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, 188 insertions, 0 deletions

diff --git a/Documentation/admin-guide/unicode.rst b/Documentation/admin-guide/unicode.rst
new file mode 100644
index 000000000..cba7e5017
--- /dev/null
+++ b/Documentation/admin-guide/unicode.rst
@@ -0,0 +1,188 @@
+Unicode support
+===============
+
+		 Last update: 2005-01-17, version 1.4
+
+Note: The original version of this document, which was maintained at
+lanana.org as part of the Linux Assigned Names And Numbers Authority
+(LANANA) project, is no longer existent.  So, this version in the
+mainline Linux kernel is now the maintained main document.
+
+Introduction
+------------
+
+The Linux kernel code has been rewritten to use Unicode to map
+characters to fonts.  By downloading a single Unicode-to-font table,
+both the eight-bit character sets and UTF-8 mode are changed to use
+the font as indicated.
+
+This changes the semantics of the eight-bit character tables subtly.
+The four character tables are now:
+
+=============== =============================== ================
+Map symbol	Map name			Escape code (G0)
+=============== =============================== ================
+LAT1_MAP	Latin-1 (ISO 8859-1)		ESC ( B
+GRAF_MAP	DEC VT100 pseudographics	ESC ( 0
+IBMPC_MAP	IBM code page 437		ESC ( U
+USER_MAP	User defined			ESC ( K
+=============== =============================== ================
+
+In particular, ESC ( U is no longer "straight to font", since the font
+might be completely different than the IBM character set.  This
+permits for example the use of block graphics even with a Latin-1 font
+loaded.
+
+Note that although these codes are similar to ISO 2022, neither the
+codes nor their uses match ISO 2022; Linux has two 8-bit codes (G0 and
+G1), whereas ISO 2022 has four 7-bit codes (G0-G3).
+
+In accordance with the Unicode standard/ISO 10646 the range U+F000 to
+U+F8FF has been reserved for OS-wide allocation (the Unicode Standard
+refers to this as a "Corporate Zone", since this is inaccurate for
+Linux we call it the "Linux Zone").  U+F000 was picked as the starting
+point since it lets the direct-mapping area start on a large power of
+two (in case 1024- or 2048-character fonts ever become necessary).
+This leaves U+E000 to U+EFFF as End User Zone.
+
+[v1.2]: The Unicodes range from U+F000 and up to U+F7FF have been
+hard-coded to map directly to the loaded font, bypassing the
+translation table.  The user-defined map now defaults to U+F000 to
+U+F0FF, emulating the previous behaviour.  In practice, this range
+might be shorter; for example, vgacon can only handle 256-character
+(U+F000..U+F0FF) or 512-character (U+F000..U+F1FF) fonts.
+
+
+Actual characters assigned in the Linux Zone
+--------------------------------------------
+
+In addition, the following characters not present in Unicode 1.1.4
+have been defined; these are used by the DEC VT graphics map.  [v1.2]
+THIS USE IS OBSOLETE AND SHOULD NO LONGER BE USED; PLEASE SEE BELOW.
+
+====== ======================================
+U+F800 DEC VT GRAPHICS HORIZONTAL LINE SCAN 1
+U+F801 DEC VT GRAPHICS HORIZONTAL LINE SCAN 3
+U+F803 DEC VT GRAPHICS HORIZONTAL LINE SCAN 7
+U+F804 DEC VT GRAPHICS HORIZONTAL LINE SCAN 9
+====== ======================================
+
+The DEC VT220 uses a 6x10 character matrix, and these characters form
+a smooth progression in the DEC VT graphics character set.  I have
+omitted the scan 5 line, since it is also used as a block-graphics
+character, and hence has been coded as U+2500 FORMS LIGHT HORIZONTAL.
+
+[v1.3]: These characters have been officially added to Unicode 3.2.0;
+they are added at U+23BA, U+23BB, U+23BC, U+23BD.  Linux now uses the
+new values.
+
+[v1.2]: The following characters have been added to represent common
+keyboard symbols that are unlikely to ever be added to Unicode proper
+since they are horribly vendor-specific.  This, of course, is an
+excellent example of horrible design.
