I am attempting to make dereferencing null pointers illegal in my build of xv6. In order to accomplish this, I have made the following changes to the source code:
changed sz = 0 to sz = PGSIZE on exec.c:42
changed i = 0 to i = PGSIZE in the function copyuvm() on vm.c:327
added i == 0 to the or conditional in function agrptr() on syscall.c:66
set entrypoint for user code 0x1000 in Makefile:149&156
When I attempt to run xv6 in qemu with these modifications, I get the warning "panic: loaduvm: address should exist" When I run the debugger, this happens the first time loaduvm() is called by the first instance of exec(). If anyone has any pointers as to what I am missing, it would be much appreciated.
Please add -Ttext 0x1000 in _forktest target of Makefile
Related
I have 4 test patterns and all written inside a case statement in the testbench. How to call each test at a time through command line during simulation?let me know the command line argument for choosing one testbench case at a time during simulation.
Thank You
I would use a "define" or $test$plusargs and $value$plusargs for that.
You can define the value of a value on the command line using the +define+ argument.
+define+TEST_TO_RUN="4"
In your code you can now grab the value using:
case(`TEST_TO_RUN)
0 : ...
4 : ...
default: // default test or giving error message and stop
endcase
But you have to re-compile the code.
You can also set a value in the code but the command line define always overrides that.
Alternative use $test$plusargs and $value$plusargs.
You can also find information about all of that here
I am instrumenting R programs using pinatrace.so tool to generate trace for read and write memory instructions. What I observe is that multiple #eof statements get printed in the trace file at different places(which should have been actually get printed only at the end of the trace). Also, the immediate next line after #eof gets distorted and is not printed properly.
I am invoking R shell and my R program using the following command:
../../../pin -follow_execv -t obj-intel64/pinatrace.so -- /home/R-3.5.3./bin/R -f hello.R
The trace file gets printed as shown:
0 0x7ffc812cd1c8
1 0x7ffc812cd1c8
0 0x7f7f8555ee78
#eof
f6971ce8
1 0x6f4518
0 0x7ffc171a0b70
.....
.....
1 0x7ffc6da8f078
0 0x7f7c38786e78
#eof
ffc171a07c8
0 0x6f4e30
0 0x6ff918
What is wrong with this instrumentation?
When Pin is invoked with the follow_execv knob, it will create a new copy of itself in every child process that is created. The new copy is not aware that another copy is running in the parent or at all. See here:
If -follow_execv is enabled and the user has not registered to get a notification, Pin will be injected into child/exec-ed process with the same command line as of current process.
If the Pintool wasn't created with -follow_execv in mind, all copies of the Pintool will normally write to the same file. This will create strange artifacts such as what you're seeing, as different processes write to the same file and terminate it while other processes are writing after the terminator.
The simplest solution is to add a PID suffix to the file, another option is to use the Follow Child Process API (linked above) to determine which subprocess is the actual R program you want to trace. Finally, R may have support for instrumentation which you could use to instrument the program itself.
I want to execute a batch file using People code in Application Engine Program. But The program have an issue returning Exec code as a non zero value (Value - 1).
Below is people code snippet below.
Global File &FileLog;
Global string &LogFileName, &Servername, &commandline;
Local string &Footer;
If &Servername = "PSNT" Then
&ScriptName = "D: && D:\psoft\PT854\appserv\prcs\RNBatchFile.bat";
End-If;
&commandline = &ScriptName;
/* Need to commit work or Exec will fail */
CommitWork();
&ExitCode = Exec("cmd.exe /c " | &commandline, %Exec_Synchronous + %FilePath_Absolute);
If &ExitCode <> 0 Then
MessageBox(0, "", 0, 0, ("Batch File Call Failed! Exit code returned by script was " | &ExitCode));
End-If;
Any help how to resolve this issue.
Best bet is to do a trace of the execution.
Thoughts:
Can you log on the the process scheduler you are running this on and execute the script OK?
Is the AE being scheduled or called at run-time?
You should not need to change directory as you are using a fully qualified path to the script.
you should not need to call "cmd /c" as this will create an additional shell for you application to run within, making debuging harder, etc.
