looping kalloc can allocate all of memory (sometimes) :3

Makefile

@@ -1,62 +1,59 @@
-SRC_DIR=src
+KERNEL=kernel.bin
-INCLUDE_DIR=include
+ISO=os_image.iso
-BUILD_DIR=build
-
-K_BIN_NAME=kernel.bin
-ISO_NAME=os_image.iso
 
+ARCH=amd64
 CC=cc
 LD=ld
 AS=nasm
 
-CFLAGS+=-std=c2x -ffreestanding -fno-stack-protector -g -Wall -Wextra -pedantic -lgcc -isystem $(INCLUDE_DIR)
+CFLAGS += -std=c2x -ffreestanding -fno-stack-protector -g -Wall -Wextra -pedantic -lgcc -isystem include
-CFLAGS+=-DPAGE_SIZE=4096
+CFLAGS += -DPAGE_SIZE=4096
 
-LDFLAGS+=-nmagic
+LDFLAGS += -nmagic -nostdlib
 
-C_SRC=$(shell find $(SRC_DIR) -type f -name "*.c")
+H_SRC = $(shell find src include -type f -name "*.h")
-C_OBJ=$(patsubst %.c,$(BUILD_DIR)/%.o,$(C_SRC))
 
-H_SRC=$(shell find $(SRC_DIR) -type f -name "*.h")
+C_SRC = $(shell find src -type f -name "*.c")
-H_INCLUDE=$(shell find $(INCLUDE_DIR) -type f -name "*.h")
+C_OBJ = $(patsubst %.c,build/%.o,$(C_SRC))
 
-A_SRC=$(shell find $(SRC_DIR) -type f -name "*.S")
+A_SRC  = $(shell find src -type f -name "*.S" -not -path "src/arch/*")
-A_OBJ=$(patsubst %.S,$(BUILD_DIR)/%.S.o,$(A_SRC))
+A_SRC += $(shell find src/arch/$(ARCH) -type f -name "*.S")
+A_OBJ  = $(patsubst %.S,build/%.S.o,$(A_SRC))
 
 .PHONY: all clean
 
-all: $(BUILD_DIR)/$(ISO_NAME)
+all: build/$(ISO)
 
 clean:
-	@printf "\033[31m  RM  \033[0m%s\n" $(BUILD_DIR)
+	@printf "\033[31m  RM  \033[0m%s\n" build
-	@rm -rf $(BUILD_DIR)/*
+	@rm -rf build/*
 
-$(A_OBJ): $(BUILD_DIR)/%.S.o : %.S
+$(A_OBJ): build/%.S.o : %.S
 	@mkdir -p $(@D)
 	@printf "\033[33m  AS  \033[0m%s\n" $<
 	@nasm $< -f elf64 -o $@
 
-$(C_OBJ): $(BUILD_DIR)/%.o : %.c
+$(C_OBJ): build/%.o : %.c
 	@mkdir -p $(@D)
 	@printf "\033[34m  CC  \033[0m%s\n" $<
 	@$(CC) -c $(CFLAGS) -o $@ $<
 
-$(BUILD_DIR)/$(K_BIN_NAME): arch/amd64/linker.ld $(A_OBJ) $(C_OBJ) $(H_SRC) $(H_INCLUDE)
+build/$(KERNEL): arch/$(ARCH)/linker.ld $(A_OBJ) $(C_OBJ) $(H_SRC)
 	@mkdir -p $(@D)
 	@printf "\033[32m  LD  \033[0m%s\n" $@
-	@$(LD) $(LDFLAGS) --no-warn-rwx-segments -T arch/amd64/linker.ld -o $(BUILD_DIR)/$(K_BIN_NAME) $(A_OBJ) $(C_OBJ)
+	@$(LD) $(LDFLAGS) --no-warn-rwx-segments -T arch/$(ARCH)/linker.ld -o build/$(KERNEL) $(A_OBJ) $(C_OBJ)
 
