET Core application (a binary distribution used by a VS Code extension) that unfortunately has diagnostic logging enabled with no apparent way to disable it (I did already ...
2
votes
2answers
63 views
How to build the GDB documentation from source?
I've downloaded the GDB source:
git clone git://sourceware.org/git/binutils-gdb.git
now how do I generate the documentation from source as can be downloaded from: https://sourceware.org/gdb/current/...
16
votes
2answers
3k views
What does C@t{++} mean in the gdb man page?
I was reading the manpage for gdb and I came across the line:
You can use GDB to debug programs written in C, C@t{++}, Fortran and Modula-2.
The C@t{++} looks like a regex but I can't seem to decode ...
4
votes
1answer
177 views
Why some libraries and other parts get repeated in the linux virtual memory with gdb?
This is the result of looking at virtual memory of a process in gdb; I have some questions regarding this:
Why are some parts of the virtual memory are repeated? For example, our program (stack6) and ...
5
votes
1answer
351 views
How to produce a VLC stack trace?
I've reported a VLC bug and included the output of gdb's bt full, but the response from a project representative is that the trace is "incomplete". How can I produce a trace that would be usable to a ...
3
votes
2answers
3k views
gdb in one command
When I debug an executable program with arguments arg1 arg2 with gdb I perform the following sequence
gdb
file ./program
run arg1 arg2
bt
quit
How can I do the same from one command line in shell ...
1
vote
0answers
346 views
Given a core-dump, how to get the files opened by the late process?
Answers to related questions all suggest using lsof or checking under /proc/NPID/, which is not helpful for when the process is already gone and only its core-dump remains.
However, it should be ...
0
votes
0answers
286 views
pstack outputs nothing. What does it mean?
Most of the time, pstack prints the stack nicely. Once in a while, I run pstack 1234 against a process 1234, and it outputs NOTHING.
I can run it again, and again it outputs nothing. Once it goes ...
0
votes
1answer
180 views
Why does pstack launch gdb (and how to prevent it)?
Running pstack on a process sometimes causes gdb to attach to that process on one of my Linux servers. Why would pstack launch gdb, and how can I prevent that?
Details:
gdb is running as: /user/bin/...
1
vote
1answer
249 views
How to trace line by line by “gdb” C/C++ code? [closed]
I have installed gdb and added -g option to my compilation command, but when I try (gdb) s or (gdb) n it says:
The program is not being run.
It only works when I try (gdb) r and goes and stops ...
-1
votes
1answer
54 views
Powerline and gdb
GDB in TUI-Mode shows strange behaviour. I'm using powerline and it seems that the font is the wrong one. Exist there a solution to have a pretty command line?
How can I invoke a program not using ...
0
votes
1answer
66 views
Install new development tools on old system
I run 32 bit Centos 6.9 Linux with installed development tools for it with command:
yum groupinstall 'Development Tools'
But it installs very old GCC and GDB. What is the best way to install newer ...
0
votes
0answers
510 views
Building newer GDB failed due C++11
I run 32 bit Centos Linux with gdb ver 7.2 on it. I need to update GDB. I got errors below while building GDB 8.1:
checking whether g++ supports C++11 features by default... no
checking whether g++ ...
1
vote
1answer
1k views
GDB command to print the address of starting of buffer (stack)
For gdb debugger
(gdb) p &buffer
This command is used to print the content of starting of buffer (stack), or print the address?
If it is content, how to print the address?
4
votes
0answers
119 views
Interrupt a slow gdb command?
I unwisely asked gdb to list all defined functions.
(gdb) info function
Now it is excitedly slurping up CPU and memory. If I'm really quick about it, GDB will stop with Ctrl-C and give me a prompt ...
6
votes
3answers
853 views
GDB step in delays
I am making a nice presentation of ARM assembly code execution and I would need GDB to step the code every 1 second infinitely long (well until I press CTRL+C). Has anyone got solution?
I don't want ...
2
votes
2answers
606 views
where does gdb put the log file?
This starts partially from why doesn't gdb like aliases
Now I put the following arguments -
gdb firefox-esr
(gdb) set logging file my-firefox-esr-1802018.log
(gdb) set pagination 0
(gdb) show ...
10
votes
4answers
1k views
why doesn't gdb like aliases [duplicate]
I made an alias ff and sourced it from ~/.zsh/aliases.zsh.
The aliases run well themselves:
alias ff
ff='firefox --safe-mode'
and it runs as expected.
But when I try to run it under gdb I get:
&...
3
votes
1answer
230 views
Accessing memory mapped registers in gdb
I'm trying to read (hopefully write as well) to the memory mapped hardware registers in a qemu virtual machine using gdb (remote connected). But it's just not working:
(gdb) p *0x2000000
Cannot ...
4
votes
0answers
277 views
gdb hangs on “quit()”
When I want to close gdb, I frequently mistype
quit()
instead of
quit
Whenever that happens, gdb hangs indeterminately, and I end up using kill -9 gdb_pid to terminate it.
I would like to ask:
...
2
votes
0answers
107 views
Is there anyway to verify validity of dlopen handle?
