Merge tag 'for-linus-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - Fixes for our new virtio code

 - Fix for the irqflags tracer

 - Kconfig coding style fixes

 - Allow BPF firmware loading in our vector driver

* tag 'for-linus-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Loadable BPF "Firmware" for vector drivers
  um: Fix Kconfig indentation
  um: virtio_uml: Disallow modular build
  um: virtio: Keep reading on -EAGAIN
  um: virtio: Remove device on disconnect
  um: Don't trace irqflags during shutdown

arch/um/Kconfig

@@ -153,7 +153,7 @@ config KERNEL_STACK_ORDER
 	  It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
 	  older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
 	  increase in the size of the state which needs to be saved when handling
-          signals.
+	  signals.
 
 config MMAPPER
 	tristate "iomem emulation driver"

arch/um/drivers/Kconfig

@@ -337,7 +337,7 @@ config UML_NET_SLIRP
 endmenu
 
 config VIRTIO_UML
-	tristate "UML driver for virtio devices"
+	bool "UML driver for virtio devices"
 	select VIRTIO
 	help
 	  This driver provides support for virtio based paravirtual device

arch/um/drivers/vector_kern.c

 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright (C) 2017 - Cambridge Greys Limited
+ * Copyright (C) 2017 - 2019 Cambridge Greys Limited
  * Copyright (C) 2011 - 2014 Cisco Systems Inc
  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
@@ -21,6 +21,9 @@
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
+#include <linux/firmware.h>
+#include <linux/fs.h>
+#include <uapi/linux/filter.h>
 #include <init.h>
 #include <irq_kern.h>
 #include <irq_user.h>
@@ -128,6 +131,23 @@ static int get_mtu(struct arglist *def)
 	return ETH_MAX_PACKET;
 }
 
+static char *get_bpf_file(struct arglist *def)
+{
+	return uml_vector_fetch_arg(def, "bpffile");
+}
+
+static bool get_bpf_flash(struct arglist *def)
+{
+	char *allow = uml_vector_fetch_arg(def, "bpfflash");
+	long result;
+
+	if (allow != NULL) {
+		if (kstrtoul(allow, 10, &result) == 0)
+			return (allow > 0);
+	}
+	return false;
+}
+
 static int get_depth(struct arglist *def)
 {
 	char *mtu = uml_vector_fetch_arg(def, "depth");
@@ -176,6 +196,7 @@ static int get_transport_options(struct arglist *def)
 	int vec_rx = VECTOR_RX;
 	int vec_tx = VECTOR_TX;
 	long parsed;
+	int result = 0;
 
 	if (vector != NULL) {
 		if (kstrtoul(vector, 10, &parsed) == 0) {
@@ -186,14 +207,16 @@ static int get_transport_options(struct arglist *def)
 		}
 	}
 
+	if (get_bpf_flash(def))
+		result = VECTOR_BPF_FLASH;
 
 	if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
-		return 0;
+		return result;
 	if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
-		return (vec_rx | VECTOR_BPF);
+		return (result | vec_rx | VECTOR_BPF);
 	if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
-		return (vec_rx | vec_tx | VECTOR_QDISC_BYPASS);
-	return (vec_rx | vec_tx);
+		return (result | vec_rx | vec_tx | VECTOR_QDISC_BYPASS);
+	return (result | vec_rx | vec_tx);
 }
 
