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, 393 insertions, 0 deletions

diff --git a/include/net/netdev_queues.h b/include/net/netdev_queues.h
new file mode 100644
index 000000000..70c9fe9e8
--- /dev/null
+++ b/include/net/netdev_queues.h
@@ -0,0 +1,393 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_NET_QUEUES_H
+#define _LINUX_NET_QUEUES_H
+
+#include <linux/netdevice.h>
+
+/**
+ * struct netdev_config - queue-related configuration for a netdev
+ * @hds_thresh:		HDS Threshold value.
+ * @hds_config:		HDS value from userspace.
+ */
+struct netdev_config {
+	u32	hds_thresh;
+	u8	hds_config;
+};
+
+struct netdev_queue_config {
+	u32	rx_page_size;
+};
+
+/* See the netdev.yaml spec for definition of each statistic */
+struct netdev_queue_stats_rx {
+	u64 bytes;
+	u64 packets;
+	u64 alloc_fail;
+
+	u64 hw_drops;
+	u64 hw_drop_overruns;
+
+	u64 csum_complete;
+	u64 csum_unnecessary;
+	u64 csum_none;
+	u64 csum_bad;
+
+	u64 hw_gro_packets;
+	u64 hw_gro_bytes;
+	u64 hw_gro_wire_packets;
+	u64 hw_gro_wire_bytes;
+
+	u64 hw_drop_ratelimits;
+};
+
+struct netdev_queue_stats_tx {
+	u64 bytes;
+	u64 packets;
+
+	u64 hw_drops;
+	u64 hw_drop_errors;
+
+	u64 csum_none;
+	u64 needs_csum;
+
+	u64 hw_gso_packets;
+	u64 hw_gso_bytes;
+	u64 hw_gso_wire_packets;
+	u64 hw_gso_wire_bytes;
+
+	u64 hw_drop_ratelimits;
+
+	u64 stop;
+	u64 wake;
+};
+
+/**
+ * struct netdev_stat_ops - netdev ops for fine grained stats
+ * @get_queue_stats_rx:	get stats for a given Rx queue
+ * @get_queue_stats_tx:	get stats for a given Tx queue
+ * @get_base_stats:	get base stats (not belonging to any live instance)
+ *
+ * Query stats for a given object. The values of the statistics are undefined
+ * on entry (specifically they are *not* zero-initialized). Drivers should
+ * assign values only to the statistics they collect. Statistics which are not
+ * collected must be left undefined.
+ *
+ * Queue objects are not necessarily persistent, and only currently active
+ * queues are queried by the per-queue callbacks. This means that per-queue
+ * statistics will not generally add up to the total number of events for
+ * the device. The @get_base_stats callback allows filling in the delta
+ * between events for currently live queues and overall device history.
+ * @get_base_stats can also be used to report any miscellaneous packets
+ * transferred outside of the main set of queues used by the networking stack.
+ * When the statistics for the entire device are queried, first @get_base_stats
+ * is issued to collect the delta, and then a series of per-queue callbacks.
+ * Only statistics which are set in @get_base_stats will be reported
+ * at the device level, meaning that unlike in queue callbacks, setting
+ * a statistic to zero in @get_base_stats is a legitimate thing to do.
+ * This is because @get_base_stats has a second function of designating which
+ * statistics are in fact correct for the entire device (e.g. when history
+ * for some of the events is not maintained, and reliable "total" cannot
+ * be provided).
+ *
+ * Ops are called under the instance lock if netdev_need_ops_lock()
+ * returns true, otherwise under rtnl_lock.
+ * Device drivers can assume that when collecting total device stats,
+ * the @get_base_stats and subsequent per-queue calls are performed
+ * "atomically" (without releasing the relevant lock).
+ *
+ * Device drivers are encouraged to reset the per-queue statistics when
+ * number of queues change. This is because the primary use case for
+ * per-queue statistics is currently to detect traffic imbalance.
