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, 560 insertions, 0 deletions

diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
new file mode 100644
index 000000000..fa9a406e1
--- /dev/null
+++ b/net/rxrpc/peer_object.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC remote transport endpoint record management
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <linux/hashtable.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/ip6_route.h>
+#include "ar-internal.h"
+
+static const struct sockaddr_rxrpc rxrpc_null_addr;
+
+/*
+ * Hash a peer key.
+ */
+static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
+					 const struct sockaddr_rxrpc *srx)
+{
+	const u16 *p;
+	unsigned int i, size;
+	unsigned long hash_key;
+
+	_enter("");
+
+	hash_key = (unsigned long)local / __alignof__(*local);
+	hash_key += srx->transport_type;
+	hash_key += srx->transport_len;
+	hash_key += srx->transport.family;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		hash_key += (u16 __force)srx->transport.sin.sin_port;
+		size = sizeof(srx->transport.sin.sin_addr);
+		p = (u16 *)&srx->transport.sin.sin_addr;
+		break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		hash_key += (u16 __force)srx->transport.sin.sin_port;
+		size = sizeof(srx->transport.sin6.sin6_addr);
+		p = (u16 *)&srx->transport.sin6.sin6_addr;
+		break;
+#endif
+	default:
+		WARN(1, "AF_RXRPC: Unsupported transport address family\n");
+		return 0;
+	}
+
+	/* Step through the peer address in 16-bit portions for speed */
+	for (i = 0; i < size; i += sizeof(*p), p++)
+		hash_key += *p;
+
+	_leave(" 0x%lx", hash_key);
+	return hash_key;
+}
+
+/*
+ * Compare a peer to a key.  Return -ve, 0 or +ve to indicate less than, same
+ * or greater than.
+ *
+ * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
+ * buckets and mid-bucket insertion, so we don't make full use of this
+ * information at this point.
+ */
+static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
+			       struct rxrpc_local *local,
+			       const struct sockaddr_rxrpc *srx,
+			       unsigned long hash_key)
+{
+	long diff;
+
+	diff = ((peer->hash_key - hash_key) ?:
+		((unsigned long)peer->local - (unsigned long)local) ?:
+		(peer->srx.transport_type - srx->transport_type) ?:
+		(peer->srx.transport_len - srx->transport_len) ?:
+		(peer->srx.transport.family - srx->transport.family));
+	if (diff != 0)
+		return diff;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		return ((u16 __force)peer->srx.transport.sin.sin_port -
+			(u16 __force)srx->transport.sin.sin_port) ?:
+			memcmp(&peer->srx.transport.sin.sin_addr,
+			       &srx->transport.sin.sin_addr,
+			       sizeof(struct in_addr));
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		return ((u16 __force)peer->srx.transport.sin6.sin6_port -
+			(u16 __force)srx->transport.sin6.sin6_port) ?:
+			memcmp(&peer->srx.transport.sin6.sin6_addr,
+			       &srx->transport.sin6.sin6_addr,
+			       sizeof(struct in6_addr));
+#endif
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
+	struct rxrpc_local *local,
+	const struct sockaddr_rxrpc *srx,
+	unsigned long hash_key)
+{
+	struct rxrpc_peer *peer;
+	struct rxrpc_net *rxnet = local->rxnet;
+
+	hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
+		if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
+		    refcount_read(&peer->ref) > 0)
+			return peer;
+	}
+
+	return NULL;
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
+					 const struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_peer *peer;
