I'm attempting to use task_policy_get from a KEXT and am receiving the following error:
sudo /usr/bin/kmutil load -p myKext
Error Domain=KMErrorDomain Code=31 "Error occurred while building a collection:
1: One or more binaries has an error which prevented linking. See other errors.
2: Could not use 'myKext' because: Failed to bind '_task_policy_get' in 'myKext' (at offset 0x320 in __DATA_CONST, __got) as could not find a kext which exports this symbol"
<key>OSBundleLibraries</key>
<dict>
<key>com.apple.kpi.bsd</key>
<string>14.0.0</string>
<key>com.apple.kpi.iokit</key>
<string>14.0.0</string>
<key>com.apple.kpi.libkern</key>
<string>14.0.0</string>
<key>com.apple.kpi.mach</key>
<string>14.0.0</string>
<key>com.apple.kpi.unsupported</key>
<string>14.0.0</string>
</dict>
I would expect that task_policy_get is a usable KPI? Can somebody point me in the right direction?
11.3 Beta (20E5210c)
Mac mini (M1, 2020)
What I am actually wanting to do is to temporarily increase the quality of service (qos) values for a process. Maybe there is a better way of doing this?
task_policy_get is a MIG interface to be called from user space. It's not listed in any .exports files in the XNU source tree, not even Private.exports, so it's not intended for calling from a kext.
Related
Hello I have installed SFML in my M1 chip Bigsur using this tutorial https://www.youtube.com/watch?v=WOyp5n2FmZY and also fixed all the error related to M1 chip.But when I run my project I get this pop ups.
popups
dyld: Library not loaded: #rpath/../Frameworks/vorbisfile.framework/Versions/A/vorbisfile
Referenced from: /Library/Frameworks/sfml-audio.framework/Versions/2.5.1/sfml-audio
Reason: no suitable image found. Did find:
/Library/Frameworks/vorbisfile.framework/Versions/A/vorbisfile: code signature in (/Library/Frameworks/vorbisfile.framework/Versions/A/vorbisfile) not valid for use in process using Library Validation: library load disallowed by system policy
It even showed pop ups for every frameworks I went to settings and gave allow for each of them. But it kept on showing same popup how can I solve this problem in BigSur
I think you will find that the library in question has been quarantined by the operating system. I would suggest:
confirm the quarantine flag ls -l# /path/to/library-or-library_bundle
remove the quarantine flag sudo xattr -d com.apple.quarantine /path/to/library-or-library_bundle
You can also go to your system preferences, then Security & Privacy. On General you see the settings for Allow apps downloaded from:. If you have a message like the one you have mentioned above, it says here "your.framework" was blocked from use because it is not from an identified developer with a button Allow Anyway next to it. Click it.
I have an OCaml program that worked fine on Ubuntu 16 but when recompiled and run on Ubuntu 20 I get the following error:-
$ ocamldebug ./linearizer
OCaml Debugger version 4.08.1
(ocd) r
Loading program... done.
Time: 89534
Program end.
Uncaught exception: Sys_error "Illegal seek"
(ocd) b
Time: 89533 - pc: 624888 - module Netaccel_link
No source file for Netaccel_link.
I thought this was due to missing dev libraries but:-
$ sudo apt install libocamlnet-ocaml-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
libocamlnet-ocaml-dev is already the newest version (4.1.6-1build6).
0 upgraded, 0 newly installed, 0 to remove and 20 not upgraded.
What setup step am I missing on Ubuntu 20?
This looks like a regression bug in libocamlnet and you should report an issue there or, I am a bit pessimistic that you will get any response, you can try to debug the issue yourself.
The problem that you are facing has nothing to do with missing libraries (they will be reported during installation or, if the package is broken, end up in linker errors). It may result, however, from some misconfiguration of the system. If that is true, then you're lucky as you can fix it yourself.
I will give you some advice that might help you in debugging this issue. For more, please try using discuss.ocaml.org as a more suitable media (SO doesn't favor this kind of a discussion and we might get deleted by admins).
The illegal seek exception is thrown when the seek operation is applied on a non-regular file, aka ESPIPE Unix error. So check your inputs. It could be that what was previously regarded as a file in Ubuntu is now a pipe or a socket.
Try to use ltrace or strace to pinpoint the culprit e.g.,
ltrace ./linearizer
or, if it overwhelms you, try strace
strace ./linearizer
Instead of using ocamldebug you can use plain gdb. You can use gdb's interfaces to provide the path to the source code (though most likely it won't work since ocamlnet is not compiled with debug information). I believe that it will give you a more meaningful backtrace.
Instead of using the system installation try using opam. Install your dependencies with opam and try older versions as well as newer versions of the OCaml compiler. Also, try different versions of ocamlnet. Ideally, try to reproduce the environment that used to work for you.
When nothing else works, you can use objdump -d and look at the disassembly of your binary. OCaml is using a pretty readable and intuitive name mangling scheme (<module_name>__<function_name>_<uid>), so you can easily find the source code (search for <module_name>.ml file and look for the <function_name> there)
Finally, just use docker or any other container to run your application. Consider switching from ocamlnet to something more modern and supported.
On Linux and Mac, when using dlopen() to load a shared library that links to another library, if linking fails because of a missing symbol, you can get the name of the missing symbol with dlerror(). It says something like
dlopen failed: cannot locate symbol "foo"
On Windows, when using LoadLibrary() to load a DLL with a missing symbol, you can only get an error code from GetLastError() which for this type of issue will always be 127. How can I figure out which symbol is missing, or a more verbose error message from LoadLibrary() that explains why the function failed?
I figured out a way using the MSYS2 terminal. Other methods might work with GUI software.