+ */
+struct netdev_stat_ops {
+	void (*get_queue_stats_rx)(struct net_device *dev, int idx,
+				   struct netdev_queue_stats_rx *stats);
+	void (*get_queue_stats_tx)(struct net_device *dev, int idx,
+				   struct netdev_queue_stats_tx *stats);
+	void (*get_base_stats)(struct net_device *dev,
+			       struct netdev_queue_stats_rx *rx,
+			       struct netdev_queue_stats_tx *tx);
+};
+
+void netdev_stat_queue_sum(struct net_device *netdev,
+			   int rx_start, int rx_end,
+			   struct netdev_queue_stats_rx *rx_sum,
+			   int tx_start, int tx_end,
+			   struct netdev_queue_stats_tx *tx_sum);
+
+enum {
+	/* The queue checks and honours the page size qcfg parameter */
+	QCFG_RX_PAGE_SIZE	= 0x1,
+};
+
+/**
+ * struct netdev_queue_mgmt_ops - netdev ops for queue management
+ *
+ * @ndo_queue_mem_size: Size of the struct that describes a queue's memory.
+ *
+ * @ndo_queue_mem_alloc: Allocate memory for an RX queue at the specified index.
+ *			 The new memory is written at the specified address.
+ *
+ * @ndo_queue_mem_free:	Free memory from an RX queue.
+ *
+ * @ndo_queue_start:	Start an RX queue with the specified memory and at the
+ *			specified index.
+ *
+ * @ndo_queue_stop:	Stop the RX queue at the specified index. The stopped
+ *			queue's memory is written at the specified address.
+ *
+ * @ndo_queue_get_dma_dev: Get dma device for zero-copy operations to be used
+ *			   for this queue. Return NULL on error.
+ *
+ * @ndo_default_qcfg:	(Optional) Populate queue config struct with defaults.
+ *			Queue config structs are passed to this helper before
+ *			the user-requested settings are applied.
+ *
+ * @ndo_validate_qcfg: (Optional) Check if queue config is supported.
+ *			Called when configuration affecting a queue may be
+ *			changing, either due to NIC-wide config, or config
+ *			scoped to the queue at a specified index.
+ *			When NIC-wide config is changed the callback will
+ *			be invoked for all queues.
+ *
+ * @ndo_queue_create:	Create a new RX queue on a virtual device that will
+ *			be paired with a physical device's queue via leasing.
+ *			Return the new queue id on success, negative error
+ *			on failure.
+ *
+ * @supported_params:	Bitmask of supported parameters, see QCFG_*.
+ *
+ * Note that @ndo_queue_mem_alloc and @ndo_queue_mem_free may be called while
+ * the interface is closed. @ndo_queue_start and @ndo_queue_stop will only
+ * be called for an interface which is open.
+ */
+struct netdev_queue_mgmt_ops {
+	size_t	ndo_queue_mem_size;
+	int	(*ndo_queue_mem_alloc)(struct net_device *dev,
+				       struct netdev_queue_config *qcfg,
+				       void *per_queue_mem,
+				       int idx);
+	void	(*ndo_queue_mem_free)(struct net_device *dev,
+				      void *per_queue_mem);
+	int	(*ndo_queue_start)(struct net_device *dev,
+				   struct netdev_queue_config *qcfg,
+				   void *per_queue_mem,
+				   int idx);
+	int	(*ndo_queue_stop)(struct net_device *dev,
+				  void *per_queue_mem,
+				  int idx);
+	void	(*ndo_default_qcfg)(struct net_device *dev,
+				    struct netdev_queue_config *qcfg);
+	int	(*ndo_validate_qcfg)(struct net_device *dev,
+				     struct netdev_queue_config *qcfg,
+				     struct netlink_ext_ack *extack);
+	struct device *	(*ndo_queue_get_dma_dev)(struct net_device *dev,
+						 int idx);
+	int	(*ndo_queue_create)(struct net_device *dev,
+				    struct netlink_ext_ack *extack);
+
+	unsigned int supported_params;
+};
+
+void netdev_queue_config(struct net_device *dev, int rxq,
+			 struct netdev_queue_config *qcfg);
+
+bool netif_rxq_has_unreadable_mp(struct net_device *dev, unsigned int rxq_idx);
+
+/**
+ * DOC: Lockless queue stopping / waking helpers.