+	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+	if (peer)
+		_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
+	return peer;
+}
+
+/*
+ * assess the MTU size for the network interface through which this peer is
+ * reached
+ */
+void rxrpc_assess_MTU_size(struct rxrpc_local *local, struct rxrpc_peer *peer)
+{
+	struct net *net = local->net;
+	struct dst_entry *dst;
+	struct rtable *rt;
+	struct flowi fl;
+	struct flowi4 *fl4 = &fl.u.ip4;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	struct flowi6 *fl6 = &fl.u.ip6;
+#endif
+
+	peer->if_mtu = 1500;
+	if (peer->max_data < peer->if_mtu - peer->hdrsize) {
+		trace_rxrpc_pmtud_reduce(peer, 0, peer->if_mtu - peer->hdrsize,
+					 rxrpc_pmtud_reduce_route);
+		peer->max_data = peer->if_mtu - peer->hdrsize;
+	}
+
+	memset(&fl, 0, sizeof(fl));
+	switch (peer->srx.transport.family) {
+	case AF_INET:
+		rt = ip_route_output_ports(
+			net, fl4, NULL,
+			peer->srx.transport.sin.sin_addr.s_addr, 0,
+			htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
+		if (IS_ERR(rt)) {
+			_leave(" [route err %ld]", PTR_ERR(rt));
+			return;
+		}
+		dst = &rt->dst;
+		break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		fl6->flowi6_iif = LOOPBACK_IFINDEX;
+		fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
+		fl6->flowi6_proto = IPPROTO_UDP;
+		memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
+		       sizeof(struct in6_addr));
+		fl6->fl6_dport = htons(7001);
+		fl6->fl6_sport = htons(7000);
+		dst = ip6_route_output(net, NULL, fl6);
+		if (dst->error) {
+			_leave(" [route err %d]", dst->error);
+			return;
+		}
+		break;
+#endif
+
+	default:
+		BUG();
+	}
+
+	peer->if_mtu = dst_mtu(dst);
+	peer->hdrsize += dst->header_len + dst->trailer_len;
+	peer->tx_seg_max = dst->dev->gso_max_segs;
+	dst_release(dst);
+
+	peer->max_data		= umin(RXRPC_JUMBO(1), peer->if_mtu - peer->hdrsize);
+	peer->pmtud_good	= 500;
+	peer->pmtud_bad		= peer->if_mtu - peer->hdrsize + 1;
+	peer->pmtud_trial	= umin(peer->max_data, peer->pmtud_bad - 1);
+	peer->pmtud_pending	= true;
+
+	_leave(" [if_mtu %u]", peer->if_mtu);
+}
+
+/*
+ * Allocate a peer.
+ */
+struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp,
+				    enum rxrpc_peer_trace why)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	peer = kzalloc_obj(struct rxrpc_peer, gfp);
+	if (peer) {
+		refcount_set(&peer->ref, 1);
+		peer->local = rxrpc_get_local(local, rxrpc_local_get_peer);
+		INIT_HLIST_HEAD(&peer->error_targets);
+		peer->service_conns = RB_ROOT;
+		seqlock_init(&peer->service_conn_lock);
+		spin_lock_init(&peer->lock);
+		peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		peer->recent_srtt_us = UINT_MAX;
+		peer->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
+		trace_rxrpc_peer(peer->debug_id, 1, why);
+	}
+
+	_leave(" = %p", peer);
+	return peer;
+}
+
+/*
+ * Initialise peer record.
+ */
+static void rxrpc_init_peer(struct rxrpc_local *local, struct rxrpc_peer *peer,
+			    unsigned long hash_key)
+{
+	peer->hash_key = hash_key;
+
+
+	switch (peer->srx.transport.family) {
+	case AF_INET:
+		peer->hdrsize = sizeof(struct iphdr);
+		break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		peer->hdrsize = sizeof(struct ipv6hdr);
+		break;
+#endif
+	default:
+		BUG();
+	}
+
+	switch (peer->srx.transport_type) {
+	case SOCK_DGRAM:
+		peer->hdrsize += sizeof(struct udphdr);
+		break;
+	default:
+		BUG();
+	}
+
+	peer->hdrsize += sizeof(struct rxrpc_wire_header);
+	peer->max_data = peer->if_mtu - peer->hdrsize;
+}
+
+/*
+ * Set up a new peer.
