Backtrace for osx core dump using lldb - macos

My kernel extension crash a several times so I want to get the correct backtrace (with function names) from the crash
Accroding to the article https://developer.apple.com/library/mac/technotes/tn2004/tn2118.html
I wanted to use gdb for this, but it seems that GDB does not understand the dump
dhcp80-241:KernelDebugKit gburanov$ sudo gdb -c /PanicDumps/core-xnu-2050.48.12-10.41.20.195-39882f44
GNU gdb 6.3.50-20050815 (Apple version gdb-1824) (Wed Feb 6 22:51:23 UTC 2013)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin".
Core file contained no thread-specific data
(gdb)
I heard that it is not possible by gdb, but lldb does not work as well
dhcp80-241:KernelDebugKit gburanov$ lldb
(lldb) target create -d -c /PanicDumps/core-xnu-2050.48.12-10.41.18.191-2c2bf92f /Volumes/KernelDebugKit/mach_kernel
Loading kernel debugging from /Volumes/KernelDebugKit/mach_kernel.dSYM/Contents/Resources/Python/mach_kernel.py
LLDB version LLDB-179.5
settings set target.process.python-os-plugin-path "/Volumes/KernelDebugKit/mach_kernel.dSYM/Contents/Resources/Python/lldbmacros/core/operating_system.py"
command script import "/Volumes/KernelDebugKit/mach_kernel.dSYM/Contents/Resources/Python/lldbmacros/xnu.py"
xnu debug macros loaded successfully. Run showlldbtypesummaries to enable type summaries.
error: Unable to find process plug-in for core file '/PanicDumps/core-xnu-2050.48.12-10.41.18.191-2c2bf92f'
(lldb)
What is the correct way to work with core dumps?

That looks like an lldb from Xcode 4.6 - I can't remember the state of core file support that version had -- and the kernel debug commands provided with the kenel dSYM aren't going to work with that lldb. You'll need to install Xcode 5.1 to get this to work.
The fact that gdb said it couldn't find a register context in the core file may indicate that you have a corrupt/truncated core file. The lldb in Xcode 5.1 will be a better check on that.

Related

gdb hangs after calling `run` on mac os catalina

system:
mac osx catalina (10.15.5)
gfortran 9.3.0 (from homebrew)
gdb 9.2 (from homebrew)
went through and followed these instructions:
https://sourceware.org/gdb/wiki/PermissionsDarwin
trying to debug on this program just to learn:
! test.f90
program main
integer :: val
val = 1
print *, val
val = 2
print *, val
end program main
compile with:
gfortran test.f90 -Og -g -o test
then at the terminal
~/Coding/gdb
> ./test
1
2
~/Coding/gdb $
> gdb test
GNU gdb (GDB) 9.2
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin19.4.0".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from test...
Reading symbols from /Users/a3r7lzz/Coding/gdb/test.dSYM/Contents/Resources/DWARF/test...
(gdb) run
Starting program: /Users/a3r7lzz/Coding/gdb/test
[New Thread 0x1803 of process 3054]
at this point nothing happens... it just hangs and can't kill it with Ctrl-C, I have to go to the activity monitor to kill gdb. Wondering if I have missed something in my setup, or if anyone has any other ideas why this might be
so before using gdb you have to create a ".gdbinit" file in your home directory.
Now every time gdb starts it will execute the commands in this file. ".gdbinit" is a file you can drop in your home directory that gdb will parse when gdb launches, either from the command line or from within Xcode.
echo "set startup-with-shell off" >> ~/.gdbinit
run this command and gdb won't hang when you use run command aur r.
You can kill the hang with Ctrl-Z.
Try running it several times, when setup correctly it seems to only work sometimes.
This hang hits gdb bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24069
You can install gdb from this source with patch:
brew install --force --build-from-source domq/gdb/gdb # a patched version based on 10.1
or you can
brew update
brew install gdb # use gdb 12.1
It works for me, and I found it from this link: https://gist.github.com/mike-myers-tob/9a6013124bad7ff074d3297db2c98247

Cross platform: Debugging using WSL under Windows fails when using shared dynamic libraries using Visual Studio 2019

I have a project consisting of a few libraries which is cross platform and runs and debugs just fine if all the source code is in one Visual Studio 2019 project. However, having the libraries in separate projects and I cannot debug from within the IDE at all. However, the executable will run perfectly ok from the command line in my WSL installation and on other Linux boxes. I have tried various things such as setting my LD_LIBRARY_PATH as one of the projects is a shared dynamic library, but nothing so far seems to work. Anyone have any ideas on this ? Thanks
Update: if I manually copy the dynamic library e.g.
cp libWSI.so /usr/lib/x86_64-linux-gnu/libWSI.so
debugging works. But this is not ideal.
The output I get from the Debugger is this:
=thread-group-added,id="i1"
GNU gdb (Ubuntu 8.1-0ubuntu3.1) 8.1.0.20180409-git
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
http://www.gnu.org/software/gdb/bugs/.
Find the GDB manual and other documentation resources online at:
http://www.gnu.org/software/gdb/documentation/.
For help, type "help".
Type "apropos word" to search for commands related to "word".
=cmd-param-changed,param="pagination",value="off"
Stopped due to shared library event (no libraries added or removed)
Loaded '/lib64/ld-linux-x86-64.so.2'. Symbols loaded.
[Inferior 1 (process 1438) exited with code 0177]
The thread 'WSITests.out' (0x59e) has exited with code 0 (0x0).
The program '' has exited with code 177 (0xb1).
My debugger won`t start even with the libs in the same folder when using dynamic linking. I have found a workaround here: https://github.com/Microsoft/VSLinux/issues/257
You have to make a script, let`s say "debug.sh", where you add the paths to your lib folders and run the debugger with --interpreter=mi argument. I suspect this gdb argument does the magic in this case.
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/mnt/c/Users/mircea.goga/source/repos/TestCoreCLRLinux/Out/
/usr/bin/gdb --interpreter=mi
In Visual Studio, set the path to this file to "Remote GDB Path" in "Debugging" section.
image

