Merge tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - New mode for time travel, external via virtio

 - Fixes for ubd to make sure no requests can get lost

 - Fixes for vector networking

 - Allow CONFIG_STATIC_LINK only when possible

 - Minor cleanups and fixes

* tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Remove some unnecessary NULL checks in vector_user.c
  um: vector: Avoid NULL ptr deference if transport is unset
  um: Make CONFIG_STATIC_LINK actually static
  um: Implement cpu_relax() as ndelay(1) for time-travel
  um: Implement ndelay/udelay in time-travel mode
  um: Implement time-travel=ext
  um: virtio: Implement VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS
  um: time-travel: Rewrite as an event scheduler
  um: Move timer-internal.h to non-shared
  hostfs: Use kasprintf() instead of fixed buffer formatting
  um: falloc.h needs to be directly included for older libc
  um: ubd: Retry buffer read on any kind of error
  um: ubd: Prevent buffer overrun on command completion
  um: Fix overlapping ELF segments when statically linked
  um: Delete never executed timer
  um: Don't overwrite ethtool driver version
  um: Fix len of file in create_pid_file
  um: Don't use console_drivers directly
  um: Cleanup CONFIG_IOSCHED_CFQ

Author: torvalds

arch/um/Kconfig

@@ -62,9 +62,12 @@ config NR_CPUS
 
 source "arch/$(HEADER_ARCH)/um/Kconfig"
 
+config FORBID_STATIC_LINK
+	bool
+
 config STATIC_LINK
 	bool "Force a static link"
-	default n
+	depends on !FORBID_STATIC_LINK
 	help
 	  This option gives you the ability to force a static link of UML.
 	  Normally, UML is linked as a shared binary.  This is inconvenient for
@@ -73,6 +76,9 @@ config STATIC_LINK
 	  Additionally, this option enables using higher memory spaces (up to
 	  2.75G) for UML.
 
+	  NOTE: This option is incompatible with some networking features which
+	  depend on features that require being dynamically loaded (like NSS).
+
 config LD_SCRIPT_STATIC
 	bool
 	default y
@@ -191,6 +197,7 @@ config UML_TIME_TRAVEL_SUPPORT
 	prompt "Support time-travel mode (e.g. for test execution)"
 	# inf-cpu mode is incompatible with the benchmarking
 	depends on !RAID6_PQ_BENCHMARK
+	depends on !SMP
 	help
 	  Enable this option to support time travel inside the UML instance.
 

arch/um/configs/i386_defconfig

@@ -26,7 +26,7 @@ CONFIG_SLAB=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
 # CONFIG_BLK_DEV_BSG is not set
-CONFIG_IOSCHED_CFQ=m
+CONFIG_IOSCHED_BFQ=m
 CONFIG_SSL=y
 CONFIG_NULL_CHAN=y
 CONFIG_PORT_CHAN=y

arch/um/configs/x86_64_defconfig

@@ -24,7 +24,7 @@ CONFIG_SLAB=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
 # CONFIG_BLK_DEV_BSG is not set
-CONFIG_IOSCHED_CFQ=m
+CONFIG_IOSCHED_BFQ=m
 CONFIG_SSL=y
 CONFIG_NULL_CHAN=y
 CONFIG_PORT_CHAN=y

arch/um/drivers/Kconfig

@@ -234,6 +234,7 @@ config UML_NET_DAEMON
 config UML_NET_VECTOR
 	bool "Vector I/O high performance network devices"
 	depends on UML_NET
+	select FORBID_STATIC_LINK
 	help
 	This User-Mode Linux network driver uses multi-message send
 	and receive functions. The host running the UML guest must have
@@ -245,6 +246,7 @@ config UML_NET_VECTOR
 config UML_NET_VDE
 	bool "VDE transport (obsolete)"
 	depends on UML_NET
+	select FORBID_STATIC_LINK
 	help
 	This User-Mode Linux network transport allows one or more running
 	UMLs on a single host to communicate with each other and also
@@ -292,6 +294,7 @@ config UML_NET_MCAST
 config UML_NET_PCAP
 	bool "pcap transport (obsolete)"
 	depends on UML_NET
+	select FORBID_STATIC_LINK
 	help
 	The pcap transport makes a pcap packet stream on the host look
 	like an ethernet device inside UML.  This is useful for making

arch/um/drivers/net_kern.c

@@ -266,7 +266,6 @@ static void uml_net_get_drvinfo(struct net_device *dev,
 				struct ethtool_drvinfo *info)
 {
 	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
-	strlcpy(info->version, "42", sizeof(info->version));
 }
 
 static const struct ethtool_ops uml_net_ethtool_ops = {
@@ -275,17 +274,6 @@ static const struct ethtool_ops uml_net_ethtool_ops = {
 	.get_ts_info	= ethtool_op_get_ts_info,
 };
 
-static void uml_net_user_timer_expire(struct timer_list *t)
-{
-#ifdef undef
-	struct uml_net_private *lp = from_timer(lp, t, tl);
-	struct connection *conn = &lp->user;
-
-	dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
-	do_connect(conn);
-#endif
-}
-
 void uml_net_setup_etheraddr(struct net_device *dev, char *str)
 {
 	unsigned char *addr = dev->dev_addr;
@@ -456,7 +444,6 @@ static void eth_configure(int n, void *init, char *mac,
 		  .add_address 		= transport->user->add_address,
 		  .delete_address  	= transport->user->delete_address });
 