+ *
+ * The netif_txq_maybe_stop() and __netif_txq_completed_wake()
+ * macros are designed to safely implement stopping
+ * and waking netdev queues without full lock protection.
+ *
+ * We assume that there can be no concurrent stop attempts and no concurrent
+ * wake attempts. The try-stop should happen from the xmit handler,
+ * while wake up should be triggered from NAPI poll context.
+ * The two may run concurrently (single producer, single consumer).
+ *
+ * The try-stop side is expected to run from the xmit handler and therefore
+ * it does not reschedule Tx (netif_tx_start_queue() instead of
+ * netif_tx_wake_queue()). Uses of the ``stop`` macros outside of the xmit
+ * handler may lead to xmit queue being enabled but not run.
+ * The waking side does not have similar context restrictions.
+ *
+ * The macros guarantee that rings will not remain stopped if there's
+ * space available, but they do *not* prevent false wake ups when
+ * the ring is full! Drivers should check for ring full at the start
+ * for the xmit handler.
+ *
+ * All descriptor ring indexes (and other relevant shared state) must
+ * be updated before invoking the macros.
+ */
+
+#define netif_txq_try_stop(txq, get_desc, start_thrs)			\
+	({								\
+		int _res;						\
+									\
+		netif_tx_stop_queue(txq);				\
+		/* Producer index and stop bit must be visible		\
+		 * to consumer before we recheck.			\
+		 * Pairs with a barrier in __netif_txq_completed_wake(). \
+		 */							\
+		smp_mb__after_atomic();					\
+									\
+		/* We need to check again in a case another		\
+		 * CPU has just made room available.			\
+		 */							\
+		_res = 0;						\
+		if (unlikely(get_desc >= start_thrs)) {			\
+			netif_tx_start_queue(txq);			\
+			_res = -1;					\
+		}							\
+		_res;							\
+	})								\
+
+/**
+ * netif_txq_maybe_stop() - locklessly stop a Tx queue, if needed
+ * @txq:	struct netdev_queue to stop/start
+ * @get_desc:	get current number of free descriptors (see requirements below!)
+ * @stop_thrs:	minimal number of available descriptors for queue to be left
+ *		enabled
+ * @start_thrs:	minimal number of descriptors to re-enable the queue, can be
+ *		equal to @stop_thrs or higher to avoid frequent waking
+ *
+ * All arguments may be evaluated multiple times, beware of side effects.
+ * @get_desc must be a formula or a function call, it must always
+ * return up-to-date information when evaluated!
+ * Expected to be used from ndo_start_xmit, see the comment on top of the file.
+ *
+ * Returns:
+ *	 0 if the queue was stopped
+ *	 1 if the queue was left enabled
+ *	-1 if the queue was re-enabled (raced with waking)
+ */
+#define netif_txq_maybe_stop(txq, get_desc, stop_thrs, start_thrs)	\
+	({								\
+		int _res;						\
+									\
+		_res = 1;						\
+		if (unlikely(get_desc < stop_thrs))			\
+			_res = netif_txq_try_stop(txq, get_desc, start_thrs); \
+		_res;							\
+	})								\
+
+/* Variant of netdev_tx_completed_queue() which guarantees smp_mb() if
+ * @bytes != 0, regardless of kernel config.
+ */
+static inline void
+netdev_txq_completed_mb(struct netdev_queue *dev_queue,
+			unsigned int pkts, unsigned int bytes)
+{
+	if (IS_ENABLED(CONFIG_BQL))
+		netdev_tx_completed_queue(dev_queue, pkts, bytes);
+	else if (bytes)
+		smp_mb();
+}
+
+/**
+ * __netif_txq_completed_wake() - locklessly wake a Tx queue, if needed
+ * @txq:	struct netdev_queue to stop/start
+ * @pkts:	number of packets completed
+ * @bytes:	number of bytes completed
+ * @get_desc:	get current number of free descriptors (see requirements below!)
