Memory corruption issue

[wysota]

"Running Valgrind" does not fix your code, it's not a magic wand. Valgrind points out problems in your source code which you have to fix yourself.

[roseicollis]

Hi wysota, yes I realized that when it crashes this time, but I don't know what do I have to fix exactly.

Valgrind prints some things like this on the console:

==2848== Invalid write of size 4
==2848==    at 0x435CA6E3: pthread_mutex_init (in /usr/lib/libpthread-2.16.so)
==2848==    by 0x808A450: TLib::CSection::CSection() (Section.cpp:11)
==2848==    by 0x80773D6: CClass1::CClass1() (Class1.cpp:15)
==2848==    by 0x807C642: CClass2::CClass2() (Class2.cpp:21)
==2848==    by 0x807C800: CClass2::Initialize() (Class1.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)
==2848==  Address 0x5b09f14 is 0 bytes after a block of size 292 alloc'd
==2848==    at 0x4008AAD: operator new(unsigned int) (vg_replace_malloc.c:292)
==2848==    by 0x807C638: CClass2::CClass2() (Class2.cpp:21)
==2848==    by 0x807C800: CClass2::Initialize() (Class2.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)
 
 
==2848== Invalid read of size 4
==2848==    at 0x438EBA44: std::string::_M_mutate(unsigned int, unsigned int, unsigned int) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x438EBC32: std::string::_M_replace_safe(unsigned int, unsigned int, char const*, unsigned int) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x438EBCDB: std::string::assign(char const*, unsigned int) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x438EBF16: std::string::operator=(char const*) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x80767B4: CClass3::CClass3() (Class3.cpp:39)
==2848==    by 0x807C6E2: CClass2::CClass2() (Class2.cpp:34)
==2848==    by 0x807C800: CClass2::Initialize() (Class2.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)
==2848==  Address 0x5b15efc is 4 bytes after a block of size 48 alloc'd
==2848==    at 0x4008AAD: operator new(unsigned int) (vg_replace_malloc.c:292)
==2848==    by 0x807C6D8: CClass2::CClass2() (Class2.cpp:34)
==2848==    by 0x807C800: CClass2::Initialize() (Class2.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)

==2848== Invalid write of size 4
==2848==    at 0x435CA6E3: pthread_mutex_init (in /usr/lib/libpthread-2.16.so)
==2848==    by 0x808A450: TLib::CSection::CSection() (Section.cpp:11)
==2848==    by 0x80773D6: CClass1::CClass1() (Class1.cpp:15)
==2848==    by 0x807C642: CClass2::CClass2() (Class2.cpp:21)
==2848==    by 0x807C800: CClass2::Initialize() (Class1.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)
==2848==  Address 0x5b09f14 is 0 bytes after a block of size 292 alloc'd
==2848==    at 0x4008AAD: operator new(unsigned int) (vg_replace_malloc.c:292)
==2848==    by 0x807C638: CClass2::CClass2() (Class2.cpp:21)
==2848==    by 0x807C800: CClass2::Initialize() (Class2.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)


==2848== Invalid read of size 4
==2848==    at 0x438EBA44: std::string::_M_mutate(unsigned int, unsigned int, unsigned int) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x438EBC32: std::string::_M_replace_safe(unsigned int, unsigned int, char const*, unsigned int) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x438EBCDB: std::string::assign(char const*, unsigned int) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x438EBF16: std::string::operator=(char const*) (in /usr/lib/libstdc++.so.6.0.17)
==2848==    by 0x80767B4: CClass3::CClass3() (Class3.cpp:39)
==2848==    by 0x807C6E2: CClass2::CClass2() (Class2.cpp:34)
==2848==    by 0x807C800: CClass2::Initialize() (Class2.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)
==2848==  Address 0x5b15efc is 4 bytes after a block of size 48 alloc'd
==2848==    at 0x4008AAD: operator new(unsigned int) (vg_replace_malloc.c:292)
==2848==    by 0x807C6D8: CClass2::CClass2() (Class2.cpp:34)
==2848==    by 0x807C800: CClass2::Initialize() (Class2.cpp:51)
==2848==    by 0x805A346: BaseWizard::BaseWizard(QWidget*) (basewizard.cpp:49)
==2848==    by 0x80523A2: main (main.cpp:26)

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There are like 5 times more that information and then it throws the program. But if I run it without valdring then it says the glibc malloc() memory corruption.

note: About that references... main and basewizard are my classes on Qt (main.cppp and basewizard is the QWizard), and Class1,2,3 and CSection are from the external libraries

[wysota]

I think the log is pretty much self explanatory. You are accessing memory which you have not allocated. Look at the lines in your code where Valgrind points and see what you do there. Either BaseWizard or CCClass* are not implemented correctly.

[roseicollis]

I think the log is pretty much self explanatory. You are accessing memory which you have not allocated. Look at the lines in your code where Valgrind points and see what you do there. Either BaseWizard or CCClass* are not implemented correctly.

Yes, it is. But I had no idea why so that's why I asked here.. maybe someone had a better idea about my problem and how /where could I find the solution.

As the last version of the external library works fine, I deduce that the problem is there so I'll let the workmate who made it to fix it.


Thank you for your help! I'll tell him now all u said that it could be.

[wysota]

Yes, it is. But I had no idea why so that's why I asked here.. maybe someone had a better idea about my problem and how /where could I find the solution.

Not seeing those lines it is hard to guess what's wrong with them

As the last version of the external library works fine, I deduce that the problem is there so I'll let the workmate who made it to fix it.

I.... wouldn't be so sure if I were you.