-	timer_setup(&lp->tl, uml_net_user_timer_expire, 0);
 	spin_lock_init(&lp->lock);
 	memcpy(lp->mac, dev->dev_addr, sizeof(lp->mac));
 

arch/um/drivers/ubd_kern.c

@@ -1592,11 +1592,11 @@ int io_thread(void *arg)
 			&io_remainder_size,
 			UBD_REQ_BUFFER_SIZE
 		);
-		if (n < 0) {
-			if (n == -EAGAIN) {
+		if (n <= 0) {
+			if (n == -EAGAIN)
 				ubd_read_poll(-1);
-				continue;
-			}
+
+			continue;
 		}
 
 		for (count = 0; count < n/sizeof(struct io_thread_req *); count++) {
@@ -1607,7 +1607,9 @@ int io_thread(void *arg)
 		written = 0;
 
 		do {
-			res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n);
+			res = os_write_file(kernel_fd,
+					    ((char *) io_req_buffer) + written,
+					    n - written);
 			if (res >= 0) {
 				written += res;
 			}

arch/um/drivers/vector_kern.c

@@ -46,7 +46,6 @@
 
 
 #define DRIVER_NAME "uml-vector"
-#define DRIVER_VERSION "01"
 struct vector_cmd_line_arg {
 	struct list_head list;
 	int unit;
@@ -198,6 +197,9 @@ static int get_transport_options(struct arglist *def)
 	long parsed;
 	int result = 0;
 
+	if (transport == NULL)
+		return -EINVAL;
+
 	if (vector != NULL) {
 		if (kstrtoul(vector, 10, &parsed) == 0) {
 			if (parsed == 0) {
@@ -1378,7 +1380,6 @@ static void vector_net_get_drvinfo(struct net_device *dev,
 				struct ethtool_drvinfo *info)
 {
 	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
-	strlcpy(info->version, DRIVER_VERSION, sizeof(info->version));
 }
 
 static int vector_net_load_bpf_flash(struct net_device *dev,

arch/um/drivers/vector_user.c

@@ -221,8 +221,7 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 	return result;
 tap_cleanup:
 	printk(UM_KERN_ERR "user_init_tap: init failed, error %d", fd);
-	if (result != NULL)
-		kfree(result);
+	kfree(result);
 	return NULL;
 }
 
@@ -266,8 +265,7 @@ static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec)
 	return result;
 hybrid_cleanup:
 	printk(UM_KERN_ERR "user_init_hybrid: init failed");
-	if (result != NULL)
-		kfree(result);
+	kfree(result);
 	return NULL;
 }
 
@@ -344,10 +342,8 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
 unix_cleanup:
 	if (fd >= 0)
 		os_close_file(fd);
-	if (remote_addr != NULL)
-		kfree(remote_addr);
-	if (result != NULL)
-		kfree(result);
+	kfree(remote_addr);
+	kfree(result);
 	return NULL;
 }
 
@@ -382,8 +378,7 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
 	return result;
 raw_cleanup:
 	printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
-	if (result != NULL)
-		kfree(result);
+	kfree(result);
 	return NULL;
 }
 

arch/um/drivers/vhost_user.h

@@ -10,9 +10,10 @@
 /* Feature bits */
 #define VHOST_USER_F_PROTOCOL_FEATURES	30
 /* Protocol feature bits */
-#define VHOST_USER_PROTOCOL_F_REPLY_ACK		3
-#define VHOST_USER_PROTOCOL_F_SLAVE_REQ		5
-#define VHOST_USER_PROTOCOL_F_CONFIG		9
+#define VHOST_USER_PROTOCOL_F_REPLY_ACK			3
+#define VHOST_USER_PROTOCOL_F_SLAVE_REQ			5
+#define VHOST_USER_PROTOCOL_F_CONFIG			9
+#define VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS	14
 /* Vring state index masks */
 #define VHOST_USER_VRING_INDEX_MASK	0xff
 #define VHOST_USER_VRING_POLL_MASK	BIT(8)
@@ -24,7 +25,8 @@
 /* Supported protocol features */
 #define VHOST_USER_SUPPORTED_PROTOCOL_F	(BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK) | \
 					 BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
-					 BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG))
+					 BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG) | \
+					 BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS))
 
 enum vhost_user_request {
 	VHOST_USER_GET_FEATURES = 1,
@@ -52,12 +54,14 @@ enum vhost_user_request {
 	VHOST_USER_SET_VRING_ENDIAN = 23,
 	VHOST_USER_GET_CONFIG = 24,
 	VHOST_USER_SET_CONFIG = 25,
+	VHOST_USER_VRING_KICK = 35,
 };
 
 enum vhost_user_slave_request {
 	VHOST_USER_SLAVE_IOTLB_MSG = 1,
 	VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
 	VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
+	VHOST_USER_SLAVE_VRING_CALL = 4,
 };
 
 struct vhost_user_header {