I am working on a migration project, here we are migrating large set of C++ libraries from Mainframe to Solaris. We have complted migration sucessfully, but while running the application, some places it crashes with 'signal SEGV (no mapping at the fault address)'.
Since the application supports on windows also, we checked with purify on windows. There are no memory leaks in the application and it works fine on windows.
Can any one suggests, what could be the other reasons which may create this type of errors. Any tools for tracing this type of errors?
It's not necessarily a memory leak. It could be that a piece of memory is referenced after it is free'ed.
My friend once came to me with a piece of code that runs fine on Windows but gives segv on Linux. It turned out that sometimes the memory is still valid after you free'ed it on Windows (probably for a short period of time) but immediately triggered segv on Linux.
The line below looks wrong to me
m_BindMap[sLabel] = b; // crashes at this line at when map size
I assume you are trying to add a number to the end of the string. Try this instead
stringstream ss;
ss << ":BIND" << ns;
string sLabel = ss.str();
Are you using g++? If so, recompile with the "-g" flag. Run the program in gdb. When it crashes type "bt" (for backtrace) and that should tell you where your problem is.
I am using CC compiler on solaris and dbx debugger. I know the call stack where it is crashing. But it is abromal crash.
map<string,CDBBindParam,less<string> >m_BindMap;
CNumString ns(CNumStringTraits(0,2,'0'));
ns = m_BindMap.size();
string sLabel = ":BIND"+ns;
CDBBindParam b(sLabel,val);
**m_BindMap[sLabel] = b;** // crashes at this line at when map size is more than 2
return sLabel;
Related
I am throwing an exception throw std::exception("dummy") (as a test) which is not being caught anywhere.
Without ProcDump attached this immediately crashes the process as it should.
When I attach ProcDump with -e to a debug build, ProcDump properly detects the unhandled exception, creates a crash dump, and exits.
But the program continues executing as if the exception has never been thrown.
I could manually crash the process after ProcDump exits but I really don't like the idea that code continues to run after a crash that is supposed to be fatal even if it is just for a few ms.
What causes this? How can I make sure that my program crashes (and the crash dump properly represents the point of the crash)? Is this an issue with ProcDump or with how I am using it?
Here is a minimal example to reproduce this:
#include <iostream>
int main() {
char c;
std::cin >> c;
if (c == 'e')
throw std::exception("dummy");
std::cout << "clean exit" << std::endl;
return 0;
}
I've tried it with m$ clang-cl and msvc. I've tried every single ProcDump switch even vaguely relevant to my issue in all possible combinations with multiple binaries.
I don't have a good answer, unfortunately. It looks that there is a bug in procdump. You may report it on the Sysinternals forum or contact Mark Russinovich (#markrussinovich) or Andrew Richards (#arichardmsft). I can confirm that it happens when you attach to the process, for example, procdump -e prog. It behaves as expected when you run the app under procdump (procdump.exe -e -x . prog.exe). Procdump runs as a debugger attached to a process, so it might 'swallow' exceptions. Of course, it should not, but the API allows it to do so.
As an alternative, before procdump gets fixed, you may consider using minidumper (I contributed to it in the past). It does not have as many command-line options as procdump, but the -e option works as expected, for example, MiniDumper.exe -ma -e2 12824.
Internally, minidumper has a very similar design to procdump and also implements a debugger engine. Here is the line handling the exception event:
https://github.com/goldshtn/minidumper/blob/master/MiniDumper/Debugger.cs#L106.
Try using the -k option on ProcDump.
So if I write the following code:
MessageBoxA(0, "Yo, wazzup!", "A Greeting From Earth", 0);
the program crashes with an access violation when it exits. When I write the code like this:
int a;
a = MessageBoxA(0, "Yo, wazzup!", "A Greeting From Earth", 0);
it doesn't crash. Now I know why it crashes when it crashes thanks to another question I asked, also regarding argument-mismatching, but I don't know why it crashes.
So why does this cause an APPCRASH? I was always under the impression that calling a function that had a return-type, without actually giving one was safe, example:
int SomeFunction (void) {
std::cout << "Hello ya'll!\n";
return 42;
}
int main (void) {
int a;
// "Correct" ?
a = SomeFunction();
a = MessageBoxA(0, "Yo, wazzup!", "A Greeting From Earth", 0);
// "Incorrect" ?
SomeFunction();
MessageBoxA(0, "Yo, wazzup!", "A Greeting From Earth", 0);
}
When I run this kind of test "clean" (in a new file) I don't get any errors. It only seems to give an error with MessageBox/MessageBoxA when run in my program. Knowing the possible causes would help me pinpoint the error as the project code is too big to post (and I would need my friend's permission to post his code anyway).
Additional Info:Compiler = GCCPlatform = Windows
EDIT:
UpdateThanks everyone for your feedback so far. So I decided to run it through a debugger... Now Code::Blocks doesn't debug a project unless it is loaded from a project file (*.cbp) - AFAIK. So I created an actual project and copy-pasted our project's main file into the projects. Then I ran in debug mode and didn't get so much as a warning. I then compiled in build mode and it ran fine.Next, I decided to open a new file in Dev-C++ and run it through the debugging and later the final build process and again I got no errors for either build or debug. I cannot reproduce this error in Dev-C++, even with our main file (as in the one that causes the error in Code::Blocks).
