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, 450 insertions, 0 deletions

diff --git a/net/ipv4/ipmr_base.c b/net/ipv4/ipmr_base.c
new file mode 100644
index 000000000..867b24bed
--- /dev/null
+++ b/net/ipv4/ipmr_base.c
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Linux multicast routing support
+ * Common logic shared by IPv4 [ipmr] and IPv6 [ip6mr] implementation
+ */
+
+#include <linux/rhashtable.h>
+#include <linux/mroute_base.h>
+
+/* Sets everything common except 'dev', since that is done under locking */
+void vif_device_init(struct vif_device *v,
+		     struct net_device *dev,
+		     unsigned long rate_limit,
+		     unsigned char threshold,
+		     unsigned short flags,
+		     unsigned short get_iflink_mask)
+{
+	RCU_INIT_POINTER(v->dev, NULL);
+	v->bytes_in = 0;
+	v->bytes_out = 0;
+	v->pkt_in = 0;
+	v->pkt_out = 0;
+	v->rate_limit = rate_limit;
+	v->flags = flags;
+	v->threshold = threshold;
+	if (v->flags & get_iflink_mask)
+		v->link = dev_get_iflink(dev);
+	else
+		v->link = dev->ifindex;
+}
+
+static void __mr_free_table(struct work_struct *work)
+{
+	struct mr_table *mrt = container_of(to_rcu_work(work),
+					    struct mr_table, work);
+
+	rhltable_destroy(&mrt->mfc_hash);
+	kfree(mrt);
+}
+
+void mr_table_free(struct mr_table *mrt)
+{
+	queue_rcu_work(system_dfl_wq, &mrt->work);
+}
+
+struct mr_table *
+mr_table_alloc(struct net *net, u32 id,
+	       struct mr_table_ops *ops,
+	       void (*expire_func)(struct timer_list *t),
+	       void (*table_set)(struct mr_table *mrt,
+				 struct net *net))
+{
+	struct mr_table *mrt;
+	int err;
+
+	mrt = kzalloc_obj(*mrt);
+	if (!mrt)
+		return ERR_PTR(-ENOMEM);
+	mrt->id = id;
+	write_pnet(&mrt->net, net);
+
+	mrt->ops = *ops;
+	err = rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params);
+	if (err) {
+		kfree(mrt);
+		return ERR_PTR(err);
+	}
+
+	INIT_RCU_WORK(&mrt->work, __mr_free_table);
+	INIT_LIST_HEAD(&mrt->mfc_cache_list);
+	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
+
+	timer_setup(&mrt->ipmr_expire_timer, expire_func, 0);
+
+	mrt->mroute_reg_vif_num = -1;
+	table_set(mrt, net);
+	return mrt;
+}
+
+void *mr_mfc_find_parent(struct mr_table *mrt, void *hasharg, int parent)
+{
+	struct rhlist_head *tmp, *list;
+	struct mr_mfc *c;
+
+	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
+	rhl_for_each_entry_rcu(c, tmp, list, mnode)
+		if (parent == -1 || parent == c->mfc_parent)
+			return c;
+
+	return NULL;
+}
+
+void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi)
+{
+	struct rhlist_head *tmp, *list;
+	struct mr_mfc *c;
+
+	list = rhltable_lookup(&mrt->mfc_hash, mrt->ops.cmparg_any,
+			       *mrt->ops.rht_params);
+	rhl_for_each_entry_rcu(c, tmp, list, mnode)
+		if (c->mfc_un.res.ttls[vifi] < 255)
+			return c;
+
+	return NULL;
+}
+
+void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg)
+{
+	struct rhlist_head *tmp, *list;
+	struct mr_mfc *c, *proxy;
+
+	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
+	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
+		if (c->mfc_un.res.ttls[vifi] < 255)
+			return c;
+
+		/* It's ok if the vifi is part of the static tree */
+		proxy = mr_mfc_find_any_parent(mrt, c->mfc_parent);
+		if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
+			return c;
+	}
+
+	return mr_mfc_find_any_parent(mrt, vifi);
+}
+
+#ifdef CONFIG_PROC_FS
+void *mr_vif_seq_idx(struct net *net, struct mr_vif_iter *iter, loff_t pos)
+{
+	struct mr_table *mrt = iter->mrt;
+
+	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
+		if (!VIF_EXISTS(mrt, iter->ct))
+			continue;
+		if (pos-- == 0)
+			return &mrt->vif_table[iter->ct];
+	}
+	return NULL;
+}
+
+void *mr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct mr_vif_iter *iter = seq->private;
