Re: [Valgrind-users] thread errors on non-threaded program

[Nicholas N. <nj...@ca...>]

On Tue, 17 Jun 2003, Geert Fannes wrote:

> hello, i have a monolythic C++ program (3766634 bytes) for which
> valgrind gives errors like beneath. i don't know what these errors mean,
> but i don't trust the threaded stuff in it, since my program is
> non-threaded (i even don't exactly know what a threaded program is, i'm
> guessing that it has to do with forking etc.)

Threads aren't quite the same as forking, although there are similarities.
But that doesn't matter in this case; you can ignore the "thread 1's
stack" bit, if your program doesn't use threads then everything runs in a
single thread which has the number 1.

The errors mean your program is writing to memory it shouldn't;  since
this memory is on your program's stack, maybe you're writing beneath the
stack pointer... maybe you are overrunning the bounds of a stack-allocated
array?

> where can i find more information about the origin of the error and the
> error itself (i'm guessing that 15180 is some error code)? did someone
> have the same error? is my program too big? why is the --num-caller not
> working for this error, while it is for others?
>
> valgrind --leak-check=yes --num-callers=30 ./test
>
> ==15180== Invalid write of size 1
> ==15180==    at 0x80C3FDC: GRV::bLoadRVsFromFile(GDLLpGBaseObject*, char
> const*, char const*, bool) (GRV.cpp:346)
> ==15180==    Address 0xBFB388EF is on thread 1's stack
> ==15180==
> ==15180== Invalid write of size 4
> ==15180==    at 0x80C3FE2: GRV::bLoadRVsFromFile(GDLLpGBaseObject*, char
> const*, char const*, bool) (GRV.cpp:357)
> ==15180==    Address 0xBFB388E4 is on thread 1's stack

15180 is the process ID number.  I'm not sure why you don't get a larger
stack trace, that is a bit odd.  But at least you have the exact lines at
which the invalid writes are happening, hopefully that's enough to find
them?

N