 
@@ -1139,6 +1162,8 @@ static int vector_net_close(struct net_device *dev)
 	}
 	tasklet_kill(&vp->tx_poll);
 	if (vp->fds->rx_fd > 0) {
+		if (vp->bpf)
+			uml_vector_detach_bpf(vp->fds->rx_fd, vp->bpf);
 		os_close_file(vp->fds->rx_fd);
 		vp->fds->rx_fd = -1;
 	}
@@ -1146,7 +1171,10 @@ static int vector_net_close(struct net_device *dev)
 		os_close_file(vp->fds->tx_fd);
 		vp->fds->tx_fd = -1;
 	}
+	if (vp->bpf != NULL)
+		kfree(vp->bpf->filter);
 	kfree(vp->bpf);
+	vp->bpf = NULL;
 	kfree(vp->fds->remote_addr);
 	kfree(vp->transport_data);
 	kfree(vp->header_rxbuffer);
@@ -1181,6 +1209,7 @@ static void vector_reset_tx(struct work_struct *work)
 	netif_start_queue(vp->dev);
 	netif_wake_queue(vp->dev);
 }
+
 static int vector_net_open(struct net_device *dev)
 {
 	struct vector_private *vp = netdev_priv(dev);
@@ -1196,6 +1225,8 @@ static int vector_net_open(struct net_device *dev)
 	vp->opened = true;
 	spin_unlock_irqrestore(&vp->lock, flags);
 
+	vp->bpf = uml_vector_user_bpf(get_bpf_file(vp->parsed));
+
 	vp->fds = uml_vector_user_open(vp->unit, vp->parsed);
 
 	if (vp->fds == NULL)
@@ -1267,8 +1298,11 @@ static int vector_net_open(struct net_device *dev)
 		if (!uml_raw_enable_qdisc_bypass(vp->fds->rx_fd))
 			vp->options |= VECTOR_BPF;
 	}
-	if ((vp->options & VECTOR_BPF) != 0)
-		vp->bpf = uml_vector_default_bpf(vp->fds->rx_fd, dev->dev_addr);
+	if (((vp->options & VECTOR_BPF) != 0) && (vp->bpf == NULL))
+		vp->bpf = uml_vector_default_bpf(dev->dev_addr);
+
+	if (vp->bpf != NULL)
+		uml_vector_attach_bpf(vp->fds->rx_fd, vp->bpf);
 
 	netif_start_queue(dev);
 
@@ -1347,6 +1381,65 @@ static void vector_net_get_drvinfo(struct net_device *dev,
 	strlcpy(info->version, DRIVER_VERSION, sizeof(info->version));
 }
 
+static int vector_net_load_bpf_flash(struct net_device *dev,
+				struct ethtool_flash *efl)
+{
+	struct vector_private *vp = netdev_priv(dev);
+	struct vector_device *vdevice;
+	const struct firmware *fw;
+	int result = 0;
+
+	if (!(vp->options & VECTOR_BPF_FLASH)) {
+		netdev_err(dev, "loading firmware not permitted: %s\n", efl->data);
+		return -1;
+	}
+
+	spin_lock(&vp->lock);
+
+	if (vp->bpf != NULL) {
+		if (vp->opened)
+			uml_vector_detach_bpf(vp->fds->rx_fd, vp->bpf);
+		kfree(vp->bpf->filter);
+		vp->bpf->filter = NULL;
+	} else {
+		vp->bpf = kmalloc(sizeof(struct sock_fprog), GFP_KERNEL);
+		if (vp->bpf == NULL) {
+			netdev_err(dev, "failed to allocate memory for firmware\n");
+			goto flash_fail;
+		}
+	}
+
+	vdevice = find_device(vp->unit);
+
+	if (request_firmware(&fw, efl->data, &vdevice->pdev.dev))
+		goto flash_fail;
+
+	vp->bpf->filter = kmemdup(fw->data, fw->size, GFP_KERNEL);
+	if (!vp->bpf->filter)
+		goto free_buffer;
+
+	vp->bpf->len = fw->size / sizeof(struct sock_filter);
+	release_firmware(fw);
+
+	if (vp->opened)
+		result = uml_vector_attach_bpf(vp->fds->rx_fd, vp->bpf);
+
+	spin_unlock(&vp->lock);
+
+	return result;
+
+free_buffer:
+	release_firmware(fw);
+
+flash_fail:
+	spin_unlock(&vp->lock);
+	if (vp->bpf != NULL)
+		kfree(vp->bpf->filter);
+	kfree(vp->bpf);
+	vp->bpf = NULL;
+	return -1;
+}
+
 static void vector_get_ringparam(struct net_device *netdev,
 				struct ethtool_ringparam *ring)
 {
@@ -1424,6 +1517,7 @@ static const struct ethtool_ops vector_net_ethtool_ops = {
 	.get_ethtool_stats = vector_get_ethtool_stats,
 	.get_coalesce	= vector_get_coalesce,
 	.set_coalesce	= vector_set_coalesce,
+	.flash_device	= vector_net_load_bpf_flash,
 };
 
