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, 162 insertions, 0 deletions

diff --git a/include/net/lapb.h b/include/net/lapb.h
new file mode 100644
index 000000000..6c0742064
--- /dev/null
+++ b/include/net/lapb.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LAPB_H
+#define _LAPB_H 
+#include <linux/lapb.h>
+#include <linux/refcount.h>
+
+#define	LAPB_HEADER_LEN MAX_HEADER		/* LAPB over Ethernet + a bit more */
+
+#define	LAPB_ACK_PENDING_CONDITION	0x01
+#define	LAPB_REJECT_CONDITION		0x02
+#define	LAPB_PEER_RX_BUSY_CONDITION	0x04
+
+/* Control field templates */
+#define	LAPB_I		0x00	/* Information frames */
+#define	LAPB_S		0x01	/* Supervisory frames */
+#define	LAPB_U		0x03	/* Unnumbered frames */
+
+#define	LAPB_RR		0x01	/* Receiver ready */
+#define	LAPB_RNR	0x05	/* Receiver not ready */
+#define	LAPB_REJ	0x09	/* Reject */
+
+#define	LAPB_SABM	0x2F	/* Set Asynchronous Balanced Mode */
+#define	LAPB_SABME	0x6F	/* Set Asynchronous Balanced Mode Extended */
+#define	LAPB_DISC	0x43	/* Disconnect */
+#define	LAPB_DM		0x0F	/* Disconnected mode */
+#define	LAPB_UA		0x63	/* Unnumbered acknowledge */
+#define	LAPB_FRMR	0x87	/* Frame reject */
+
+#define LAPB_ILLEGAL	0x100	/* Impossible to be a real frame type */
+
+#define	LAPB_SPF	0x10	/* Poll/final bit for standard LAPB */
+#define	LAPB_EPF	0x01	/* Poll/final bit for extended LAPB */
+
+#define	LAPB_FRMR_W	0x01	/* Control field invalid	*/
+#define	LAPB_FRMR_X	0x02	/* I field invalid		*/
+#define	LAPB_FRMR_Y	0x04	/* I field too long		*/
+#define	LAPB_FRMR_Z	0x08	/* Invalid N(R)			*/
+
+#define	LAPB_POLLOFF	0
+#define	LAPB_POLLON	1
+
+/* LAPB C-bit */
+#define LAPB_COMMAND	1
+#define LAPB_RESPONSE	2
+
+#define	LAPB_ADDR_A	0x03
+#define	LAPB_ADDR_B	0x01
+#define	LAPB_ADDR_C	0x0F
+#define	LAPB_ADDR_D	0x07
+
+/* Define Link State constants. */
+enum {
+	LAPB_STATE_0,	/* Disconnected State		*/
+	LAPB_STATE_1,	/* Awaiting Connection State	*/
+	LAPB_STATE_2,	/* Awaiting Disconnection State	*/
+	LAPB_STATE_3,	/* Data Transfer State		*/
+	LAPB_STATE_4	/* Frame Reject State		*/
+};
+
+#define	LAPB_DEFAULT_MODE		(LAPB_STANDARD | LAPB_SLP | LAPB_DTE)
+#define	LAPB_DEFAULT_WINDOW		7		/* Window=7 */
+#define	LAPB_DEFAULT_T1			(5 * HZ)	/* T1=5s    */
+#define	LAPB_DEFAULT_T2			(1 * HZ)	/* T2=1s    */
+#define	LAPB_DEFAULT_N2			20		/* N2=20    */
+
+#define	LAPB_SMODULUS	8
+#define	LAPB_EMODULUS	128
+
+/*
+ *	Information about the current frame.
+ */
+struct lapb_frame {
+	unsigned short		type;		/* Parsed type		*/
+	unsigned short		nr, ns;		/* N(R), N(S)		*/
+	unsigned char		cr;		/* Command/Response	*/
+	unsigned char		pf;		/* Poll/Final		*/
+	unsigned char		control[2];	/* Original control data*/
+};
+
+/*
+ *	The per LAPB connection control structure.
+ */
+struct lapb_cb {
+	struct list_head	node;
+	struct net_device	*dev;
+
+	/* Link status fields */
+	unsigned int		mode;
+	unsigned char		state;
+	unsigned short		vs, vr, va;
+	unsigned char		condition;
+	unsigned short		n2, n2count;
+	unsigned short		t1, t2;
+	struct timer_list	t1timer, t2timer;
+	bool			t1timer_running, t2timer_running;
+
+	/* Internal control information */
+	struct sk_buff_head	write_queue;
+	struct sk_buff_head	ack_queue;
+	unsigned char		window;
+	const struct lapb_register_struct *callbacks;
+
+	/* FRMR control information */
+	struct lapb_frame	frmr_data;
+	unsigned char		frmr_type;
+
+	spinlock_t		lock;
+	refcount_t		refcnt;
+};
+
+/* lapb_iface.c */
+void lapb_connect_confirmation(struct lapb_cb *lapb, int);
+void lapb_connect_indication(struct lapb_cb *lapb, int);
+void lapb_disconnect_confirmation(struct lapb_cb *lapb, int);
+void lapb_disconnect_indication(struct lapb_cb *lapb, int);
+int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *);
+int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *);
+
+/* lapb_in.c */
+void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *);
+
+/* lapb_out.c */
+void lapb_kick(struct lapb_cb *lapb);
+void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *, int);
+void lapb_establish_data_link(struct lapb_cb *lapb);
+void lapb_enquiry_response(struct lapb_cb *lapb);
+void lapb_timeout_response(struct lapb_cb *lapb);
+void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short);
+void lapb_check_need_response(struct lapb_cb *lapb, int, int);
+
+/* lapb_subr.c */
+void lapb_clear_queues(struct lapb_cb *lapb);
+void lapb_frames_acked(struct lapb_cb *lapb, unsigned short);
+void lapb_requeue_frames(struct lapb_cb *lapb);
+int lapb_validate_nr(struct lapb_cb *lapb, unsigned short);
+int lapb_decode(struct lapb_cb *lapb, struct sk_buff *, struct lapb_frame *);
+void lapb_send_control(struct lapb_cb *lapb, int, int, int);
+void lapb_transmit_frmr(struct lapb_cb *lapb);
+
+/* lapb_timer.c */
+void lapb_start_t1timer(struct lapb_cb *lapb);
+void lapb_start_t2timer(struct lapb_cb *lapb);
+void lapb_stop_t1timer(struct lapb_cb *lapb);
+void lapb_stop_t2timer(struct lapb_cb *lapb);
+int lapb_t1timer_running(struct lapb_cb *lapb);
+
+/*
+ * Debug levels.
+ *	0 = Off
+ *	1 = State Changes
+ *	2 = Packets I/O and State Changes
+ *	3 = Hex dumps, Packets I/O and State Changes.
+ */
+#define	LAPB_DEBUG	0
+
+#define lapb_dbg(level, fmt, ...)			\
+do {							\
+	if (level < LAPB_DEBUG)				\
+		pr_debug(fmt, ##__VA_ARGS__);		\
+} while (0)
+
+#endif