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, 358 insertions, 0 deletions

diff --git a/lib/dhry.h b/lib/dhry.h
new file mode 100644
index 000000000..e1a4db8e2
--- /dev/null
+++ b/lib/dhry.h
@@ -0,0 +1,358 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ ****************************************************************************
+ *
+ *                   "DHRYSTONE" Benchmark Program
+ *                   -----------------------------
+ *
+ *  Version:    C, Version 2.1
+ *
+ *  File:       dhry.h (part 1 of 3)
+ *
+ *  Date:       May 25, 1988
+ *
+ *  Author:     Reinhold P. Weicker
+ *                      Siemens AG, AUT E 51
+ *                      Postfach 3220
+ *                      8520 Erlangen
+ *                      Germany (West)
+ *                              Phone:  [+49]-9131-7-20330
+ *                                      (8-17 Central European Time)
+ *                              Usenet: ..!mcsun!unido!estevax!weicker
+ *
+ *              Original Version (in Ada) published in
+ *              "Communications of the ACM" vol. 27., no. 10 (Oct. 1984),
+ *              pp. 1013 - 1030, together with the statistics
+ *              on which the distribution of statements etc. is based.
+ *
+ *              In this C version, the following C library functions are used:
+ *              - strcpy, strcmp (inside the measurement loop)
+ *              - printf, scanf (outside the measurement loop)
+ *              In addition, Berkeley UNIX system calls "times ()" or "time ()"
+ *              are used for execution time measurement. For measurements
+ *              on other systems, these calls have to be changed.
+ *
+ *  Collection of Results:
+ *              Reinhold Weicker (address see above) and
+ *
+ *              Rick Richardson
+ *              PC Research. Inc.
+ *              94 Apple Orchard Drive
+ *              Tinton Falls, NJ 07724
+ *                      Phone:  (201) 389-8963 (9-17 EST)
+ *                      Usenet: ...!uunet!pcrat!rick
+ *
+ *      Please send results to Rick Richardson and/or Reinhold Weicker.
+ *      Complete information should be given on hardware and software used.
+ *      Hardware information includes: Machine type, CPU, type and size
+ *      of caches; for microprocessors: clock frequency, memory speed
+ *      (number of wait states).
+ *      Software information includes: Compiler (and runtime library)
+ *      manufacturer and version, compilation switches, OS version.
+ *      The Operating System version may give an indication about the
+ *      compiler; Dhrystone itself performs no OS calls in the measurement loop.
+ *
+ *      The complete output generated by the program should be mailed
+ *      such that at least some checks for correctness can be made.
+ *
+ ***************************************************************************
+ *
+ *  History:    This version C/2.1 has been made for two reasons:
+ *
+ *              1) There is an obvious need for a common C version of
+ *              Dhrystone, since C is at present the most popular system
+ *              programming language for the class of processors
+ *              (microcomputers, minicomputers) where Dhrystone is used most.
+ *              There should be, as far as possible, only one C version of
+ *              Dhrystone such that results can be compared without
+ *              restrictions. In the past, the C versions distributed
+ *              by Rick Richardson (Version 1.1) and by Reinhold Weicker
+ *              had small (though not significant) differences.
+ *
+ *              2) As far as it is possible without changes to the Dhrystone
+ *              statistics, optimizing compilers should be prevented from
+ *              removing significant statements.
+ *
+ *              This C version has been developed in cooperation with
+ *              Rick Richardson (Tinton Falls, NJ), it incorporates many
+ *              ideas from the "Version 1.1" distributed previously by
+ *              him over the UNIX network Usenet.
+ *              I also thank Chaim Benedelac (National Semiconductor),
+ *              David Ditzel (SUN), Earl Killian and John Mashey (MIPS),
+ *              Alan Smith and Rafael Saavedra-Barrera (UC at Berkeley)
+ *              for their help with comments on earlier versions of the
+ *              benchmark.