-$(BUILD_DIR)/$(ISO_NAME): $(BUILD_DIR)/$(K_BIN_NAME) grub.cfg
+build/$(ISO): build/$(KERNEL) grub.cfg
 	@mkdir -p $(@D)
-	@mkdir -p $(BUILD_DIR)/iso/boot/grub
+	@mkdir -p build/iso/boot/grub
-	@cp grub.cfg $(BUILD_DIR)/iso/boot/grub
+	@cp grub.cfg build/iso/boot/grub
-	@cp $(BUILD_DIR)/$(K_BIN_NAME) $(BUILD_DIR)/iso/boot
+	@cp build/$(KERNEL) build/iso/boot
-	@printf "\033[35m ISO  \033[0m%s\n" $(BUILD_DIR)/$(ISO_NAME)
+	@printf "\033[35m ISO  \033[0m%s\n" build/$(ISO)
-	@grub-mkrescue -o $(BUILD_DIR)/$(ISO_NAME) $(BUILD_DIR)/iso 2> /dev/null
+	@grub-mkrescue -o build/$(ISO) build/iso 2> /dev/null
 
 run: all
 	@qemu-system-x86_64 \
-		-cdrom $(BUILD_DIR)/$(ISO_NAME) \
+		-cdrom build/$(ISO) \
 		-serial stdio \
 		-display gtk,show-menubar=off,zoom-to-fit=on \
 		-m 1G \

arch/amd64/linker.ld

@@ -31,6 +31,7 @@ SECTIONS {
 
 	.bss BLOCK(4K) : ALIGN(4K)
 	{
+		*(COMMON)
 		*(.bss)
 	}
 

src/arch/amd64/paging.c

@@ -103,7 +103,7 @@ static void load_pd(void *phys) {
 		return;
 	pt->address = (uint64_t)phys >> 12;
 	pt->flags = F_PRESENT | F_WRITEABLE;
-	invlpg(pdpt_mapped);
+	invlpg(pd_mapped);
 }
 
 static void load_pt(void *phys) {
@@ -456,10 +456,14 @@ static int map_pages(
 
 		page->address = (uint64_t)phys >> 12;
 		page->flags = F_PRESENT | flags;
-		invlpg(virt);
+
+		if (flags & F_GLOBAL)
+			invlpg(virt);
 
 	}
 
+	__asm volatile("mov %cr3, %rax; mov %rax, %cr3;");
+
 	return 0;
 
 failed:

src/kmain.c

@@ -8,8 +8,8 @@
 
 void kmain(struct boot_info *info) {
 	memory_init(&info->map);
-	//acpi_init(info->acpi_table);
 	//fb_init(1024, 768);
+	//acpi_init(info->acpi_table);
 
 	kprintf("enterd kmain\n");
 
@@ -17,7 +17,7 @@ void kmain(struct boot_info *info) {
 	*(char *)(0xB8000 + 0x146) = 'i';
 
 	while (1) {
-		//kprintf("ret: 0x%p\n", kalloc(1024));
+		__asm__("hlt;");
 		// loop so we dont halt
 		// this allows interrupts to fire
 	}

src/lib.c

@@ -31,7 +31,6 @@ void *memmove(void *dest, const void *src, unsigned long n) {
 }
 
 void *memset(void *restrict dest, int c, unsigned long n) {
-
 	unsigned char *d = dest;
 	for (; n; n--) *d++ = c;
 	return dest;

src/memory/memory.c

@@ -1,4 +1,3 @@
-#include "serial.h"
 #include <memory.h>
 #include <stdint.h>
 #include <lib.h>
@@ -52,6 +51,7 @@ void *kalloc_new(size_t size) {
 		node = 0;
 	}
 
+	memset(addr, 0, pages * PAGE_SIZE);
 	struct page_header *header = addr;
     header->magic = 0xBEEFCAFE;
 	header->used = size;
@@ -66,6 +66,8 @@ void *kalloc_new(size_t size) {
 
 	if (end_header != NULL) {
 		end_header->next = header;
+	} else {
+		end_header = header;
 	}
 
 	return mem;
@@ -146,7 +148,12 @@ void *krealloc(void *src, size_t dst_len) {
 		return NULL; // allocation failed
 	}
 
+	if (dst_len < src_len)
+		src_len = dst_len;
+
 	memcpy(dst, src, src_len);
+	kfree(src);
+
 	return dst;
 }
 
@@ -159,7 +166,7 @@ void kfree(void *ptr) {
 
 	header = get_header(ptr);
 
-	if (header == NULL || header->used == 0) {
+	if (header == NULL) {
 		panic("attempted to kfree invalid pointer");
 	}
 

src/memory/physalloc.c

@@ -1,4 +1,3 @@
-#include "serial.h"
 #include <memory.h>
 #include <stdint.h>
 #include <lib.h>
@@ -15,8 +14,6 @@ extern char kernel_end;
 // between memory_start and kernel_start will be the bitmap
 static uintptr_t memory_start = 0;
 
