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Hello,
My current method of hooking a api function is overwriting (while keeping the old instructions) the start of the function with a jmp instruction and a relative address.
Now I have a question about how to handle cases where the relative jump is larger than 2GB of address.
If I understand correctly this can only happen in 64bit system, right?
So I can test it by:
QWORD *my_address = (QWORD *) &myfunction;
QWORD *original_address = (QWORD *) &orignalfunction;
QWORD jump = my_address - original_address;
if (my_address > original_address && my_address - original_address > 2GB) ||
(original_address > my_address && original_address - my_address) {
//use a 64bit relative jump
}
else {
//use a 32bit relative jump
}
Will this method work on both 64bit and 32bit system/operating systems?
What instruction can use for the above 2gb case? (64bit systems)?
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Well,
I take it that you are fully familiar with Intel I86 assembler code. You must use a 64 bit Jump (jmp64)instruction to jump more than 2GB, which is larger than, and has a different opcode to, the 32 bit equivalent. At the Target of the Jmp, you must replicate all code you overwrote with your jmp64 instruction, and jump back to the first usable opcode after the Jmp64. That can require a bit of doing, in particular if your jmp64 overwrites conditional branches.
BTW I have not yet seen code which exceeds 2 GB. Undoubtedly though, MS will produce something of this size in the future. At least when that happens, you are prepared.
regards, 
Bram van Kampen
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Hi
I am using the following createfile function to open a file in network share.
HANDLE file = CreateFile(
File,
GENERIC_READ ,
FILE_SHARE_READ,
0,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
0
);
When the file name is \\10.195.1.54\Temp\expample.ini file it is giving error 5.
But when i input the network share name instead of ip like \\Extream\Temp\expample.ini it is opening.
can you please help me what is the problem i am having?
Birajendu
SonicWALL
Bangalore
India
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the system GetLastError API often can tell you about error details especially when you also try to retrieve the rror code and tranlate it into readable text. Use the following snippget of code and tell us what is the message you receive. That case you may be even be able to understand the pbm yourself.
std::string GetFormattedSystemError()
{
LPVOID lpMsgBuf;
LPVOID lpDisplayBuf;
DWORD dw = GetLastError();
FormatMessageA(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
dw,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &lpMsgBuf,
0, NULL );
char* pMessage = (char*) lpMsgBuf;
return std::string(pMessage);
}
Good luck.
Easy Profiler : a compile-time profiler for C++
www.potatosoftware.com
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birajendu wrote: When the file name is \\10.195.1.54\Temp\expample.ini file it is giving error 5.
Which equates to ERROR_ACCESS_DENIED. Are you sure that the Extream server has an IP address of 10.195.1.54?
"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
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Yes i am sure about that.cause i can open that loaction through exploler using \\10.195.1.54\temp.
it is not about the perticular extreme server in my Corporate lan. This happens with all PC prsent in Lan, If i try thru the name of the system than it works fine , but though IP it does not work.... No idea why?
I gave a another try.I connected two PC to a router. So here i got IP from router.There is no scenario of DNS here, so i tried trough IP only(some thing like \\192.168.1.2\temp\emaple.ini) and worked perfactly.
SO i am confused where is the problem?
Birajendu
SonicWALL
Bangalore
India
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I've found that calling GdiplusStartup() before CWinThread::Run is called will not work so I have been putting my logic that ensures GdiplusStartup() is called once per app instance in the CDocument constructor.
This worked fine if I only used GDI+ in the CView related code. However, I now have a need to use it as soon as possible during the application initialization.
Does anyone know of a good spot to initialize GDI+ during the application or thread initialization stages?
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When designing CWinApp based applications I always put it in the CWinApp derived constructor.
Best Wishes,
-David Delaune
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Hmmm, there must have been some issue with when to call this in Visual C++ 6.0 using the Platform SDK because I remember it wasn't that easy in those days. I remember trying to call it in various places in the CWinApp derived class but I ended up with some odd errors back then so I got it in my head that I needed to time it properly to avoid conflicts.