+	struct net *net = seq_file_net(seq);
+	struct mr_table *mrt = iter->mrt;
+
+	++*pos;
+	if (v == SEQ_START_TOKEN)
+		return mr_vif_seq_idx(net, iter, 0);
+
+	while (++iter->ct < mrt->maxvif) {
+		if (!VIF_EXISTS(mrt, iter->ct))
+			continue;
+		return &mrt->vif_table[iter->ct];
+	}
+	return NULL;
+}
+
+void *mr_mfc_seq_idx(struct net *net,
+		     struct mr_mfc_iter *it, loff_t pos)
+{
+	struct mr_table *mrt = it->mrt;
+	struct mr_mfc *mfc;
+
+	rcu_read_lock();
+	it->cache = &mrt->mfc_cache_list;
+	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
+		if (pos-- == 0)
+			return mfc;
+	rcu_read_unlock();
+
+	spin_lock_bh(it->lock);
+	it->cache = &mrt->mfc_unres_queue;
+	list_for_each_entry(mfc, it->cache, list)
+		if (pos-- == 0)
+			return mfc;
+	spin_unlock_bh(it->lock);
+
+	it->cache = NULL;
+	return NULL;
+}
+
+void *mr_mfc_seq_next(struct seq_file *seq, void *v,
+		      loff_t *pos)
+{
+	struct mr_mfc_iter *it = seq->private;
+	struct net *net = seq_file_net(seq);
+	struct mr_table *mrt = it->mrt;
+	struct mr_mfc *c = v;
+
+	++*pos;
+
+	if (v == SEQ_START_TOKEN)
+		return mr_mfc_seq_idx(net, seq->private, 0);
+
+	if (c->list.next != it->cache)
+		return list_entry(c->list.next, struct mr_mfc, list);
+
+	if (it->cache == &mrt->mfc_unres_queue)
+		goto end_of_list;
+
+	/* exhausted cache_array, show unresolved */
+	rcu_read_unlock();
+	it->cache = &mrt->mfc_unres_queue;
+
+	spin_lock_bh(it->lock);
+	if (!list_empty(it->cache))
+		return list_first_entry(it->cache, struct mr_mfc, list);
+
+end_of_list:
+	spin_unlock_bh(it->lock);
+	it->cache = NULL;
+
+	return NULL;
+}
+#endif
+
+int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
+		   struct mr_mfc *c, struct rtmsg *rtm)
+{
+	struct net_device *vif_dev;
+	struct rta_mfc_stats mfcs;
+	struct nlattr *mp_attr;
+	struct rtnexthop *nhp;
+	unsigned long lastuse;
+	int ct;
+
+	/* If cache is unresolved, don't try to parse IIF and OIF */
+	if (c->mfc_parent >= MAXVIFS) {
+		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
+		return -ENOENT;
+	}
+
+	rcu_read_lock();
+	vif_dev = rcu_dereference(mrt->vif_table[c->mfc_parent].dev);
+	if (vif_dev && nla_put_u32(skb, RTA_IIF, READ_ONCE(vif_dev->ifindex)) < 0) {
+		rcu_read_unlock();
+		return -EMSGSIZE;
+	}
+	rcu_read_unlock();
+
+	if (c->mfc_flags & MFC_OFFLOAD)
+		rtm->rtm_flags |= RTNH_F_OFFLOAD;
+
+	mp_attr = nla_nest_start_noflag(skb, RTA_MULTIPATH);
+	if (!mp_attr)
+		return -EMSGSIZE;
+
+	rcu_read_lock();
+	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
+		struct vif_device *vif = &mrt->vif_table[ct];
+
+		vif_dev = rcu_dereference(vif->dev);
+		if (vif_dev && c->mfc_un.res.ttls[ct] < 255) {
+
+			nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
+			if (!nhp) {
+				rcu_read_unlock();
+				nla_nest_cancel(skb, mp_attr);
+				return -EMSGSIZE;
+			}
+
+			nhp->rtnh_flags = 0;
+			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
+			nhp->rtnh_ifindex = READ_ONCE(vif_dev->ifindex);
+			nhp->rtnh_len = sizeof(*nhp);
+		}
+	}
+	rcu_read_unlock();
+
+	nla_nest_end(skb, mp_attr);
+
+	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
+	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
+
+	mfcs.mfcs_packets = atomic_long_read(&c->mfc_un.res.pkt);
+	mfcs.mfcs_bytes = atomic_long_read(&c->mfc_un.res.bytes);
+	mfcs.mfcs_wrong_if = atomic_long_read(&c->mfc_un.res.wrong_if);
+	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
+	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
+			      RTA_PAD))
+		return -EMSGSIZE;
+
+	rtm->rtm_type = RTN_MULTICAST;
+	return 1;
+}
+
+static bool mr_mfc_uses_dev(const struct mr_table *mrt,
+			    const struct mr_mfc *c,
+			    const struct net_device *dev)
+{
+	int ct;
+
+	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
+		const struct net_device *vif_dev;
