Fixed #GP from pmm_free()

kernel/src/pmm.c

@@ -9,35 +9,48 @@
 uint64_t* pmm_head = NULL;
 
 int pmm_init(void) {
+	size_t total_mem = 0;
+
 	debugf("[pmm] Physical memory map:\n"); // We're gonna use the loop to also print the memmap
 	for (size_t i = 0; i < bootloader.mm_entry_count; i++) {
 		struct limine_memmap_entry* entry = bootloader.mm_entries[i];
 		
 		debugf(
-			"\t0x%x - 0x%x (%d bytes), type %d\n",
+			"\t%p - %p (%d bytes), type %d\n",
 			entry->base, entry->base + entry->length, entry->length, entry->type
 		);
 
 		if (entry->type != LIMINE_MEMMAP_USABLE) continue;
 
+		// Limine spec says that it'll be aligned, but just as a sanity check
+		if (entry->base % PAGE_SIZE != 0) {
+			size_t diff = PAGE_SIZE - (entry->base % PAGE_SIZE);
+			debugf("\t Not 4 kiB aligned, shifting %p -> %p (%d bytes).\n", entry->base, entry->base + diff, diff);
+			entry->base += diff;
+			entry->length -= diff;
+		}
+
 		for (offset_t offset = 0; offset < entry->length; offset += PAGE_SIZE) {
-			uint64_t* addr = (uint64_t*)(entry->base + offset + bootloader.hhdm_offset);
+			uint64_t* addr = TO_VIRT(entry->base) + offset;
 			*addr = (uint64_t)pmm_head;
 			pmm_head = addr;
+			total_mem += PAGE_SIZE;
 		}
 	}
 
+	debugf("[pmm] %d bytes of available memory.\n", total_mem);
+
 	return 0;
 }
 
 void* pmm_alloc() {
 	uint64_t* addr = pmm_head;
 	pmm_head = (uint64_t*)(*addr);
-	return addr - bootloader.hhdm_offset;
+	return TO_PHYS(addr);
 }
 
 void pmm_free(void* page) {
-	uint64_t* addr = (uint64_t*)(page - bootloader.hhdm_offset);
+	uint64_t* addr = TO_VIRT(page);
 	*addr = (uint64_t)pmm_head;
 	pmm_head = addr;
 }