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, 264 insertions, 0 deletions

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
new file mode 100644
index 000000000..2bff41aac
--- /dev/null
+++ b/include/net/rtnetlink.h
@@ -0,0 +1,264 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_RTNETLINK_H
+#define __NET_RTNETLINK_H
+
+#include <linux/rtnetlink.h>
+#include <linux/srcu.h>
+#include <net/netlink.h>
+
+typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *,
+			      struct netlink_ext_ack *);
+typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
+
+enum rtnl_link_flags {
+	RTNL_FLAG_DOIT_UNLOCKED		= BIT(0),
+#define RTNL_FLAG_DOIT_PERNET		RTNL_FLAG_DOIT_UNLOCKED
+#define RTNL_FLAG_DOIT_PERNET_WIP	RTNL_FLAG_DOIT_UNLOCKED
+	RTNL_FLAG_BULK_DEL_SUPPORTED	= BIT(1),
+	RTNL_FLAG_DUMP_UNLOCKED		= BIT(2),
+	RTNL_FLAG_DUMP_SPLIT_NLM_DONE	= BIT(3),	/* legacy behavior */
+};
+
+enum rtnl_kinds {
+	RTNL_KIND_NEW,
+	RTNL_KIND_DEL,
+	RTNL_KIND_GET,
+	RTNL_KIND_SET
+};
+#define RTNL_KIND_MASK 0x3
+
+static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype)
+{
+	return msgtype & RTNL_KIND_MASK;
+}
+
+/**
+ *	struct rtnl_msg_handler - rtnetlink message type and handlers
+ *
+ *	@owner: NULL for built-in, THIS_MODULE for module
+ *	@protocol: Protocol family or PF_UNSPEC
+ *	@msgtype: rtnetlink message type
+ *	@doit: Function pointer called for each request message
+ *	@dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
+ *	@flags: rtnl_link_flags to modify behaviour of doit/dumpit functions
+ */
+struct rtnl_msg_handler {
+	struct module *owner;
+	int protocol;
+	int msgtype;
+	rtnl_doit_func doit;
+	rtnl_dumpit_func dumpit;
+	int flags;
+};
+
+void rtnl_unregister_all(int protocol);
+
+int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n);
+void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n);
+
+#define rtnl_register_many(handlers)				\
+	__rtnl_register_many(handlers, ARRAY_SIZE(handlers))
+#define rtnl_unregister_many(handlers)				\
+	__rtnl_unregister_many(handlers, ARRAY_SIZE(handlers))
+
+static inline int rtnl_msg_family(const struct nlmsghdr *nlh)
+{
+	if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg))
+		return ((struct rtgenmsg *) nlmsg_data(nlh))->rtgen_family;
+	else
+		return AF_UNSPEC;
+}
+
+/**
+ * struct rtnl_newlink_params - parameters of rtnl_link_ops::newlink()
+ *
+ * @src_net: Source netns of rtnetlink socket
+ * @link_net: Link netns by IFLA_LINK_NETNSID, NULL if not specified
+ * @peer_net: Peer netns
+ * @tb: IFLA_* attributes
+ * @data: IFLA_INFO_DATA attributes
+ */
+struct rtnl_newlink_params {
+	struct net *src_net;
+	struct net *link_net;
+	struct net *peer_net;
+	struct nlattr **tb;
+	struct nlattr **data;
+};
+
+/* Get effective link netns from newlink params. Generally, this is link_net
+ * and falls back to src_net. But for compatibility, a driver may * choose to
+ * use dev_net(dev) instead.
+ */
+static inline struct net *rtnl_newlink_link_net(struct rtnl_newlink_params *p)
+{
+	return p->link_net ? : p->src_net;
+}
+
+/* Get peer netns from newlink params. Fallback to link netns if peer netns is
+ * not specified explicitly.
+ */
+static inline struct net *rtnl_newlink_peer_net(struct rtnl_newlink_params *p)
+{
+	return p->peer_net ? : rtnl_newlink_link_net(p);
+}
+
+/**
+ *	struct rtnl_link_ops - rtnetlink link operations
+ *
+ *	@list: Used internally, protected by link_ops_mutex and SRCU
+ *	@srcu: Used internally
+ *	@kind: Identifier
+ *	@netns_refund: Physical device, move to init_net on netns exit
+ *	@peer_type: Peer device specific netlink attribute number (e.g. VETH_INFO_PEER)
+ *	@maxtype: Highest device specific netlink attribute number
+ *	@policy: Netlink policy for device specific attribute validation
+ *	@validate: Optional validation function for netlink/changelink parameters
+ *	@alloc: netdev allocation function, can be %NULL and is then used
+ *		in place of alloc_netdev_mqs(), in this case @priv_size
+ *		and @setup are unused. Returns a netdev or ERR_PTR().
+ *	@priv_size: sizeof net_device private space
+ *	@setup: net_device setup function
+ *	@newlink: Function for configuring and registering a new device
+ *	@changelink: Function for changing parameters of an existing device
+ *	@dellink: Function to remove a device
+ *	@get_size: Function to calculate required room for dumping device
+ *		   specific netlink attributes
+ *	@fill_info: Function to dump device specific netlink attributes
+ *	@get_xstats_size: Function to calculate required room for dumping device
+ *			  specific statistics
+ *	@fill_xstats: Function to dump device specific statistics
+ *	@get_num_tx_queues: Function to determine number of transmit queues
+ *			    to create when creating a new device.