GDB 7.6 STL pretty print with gcc-4.8 and mac os 10.9

I'm struggling to get the pretty prints as described here in gdb working on my mac. I downloaded the latest gdb through macports and using gcc-4.8.
I loaded the ~/.gdbinit file and the printers are registered, but whenever I call
print myVector it gives me the raw output.
Any suggestions what I could do? Thanks a lot guys!
To have pretty printer with libc++ (new library used in Clang++/LLVM) use this new pretty printer:
https://github.com/koutheir/libcxx-pretty-printers
The .gdbinit is almost the same (see sample)
I've just tried with Eclipse Luna on OS X 10.10 and it works.
Any suggestions what I could do?
You can try to register pretty printers directly from gdb command line, bypassing .gdbinit file to narrow down the problem:
ks#ks-comp:~$ gdb -n
GNU gdb (GDB) 7.6.1-ubuntu
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
(gdb) python
>import sys
>sys.path.insert(0, '/home/ks/stlPrettyPrinter')
>from libstdcxx.v6.printers import register_libstdcxx_printers
>register_libstdcxx_printers (None)
>end
(gdb)
Note, that I've checked out pretty printers in /home/ks/stlPrettyPrinter folder:
ks#ks-comp:~$ ls -a /home/ks/stlPrettyPrinter
. .. hook.in index.html libstdcxx Makefile.am Makefile.in patch.txt .svn
ks#ks-comp:~$
If you're using the STL implementation in libc++ (the default with clang), GDB won't know how to pretty print the STL containers
Switch to using GNU libstdc++, and STL pretty printing in gdb should work.
STL pretty printers are implemented as Python programs that know about the implementation details of the STL containers and are maintained along with the STL implementations.
libc++ does not ship STL pretty printers that confirm to the GDB Python pretty printer API
Since you got your gcc-4.8 from MacPorts and MacPorts: Using the Right Compiler claims that gcc-* defaults to libstdc++ you should just avoid passing the -stdlib= option when using gcc.

How Should I Debug Samba with GDB

I'm not good at English, and I'm sorry about that.
Now, There is a question about when I debug samba with GDB.
# gdb /usr/local/samba/sbin/smbd
GNU gdb Red Hat Linux (5.2.1-4)
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-redhat-linux"...
(gdb) r
Starting program: /usr/local/samba/sbin/smbd
Program exited normally.
(gdb) info program
The program being debugged is not being run.
So, How should I debug samba with GDB?
ps: Version of Samba 3.0.5 I install samba from source code.
you may use sudo ./smbd -i to start smbd and see what's wrong with it.
in my case:
smbd try to find smb.conf in /usr/local/samba/etc/smb.conf and there isn't one, so exit.
i copy /etc/samba/smb.conf to the disired path , then everything ok.
hope this can help you.
Download samba source code from http://www.samba.org and compile it (without source code, it will be impossible to do symbolic debugging).
Stop or kill any other samba instances.
Start samba under gdb:
gdb <path/to/compiled/smbd>
Specify smbd parameters:
set args -i -M single
Parameters -i -M single force smbd to start as single process, do not daemonize and print all messages and errors to stdout/stderr.
Now, you can set breakpoints and trace your source code as you normally would with any other program.
Note: instead of using gdb, you might find more convenient to use gdb-tui (gdb text user interface), or use other debuggers like ddd.

Mac OS X Debug Error

On startup of my application with gdb, I am getting weird errors that look like:
unable to read unknown load command 0x22
The whole trace looks something like this:
[Session started at 2009-12-17 10:28:24 -0500.]
GNU gdb 6.3.50-20050815 (Apple version gdb-966) (Tue Mar 10 02:43:13 UTC 2009)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-apple-darwin".tty /dev/ttys003
Loading program into debugger…
sharedlibrary apply-load-rules all
warning: Unable to read symbols for "#loader_path/../Frameworks/Sparkle.framework/Versions/A/Sparkle" (file not found).
warning: Unable to read symbols from "Sparkle" (not yet mapped into memory).
unable to read unknown load command 0x22
unable to read unknown load command 0x22
Program loaded.
run
[Switching to process 9051 local thread 0x2e03]
Running…
unable to read unknown load command 0x22
unable to read unknown load command 0x22
I have tried every sort of analysis tool available, haven't been able to find any memory leaks or anything that could cause these unknown errors.
Help?
This problem has a two part fix.
One make sure that you have Sparkle Copying in in the Copy Frameworks build phase.
Secondly, adding the following script as a buildphase after the Copy Frameworks helps fix the load path on some machines.
install_name_tool -change "#loader_path/../Frameworks/Sparkle.framework/Versions/A/Sparkle" "#executable_path/../Frameworks/Sparkle.framework/Versions/A/Sparkle" "$BUILT_PRODUCTS_DIR/$EXECUTABLE_PATH"
Below is a screenshot of what this buildphase looks like in my project.
Build Phase Example http://grab.by/1OkU
And here is a screenshot of my target steps.
Target Steps http://grab.by/1fCu

Resources