I guess this is no longer a problem so I apologize for the question.
thanks for the help.
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This appears to work at first, but if I try to use an open file verb on a data file, I get a "Windows cannot find file (some file path)" error.
This does not happen if I initialize GDI+ later in the process.
NOTE: I'm only using GDI+ in my CView derived OnDraw code during this test.
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I seem to remember putting it into the InitInstance method of my CWinApp derived class.
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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That works if I just open the application and then do a File/New or File/Open but if I try to run an open verb on a data file, I get a "Windows cannot find file "Some file path", then the application window opens and the document shows. (The error message box remains somewhere in the z-order.
This does not happen if I don't initialize GDI+ until the CDocument Constructor is called.
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Call Gdiplus::GdiplusStartup() in (CWinApp Derived Class)::InitInstance()
Call Gdiplus::GdiplusShutdown() in (CWinApp Derived Class)::ExitInstance()
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That does not seem to like file open verbs. If I double click on a data file for that MFC application, I get an error "Windows cannot find file (Some file path)".
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What are you talking about? What does GdiPlus have to do with file open verbs?
I created a test MDI application and replicated this behavior. It appears that the GdiPlusStartup causes a problem with DDE. The error is a child window of WindowsExplorer. Even more odd, if you exit the mdi app right after the GdiPlusStartup() call, the error still happens.
This appears to be a Microsoft bug.
modified on Monday, August 17, 2009 3:16 PM
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Joe Woodbury wrote: What are you talking about? What does GdpiPlus have to do with file open verbs?
Thread timing maybe. I dunno. I get the Windows error when I try to double click on an MDI Doc/View application data file when I try to initialize GDI+ where you advised.
It's a mystery to me as well but it is happening.
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Hmm, threw a quick MDI app together and am seeing what you describe. This is a true head scratcher.
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I think I tried suppressing the background thread before and failed but I decided to try this again. This MSDN article appears to discuss the problem but I get a runtime error if I try to implement their code snippet.
Special CWinApp Services[^]
Here on Code Project, this individuals approach to suppressing the background thread (when using GDI+ from a DLL) appears to make the problem go away. I'm not sure what is different about the two since InitInstance is called before CWinThread::Run.
Using GDI+ with MFC or native C/C++[^]
Anyway, thank you for taking some time out to investigate this. We'll see if this approach holds together.
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I got the first solution to run in VS 2005 SP1 with a bare bones app.
I need to store this solution away in my bag-o-tricks.
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Good Monday! (yeah, there goes the sympathy votes!)
I have a small dialog that let the user select one item out of around 250 items.
The items are grouped into logical categories; so I'm looking at doing something like
have two lists, one with the categories, and one containing the subsets represented
by the selected category. (i.e. a bit like the toolbar/command customize of VS2008)
Is there other new ways to present that kind of information ?
Thanks.
Max.
This signature was proudly tested on animals.
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Would a simple tree control do the trick ? Because IMHO it looks better than having two separate lists.
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Maximilien wrote: Is there other new ways to present that kind of information ?
Other: yes. New: probably.
You can put all the info in a single control with list and expansion capabilities, such as a TreeView. Here is an example[^]. It could start of in collapsed state, and expand when one of the pluses gets clicked, possibly collapsing any previous expansions.
[EDIT]link fixed]/EDIT]
Luc Pattyn [Forum Guidelines] [My Articles]
The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.
modified on Monday, August 17, 2009 10:49 AM
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Example link is not opening, can you check once?
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Link now fixed. Sorry for that.
Luc Pattyn [Forum Guidelines] [My Articles]
The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.
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As a UI layout, in a small surface, I suggest a top combobox populated with categories
and a bottom checkedListbox having the same width and populated with the "selectable" items.
Of course you intercept the combobox selection change event and you refill the listbox with item
belonging to the new active category only.
Easy Profiler : a compile-time profiler for C++
www.potatosoftware.com
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