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, 217 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-net-statistics b/Documentation/ABI/testing/sysfs-class-net-statistics
new file mode 100644
index 000000000..53e508c69
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-net-statistics
@@ -0,0 +1,217 @@
+What:		/sys/class/net/<iface>/statistics/collisions
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of collisions seen by this network device.
+		This value might not be relevant with all MAC layers.
+
+What:		/sys/class/net/<iface>/statistics/multicast
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of multicast packets received by this
+		network device.
+
+What:		/sys/class/net/<iface>/statistics/rx_bytes
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of bytes received by this network device.
+		See the network driver for the exact meaning of when this
+		value is incremented.
+
+What:		/sys/class/net/<iface>/statistics/rx_compressed
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of compressed packets received by this
+		network device. This value might only be relevant for interfaces
+		that support packet compression (e.g: PPP).
+
+What:		/sys/class/net/<iface>/statistics/rx_crc_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets received with a CRC (FCS) error
+		by this network device. Note that the specific meaning might
+		depend on the MAC layer used by the interface.
+
+What:		/sys/class/net/<iface>/statistics/rx_dropped
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets received by the network device
+		but dropped, that are not forwarded to the upper layers for
+		packet processing. See the network driver for the exact
+		meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/rx_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of receive errors on this network device.
+		See the network driver for the exact meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/rx_fifo_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of receive FIFO errors seen by this
+		network device. See the network driver for the exact
+		meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/rx_frame_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of received frames with error, such as
+		alignment errors. Note that the specific meaning depends on
+		on the MAC layer protocol used. See the network driver for
+		the exact meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/rx_length_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of received error packet with a length
+		error, oversized or undersized. See the network driver for the
+		exact meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/rx_missed_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of received packets that have been missed
+		due to lack of capacity in the receive side. See the network
+		driver for the exact meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/rx_nohandler
+Date:		February 2016
+KernelVersion:	4.6
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of received packets that were dropped on
+		an inactive device by the network core.
+
+What:		/sys/class/net/<iface>/statistics/rx_over_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of received packets that are oversized
+		compared to what the network device is configured to accept
+		(e.g: larger than MTU). See the network driver for the exact
+		meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/rx_packets
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the total number of good packets received by this
+		network device.
+
+What:		/sys/class/net/<iface>/statistics/tx_aborted_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets that have been aborted
+		during transmission by a network device (e.g: because of
+		a medium collision). See the network driver for the exact
+		meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/tx_bytes
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of bytes transmitted by a network
+		device. See the network driver for the exact meaning of this
+		value, in particular whether this accounts for all successfully
+		transmitted packets or all packets that have been queued for
+		transmission.
+
+What:		/sys/class/net/<iface>/statistics/tx_carrier_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets that could not be transmitted
+		because of carrier errors (e.g: physical link down). See the
+		network driver for the exact meaning of this value.
+
+What:		/sys/class/net/<iface>/statistics/tx_compressed
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of transmitted compressed packets. Note
+		this might only be relevant for devices that support
+		compression (e.g: PPP).
+
+What:		/sys/class/net/<iface>/statistics/tx_dropped
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets dropped during transmission.
+		See the driver for the exact reasons as to why the packets were
+		dropped.
+
+What:		/sys/class/net/<iface>/statistics/tx_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets in error during transmission by
+		a network device. See the driver for the exact reasons as to
+		why the packets were dropped.
+
+What:		/sys/class/net/<iface>/statistics/tx_fifo_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets having caused a transmit
+		FIFO error. See the driver for the exact reasons as to why the
+		packets were dropped.
+
+What:		/sys/class/net/<iface>/statistics/tx_heartbeat_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets transmitted that have been
+		reported as heartbeat errors. See the driver for the exact
+		reasons as to why the packets were dropped.
+
+What:		/sys/class/net/<iface>/statistics/tx_packets
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets transmitted by a network
+		device. See the driver for whether this reports the number of all
+		attempted or successful transmissions.
+
+What:		/sys/class/net/<iface>/statistics/tx_window_errors
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the number of packets not successfully transmitted
+		due to a window collision. The specific meaning depends on the
+		MAC layer used.  On Ethernet this is usually used to report
+		late collisions errors.