 
@@ -1528,8 +1622,9 @@ static void vector_eth_configure(
 		.in_write_poll		= false,
 		.coalesce		= 2,
 		.req_size		= get_req_size(def),
-		.in_error		= false
-		});
+		.in_error		= false,
+		.bpf			= NULL
+	});
 
 	dev->features = dev->hw_features = (NETIF_F_SG | NETIF_F_FRAGLIST);
 	tasklet_init(&vp->tx_poll, vector_tx_poll, (unsigned long)vp);

arch/um/drivers/vector_kern.h

@@ -29,10 +29,13 @@
 #define VECTOR_TX (1 << 1)
 #define VECTOR_BPF (1 << 2)
 #define VECTOR_QDISC_BYPASS (1 << 3)
+#define VECTOR_BPF_FLASH (1 << 4)
 
 #define ETH_MAX_PACKET 1500
 #define ETH_HEADER_OTHER 32 /* just in case someone decides to go mad on QnQ */
 
+#define MAX_FILTER_PROG (2 << 16)
+
 struct vector_queue {
 	struct mmsghdr *mmsg_vector;
 	void **skbuff_vector;
@@ -118,10 +121,13 @@ struct vector_private {
 	bool in_write_poll;
 	bool in_error;
 
+	/* guest allowed to use ethtool flash to load bpf */
+	bool bpf_via_flash;
+
 	/* ethtool stats */
 
 	struct vector_estats estats;
-	void *bpf;
+	struct sock_fprog *bpf;
 
 	char user[0];
 };

arch/um/drivers/vector_user.c

@@ -46,7 +46,8 @@
 #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
 #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
 #define UNIX_BIND_FAIL "unix_open : could not bind socket err=%i"
-#define BPF_ATTACH_FAIL "Failed to attach filter size %d to %d, err %d\n"
+#define BPF_ATTACH_FAIL "Failed to attach filter size %d prog %px to %d, err %d\n"
+#define BPF_DETACH_FAIL "Failed to detach filter size %d prog %px to %d, err %d\n"
 
 #define MAX_UN_LEN 107
 
@@ -660,31 +661,44 @@ int uml_vector_recvmmsg(
 	else
 		return -errno;
 }
-int uml_vector_attach_bpf(int fd, void *bpf, int bpf_len)
+int uml_vector_attach_bpf(int fd, void *bpf)
 {
-	int err = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, bpf, bpf_len);
+	struct sock_fprog *prog = bpf;
+
+	int err = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, bpf, sizeof(struct sock_fprog));
 
 	if (err < 0)
-		printk(KERN_ERR BPF_ATTACH_FAIL, bpf_len, fd, -errno);
+		printk(KERN_ERR BPF_ATTACH_FAIL, prog->len, prog->filter, fd, -errno);
 	return err;
 }
 
-#define DEFAULT_BPF_LEN 6
+int uml_vector_detach_bpf(int fd, void *bpf)
+{
+	struct sock_fprog *prog = bpf;
 