-typedef unsigned char page[4096];
-
 struct memory_area {
 	uint64_t len;
 	uintptr_t addr;
@@ -26,9 +23,8 @@ static uint64_t *bitmap;
 static uint64_t total_memory;
 static uint64_t free_memory;
 static uint64_t page_count;
-static uint64_t page_free_start;
 static uint64_t segment_count;
-static struct memory_area *page_start;
+struct memory_area *page_start;
 
 static int n_pages(const struct memory_area *m) {
 	return m->len / PAGE_SIZE;
@@ -37,7 +33,7 @@ static int n_pages(const struct memory_area *m) {
 static void *page_at(int i) {
 	int cur_page = 0;
 	for (uint64_t idx = 0; idx < segment_count; idx++) {
-		struct memory_area *m = &page_start[idx];
+		const struct memory_area *m = page_start;
 		int pages = n_pages(m);
 		if (i - cur_page < pages) {
 			return (void *) (m->addr + (PAGE_SIZE * (i - cur_page)));
@@ -47,10 +43,11 @@ static void *page_at(int i) {
 	return NULL;
 }
 
-static long page_idx(page p) {
+static long page_idx(void *page) {
-	uintptr_t addr = (uintptr_t) p;
+	uintptr_t addr = (uintptr_t) page;
 	int cur_page = 0;
-	for (struct memory_area *m = page_start; m != NULL; m++) {
+	for (uint64_t idx = 0; idx < segment_count; idx++) {
+		const struct memory_area *m = page_start;
 		if ((uintptr_t) m + m->len > addr) {
 			return cur_page + ((addr - m->addr) / PAGE_SIZE);
 		}
@@ -82,15 +79,9 @@ void *alloc_phys_pages(int pages) {
 
 	int n_contiguous = 0;
 	int free_region_start = 0;
-	bool first = true;
+	for (uint64_t i = 0; i < page_count; i++) {
-	for (uint64_t i = page_free_start; i < page_count; i++) {
 		bool free = !bitmap_get(i);
 
-		if (first) {
-			first = false;
-			page_free_start = i;
-		}
-
 		if (free) {
 			if (n_contiguous == 0) free_region_start = i;
 			n_contiguous++;
@@ -113,8 +104,6 @@ void free_phys_pages(void *ptr, int pages) {
 	long idx = page_idx(ptr);
 	if (idx == -1) return;
 
-	if ((unsigned) idx < page_free_start) page_free_start = idx;
-
 	for (int i = 0; i < pages; i++)
 		bitmap_set(idx + pages, false);
 }
@@ -165,7 +154,6 @@ void memory_init(struct memory_map *map) {
 	total_memory = 0;
 	free_memory = 0;
 	page_count = 0;
-	page_free_start = 0;
 	page_start = NULL;
 
 	segment_count = 0;
@@ -181,21 +169,21 @@ void memory_init(struct memory_map *map) {
 		segment_count++;
 	}
 
-	long bitmap_pages = page_count / 64 / PAGE_SIZE + 1;
+	long bitmap_pages = (page_count / 64 / PAGE_SIZE) + 1;
-	free_memory = page_count * PAGE_SIZE;
-
-	//HACK: terrible hack bad bad bad bad
 	long bitmap_size = bitmap_pages * PAGE_SIZE;
 	bitmap = (uint64_t *) page_align(kaddr(kernel_end));
 
 	long page_area_size = segment_count * sizeof(struct memory_area);
 	char *page_area_addr = (char *)bitmap + bitmap_size;
+	page_area_addr = (char *) page_align((uintptr_t) page_area_addr);
+
+	memory_start = page_align((uintptr_t)page_area_addr + page_area_size);
+
 	bitmap = mmap(bitmap, bitmap_size);
 	memset(bitmap, 0, bitmap_size);
-
-	memory_start = page_align(kaddr(kernel_end) + bitmap_size + page_area_size);
-
 	page_area_addr = mmap(page_area_addr, page_area_size);
+	memset(page_area_addr, 0, page_area_size);
+
 	page_start = (struct memory_area *) page_area_addr;
 
 	struct memory_area *area = page_start;

src/memory/virtalloc.c

@@ -35,6 +35,32 @@ static struct addr_node *get_node_idx(int idx) {
 	}
 }
 
+static void update_node_ptrs(
+		struct addr_node *old,
+		struct addr_node *new,
+		int old_len,
+		int new_len
+) {
+	if (old == NULL)
+		return;
+	int idx = 0;
+	for (int i = 0; i < old_len; i++) {
+		struct addr_node *o = &old[i];
+		if (o && !o->is_used)
+			continue;
+		struct addr_node *n = &new[idx++];
+		*n = *o;
+		if (n->prev != NULL)
+			n->prev->next = n;
+		if (n->next != NULL)
+			n->next->prev = n;
+	}
+	for (int i = idx; i < new_len; i++) {
+		struct addr_node *n = &new[idx++];
+		n->is_used = false;
+	}
+}
+
 static struct addr_node *get_node(void) {
 	size_t count = BSS_NODES + alloc_node_count;
 