+ */
+static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_local *local,
+					    struct sockaddr_rxrpc *srx,
+					    unsigned long hash_key,
+					    gfp_t gfp)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	peer = rxrpc_alloc_peer(local, gfp, rxrpc_peer_new_client);
+	if (peer) {
+		memcpy(&peer->srx, srx, sizeof(*srx));
+		rxrpc_init_peer(local, peer, hash_key);
+		rxrpc_assess_MTU_size(local, peer);
+	}
+
+	_leave(" = %p", peer);
+	return peer;
+}
+
+static void rxrpc_free_peer(struct rxrpc_peer *peer)
+{
+	trace_rxrpc_peer(peer->debug_id, 0, rxrpc_peer_free);
+	rxrpc_put_local(peer->local, rxrpc_local_put_peer);
+	kfree_rcu(peer, rcu);
+}
+
+/*
+ * Set up a new incoming peer.  There shouldn't be any other matching peers
+ * since we've already done a search in the list from the non-reentrant context
+ * (the data_ready handler) that is the only place we can add new peers.
+ * Called with interrupts disabled.
+ */
+void rxrpc_new_incoming_peer(struct rxrpc_local *local, struct rxrpc_peer *peer)
+{
+	struct rxrpc_net *rxnet = local->rxnet;
+	unsigned long hash_key;
+
+	hash_key = rxrpc_peer_hash_key(local, &peer->srx);
+	rxrpc_init_peer(local, peer, hash_key);
+
+	spin_lock(&rxnet->peer_hash_lock);
+	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
+	list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
+	spin_unlock(&rxnet->peer_hash_lock);
+}
+
+/*
+ * obtain a remote transport endpoint for the specified address
+ */
+struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *local,
+				     struct sockaddr_rxrpc *srx, gfp_t gfp)
+{
+	struct rxrpc_peer *peer, *candidate;
+	struct rxrpc_net *rxnet = local->rxnet;
+	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+	_enter("{%pISp}", &srx->transport);
+
+	/* search the peer list first */
+	rcu_read_lock();
+	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+	if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
+		peer = NULL;
+	rcu_read_unlock();
+
+	if (!peer) {
+		/* The peer is not yet present in hash - create a candidate
+		 * for a new record and then redo the search.
+		 */
+		candidate = rxrpc_create_peer(local, srx, hash_key, gfp);
+		if (!candidate) {
+			_leave(" = NULL [nomem]");
+			return NULL;
+		}
+
+		spin_lock_bh(&rxnet->peer_hash_lock);
+
+		/* Need to check that we aren't racing with someone else */
+		peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+		if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
+			peer = NULL;
+		if (!peer) {
+			hash_add_rcu(rxnet->peer_hash,
+				     &candidate->hash_link, hash_key);
+			list_add_tail(&candidate->keepalive_link,
+				      &rxnet->peer_keepalive_new);
+		}
+
+		spin_unlock_bh(&rxnet->peer_hash_lock);
+
+		if (peer)
+			rxrpc_free_peer(candidate);
+		else
+			peer = candidate;
+	}
+
+	_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
+	return peer;
+}
+
+/*
+ * Get a ref on a peer record.
+ */
+struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
+{
+	int r;
+
+	__refcount_inc(&peer->ref, &r);
+	trace_rxrpc_peer(peer->debug_id, r + 1, why);
+	return peer;
+}
+
+/*
+ * Get a ref on a peer record unless its usage has already reached 0.
+ */
+struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer,
+					enum rxrpc_peer_trace why)
+{
+	int r;
+
+	if (peer) {
+		if (__refcount_inc_not_zero(&peer->ref, &r))
+			trace_rxrpc_peer(peer->debug_id, r + 1, why);
+		else
+			peer = NULL;
+	}
+	return peer;
+}
+
+/*
+ * Discard a peer record.
+ */
+static void __rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+	struct rxrpc_net *rxnet = peer->local->rxnet;
+
+	ASSERT(hlist_empty(&peer->error_targets));
+
+	spin_lock_bh(&rxnet->peer_hash_lock);
+	hash_del_rcu(&peer->hash_link);
+	list_del_init(&peer->keepalive_link);
+	spin_unlock_bh(&rxnet->peer_hash_lock);
+
+	rxrpc_free_peer(peer);
+}
+
+/*
+ * Drop a ref on a peer record.