+
+====== ======================================
+U+F810 KEYBOARD SYMBOL FLYING FLAG
+U+F811 KEYBOARD SYMBOL PULLDOWN MENU
+U+F812 KEYBOARD SYMBOL OPEN APPLE
+U+F813 KEYBOARD SYMBOL SOLID APPLE
+====== ======================================
+
+Klingon language support
+------------------------
+
+In 1996, Linux was the first operating system in the world to add
+support for the artificial language Klingon, created by Marc Okrand
+for the "Star Trek" television series.	This encoding was later
+adopted by the ConScript Unicode Registry and proposed (but ultimately
+rejected) for inclusion in Unicode Plane 1.  Thus, it remains as a
+Linux/CSUR private assignment in the Linux Zone.
+
+This encoding has been endorsed by the Klingon Language Institute.
+For more information, contact them at:
+
+	http://www.kli.org/
+
+Since the characters in the beginning of the Linux CZ have been more
+of the dingbats/symbols/forms type and this is a language, I have
+located it at the end, on a 16-cell boundary in keeping with standard
+Unicode practice.
+
+.. note::
+
+  This range is now officially managed by the ConScript Unicode
+  Registry.  The normative reference is at:
+
+	https://www.evertype.com/standards/csur/klingon.html
+
+Klingon has an alphabet of 26 characters, a positional numeric writing
+system with 10 digits, and is written left-to-right, top-to-bottom.
+
+Several glyph forms for the Klingon alphabet have been proposed.
+However, since the set of symbols appear to be consistent throughout,
+with only the actual shapes being different, in keeping with standard
+Unicode practice these differences are considered font variants.
+
+======	=======================================================
+U+F8D0	KLINGON LETTER A
+U+F8D1	KLINGON LETTER B
+U+F8D2	KLINGON LETTER CH
+U+F8D3	KLINGON LETTER D
+U+F8D4	KLINGON LETTER E
+U+F8D5	KLINGON LETTER GH
+U+F8D6	KLINGON LETTER H
+U+F8D7	KLINGON LETTER I
+U+F8D8	KLINGON LETTER J
+U+F8D9	KLINGON LETTER L
+U+F8DA	KLINGON LETTER M
+U+F8DB	KLINGON LETTER N
+U+F8DC	KLINGON LETTER NG
+U+F8DD	KLINGON LETTER O
+U+F8DE	KLINGON LETTER P
+U+F8DF	KLINGON LETTER Q
+	- Written <q> in standard Okrand Latin transliteration
+U+F8E0	KLINGON LETTER QH
+	- Written <Q> in standard Okrand Latin transliteration
+U+F8E1	KLINGON LETTER R
+U+F8E2	KLINGON LETTER S
+U+F8E3	KLINGON LETTER T
+U+F8E4	KLINGON LETTER TLH
+U+F8E5	KLINGON LETTER U
+U+F8E6	KLINGON LETTER V
+U+F8E7	KLINGON LETTER W
+U+F8E8	KLINGON LETTER Y
+U+F8E9	KLINGON LETTER GLOTTAL STOP
+
+U+F8F0	KLINGON DIGIT ZERO
+U+F8F1	KLINGON DIGIT ONE
+U+F8F2	KLINGON DIGIT TWO
+U+F8F3	KLINGON DIGIT THREE
+U+F8F4	KLINGON DIGIT FOUR
+U+F8F5	KLINGON DIGIT FIVE
+U+F8F6	KLINGON DIGIT SIX
+U+F8F7	KLINGON DIGIT SEVEN
+U+F8F8	KLINGON DIGIT EIGHT
+U+F8F9	KLINGON DIGIT NINE
+
+U+F8FD	KLINGON COMMA
+U+F8FE	KLINGON FULL STOP
+U+F8FF	KLINGON SYMBOL FOR EMPIRE
+======	=======================================================
+
+Other Fictional and Artificial Scripts
+--------------------------------------
+
+Since the assignment of the Klingon Linux Unicode block, a registry of
+fictional and artificial scripts has been established by John Cowan
+<jcowan@reutershealth.com> and Michael Everson <everson@evertype.com>.
+The ConScript Unicode Registry is accessible at:
+
+	  https://www.evertype.com/standards/csur/
+
+The ranges used fall at the low end of the End User Zone and can hence
+not be normatively assigned, but it is recommended that people who
+wish to encode fictional scripts use these codes, in the interest of
+interoperability.  For Klingon, CSUR has adopted the Linux encoding.
+The CSUR people are driving adding Tengwar and Cirth into Unicode
+Plane 1; the addition of Klingon to Unicode Plane 1 has been rejected
+and so the above encoding remains official.