Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 182 insertions, 0 deletions

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
new file mode 100644
index 000000000..365925c9d
--- /dev/null
+++ b/include/net/inet_frag.h
@@ -0,0 +1,182 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_FRAG_H__
+#define __NET_FRAG_H__
+
+#include <linux/rhashtable-types.h>
+#include <linux/completion.h>
+#include <linux/in6.h>
+#include <linux/rbtree_types.h>
+#include <linux/refcount.h>
+#include <net/dropreason-core.h>
+
+/* Per netns frag queues directory */
+struct fqdir {
+	/* sysctls */
+	long			high_thresh;
+	long			low_thresh;
+	int			timeout;
+	int			max_dist;
+	struct inet_frags	*f;
+	struct net		*net;
+	bool			dead;
+
+	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
+
+	/* Keep atomic mem on separate cachelines in structs that include it */
+	atomic_long_t		mem ____cacheline_aligned_in_smp;
+	struct work_struct	destroy_work;
+	struct llist_node	free_list;
+};
+
+/**
+ * enum: fragment queue flags
+ *
+ * @INET_FRAG_FIRST_IN: first fragment has arrived
+ * @INET_FRAG_LAST_IN: final fragment has arrived
+ * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction
+ * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable
+ * @INET_FRAG_DROP: if skbs must be dropped (instead of being consumed)
+ */
+enum {
+	INET_FRAG_FIRST_IN	= BIT(0),
+	INET_FRAG_LAST_IN	= BIT(1),
+	INET_FRAG_COMPLETE	= BIT(2),
+	INET_FRAG_HASH_DEAD	= BIT(3),
+	INET_FRAG_DROP		= BIT(4),
+};
+
+struct frag_v4_compare_key {
+	__be32		saddr;
+	__be32		daddr;
+	u32		user;
+	u32		vif;
+	__be16		id;
+	u16		protocol;
+};
+
+struct frag_v6_compare_key {
+	struct in6_addr	saddr;
+	struct in6_addr	daddr;
+	u32		user;
+	__be32		id;
+	u32		iif;
+};
+
+/**
+ * struct inet_frag_queue - fragment queue
+ *
+ * @node: rhash node
+ * @key: keys identifying this frag.
+ * @timer: queue expiration timer
+ * @lock: spinlock protecting this frag
+ * @refcnt: reference count of the queue
+ * @rb_fragments: received fragments rb-tree root
+ * @fragments_tail: received fragments tail
+ * @last_run_head: the head of the last "run". see ip_fragment.c
+ * @stamp: timestamp of the last received fragment
+ * @len: total length of the original datagram
+ * @meat: length of received fragments so far
+ * @tstamp_type: stamp has a mono delivery time (EDT)
+ * @flags: fragment queue flags
+ * @max_size: maximum received fragment size
+ * @fqdir: pointer to struct fqdir
+ * @rcu: rcu head for freeing deferall
+ */
+struct inet_frag_queue {
+	struct rhash_head	node;
+	union {
+		struct frag_v4_compare_key v4;
+		struct frag_v6_compare_key v6;
+	} key;
+	struct timer_list	timer;
+	spinlock_t		lock;
+	refcount_t		refcnt;
+	struct rb_root		rb_fragments;
+	struct sk_buff		*fragments_tail;
+	struct sk_buff		*last_run_head;
+	ktime_t			stamp;
+	int			len;
+	int			meat;
+	u8			tstamp_type;
+	__u8			flags;
+	u16			max_size;
+	struct fqdir		*fqdir;
+	struct rcu_head		rcu;
+};
+
+struct inet_frags {
+	unsigned int		qsize;
+
+	void			(*constructor)(struct inet_frag_queue *q,
+					       const void *arg);
+	void			(*destructor)(struct inet_frag_queue *);
+	void			(*frag_expire)(struct timer_list *t);
+	struct kmem_cache	*frags_cachep;
+	const char		*frags_cache_name;
+	struct rhashtable_params rhash_params;
+	refcount_t		refcnt;
+	struct completion	completion;
+};
+
+int inet_frags_init(struct inet_frags *);
+void inet_frags_fini(struct inet_frags *);
+
+int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net);
+
+void fqdir_pre_exit(struct fqdir *fqdir);
+void fqdir_exit(struct fqdir *fqdir);
+
+void inet_frag_kill(struct inet_frag_queue *q, int *refs);
+void inet_frag_destroy(struct inet_frag_queue *q);
+struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key);
+
+void inet_frag_queue_flush(struct inet_frag_queue *q,
+			   enum skb_drop_reason reason);
+
+static inline void inet_frag_putn(struct inet_frag_queue *q, int refs)
+{
+	if (refs && refcount_sub_and_test(refs, &q->refcnt))
+		inet_frag_destroy(q);
+}
+
+/* Memory Tracking Functions. */
+
+static inline long frag_mem_limit(const struct fqdir *fqdir)
+{
+	return atomic_long_read(&fqdir->mem);
+}
+
+static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val)
+{
+	atomic_long_sub(val, &fqdir->mem);
+}
+
+static inline void add_frag_mem_limit(struct fqdir *fqdir, long val)
+{
+	atomic_long_add(val, &fqdir->mem);
+}
+
+/* RFC 3168 support :
+ * We want to check ECN values of all fragments, do detect invalid combinations.
+ * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
+ */
+#define	IPFRAG_ECN_NOT_ECT	0x01 /* one frag had ECN_NOT_ECT */
+#define	IPFRAG_ECN_ECT_1	0x02 /* one frag had ECN_ECT_1 */
+#define	IPFRAG_ECN_ECT_0	0x04 /* one frag had ECN_ECT_0 */
+#define	IPFRAG_ECN_CE		0x08 /* one frag had ECN_CE */
+
+extern const u8 ip_frag_ecn_table[16];
+
+/* Return values of inet_frag_queue_insert() */
+#define IPFRAG_OK	0
+#define IPFRAG_DUP	1
+#define IPFRAG_OVERLAP	2
+int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
+			   int offset, int end);
+void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
+			      struct sk_buff *parent);
+void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
+			    void *reasm_data, bool try_coalesce);
+struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
+
+#endif