ConclusionThe fault must lie in Code::Blocks. AFAIK, they both use GCC so I am pretty confused. The only thing I can think of is a version difference or perhaps my compiler settings or something equally obscure. Could optimizer settings or any other compiler settings somehow cause this kind of error?
The version with the return value does not crash because it had one int more on the stack. Your erroneous code reads over the bounds of the stack and then runs into an access violation. But if you have more on the stack you will not hit the guard page, because that is just enough extra stack. If the the erroneous code only reads it is sort of OK, but still broken.
We had one bit of WTF inducing code that was like so:
char dummy[52];
some_function();
There was thankfully a longish comment explaining that removing dummy, makes some_function crash. It was in a very old application so nobody dared touch it and the some_function was totally different module we had no control over. Oh yea and that application was running smoothly in the field for over 20 years in industrial installations, like refineries or nuclear power plants... ^_^
I have a 64 bits C++ server application running on windows 7 and when it does a select on the database and calls next() on the result set the process simply dies, no exceptions, no dumps and no debug info after ResultSet->next(). Writes on the database works with no problems and both reads and writes works on the 32 bit version
I'm using the 11.2 version of the win64 oracle libraries that came with instant client and SDK
EDIT: it's the simplest of codes
const std::string sql("select * from schedule_import");
std::auto_ptr<IRecordSet> query = m_conn->Open(sql);
while(query->Next()) // dies
{
const std::string key(query->GetField("bean_key"));
//...
IRecordSet is just an interface for common functions of DB drivers like next, getField and it's implemented in here
bool OracleRecordSet::Next()
{
return m_pResultSet->next() != NULL; //crashes here
}
where m_pResultSet is a oracle::occi::ResultSet*
I'm not familiared with Oracle API, but question is if m_pResultSet is not NULL (in case of segmentation fault) and if there is no exception (in case of abort(), raise() stack).
BR!
After a lot of trys my problem is solved.
I was linking my debug program to oraocci11.lib because I didn't have the debug version and I thought it didn't matter much. After a bit of search I've found the debug version of the library, oraocci11d.lib, with the corresponding dll and the crash is gone
I have a Visual C++ 9 Win32 application that uses a third-party library. When a function from that library is called with a certain set of parameters the program crashes with "exception code 0xC000000D".
I tried to attach Visual Studio debugger - no exceptions are thrown (neither C++ nor structured like access violations) and terminate() is not called either. Still the program just ends silently.
How does it happen that the program just ends abnormally but without stopping in the debugger? How can I localize the problem?
That's STATUS_INVALID_PARAMETER, use WinDbg to track down who threw it (i.e. attach WinDbg, sxe eh then g.
Other answers and comments to the question helped a lot. Here's what I did.
I notices that if I run the program under Visual Studio debugger it just ends silently, but if I run it without debugger it crashes with a message box (usual Windows message box saying that I lost my unsaved data and everyone is sooo sorry).
So I started the program wihtout debugger, let it crash and then - while the message box was still there - attached the debugger and hit "Break". Here's the call stack:
ntdll.dll!_KiFastSystemCallRet#0()
ntdll.dll!_ZwWaitForMultipleObjects#20() + 0xc bytes
kernel32.dll!_WaitForMultipleObjectsEx#20() - 0x48 bytes
kernel32.dll!_WaitForMultipleObjects#16() + 0x18 bytes
faultrep.dll!StartDWException() + 0x5df bytes
faultrep.dll!ReportFault() + 0x533 bytes
kernel32.dll!_UnhandledExceptionFilter#4() + 0x55c bytes
//SomeThirdPartyLibraryFunctionAddress
//SomeThirdPartyLibraryFunctionAddress
//SomeThirdPartyLibraryFunctionAddress
//SomeThirdPartyLibraryFunctionAddress
//OurCodeInvokingThirdPartyLibraryCode
so obviously that's some problem inside the trird-party library. According to MSDN, UnhandledExceptionFilter() is called in fatal situations and clearly the call is done because of some problem in the library code. So we'll try to work the problem out with the library vendor first.
If you don't have source and debugging information for your 3rd party library, you will not be able to step into it with the debugger. As I see it, your choices are;
Put together a simple test case illustrating the crash and send it onto the library developer
Wrap that library function in your own code that checks for illegal parameters and throw an exception / return an error code when they are passed by your own application
Rewrite the parts of the library that do not work or use an alternative
Very difficult to fix code that is provided as object only
Edit You might also be able to exit more gracefully using __try __finally around your main message loop, something like
int CMyApp::Run()
{
__try
{
int i = CWinApp::Run();
m_Exitok = MAGIC_EXIT_NO;
return i;
}
__finally
{
if (m_Exitok != MAGIC_EXIT_NO)
FaultHandler();
}
}
I have a program that makes heavy use of QSharedPointer. When I execute my program it runs fine, but when I debug it with GDB it starts throwing errors. "Invalid Address specified to RtlFreeHeap" is thrown in the following code:
QSharedPointer<PersistentList> p =
PersistentList::createEx(wrap("abc")).dynamicCast<PersistentList>();
QSharedPointer<IPersistentCollection> c = p->empty(); // Error thrown after this line
QSharedPointer<IPersistentCollection> ASeq::empty()
{
return QSharedPointer<EmptyList>(new EmptyList());
}
If I disable the p->empty() line the program runs just fine. Any ideas?
The problem is likely elsewhere in your code. Run it under Valgrind and see if you're touching any memory that's not yours, or using uninitialized data, etc.