Run a trace, and drop us the output. :) HTH
What about changing the working directory to D: inside of the script instead? You are invoking two commands and I'm wondering what the shell is returning to exec. I'm assuming you wrote your script to give the appropriate return code and that isn't the problem.
I couldn't tell from the question text, but are you looking for a negative result, such as -1? I think return codes are usually positive. 0 for success, some other positive number for failure. Negative numbers may be acceptable, but am wondering if Exec doesn't like negative numbers?
Perhaps the PeopleCode ChDir function still works as an alternative to two commands in one line? I haven't tried it for a LONG time.
Another alternative that gives you significant control over the process is to use java.lang.Runtime.exec from PeopleCode: http://jjmpsj.blogspot.com/2010/02/exec-processes-while-controlling-stdin.html.
I am attempting to design a front end GUI for a CLI program by the name of eac3to.exe. The problem as I see it is that this program sends all of it's output to a cmd window. This is giving me no end of trouble because I need to get a lot of this output into a GUI window. This sounds easy enough, but I am begining to wonder whether I have found one of AutoIt's limitations?
I can use the Run() function with a windows internal command such as Dir and then get the output into a variable with the AutoIt StdoutRead() function, but I just can't get the output from an external program such as eac3to.exe - it just doesn't seem to work whatever I do! Just for testing purposesI I don't even need to get the output to a a GUI window: just printing it with ConsoleWrite() is good enough as this proves that I was able to read it into a variable. So at this stage that's all I need to do - get the text (usually about 10 lines) that has been output to a cmd window by my external CLI program into a variable. Once I can do this the rest will be a lot easier. This is what I have been trying, but it never works:
Global $iPID = Run("C:\VIDEO_EDITING\eac3to\eac3to.exe","", #SW_SHOW)
Global $ScreenOutput = StdoutRead($iPID)
ConsoleWrite($ScreenOutput & #CRLF)
After running this script all I get from the consolWrite() is a blank line - not the text data that was output as a result of running eac3to.exe (running eac3to without any arguments just lists a screen of help text relating to all the commandline options), and that's what I am trying to get into a variable so that I can put it to use later in the program.
Before I suggest a solution let me just tell you that Autoit has one
of the best help files out there. Use it.
You are missing $STDOUT_CHILD = Provide a handle to the child's STDOUT stream.
Also, you can't just do RUN and immediately call stdoutRead. At what point did you give the app some time to do anything and actually print something back to the console?
You need to either use ProcessWaitClose and read the stream then or, you should read the stream in a loop. Simplest check would be to set a sleep between RUN and READ and see what happens.
#include <AutoItConstants.au3>
Global $iPID = Run("C:\VIDEO_EDITING\eac3to\eac3to.exe","", #SW_SHOW, $STDOUT_CHILD)
; Wait until the process has closed using the PID returned by Run.
ProcessWaitClose($iPID)
; Read the Stdout stream of the PID returned by Run. This can also be done in a while loop. Look at the example for StderrRead.
; If the proccess doesnt end when finished you need to put this inside of a loop.
Local $ScreenOutput = StdoutRead($iPID)
ConsoleWrite($ScreenOutput & #CRLF)
I've tried to find a table with the definition for each COMPSTAT (related to the tool Control-M workload Automation) return code but without any success.
Can anyone tell me if such a table exists?
Thank you.
It's the return code from whatever task was being executed at that time. By convention, a zero value means 'OK', and anything non-zero means an error of some kind.
Different utilities (i.e. external commands) have different possible return codes, so if the command were SCP then you would look up the code in the SCP documentation, and find that for example, '67' meant 'key exchange failed'.
There is no table that contains the definition of each COMPSTAT return code.
OSCOMPSTAT stand for Control-M Operating System Completion Status.
The value of COMPSTAT is set by the exit code of the command that was called.
Example:
After calling the command [cat file1.txt] the value of COMPSTAT will be:
0 if the file "file1.txt" is found
1 if the file "file1.txt" is not found
After calling the command [ctmfw] the value of COMPSTAT will be:
0 if the specified file is found
7 if the specified file is not found