+ */
+void rxrpc_put_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
+{
+	unsigned int debug_id;
+	bool dead;
+	int r;
+
+	if (peer) {
+		debug_id = peer->debug_id;
+		dead = __refcount_dec_and_test(&peer->ref, &r);
+		trace_rxrpc_peer(debug_id, r - 1, why);
+		if (dead)
+			__rxrpc_put_peer(peer);
+	}
+}
+
+/*
+ * Make sure all peer records have been discarded.
+ */
+void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_peer *peer;
+	int i;
+
+	for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
+		if (hlist_empty(&rxnet->peer_hash[i]))
+			continue;
+
+		hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
+			pr_err("Leaked peer %x {%u} %pISp\n",
+			       peer->debug_id,
+			       refcount_read(&peer->ref),
+			       &peer->srx.transport);
+		}
+	}
+}
+
+/**
+ * rxrpc_kernel_get_call_peer - Get the peer address of a call
+ * @sock: The socket on which the call is in progress.
+ * @call: The call to query
+ *
+ * Get a record for the remote peer in a call.
+ *
+ * Return: The call's peer record.
+ */
+struct rxrpc_peer *rxrpc_kernel_get_call_peer(struct socket *sock, struct rxrpc_call *call)
+{
+	return rxrpc_get_peer(call->peer, rxrpc_peer_get_application);
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_call_peer);
+
+/**
+ * rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT
+ * @peer: The peer to query
+ *
+ * Get the call's peer smoothed RTT.
+ *
+ * Return: The RTT in uS or %UINT_MAX if we have no samples.
+ */
+unsigned int rxrpc_kernel_get_srtt(const struct rxrpc_peer *peer)
+{
+	return READ_ONCE(peer->recent_srtt_us);
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_srtt);
+
+/**
+ * rxrpc_kernel_remote_srx - Get the address of a peer
+ * @peer: The peer to query
+ *
+ * Get a pointer to the address from a peer record.  The caller is responsible
+ * for making sure that the address is not deallocated.  A fake address will be
+ * substituted if %peer in NULL.
+ *
+ * Return: The rxrpc address record or a fake record.
+ */
+const struct sockaddr_rxrpc *rxrpc_kernel_remote_srx(const struct rxrpc_peer *peer)
+{
+	return peer ? &peer->srx : &rxrpc_null_addr;
+}
+EXPORT_SYMBOL(rxrpc_kernel_remote_srx);
+
+/**
+ * rxrpc_kernel_remote_addr - Get the peer transport address of a call
+ * @peer: The peer to query
+ *
+ * Get a pointer to the transport address from a peer record.  The caller is
+ * responsible for making sure that the address is not deallocated.  A fake
+ * address will be substituted if %peer in NULL.
+ *
+ * Return: The transport address record or a fake record.
+ */
+const struct sockaddr *rxrpc_kernel_remote_addr(const struct rxrpc_peer *peer)
+{
+	return (const struct sockaddr *)
+		(peer ? &peer->srx.transport : &rxrpc_null_addr.transport);
+}
+EXPORT_SYMBOL(rxrpc_kernel_remote_addr);
+
+/**
+ * rxrpc_kernel_set_peer_data - Set app-specific data on a peer.
+ * @peer: The peer to alter
+ * @app_data: The data to set
+ *
+ * Set the app-specific data on a peer.  AF_RXRPC makes no effort to retain
+ * anything the data might refer to.
+ *
+ * Return: The previous app_data.
+ */
+unsigned long rxrpc_kernel_set_peer_data(struct rxrpc_peer *peer, unsigned long app_data)
+{
+	return xchg(&peer->app_data, app_data);
+}
+EXPORT_SYMBOL(rxrpc_kernel_set_peer_data);
+
+/**
+ * rxrpc_kernel_get_peer_data - Get app-specific data from a peer.
+ * @peer: The peer to query
+ *
+ * Retrieve the app-specific data from a peer.
+ *
+ * Return: The peer's app data.
+ */
+unsigned long rxrpc_kernel_get_peer_data(const struct rxrpc_peer *peer)
+{
+	return peer->app_data;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_peer_data);