+ *
+ *  Changes:    In the initialization part, this version follows mostly
+ *              Rick Richardson's version distributed via Usenet, not the
+ *              version distributed earlier via floppy disk by Reinhold Weicker.
+ *              As a concession to older compilers, names have been made
+ *              unique within the first 8 characters.
+ *              Inside the measurement loop, this version follows the
+ *              version previously distributed by Reinhold Weicker.
+ *
+ *              At several places in the benchmark, code has been added,
+ *              but within the measurement loop only in branches that
+ *              are not executed. The intention is that optimizing compilers
+ *              should be prevented from moving code out of the measurement
+ *              loop, or from removing code altogether. Since the statements
+ *              that are executed within the measurement loop have NOT been
+ *              changed, the numbers defining the "Dhrystone distribution"
+ *              (distribution of statements, operand types and locality)
+ *              still hold. Except for sophisticated optimizing compilers,
+ *              execution times for this version should be the same as
+ *              for previous versions.
+ *
+ *              Since it has proven difficult to subtract the time for the
+ *              measurement loop overhead in a correct way, the loop check
+ *              has been made a part of the benchmark. This does have
+ *              an impact - though a very minor one - on the distribution
+ *              statistics which have been updated for this version.
+ *
+ *              All changes within the measurement loop are described
+ *              and discussed in the companion paper "Rationale for
+ *              Dhrystone version 2".
+ *
+ *              Because of the self-imposed limitation that the order and
+ *              distribution of the executed statements should not be
+ *              changed, there are still cases where optimizing compilers
+ *              may not generate code for some statements. To a certain
+ *              degree, this is unavoidable for small synthetic benchmarks.
+ *              Users of the benchmark are advised to check code listings
+ *              whether code is generated for all statements of Dhrystone.
+ *
+ *              Version 2.1 is identical to version 2.0 distributed via
+ *              the UNIX network Usenet in March 1988 except that it corrects
+ *              some minor deficiencies that were found by users of version 2.0.
+ *              The only change within the measurement loop is that a
+ *              non-executed "else" part was added to the "if" statement in
+ *              Func_3, and a non-executed "else" part removed from Proc_3.
+ *
+ ***************************************************************************
+ *
+ *  Compilation model and measurement (IMPORTANT):
+ *
+ *  This C version of Dhrystone consists of three files:
+ *  - dhry.h (this file, containing global definitions and comments)
+ *  - dhry_1.c (containing the code corresponding to Ada package Pack_1)
+ *  - dhry_2.c (containing the code corresponding to Ada package Pack_2)
+ *
+ *  The following "ground rules" apply for measurements:
+ *  - Separate compilation
+ *  - No procedure merging
+ *  - Otherwise, compiler optimizations are allowed but should be indicated
+ *  - Default results are those without register declarations
+ *  See the companion paper "Rationale for Dhrystone Version 2" for a more
+ *  detailed discussion of these ground rules.
+ *
+ *  For 16-Bit processors (e.g. 80186, 80286), times for all compilation
+ *  models ("small", "medium", "large" etc.) should be given if possible,
+ *  together with a definition of these models for the compiler system used.
+ *
+ **************************************************************************
+ *
+ *  Dhrystone (C version) statistics:
+ *
+ *  [Comment from the first distribution, updated for version 2.
+ *   Note that because of language differences, the numbers are slightly
+ *   different from the Ada version.]
+ *
+ *  The following program contains statements of a high level programming
+ *  language (here: C) in a distribution considered representative:
+ *
+ *    assignments                  52 (51.0 %)
+ *    control statements           33 (32.4 %)
+ *    procedure, function calls    17 (16.7 %)
+ *
+ *  103 statements are dynamically executed. The program is balanced with
+ *  respect to the three aspects:
+ *
+ *    - statement type
+ *    - operand type
+ *    - operand locality
+ *         operand global, local, parameter, or constant.
+ *
+ *  The combination of these three aspects is balanced only approximately.
