c - what happens when we call Malloc with negative parameter?

Question

7.22.3.4 The malloc function The malloc function allocates space for an object whose size is specified by size and whose value is indeterminate.

Prototype: void *malloc(size_t size);

I tried passing a negative value as a parameter: malloc(negative) returns NULL.

Is it because the [size_t] negative converted to unsigned [some big value] and cannot allot required space or is the function checking parameter and returns NULL?

If its getting converted to big positive, then when calling malloc(INT_MIN+2) it still returns NULL, but malloc(0) alloted to pointer and *p = somevalue works. What about this?

Is it implementation defined?

Read this link:malloc(0)

Answer 1

A size_t value is always positive even if you pass a negative value to malloc. The negative value is converted to an unsigned value of type size_t which leads to a huge positive value.

Example:

char *p = malloc(-2);

is equivalent to:

char *p = malloc(SIZE_MAX - 1);  // SIZE_MAX is the maximum
                                 // size_t value