-void *uml_vector_default_bpf(int fd, void *mac)
+	int err = setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, bpf, sizeof(struct sock_fprog));
+	if (err < 0)
+		printk(KERN_ERR BPF_DETACH_FAIL, prog->len, prog->filter, fd, -errno);
+	return err;
+}
+void *uml_vector_default_bpf(void *mac)
 {
 	struct sock_filter *bpf;
 	uint32_t *mac1 = (uint32_t *)(mac + 2);
 	uint16_t *mac2 = (uint16_t *) mac;
-	struct sock_fprog bpf_prog = {
-		.len = 6,
-		.filter = NULL,
-	};
+	struct sock_fprog *bpf_prog;
 
+	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
+	if (bpf_prog) {
+		bpf_prog->len = DEFAULT_BPF_LEN;
+		bpf_prog->filter = NULL;
+	} else {
+		return NULL;
+	}
 	bpf = uml_kmalloc(
 		sizeof(struct sock_filter) * DEFAULT_BPF_LEN, UM_GFP_KERNEL);
-	if (bpf != NULL) {
-		bpf_prog.filter = bpf;
+	if (bpf) {
+		bpf_prog->filter = bpf;
 		/* ld	[8] */
 		bpf[0] = (struct sock_filter){ 0x20, 0, 0, 0x00000008 };
 		/* jeq	#0xMAC[2-6] jt 2 jf 5*/
@@ -697,12 +711,56 @@ void *uml_vector_default_bpf(int fd, void *mac)
 		bpf[4] = (struct sock_filter){ 0x6, 0, 0, 0x00000000 };
 		/* ret	#0x40000 */
 		bpf[5] = (struct sock_filter){ 0x6, 0, 0, 0x00040000 };
-		if (uml_vector_attach_bpf(
-			fd, &bpf_prog, sizeof(struct sock_fprog)) < 0) {
-			kfree(bpf);
-			bpf = NULL;
-		}
+	} else {
+		kfree(bpf_prog);
+		bpf_prog = NULL;
 	}
-	return bpf;
+	return bpf_prog;
 }
 
+/* Note - this function requires a valid mac being passed as an arg */
+
+void *uml_vector_user_bpf(char *filename)
+{
+	struct sock_filter *bpf;
+	struct sock_fprog *bpf_prog;
+	struct stat statbuf;
+	int res, ffd = -1;
+
+	if (filename == NULL)
+		return NULL;
+
+	if (stat(filename, &statbuf) < 0) {
+		printk(KERN_ERR "Error %d reading bpf file", -errno);
+		return false;
+	}
+	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
+	if (bpf_prog != NULL) {
+		bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
+		bpf_prog->filter = NULL;
+	}
+	ffd = os_open_file(filename, of_read(OPENFLAGS()), 0);
+	if (ffd < 0) {
+		printk(KERN_ERR "Error %d opening bpf file", -errno);
+		goto bpf_failed;
+	}
+	bpf = uml_kmalloc(statbuf.st_size, UM_GFP_KERNEL);
+	if (bpf == NULL) {
+		printk(KERN_ERR "Failed to allocate bpf buffer");
+		goto bpf_failed;
+	}
+	bpf_prog->filter = bpf;
+	res = os_read_file(ffd, bpf, statbuf.st_size);
+	if (res < statbuf.st_size) {
+		printk(KERN_ERR "Failed to read bpf program %s, error %d", filename, res);
+		kfree(bpf);
+		goto bpf_failed;
+	}
+	os_close_file(ffd);
+	return bpf_prog;
+bpf_failed:
+	if (ffd > 0)
+		os_close_file(ffd);
+	kfree(bpf_prog);
+	return NULL;
+}

arch/um/drivers/vector_user.h

@@ -28,6 +28,8 @@
 #define TRANS_BESS "bess"
 #define TRANS_BESS_LEN strlen(TRANS_BESS)
 
