defensive programming; dont be lazy

Author: braindigitalis

src/ahci.c

@@ -197,6 +197,9 @@ void probe_port(ahci_hba_mem_t *abar, pci_dev_t dev)
 				port_rebase(&abar->ports[i], i);
 				storage_device_t* sd = NULL;
 				sd = kmalloc(sizeof(storage_device_t));
+				if (!sd) {
+					return;
+				}
 				sd->opaque1 = i;
 				sd->opaque2 = (void*)abar;
 				sd->blockread = storage_device_ahci_block_read;

src/arp.c

@@ -85,6 +85,9 @@ void arp_send_packet(uint8_t* dst_hardware_addr, uint8_t* dst_protocol_addr) {
 		return;
 	}
 	arp_packet_t * arp_packet = kmalloc(sizeof(arp_packet_t));
+	if (!arp_packet) {
+		return;
+	}
 	static const char broadcast_ip_address[4] = { 255, 255, 255, 255 };
 
 	dev->get_mac_addr(arp_packet->src_hardware_addr);

src/basic/main.c

@@ -103,6 +103,9 @@ const char* auto_number(const char* program, uint64_t line, uint64_t increment)
 	char line_buffer[MAX_STRINGLEN];
 	char* line_ptr = line_buffer;
 	bool insert_line = true, ended = false;
+	if (!newprog) {
+		return NULL;
+	}
 	*newprog = 0;
 	while (true) {
 		if (insert_line) {
@@ -131,7 +134,7 @@ const char* auto_number(const char* program, uint64_t line, uint64_t increment)
 	}
 	strlcat(newprog, "\n", new_size_max);
 	const char* corrected = strdup(newprog);
-	kfree(newprog);
+	kfree_null(&newprog);
 	return corrected;
 }
 

src/debugger.c

@@ -294,6 +294,9 @@ void init_debug()
 	uint32_t sizebytes = 0;
 	symbol_table = kmalloc(sizeof(symbol_t));
 	symbol_t* thisentry = symbol_table;
+	if (!symbol_table) {
+		return;
+	}
 
 	while (offset < filesize) {
 		counter = 0;
@@ -327,6 +330,9 @@ void init_debug()
 
 		if (*type == 'T') {
 			thisentry->name = kmalloc(length);
+			if (!thisentry->name) {
+				break;
+			}
 			memcpy(thisentry->name, symbol, length);
 			thisentry->address = hextoint(symbol_address);
 			thisentry->type = *type;

src/devfs.c

@@ -23,6 +23,9 @@ int devfs_attach([[maybe_unused]] const char* device, const char* path)
 void init_devfs()
 {
 	devfs = kmalloc(sizeof(filesystem_t));
+	if (!devfs) {
+		return;
+	}
 	strlcpy(devfs->name, "devfs", 31);
 	devfs->mount = devfs_attach;
 	devfs->getdir = devfs_get_directory;
@@ -35,6 +38,10 @@ void init_devfs()
 	devfs->rm = NULL;
 	register_filesystem(devfs);
 	devfs_entries = kmalloc(sizeof(fs_directory_entry_t));
+	if (!devfs_entries) {
+		kfree_null(&devfs);
+		return;
+	}
 	devfs_entries->next = NULL;
 	devfs_entries->size = 0;
 	devfs_entries->flags = 0;

src/dhcp.c

@@ -48,6 +48,9 @@ void dhcp_discover() {
 	uint8_t request_ip[4] = { 0, 0, 0, 0 };
 	uint8_t dst_ip[4] = { 0xff, 0xff, 0xff, 0xff };
 	dhcp_packet_t* packet = kmalloc(sizeof(dhcp_packet_t));
+	if (!packet) {
+		return;
+	}
 	udp_register_daemon(DHCP_DST_PORT, &dhcp_handle_packet);
 	kprintf("Configuring network via DHCP\n");
 	memset(packet, 0, sizeof(dhcp_packet_t));
@@ -59,6 +62,9 @@ void dhcp_discover() {
 void dhcp_request(uint8_t* request_ip, uint32_t xid, uint32_t server_ip) {
 	uint8_t dst_ip[4] = { 0xff, 0xff, 0xff, 0xff };
 	dhcp_packet_t* packet = kmalloc(sizeof(dhcp_packet_t));
+	if (!packet) {
+		return;
+	}
 	memset(packet, 0, sizeof(dhcp_packet_t));
 	uint16_t optsize = make_dhcp_packet(packet, DHCPREQUEST, request_ip, xid, server_ip);
 	udp_send_packet(dst_ip, DHCP_DST_PORT, DHCP_SRC_PORT, packet, optsize);

src/e1000.c

@@ -353,6 +353,9 @@ bool e1000_start(pci_dev_t *pci_device) {
 	kprintf("e1000: MAC %02x:%02x:%02x:%02x:%02x:%02x\n", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 
 	netdev_t* net = kmalloc(sizeof(netdev_t));
+	if (!net) {
+		return false;
+	}
 	net->opaque = NULL;
 	net->deviceid = (INTEL_VEND << 16) | e1000_device_id;
 	make_unique_device_name("net", net->name);

src/ethernet.c

@@ -10,6 +10,9 @@ int ethernet_send_packet(uint8_t* dst_mac_addr, uint8_t* data, int len, uint16_t
 	}
 
 	ethernet_frame_t * frame = kmalloc(sizeof(ethernet_frame_t) + len);
+	if (!frame) {
+		return 0;
+	}
 	void * frame_data = (void*)frame + sizeof(ethernet_frame_t);
 
 	dev->get_mac_addr(src_mac_addr);
@@ -48,6 +51,9 @@ bool ethernet_register_iee802_number(uint16_t protocol_number, ethernet_protocol
 {
 	if (protocol_handlers == NULL) {
 		protocol_handlers = kmalloc(sizeof(void*) * UINT16_MAX);
+		if (!protocol_handlers) {
+			return false;
+		}
 	}
 	if (protocol_handlers[protocol_number] == NULL) {
 		protocol_handlers[protocol_number] = handler;