@@ -43,10 +69,13 @@ static struct addr_node *get_node(void) {
 		int new_alloc = alloc_node_count * 2;
 		if (new_alloc < 8)
 			new_alloc = 8;
-		int allocated = new_alloc - alloc_node_count;
+		struct addr_node *new_nodes;
-		int old = new_alloc - allocated;
+		new_nodes = kalloc(sizeof(struct addr_node) * new_alloc);
-		alloc_nodes = krealloc(alloc_nodes, sizeof(struct addr_node) * new_alloc);
+		if (new_nodes == NULL)
-		memset(alloc_nodes + old, 0, sizeof(struct addr_node) + allocated);;
+			panic("virt addr alloc nodes is null");
+		update_node_ptrs(alloc_nodes, new_nodes, alloc_node_count, new_alloc);
+		kfree(alloc_nodes);
+		alloc_nodes = new_nodes;
 		alloc_node_count = new_alloc;
 		is_allocating = false;
 		count = BSS_NODES + alloc_node_count;
@@ -83,45 +112,15 @@ void virtaddr_init(void) {
 	start_node = &bootstrap_nodes[0];
 }
 
-void *virtaddr_alloc(int n_pages) {
-
-	if (n_pages < 1)
-		return NULL;
-
-	long n_length = n_pages * PAGE_SIZE;
-	struct addr_node *node = start_node;
-
-	for (; node != NULL ; node = node->next) {
-
-		if (node->is_alloc)
-			continue;
-
-		long length = node->end - node->start;
-		if (length >= n_length) {
-			struct addr_node *new = get_node();
-			if (node->prev != NULL) {
-				node->prev->next = new;
-			}
-			new->next = node;
-			node->prev = new;
-			new->start = node->start;
-			new->end = new->start + n_length;
-			node->start = new->end;
-			new->is_alloc = true;
-			new->is_used = true;
-			new->next = node;
-			return (void *) new->start;
-		}
-	}
-
-	return NULL;
-}
-
 static void merge_back(struct addr_node *node) {
-	while (node->prev && !node->is_alloc) {
+	while(node->prev) {
+		if (node->is_alloc != node->prev->is_alloc)
+			break;
 		struct addr_node *temp = node->prev;
-		node->start = node->prev->start;
+		node->start = temp->start;
-		node->prev = node->prev->prev;
+		node->prev = temp->prev;
+		if (temp->prev)
+			temp->prev->next = node;
 		free_node(temp);
 	}
 	if (node->prev == NULL) {
@@ -130,14 +129,61 @@ static void merge_back(struct addr_node *node) {
 }
 
 static void merge_forward(struct addr_node *node) {
+<<<<<<< HEAD
 	while (node->next && !node->is_alloc) {
+=======
+	while(node->next) {
+		if (node->is_alloc != node->next->is_alloc)
+			break;
+>>>>>>> ea2de5a (looping kalloc can allocate all of memory (sometimes) :3)
 		struct addr_node *temp = node->next;
-		node->end = node->next->end;
+		node->end = temp->end;
-		node->next = node->next->next;
+		node->next = temp->next;
+		if (temp->next)
+			temp->next->prev = node;
 		free_node(temp);
 	}
 }
 
+
+void *virtaddr_alloc(int n_pages) {
+	if (n_pages < 1)
+		return NULL;
+	long n_length = n_pages * PAGE_SIZE;
+	struct addr_node *node = start_node;
+
+	for (; node != NULL ; node = node->next) {
+		long length = node->end - node->start;
+		if (node->is_alloc)
+			continue;
+
+		if (length >= n_length) {
+			struct addr_node *new = get_node();
+			if (node->prev != NULL) {
+				node->prev->next = new;
+			} else {
+				start_node = new;
+			}
+			new->next = node;
+			new->prev = node->prev;
+			node->prev = new;
+			new->start = node->start;
+			new->end = new->start + n_length;
+			node->start = new->end;
+			new->is_alloc = true;
+			new->is_used = true;
+			new->next = node;
+			return (void*)new->start;
+			//void *mem = (void *) new->start;
+			//merge_back(new);
+			//merge_forward(new);
+			//return mem;
+		}
+	}
+
+	return NULL;
+}
+
 long virtaddr_free(void *virtaddr) {
 
 	uintptr_t virt = (uintptr_t) virtaddr;