When you encounter errors, start with the 1. one , it might be the cause of the following errors. In this stack trace, the interresting pieces is the code of your program, as we can assume the code in the runtime/standard library to work. Valgrind tells you 2 things here: You’re accessing memory you’re not … Read more
you end up with cant_corte[i] is 0, and then you strv[i][cant_corte[i] -1] = ‘\0’; so strv[i][-1] is not a valid address to write. i do encourage you to learn how to use valgrind with gdb as explained at http://valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.gdbserver-simple
You don’t have enough space in fn. By strcat’ing on to it you overwrite the end of its stack allocation and into the stack .. hence the segmentation fault. You could try the following instead: You just have to be sure that the whole path and filename can fit into 255 characters. Alternatively you could … Read more
i am having a probem with valgrind givin me an error saying “Access not within mapped region at address 0x8”. It then says “at 0x400606: append_linked_list (testing2.c:64) by 0x400563: main (testing2.c:32)”. Line 64 is list->tail->next = newNode;, and line 32 is just calling the function which line 64 is in append_linked_list(list, (void *) argv[i]);. When … Read more
There is more than one way to define “memory leak”. In particular, there are two primary definitions of “memory leak” that are in common usage among programmers. The first commonly used definition of “memory leak” is, “Memory was allocated and was not subsequently freed before the program terminated.” However, many programmers (rightly) argue that certain … Read more
Before I read your code. Valgrind reporting invalid free error is not because of leaked memory, but you try to free invalid memory (or free same memory more than once). Compiling your code with the compilter flag -g (gdb debug), will enable more debug information, making the backtraces from valgrind much better. A quick guess:
Some more good commercial tools: Purify Insure++
I’ll explain the first error to you. At line 331, you’re probably reading an (unsigned) int, in a part of the memory you haven’t allocated for your own program. This part gives more information about the part of memory you tried to read. It says you’ve already used the memory, but reallox freed it. That … Read more
The most likely cause of uninitialized value is that at least one of b->nextU or b->U that you are adding to delta_U is itself uninitialized. That is: You would like Valgrind to report when foo becomes uninitialized. Unfortunately, doing so produces too many “false positive” warnings to be practical. You can insert into your loop calls to VALGRIND_CHECK_MEM_IS_DEFINED (see Valgrind user manual), and Valgrind … Read more
This looks wrong: Should probably be: (spaces added for convenience). EDIT: Some additional explanation: When you say return_data[i]=… you are trying to write something into return_data[i]. Now, return_data is char**, so return_data[i] is char*. So you are writing a pointer into some location in memory. It looks like your pointers are 8 bytes long (which is fine), but you’ve only allocated 6 bytes: MAX_SOURCE_STRING+1. So … Read more