#define Labyrinth (void *)alloc_page(gfp_atomic) ((new))

In this example, the labyrinth macro is used to allocate a page of memory in an atomic context. If the allocation fails, an error message is printed.

: This is a preprocessor directive in C that allows you to define a macro. A macro is a piece of code that is replaced by its value or another piece of code at compile time. #define labyrinth (void *)alloc_page(gfp_atomic)

When using this macro, keep in mind:

The student, Kai, rubbed their eyes. “It’s for the memory allocator. The kernel panics when the page fault handler runs out of scratch space. So I’m defining a labyrinth —a raw, atomic page of memory we can escape into when the normal paths are blocked.” In this example, the labyrinth macro is used

static int __init my_module_init(void) { void *my_page = labyrinth; if (my_page) { printk(KERN_INFO "Memory allocated successfully\n"); // Use my_page } else { printk(KERN_INFO "Memory allocation failed\n"); } return 0; } A macro is a piece of code that