malloc

A simple implementation of glibc function malloc(), free() and realloc().

Compiled as a shared library.

For more informations see man malloc.

Malloc functions

The malloc() function allocates size bytes and returns a pointer to the allocated memory. The memory is not initialized. If size is 0, then malloc() returns either NULL, or a unique pointer value that can later be successfully passed to free().

Free functions

The free() function frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc() or realloc(). Otherwise, or if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed.

Realloc functions

The realloc() function changes the size of the memory block pointed to by ptr to size bytes. The contents will be unchanged in the range from the start of the region up to the minimum of the old and new sizes. If the new size is larger than the old size, the added memory will not be initialized. If ptr is NULL, then the call is equivalent to malloc(size), for all values of size; if size is equal to zero, and ptr is not NULL, then the call is equivalent to free(ptr). Unless ptr is NULL, it must have been returned by an earlier call to malloc() or realloc(). If the area pointed to was moved, a free(ptr) is done.

Compile

compiling:

make

cleaning obj files:

make clean

cleaning binary files:

make fclean

cleaning all and compile:

make re

How to use it

You just need to upload your malloc library instead of the glibc malloc library with this command

export LD_PRELOAD=./libmy_malloc.so

or execute your program with your malloc library

LD_PRELOAD=./libmy_malloc.so ./a.out