In kernel you’ll see two type of variaidic macro

1

#define __stringify(x...)	   __stringify_1(x)

this is same as

1

#define __stringify(...)	   __stringify_1(__VA_ARGS__)

In standard C99 and later, a variadic macro must look like above one, However, GCC introduced an extension that allows you to give a name to the variable arguments by placing the ellipsis immediately after an identifier (x...). When you write x..., the compiler treats x as a named parameter that bundles everything passed into the macro (including any commas separating multiple arguments).

Note: there is ellipsis (...) parameter for c function also, that allow the function to accept any number of pararmeters.