+#define DEFAULT_BPF_LEN 6
+
 #ifndef IPPROTO_GRE
 #define IPPROTO_GRE 0x2F
 #endif
@@ -95,8 +97,10 @@ extern int uml_vector_recvmmsg(
 	unsigned int vlen,
 	unsigned int flags
 );
-extern void *uml_vector_default_bpf(int fd, void *mac);
-extern int uml_vector_attach_bpf(int fd, void *bpf, int bpf_len);
+extern void *uml_vector_default_bpf(void *mac);
+extern void *uml_vector_user_bpf(char *filename);
+extern int uml_vector_attach_bpf(int fd, void *bpf);
+extern int uml_vector_detach_bpf(int fd, void *bpf);
 extern bool uml_raw_enable_qdisc_bypass(int fd);
 extern bool uml_raw_enable_vnet_headers(int fd);
 extern bool uml_tap_enable_vnet_headers(int fd);

arch/um/drivers/virtio_uml.c

@@ -4,12 +4,12 @@
  *
  * Copyright(c) 2019 Intel Corporation
  *
- * This module allows virtio devices to be used over a vhost-user socket.
+ * This driver allows virtio devices to be used over a vhost-user socket.
  *
  * Guest devices can be instantiated by kernel module or command line
  * parameters. One device will be created for each parameter. Syntax:
  *
- *		[virtio_uml.]device=<socket>:<virtio_id>[:<platform_id>]
+ *		virtio_uml.device=<socket>:<virtio_id>[:<platform_id>]
  * where:
  *		<socket>	:= vhost-user socket path to connect
  *		<virtio_id>	:= virtio device id (as in virtio_ids.h)
@@ -42,6 +42,13 @@
 #define to_virtio_uml_device(_vdev) \
 	container_of(_vdev, struct virtio_uml_device, vdev)
 
+struct virtio_uml_platform_data {
+	u32 virtio_device_id;
+	const char *socket_path;
+	struct work_struct conn_broken_wk;
+	struct platform_device *pdev;
+};
+
 struct virtio_uml_device {
 	struct virtio_device vdev;
 	struct platform_device *pdev;
@@ -50,6 +57,7 @@ struct virtio_uml_device {
 	u64 features;
 	u64 protocol_features;
 	u8 status;
+	u8 registered:1;
 };
 
 struct virtio_uml_vq_info {
@@ -83,7 +91,7 @@ static int full_sendmsg_fds(int fd, const void *buf, unsigned int len,
 	return 0;
 }
 
-static int full_read(int fd, void *buf, int len)
+static int full_read(int fd, void *buf, int len, bool abortable)
 {
 	int rc;
 
@@ -93,7 +101,7 @@ static int full_read(int fd, void *buf, int len)
 			buf += rc;
 			len -= rc;
 		}
-	} while (len && (rc > 0 || rc == -EINTR));
+	} while (len && (rc > 0 || rc == -EINTR || (!abortable && rc == -EAGAIN)));
 
 	if (rc < 0)
 		return rc;
@@ -104,28 +112,37 @@ static int full_read(int fd, void *buf, int len)
 
 static int vhost_user_recv_header(int fd, struct vhost_user_msg *msg)
 {
-	return full_read(fd, msg, sizeof(msg->header));
+	return full_read(fd, msg, sizeof(msg->header), true);
 }
 
-static int vhost_user_recv(int fd, struct vhost_user_msg *msg,
+static int vhost_user_recv(struct virtio_uml_device *vu_dev,
+			   int fd, struct vhost_user_msg *msg,
 			   size_t max_payload_size)
 {
 	size_t size;
 	int rc = vhost_user_recv_header(fd, msg);
 