+ *	@get_num_rx_queues: Function to determine number of receive queues
+ *			    to create when creating a new device.
+ *	@get_link_net: Function to get the i/o netns of the device
+ *	@get_linkxstats_size: Function to calculate the required room for
+ *			      dumping device-specific extended link stats
+ *	@fill_linkxstats: Function to dump device-specific extended link stats
+ */
+struct rtnl_link_ops {
+	struct list_head	list;
+	struct srcu_struct	srcu;
+
+	const char		*kind;
+
+	size_t			priv_size;
+	struct net_device	*(*alloc)(struct nlattr *tb[],
+					  const char *ifname,
+					  unsigned char name_assign_type,
+					  unsigned int num_tx_queues,
+					  unsigned int num_rx_queues);
+	void			(*setup)(struct net_device *dev);
+
+	bool			netns_refund;
+	const u16		peer_type;
+	unsigned int		maxtype;
+	const struct nla_policy	*policy;
+	int			(*validate)(struct nlattr *tb[],
+					    struct nlattr *data[],
+					    struct netlink_ext_ack *extack);
+
+	int			(*newlink)(struct net_device *dev,
+					   struct rtnl_newlink_params *params,
+					   struct netlink_ext_ack *extack);
+	int			(*changelink)(struct net_device *dev,
+					      struct nlattr *tb[],
+					      struct nlattr *data[],
+					      struct netlink_ext_ack *extack);
+	void			(*dellink)(struct net_device *dev,
+					   struct list_head *head);
+
+	size_t			(*get_size)(const struct net_device *dev);
+	int			(*fill_info)(struct sk_buff *skb,
+					     const struct net_device *dev);
+
+	size_t			(*get_xstats_size)(const struct net_device *dev);
+	int			(*fill_xstats)(struct sk_buff *skb,
+					       const struct net_device *dev);
+	unsigned int		(*get_num_tx_queues)(void);
+	unsigned int		(*get_num_rx_queues)(void);
+
+	unsigned int		slave_maxtype;
+	const struct nla_policy	*slave_policy;
+	int			(*slave_changelink)(struct net_device *dev,
+						    struct net_device *slave_dev,
+						    struct nlattr *tb[],
+						    struct nlattr *data[],
+						    struct netlink_ext_ack *extack);
+	size_t			(*get_slave_size)(const struct net_device *dev,
+						  const struct net_device *slave_dev);
+	int			(*fill_slave_info)(struct sk_buff *skb,
+						   const struct net_device *dev,
+						   const struct net_device *slave_dev);
+	struct net		*(*get_link_net)(const struct net_device *dev);
+	size_t			(*get_linkxstats_size)(const struct net_device *dev,
+						       int attr);
+	int			(*fill_linkxstats)(struct sk_buff *skb,
+						   const struct net_device *dev,
+						   int *prividx, int attr);
+};
+
+int rtnl_link_register(struct rtnl_link_ops *ops);
+void rtnl_link_unregister(struct rtnl_link_ops *ops);
+
+/**
+ * 	struct rtnl_af_ops - rtnetlink address family operations
+ *
+ *	@list: Used internally, protected by RTNL and SRCU
+ *	@srcu: Used internally
+ * 	@family: Address family
+ * 	@fill_link_af: Function to fill IFLA_AF_SPEC with address family
+ * 		       specific netlink attributes.
+ * 	@get_link_af_size: Function to calculate size of address family specific
+ * 			   netlink attributes.
+ *	@validate_link_af: Validate a IFLA_AF_SPEC attribute, must check attr
+ *			   for invalid configuration settings.
+ * 	@set_link_af: Function to parse a IFLA_AF_SPEC attribute and modify
+ *		      net_device accordingly.
+ */
+struct rtnl_af_ops {
+	struct list_head	list;
+	struct srcu_struct	srcu;
+
+	int			family;
+
+	int			(*fill_link_af)(struct sk_buff *skb,
+						const struct net_device *dev,
+						u32 ext_filter_mask);
+	size_t			(*get_link_af_size)(const struct net_device *dev,
+						    u32 ext_filter_mask);
+
+	int			(*validate_link_af)(const struct net_device *dev,
+						    const struct nlattr *attr,
+						    struct netlink_ext_ack *extack);
+	int			(*set_link_af)(struct net_device *dev,
+					       const struct nlattr *attr,
+					       struct netlink_ext_ack *extack);
+	int			(*fill_stats_af)(struct sk_buff *skb,
+						 const struct net_device *dev);
+	size_t			(*get_stats_af_size)(const struct net_device *dev);
+};
+
+int rtnl_af_register(struct rtnl_af_ops *ops);
+void rtnl_af_unregister(struct rtnl_af_ops *ops);
+
+struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[]);
+struct net_device *rtnl_create_link(struct net *net, const char *ifname,
+				    unsigned char name_assign_type,
+				    const struct rtnl_link_ops *ops,
+				    struct nlattr *tb[],
+				    struct netlink_ext_ack *extack);
+int rtnl_delete_link(struct net_device *dev, u32 portid, const struct nlmsghdr *nlh);
+int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm,
+			u32 portid, const struct nlmsghdr *nlh);
+
+int rtnl_nla_parse_ifinfomsg(struct nlattr **tb, const struct nlattr *nla_peer,
+			     struct netlink_ext_ack *exterr);
+struct net *rtnl_get_net_ns_capable(struct sock *sk, int netnsid);
+bool rtnl_dev_link_net_capable(const struct net_device *dev,
+			       const struct net *link_net);
+
+#define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)
+
+#endif