In my case after my program cas dlclose program is crashing and I am not getting stack trace for dlclose or any function on upper frames. I know handle value of dlclose . Is there anyway to check if ...
1
vote
1answer
727 views
How to quit an application running in gdb gracefully when the application isn't reponding.
This is somewhat related to gdb set overwrite logging on should overwrite gdb.txt correct? .
Let's say I'm running a session of some application. For example purposes, let me take the example of ...
1
vote
2answers
3k views
Turning off kASLR to debug linux kernel using qemu and gdb
I'm trying to debug linux kernel using qemu and gdb. The problem is that gdb won't stop at breakpoint. I've searched about it and found that turning kASLR off may help, because kASLR confuses gdb.
...
1
vote
1answer
408 views
How do I find detached debug symbols for decompilation?
I am trying to debug a segfault without code a binary in a nonstandard path (specifically in /frs/alg/alg/bin/) and I was noticing that the decompiled code has fewer symbols than when debugging under ...
3
votes
1answer
202 views
gdb set overwrite logging on should overwrite gdb.txt correct?
I was looking at Logging Output and had been trying this particular command -
set logging overwrite on
AFAI understood it, that command is supposed to overwrite the contents of gdb.txt but it does ...
0
votes
1answer
310 views
Quit program run by GDB when terminate screen
I am running my program using screen and GDB.
How I run my program:
screen -dmS adapter "./run-adapter.sh"
In run-adapter.sh
gdb -ex "handle SIGPIPE nostop noprint pass" -ex run -args ./Adapter ...
4
votes
1answer
1k views
Hardware breakpoint in GDB +QEMU missing start_kernel
I am trying to debug a kernel running on QEMU with GDB.
The kernel has been compiled with these options:
CONFIG_DEBUG_INFO=y
CONFIG_GDB_SCRIPTS=y
I launch the kernel in qemu with the following ...
1
vote
1answer
40 views
Switching between shared buffers in emacs gdb mode without mouse (in text-terminal)
From the documentation link here: https://www.gnu.org/software/emacs/manual/html_node/emacs/Other-GDB-Buffers.html
When gdb-many-windows is non-nil, the locals buffer shares its window with the ...
9
votes
3answers
5k views
Why does GDB need the executable as well as the core dump?
I'm debugging using core dumps, and note that gdb needs you to supply the executable as well as the core dump. Why is this? If the core dump contains all the memory that the process uses, isn't the ...
1
vote
0answers
61 views
Redirect the output to an already running program
I have a program running on terminal 1 and waiting for input from stdin. I programmed this program so it is vulnerable to buffer-overflow. I want to change it's flow to function2() within the program ...
0
votes
1answer
69 views
is there a way to know if signals are present in your application and which signals are there? [closed]
Please see what does `handle SIG33 pass nostop noprint` does when used in gdb . I am guessing from the answer shared by Stephen Kitt, that info. about signals is in the source code somewhere. If I ...
0
votes
1answer
668 views
what does `handle SIG33 pass nostop noprint` does when used in gdb
In gdb, the usual instructions for debugging given are -
gdb $package
set logging on
set pagination 0
handle SIG33 pass nostop noprint
run
and of course than collecting backtraces and all. Of ...
1
vote
2answers
329 views
Can GDB decode core if it were piped?
I have huge core files, and hence set the core_pattern is set to gzip as they are written.
Later if the backtrace is to be obtained, first gunzip has to be done (and it takes a very long time!) ...
3
votes
1answer
2k views
ptrace: Operation not permitted when attaching to a zombie process
I have a reproducible situation where a compiler instance goes into a zombie state when I rebuild a package, but gdb won't permit me to attach:
serenity ~ # ps ax | grep defunct
11351 pts/1 Z+ ...
2
votes
1answer
2k views
gdb doesn't step into function although source is available
I have a shared library compiled with -g -O0 including:
void MyClass::whatever()
{
...
doSomething(myImage, myPoints);
...
}
bool MyClass::doSomething(const Image& image, std::vector<cv:...
2
votes
1answer
762 views
Debug a setuid binary as non-root
I have a CentOS 7 system. I need to attach my GDB to an already running application, but get the (apparently usual) "ptrace: Operation not permitted." error. Running GDB as root prevents the error, ...
0
votes
1answer
246 views
guile2.0 conflicts guile?
I'm trying to install gdb which requires guile2.0 as dependency.
However guile ver.2.0.11-3 is already installed, as a dependency of make.
Now when pacman tries to install guile2.0, installation ...
-1
votes
1answer
117 views
Transferring control of ptrace to another process
I asked this question in the reverse engineering stackexchange: https://reverseengineering.stackexchange.com/questions/15169/transferring-control-of-ptrace-to-another-process
because I thought a ...
3
votes
1answer
1k views
Measure exact clock cycles for a C/assembly program
I need to measure the exact number of clock cycles it takes to execute a program. I already used the clock() function but it's values are dependent on system parameters. I could not figure out how to ...
7
votes
1answer
3k views
What exactly is and what does a core dump of process contain?
It's clear that GDB can generate a core dump of process for example via its wrapper - gcore, however it's not clear what exactly it includes and it's really hard to find an answear because different ...
