Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 379 insertions, 0 deletions

diff --git a/drivers/net/wan/hdlc.c b/drivers/net/wan/hdlc.c
new file mode 100644
index 000000000..cbed10b1d
--- /dev/null
+++ b/drivers/net/wan/hdlc.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic HDLC support routines for Linux
+ *
+ * Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
+ *
+ * Currently supported:
+ *	* raw IP-in-HDLC
+ *	* Cisco HDLC
+ *	* Frame Relay with ANSI or CCITT LMI (both user and network side)
+ *	* PPP
+ *	* X.25
+ *
+ * Use sethdlc utility to set line parameters, protocol and PVCs
+ *
+ * How does it work:
+ * - proto->open(), close(), start(), stop() calls are serialized.
+ *   The order is: open, [ start, stop ... ] close ...
+ * - proto->start() and stop() are called with spin_lock_irq held.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/hdlc.h>
+#include <linux/if_arp.h>
+#include <linux/inetdevice.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/pkt_sched.h>
+#include <linux/poll.h>
+#include <linux/rtnetlink.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/net_namespace.h>
+
+static const char *version = "HDLC support module revision 1.22";
+
+#undef DEBUG_LINK
+
+static struct hdlc_proto *first_proto;
+
+static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
+		    struct packet_type *p, struct net_device *orig_dev)
+{
+	struct hdlc_device *hdlc;
+
+	/* First make sure "dev" is an HDLC device */
+	if (!(dev->priv_flags & IFF_WAN_HDLC)) {
+		kfree_skb(skb);
+		return NET_RX_SUCCESS;
+	}
+
+	hdlc = dev_to_hdlc(dev);
+
+	if (!net_eq(dev_net(dev), &init_net)) {
+		kfree_skb(skb);
+		return 0;
+	}
+
+	BUG_ON(!hdlc->proto->netif_rx);
+	return hdlc->proto->netif_rx(skb);
+}
+
+netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	hdlc_device *hdlc = dev_to_hdlc(dev);
+
+	if (hdlc->proto->xmit)
+		return hdlc->proto->xmit(skb, dev);
+
+	return hdlc->xmit(skb, dev); /* call hardware driver directly */
+}
+EXPORT_SYMBOL(hdlc_start_xmit);
+
+static inline void hdlc_proto_start(struct net_device *dev)
+{
+	hdlc_device *hdlc = dev_to_hdlc(dev);
+
+	if (hdlc->proto->start)
+		hdlc->proto->start(dev);
+}
+
+static inline void hdlc_proto_stop(struct net_device *dev)
+{
+	hdlc_device *hdlc = dev_to_hdlc(dev);
+
+	if (hdlc->proto->stop)
+		hdlc->proto->stop(dev);
+}
+
+static int hdlc_device_event(struct notifier_block *this, unsigned long event,
+			     void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	hdlc_device *hdlc;
+	unsigned long flags;
+	int on;
+
+	if (!net_eq(dev_net(dev), &init_net))
+		return NOTIFY_DONE;
+
+	if (!(dev->priv_flags & IFF_WAN_HDLC))
+		return NOTIFY_DONE; /* not an HDLC device */
+
+	if (event != NETDEV_CHANGE)
+		return NOTIFY_DONE; /* Only interested in carrier changes */
+
+	on = netif_carrier_ok(dev);
+
+#ifdef DEBUG_LINK
+	printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
+	       dev->name, on);
+#endif
+
+	hdlc = dev_to_hdlc(dev);
+	spin_lock_irqsave(&hdlc->state_lock, flags);
+
+	if (hdlc->carrier == on)
+		goto carrier_exit; /* no change in DCD line level */
+
+	hdlc->carrier = on;
+
+	if (!hdlc->open)
+		goto carrier_exit;
+
+	if (hdlc->carrier) {
+		netdev_info(dev, "Carrier detected\n");
+		hdlc_proto_start(dev);
+	} else {
+		netdev_info(dev, "Carrier lost\n");
+		hdlc_proto_stop(dev);
+	}
+
+carrier_exit:
+	spin_unlock_irqrestore(&hdlc->state_lock, flags);
+	return NOTIFY_DONE;
+}
+
+/* Must be called by hardware driver when HDLC device is being opened */
+int hdlc_open(struct net_device *dev)
+{
+	hdlc_device *hdlc = dev_to_hdlc(dev);
+#ifdef DEBUG_LINK
+	printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
+	       hdlc->carrier, hdlc->open);
+#endif
+
+	if (!hdlc->proto)
+		return -ENOSYS;	/* no protocol attached */
+
+	if (hdlc->proto->open) {
+		int result = hdlc->proto->open(dev);
+
+		if (result)
+			return result;
+	}
+
+	spin_lock_irq(&hdlc->state_lock);
+
+	if (hdlc->carrier) {
+		netdev_info(dev, "Carrier detected\n");
+		hdlc_proto_start(dev);
+	} else {
+		netdev_info(dev, "No carrier\n");
+	}
+
+	hdlc->open = 1;
+
+	spin_unlock_irq(&hdlc->state_lock);
+	return 0;
+}
+EXPORT_SYMBOL(hdlc_open);
+
+/* Must be called by hardware driver when HDLC device is being closed */
+void hdlc_close(struct net_device *dev)
+{
+	hdlc_device *hdlc = dev_to_hdlc(dev);
+#ifdef DEBUG_LINK
+	printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
+	       hdlc->carrier, hdlc->open);
+#endif
+
+	spin_lock_irq(&hdlc->state_lock);
+
+	hdlc->open = 0;
+	if (hdlc->carrier)
+		hdlc_proto_stop(dev);
+
+	spin_unlock_irq(&hdlc->state_lock);
+
+	if (hdlc->proto->close)
+		hdlc->proto->close(dev);
+}
+EXPORT_SYMBOL(hdlc_close);
+
+int hdlc_ioctl(struct net_device *dev, struct if_settings *ifs)
+{
+	struct hdlc_proto *proto = first_proto;
+	int result;
+
+	if (dev_to_hdlc(dev)->proto) {
+		result = dev_to_hdlc(dev)->proto->ioctl(dev, ifs);
+		if (result != -EINVAL)
+			return result;
+	}
+
+	/* Not handled by currently attached protocol (if any) */
+
+	while (proto) {
+		result = proto->ioctl(dev, ifs);
+		if (result != -EINVAL)
+			return result;
+		proto = proto->next;
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL(hdlc_ioctl);
+
+static const struct header_ops hdlc_null_ops;
+
+static void hdlc_setup_dev(struct net_device *dev)
+{
+	/* Re-init all variables changed by HDLC protocol drivers,
+	 * including ether_setup() called from hdlc_raw_eth.c.