+	if (rc == -ECONNRESET && vu_dev->registered) {
+		struct virtio_uml_platform_data *pdata;
+
+		pdata = vu_dev->pdev->dev.platform_data;
+
+		virtio_break_device(&vu_dev->vdev);
+		schedule_work(&pdata->conn_broken_wk);
+	}
 	if (rc)
 		return rc;
 	size = msg->header.size;
 	if (size > max_payload_size)
 		return -EPROTO;
-	return full_read(fd, &msg->payload, size);
+	return full_read(fd, &msg->payload, size, false);
 }
 
 static int vhost_user_recv_resp(struct virtio_uml_device *vu_dev,
 				struct vhost_user_msg *msg,
 				size_t max_payload_size)
 {
-	int rc = vhost_user_recv(vu_dev->sock, msg, max_payload_size);
+	int rc = vhost_user_recv(vu_dev, vu_dev->sock, msg, max_payload_size);
 
 	if (rc)
 		return rc;
@@ -155,7 +172,7 @@ static int vhost_user_recv_req(struct virtio_uml_device *vu_dev,
 			       struct vhost_user_msg *msg,
 			       size_t max_payload_size)
 {
-	int rc = vhost_user_recv(vu_dev->req_fd, msg, max_payload_size);
+	int rc = vhost_user_recv(vu_dev, vu_dev->req_fd, msg, max_payload_size);
 
 	if (rc)
 		return rc;
@@ -963,11 +980,6 @@ static void virtio_uml_release_dev(struct device *d)
 
 /* Platform device */
 
-struct virtio_uml_platform_data {
-	u32 virtio_device_id;
-	const char *socket_path;
-};
-
 static int virtio_uml_probe(struct platform_device *pdev)
 {
 	struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
@@ -1005,6 +1017,7 @@ static int virtio_uml_probe(struct platform_device *pdev)
 	rc = register_virtio_device(&vu_dev->vdev);
 	if (rc)
 		put_device(&vu_dev->vdev.dev);
+	vu_dev->registered = 1;
 	return rc;
 
 error_init:
@@ -1034,13 +1047,31 @@ static struct device vu_cmdline_parent = {
 static bool vu_cmdline_parent_registered;
 static int vu_cmdline_id;
 
+static int vu_unregister_cmdline_device(struct device *dev, void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
+
+	kfree(pdata->socket_path);
+	platform_device_unregister(pdev);
+	return 0;
+}
+
+static void vu_conn_broken(struct work_struct *wk)
+{
+	struct virtio_uml_platform_data *pdata;
+
+	pdata = container_of(wk, struct virtio_uml_platform_data, conn_broken_wk);
+	vu_unregister_cmdline_device(&pdata->pdev->dev, NULL);
+}
+
 static int vu_cmdline_set(const char *device, const struct kernel_param *kp)
 {
 	const char *ids = strchr(device, ':');
 	unsigned int virtio_device_id;
 	int processed, consumed, err;
 	char *socket_path;
-	struct virtio_uml_platform_data pdata;
+	struct virtio_uml_platform_data pdata, *ppdata;
 	struct platform_device *pdev;
 
 	if (!ids || ids == device)
@@ -1079,6 +1110,11 @@ static int vu_cmdline_set(const char *device, const struct kernel_param *kp)
 	err = PTR_ERR_OR_ZERO(pdev);
 	if (err)
 		goto free;
+
+	ppdata = pdev->dev.platform_data;
+	ppdata->pdev = pdev;
+	INIT_WORK(&ppdata->conn_broken_wk, vu_conn_broken);
+
 	return 0;
 
 free:
@@ -1121,16 +1157,6 @@ __uml_help(vu_cmdline_param_ops,
 );
 
 
-static int vu_unregister_cmdline_device(struct device *dev, void *data)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
-
-	kfree(pdata->socket_path);
-	platform_device_unregister(pdev);
-	return 0;
-}
-
 static void vu_unregister_cmdline_devices(void)
 {
 	if (vu_cmdline_parent_registered) {

arch/um/os-Linux/main.c

@@ -170,7 +170,7 @@ int __init main(int argc, char **argv, char **envp)
 	 * that they won't be delivered after the exec, when
 	 * they are definitely not expected.
 	 */
-	unblock_signals_trace();
+	unblock_signals();
 
 	os_info("\n");
 	/* Reboot */