+ * @start_thrs:	minimal number of descriptors to re-enable the queue
+ * @down_cond:	down condition, predicate indicating that the queue should
+ *		not be woken up even if descriptors are available
+ *
+ * All arguments may be evaluated multiple times.
+ * @get_desc must be a formula or a function call, it must always
+ * return up-to-date information when evaluated!
+ * Reports completed pkts/bytes to BQL.
+ *
+ * Returns:
+ *	 0 if the queue was woken up
+ *	 1 if the queue was already enabled (or disabled but @down_cond is true)
+ *	-1 if the queue was left unchanged (@start_thrs not reached)
+ */
+#define __netif_txq_completed_wake(txq, pkts, bytes,			\
+				   get_desc, start_thrs, down_cond)	\
+	({								\
+		int _res;						\
+									\
+		/* Report to BQL and piggy back on its barrier.		\
+		 * Barrier makes sure that anybody stopping the queue	\
+		 * after this point sees the new consumer index.	\
+		 * Pairs with barrier in netif_txq_try_stop().		\
+		 */							\
+		netdev_txq_completed_mb(txq, pkts, bytes);		\
+									\
+		_res = -1;						\
+		if (pkts && likely(get_desc >= start_thrs)) {		\
+			_res = 1;					\
+			if (unlikely(netif_tx_queue_stopped(txq)) &&	\
+			    !(down_cond)) {				\
+				netif_tx_wake_queue(txq);		\
+				_res = 0;				\
+			}						\
+		}							\
+		_res;							\
+	})
+
+#define netif_txq_completed_wake(txq, pkts, bytes, get_desc, start_thrs) \
+	__netif_txq_completed_wake(txq, pkts, bytes, get_desc, start_thrs, false)
+
+/* subqueue variants follow */
+
+#define netif_subqueue_try_stop(dev, idx, get_desc, start_thrs)		\
+	({								\
+		struct netdev_queue *_txq;				\
+									\
+		_txq = netdev_get_tx_queue(dev, idx);			\
+		netif_txq_try_stop(_txq, get_desc, start_thrs);		\
+	})
+
+static inline void netif_subqueue_sent(const struct net_device *dev,
+				       unsigned int idx, unsigned int bytes)
+{
+	struct netdev_queue *txq;
+
+	txq = netdev_get_tx_queue(dev, idx);
+	netdev_tx_sent_queue(txq, bytes);
+}
+
+static inline unsigned int netif_xmit_timeout_ms(struct netdev_queue *txq)
+{
+	unsigned long trans_start = READ_ONCE(txq->trans_start);
+
+	if (netif_xmit_stopped(txq) &&
+	    time_after(jiffies, trans_start + txq->dev->watchdog_timeo))
+		return jiffies_to_msecs(jiffies - trans_start);
+
+	return 0;
+}
+
+#define netif_subqueue_maybe_stop(dev, idx, get_desc, stop_thrs, start_thrs) \
+	({								\
+		struct netdev_queue *_txq;				\
+									\
+		_txq = netdev_get_tx_queue(dev, idx);			\
+		netif_txq_maybe_stop(_txq, get_desc, stop_thrs, start_thrs); \
+	})
+
+#define netif_subqueue_completed_wake(dev, idx, pkts, bytes,		\
+				      get_desc, start_thrs)		\
+	({								\
+		struct netdev_queue *_txq;				\
+									\
+		_txq = netdev_get_tx_queue(dev, idx);			\
+		netif_txq_completed_wake(_txq, pkts, bytes,		\
+					 get_desc, start_thrs);		\
+	})
+
+struct device *netdev_queue_get_dma_dev(struct net_device *dev,
+					unsigned int idx,
+					enum netdev_queue_type type);
+bool netdev_can_create_queue(const struct net_device *dev,
+			     struct netlink_ext_ack *extack);
+bool netdev_can_lease_queue(const struct net_device *dev,
+			    struct netlink_ext_ack *extack);
+bool netdev_queue_busy(struct net_device *dev, unsigned int idx,
+		       enum netdev_queue_type type,
+		       struct netlink_ext_ack *extack);
+#endif /* _LINUX_NET_QUEUES_H */