+	 */
+	dev->flags		 = IFF_POINTOPOINT | IFF_NOARP;
+	dev->priv_flags		 = IFF_WAN_HDLC;
+	dev->mtu		 = HDLC_MAX_MTU;
+	dev->min_mtu		 = 68;
+	dev->max_mtu		 = HDLC_MAX_MTU;
+	dev->type		 = ARPHRD_RAWHDLC;
+	dev->hard_header_len	 = 0;
+	dev->needed_headroom	 = 0;
+	dev->addr_len		 = 0;
+	dev->header_ops		 = &hdlc_null_ops;
+}
+
+static void hdlc_setup(struct net_device *dev)
+{
+	hdlc_device *hdlc = dev_to_hdlc(dev);
+
+	hdlc_setup_dev(dev);
+	hdlc->carrier = 1;
+	hdlc->open = 0;
+	spin_lock_init(&hdlc->state_lock);
+}
+
+struct net_device *alloc_hdlcdev(void *priv)
+{
+	struct net_device *dev;
+
+	dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d",
+			   NET_NAME_UNKNOWN, hdlc_setup);
+	if (dev)
+		dev_to_hdlc(dev)->priv = priv;
+	return dev;
+}
+EXPORT_SYMBOL(alloc_hdlcdev);
+
+void unregister_hdlc_device(struct net_device *dev)
+{
+	rtnl_lock();
+	detach_hdlc_protocol(dev);
+	unregister_netdevice(dev);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(unregister_hdlc_device);
+
+int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
+			 size_t size)
+{
+	int err;
+
+	err = detach_hdlc_protocol(dev);
+	if (err)
+		return err;
+
+	if (!try_module_get(proto->module))
+		return -ENOSYS;
+
+	if (size) {
+		dev_to_hdlc(dev)->state = kmalloc(size, GFP_KERNEL);
+		if (!dev_to_hdlc(dev)->state) {
+			module_put(proto->module);
+			return -ENOBUFS;
+		}
+	}
+	dev_to_hdlc(dev)->proto = proto;
+
+	return 0;
+}
+EXPORT_SYMBOL(attach_hdlc_protocol);
+
+int detach_hdlc_protocol(struct net_device *dev)
+{
+	hdlc_device *hdlc = dev_to_hdlc(dev);
+	int err;
+
+	if (hdlc->proto) {
+		err = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE, dev);
+		err = notifier_to_errno(err);
+		if (err) {
+			netdev_err(dev, "Refused to change device type\n");
+			return err;
+		}
+
+		if (hdlc->proto->detach)
+			hdlc->proto->detach(dev);
+		module_put(hdlc->proto->module);
+		hdlc->proto = NULL;
+	}
+	kfree(hdlc->state);
+	hdlc->state = NULL;
+	hdlc_setup_dev(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL(detach_hdlc_protocol);
+
+void register_hdlc_protocol(struct hdlc_proto *proto)
+{
+	rtnl_lock();
+	proto->next = first_proto;
+	first_proto = proto;
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(register_hdlc_protocol);
+
+void unregister_hdlc_protocol(struct hdlc_proto *proto)
+{
+	struct hdlc_proto **p;
+
+	rtnl_lock();
+	p = &first_proto;
+	while (*p != proto) {
+		BUG_ON(!*p);
+		p = &((*p)->next);
+	}
+	*p = proto->next;
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(unregister_hdlc_protocol);
+
+MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
+MODULE_DESCRIPTION("HDLC support module");
+MODULE_LICENSE("GPL v2");
+
+static struct packet_type hdlc_packet_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_HDLC),
+	.func = hdlc_rcv,
+};
+
+static struct notifier_block hdlc_notifier = {
+	.notifier_call = hdlc_device_event,
+};
+
+static int __init hdlc_module_init(void)
+{
+	int result;
+
+	pr_info("%s\n", version);
+	result = register_netdevice_notifier(&hdlc_notifier);
+	if (result)
+		return result;
+	dev_add_pack(&hdlc_packet_type);
+	return 0;
+}
+
+static void __exit hdlc_module_exit(void)
+{
+	dev_remove_pack(&hdlc_packet_type);
+	unregister_netdevice_notifier(&hdlc_notifier);
+}
+
+module_init(hdlc_module_init);
+module_exit(hdlc_module_exit);