+		const struct vif_device *vif;
+
+		vif = &mrt->vif_table[ct];
+		vif_dev = rcu_access_pointer(vif->dev);
+		if (vif_dev && c->mfc_un.res.ttls[ct] < 255 &&
+		    vif_dev == dev)
+			return true;
+	}
+	return false;
+}
+
+int mr_table_dump(struct mr_table *mrt, struct sk_buff *skb,
+		  struct netlink_callback *cb,
+		  int (*fill)(struct mr_table *mrt, struct sk_buff *skb,
+			      u32 portid, u32 seq, struct mr_mfc *c,
+			      int cmd, int flags),
+		  spinlock_t *lock, struct fib_dump_filter *filter)
+{
+	unsigned int e = 0, s_e = cb->args[1];
+	unsigned int flags = NLM_F_MULTI;
+	struct mr_mfc *mfc;
+	int err;
+
+	if (filter->filter_set)
+		flags |= NLM_F_DUMP_FILTERED;
+
+	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list,
+				lockdep_rtnl_is_held()) {
+		if (e < s_e)
+			goto next_entry;
+		if (filter->dev &&
+		    !mr_mfc_uses_dev(mrt, mfc, filter->dev))
+			goto next_entry;
+
+		err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
+			   cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
+		if (err < 0)
+			goto out;
+next_entry:
+		e++;
+	}
+
+	spin_lock_bh(lock);
+	list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
+		if (e < s_e)
+			goto next_entry2;
+
+		err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
+			   cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
+		if (err < 0) {
+			spin_unlock_bh(lock);
+			goto out;
+		}
+next_entry2:
+		e++;
+	}
+	spin_unlock_bh(lock);
+	err = 0;
+out:
+	cb->args[1] = e;
+	return err;
+}
+
+int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
+		     struct mr_table *(*iter)(struct net *net,
+					      struct mr_table *mrt),
+		     int (*fill)(struct mr_table *mrt,
+				 struct sk_buff *skb,
+				 u32 portid, u32 seq, struct mr_mfc *c,
+				 int cmd, int flags),
+		     spinlock_t *lock, struct fib_dump_filter *filter)
+{
+	unsigned int t = 0, s_t = cb->args[0];
+	struct net *net = sock_net(skb->sk);
+	struct mr_table *mrt;
+	int err;
+
+	/* multicast does not track protocol or have route type other
+	 * than RTN_MULTICAST
+	 */
+	if (filter->filter_set) {
+		if (filter->protocol || filter->flags ||
+		    (filter->rt_type && filter->rt_type != RTN_MULTICAST))
+			return skb->len;
+	}
+
+	rcu_read_lock();
+	for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
+		if (t < s_t)
+			goto next_table;
+
+		err = mr_table_dump(mrt, skb, cb, fill, lock, filter);
+		if (err < 0)
+			break;
+		cb->args[1] = 0;
+next_table:
+		t++;
+	}
+	rcu_read_unlock();
+
+	cb->args[0] = t;
+
+	return skb->len;
+}
+
+int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
+	    int (*rules_dump)(struct net *net,
+			      struct notifier_block *nb,
+			      struct netlink_ext_ack *extack),
+	    struct mr_table *(*mr_iter)(struct net *net,
+					struct mr_table *mrt),
+	    struct netlink_ext_ack *extack)
+{
+	struct mr_table *mrt;
+	int err;
+
+	err = rules_dump(net, nb, extack);
+	if (err)
+		return err;
+
+	for (mrt = mr_iter(net, NULL); mrt; mrt = mr_iter(net, mrt)) {
+		struct vif_device *v = &mrt->vif_table[0];
+		struct net_device *vif_dev;
+		struct mr_mfc *mfc;
+		int vifi;
+
+		/* Notifiy on table VIF entries */
+		rcu_read_lock();
+		for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) {
+			vif_dev = rcu_dereference(v->dev);
+			if (!vif_dev)
+				continue;
+
+			err = mr_call_vif_notifier(nb, family,
+						   FIB_EVENT_VIF_ADD, v,
+						   vif_dev, vifi,
+						   mrt->id, extack);
+			if (err)
+				break;
+		}
+		rcu_read_unlock();
+
+		if (err)
+			return err;
+
+		/* Notify on table MFC entries */
+		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
+			err = mr_call_mfc_notifier(nb, family,
+						   FIB_EVENT_ENTRY_ADD,
+						   mfc, mrt->id, extack);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}