A major caveat is that this can't be done in pure C/C++ and released for end users. It's for developers only, but it's better than nothing.
Install Debugging Tools for Windows by downloading the Windows SDK and unchecking everything except Debugging Tools.
I could be wrong, but it seems that installing this software installs a hook into the Windows kernel to allow LoadLibrary() to write verbose information to stderr.
Open the MSYS2 Mingw64 terminal as an administrator and run
'/c/Program Files (x86)/Windows Kits/10/Debuggers/x64/gflags.exe' -i main.exe +sls
This prints the following to the terminal to confirm that the registry has been changed.
Current Registry Settings for main.exe executable are: 00000002
sls - Show Loader Snaps
Use -sls instead of +sls if you need to undo, since I believe that the change takes place for all programs called main.exe in Windows globally, not just for your file.
Then running main.exe should print debug information to stderr, but since I'm debugging an -mwindows application, it's not working for me.
But for some reason, running the binary with MSYS2's gdb allows this debug information to be printed to stderr.
Install mingw-w64-x86_64-gdb with MSYS2 and run gdb ./main.exe and type run or r.
Search for a section similar to the following.
warning: 1ec8:43a0 # 764081125 - LdrpNameToOrdinal - WARNING: Procedure "foo" could not be located in DLL at base 0x000000006FC40000.
warning: 1ec8:43a0 # 764081125 - LdrpReportError - ERROR: Locating export "foo" for DLL "C:\whatever\plugin.dll" failed with status: 0xc0000139.
warning: 1ec8:43a0 # 764081125 - LdrpGenericExceptionFilter - ERROR: Function LdrpSnapModule raised exception 0xc0000139
Exception record: .exr 00000000050BE5F0
Context record: .cxr 00000000050BE100
warning: 1ec8:43a0 # 764081125 - LdrpProcessWork - ERROR: Unable to load DLL: "C:\whatever\plugin.dll", Parent Module: "(null)", Status: 0xc0000139
warning: 1ec8:43a0 # 764081171 - LdrpLoadDllInternal - RETURN: Status: 0xc0000139
warning: 1ec8:43a0 # 764081171 - LdrLoadDll - RETURN: Status: 0xc0000139
Great! It says Procedure "foo" could not be located in DLL so we have our missing symbol, just like in POSIX/UNIX's dlopen().
While the answer from Remy Lebeau is technically correct, determining the missing symbol from GetLastError() is still possible on a Windows platform. To understand what exactly is missing, understanding the terminology is critical.
Symbol:
When a DLL is compiled, it's functions are referenced by symbols.
These symbols directly relate to the functions name (the symbols are
represented by visible and readable strings), its return type, and
it's parameters. The symbols can actually be read directly through a
text editor although difficult to find in large DLLs.DLL Symbols - C++ Forum
To have a missing symbol implies that a function within cannot be found. If this error occurs prior to using GetProcAddress(), then it's possible that any number of functions cannot be loaded due to missing prerequisites. This means it is possible that a library that you are attempting to load also requires a library that the first cannot load. These levels of dependency may go on for an unknown number of layers, but the only answer that GetLastError() can determine is that there was a missing symbol. One such method is by using Dependency Walker to determine the missing library the first library requires. Once all required libraries are available and can be found by that library (which can be its own can of worms), that library can be loaded via LoadLibrary().
I am getting an error:
"Error occurred during initialization of VM
Unable to load native library: Can't find dependent libraries"
The error arises when I try to execute my exe file.
I have created exe file through pyinstaller on a django application. Application uses pylucine library. I think it may be the issue of error.
How to fix the error?
Since I can't be certain given you've provided very few details here is a shot in the dark to help solve your problem:
First, try removing the jvm.dll file that gets packaged with the pyinstaller -D youmodule.py command (for now work with the directory command rather than -F option). The reason why is here.
With that jvm.dll file gone, you should start seeing the actual error code - and with that the java class or dependency that isn't being loaded.
If it's a java class that isn't being properly loaded then you know instantly it must not be correcly represented in the classpath environment variable and you should do everything in your power to make sure it is:
e.g.: os.environ['CLASSPATH'] += 'the/path/to/the/jar'
Otherwise, consider bulking up your question with more details, especially if you can get a more meaningful error output.
I had the same error trying to run a .exe built with PyInstaller through wine.
My problem went away by adding C:\Program Files\Java\ [your jdk version here] \jre\bin\server to the PATH environment variable in wine - I suppose it might be the same in Windows.
It also reappeared if I tried to build with C:\Program Files\Java\ [your jdk version here] \jre\bin\server in my PATH, so I had to build without it and then append it before running it (I have no explanation as to why this happens).
After the program I am debugging crashes, I am left with heap dump *.mdmp file & appcompat.txt in my Temp directory. I understand that appcompat.txt is an error report. Is there a description of its format?
My appcompat.txt lists a number of DLLs. Am I correct assuming that the reason for a crash could have only come from one of the listed DLLs? Can I limit my debugging effort to the DLLs listed in appcompat.txt?
Thanks in advance!
The minidump file is far more informative for diagnosing crashes:
Install Debugging Tools for Windows, if you don't already have it.
Set up the symbol path variable _NT_SYMBOL_PATH to point to the Microsoft symbol server
Run Windbg and do File -> Open Crash Dump and locate your .dmp or .mdmp file
Type !analyze -v.
This will try to isolate the location of the crash. Note that just because a crash occurs in a particular dll it doesn't mean that is where the bug resides - it could be because an invalid parameter has been passed in from your application code. The analysis should hopefully show you a meaningful stack and an error code which should help in working out the actual cause of the crash.