+ *
+ *  1. Statement Type:
+ *  -----------------             number
+ *
+ *     V1 = V2                     9
+ *       (incl. V1 = F(..)
+ *     V = Constant               12
+ *     Assignment,                 7
+ *       with array element
+ *     Assignment,                 6
+ *       with record component
+ *                                --
+ *                                34       34
+ *
+ *     X = Y +|-|"&&"|"|" Z        5
+ *     X = Y +|-|"==" Constant     6
+ *     X = X +|- 1                 3
+ *     X = Y *|/ Z                 2
+ *     X = Expression,             1
+ *           two operators
+ *     X = Expression,             1
+ *           three operators
+ *                                --
+ *                                18       18
+ *
+ *     if ....                    14
+ *       with "else"      7
+ *       without "else"   7
+ *           executed        3
+ *           not executed    4
+ *     for ...                     7  |  counted every time
+ *     while ...                   4  |  the loop condition
+ *     do ... while                1  |  is evaluated
+ *     switch ...                  1
+ *     break                       1
+ *     declaration with            1
+ *       initialization
+ *                                --
+ *                                34       34
+ *
+ *     P (...)  procedure call    11
+ *       user procedure      10
+ *       library procedure    1
+ *     X = F (...)
+ *             function  call      6
+ *       user function        5
+ *       library function     1
+ *                                --
+ *                                17       17
+ *                                        ---
+ *                                        103
+ *
+ *    The average number of parameters in procedure or function calls
+ *    is 1.82 (not counting the function values as implicit parameters).
+ *
+ *
+ *  2. Operators
+ *  ------------
+ *                          number    approximate
+ *                                    percentage
+ *
+ *    Arithmetic             32          50.8
+ *
+ *       +                     21          33.3
+ *       -                      7          11.1
+ *       *                      3           4.8
+ *       / (int div)            1           1.6
+ *
+ *    Comparison             27           42.8
+ *
+ *       ==                     9           14.3
+ *       /=                     4            6.3
+ *       >                      1            1.6
+ *       <                      3            4.8
+ *       >=                     1            1.6
+ *       <=                     9           14.3
+ *
+ *    Logic                   4            6.3
+ *
+ *       && (AND-THEN)          1            1.6
+ *       |  (OR)                1            1.6
+ *       !  (NOT)               2            3.2
+ *
+ *                           --          -----
+ *                           63          100.1
+ *
+ *
+ *  3. Operand Type (counted once per operand reference):
+ *  ---------------
+ *                          number    approximate
+ *                                    percentage
+ *
+ *     Integer               175        72.3 %
+ *     Character              45        18.6 %
+ *     Pointer                12         5.0 %
+ *     String30                6         2.5 %
+ *     Array                   2         0.8 %
+ *     Record                  2         0.8 %
+ *                           ---       -------
+ *                           242       100.0 %
+ *
+ *  When there is an access path leading to the final operand (e.g. a record
+ *  component), only the final data type on the access path is counted.
+ *
+ *
+ *  4. Operand Locality:
+ *  -------------------
+ *                                number    approximate
+ *                                          percentage
+ *
+ *     local variable              114        47.1 %
+ *     global variable              22         9.1 %
+ *     parameter                    45        18.6 %
+ *        value                        23         9.5 %
+ *        reference                    22         9.1 %
+ *     function result               6         2.5 %
+ *     constant                     55        22.7 %
+ *                                 ---       -------
+ *                                 242       100.0 %
+ *
+ *
+ *  The program does not compute anything meaningful, but it is syntactically
+ *  and semantically correct. All variables have a value assigned to them
+ *  before they are used as a source operand.
+ *
+ *  There has been no explicit effort to account for the effects of a
+ *  cache, or to balance the use of long or short displacements for code or
+ *  data.
+ *
+ ***************************************************************************
+ */
+
+typedef enum {
+	Ident_1,
+	Ident_2,
+	Ident_3,
+	Ident_4,
+	Ident_5
+} Enumeration;	/* for boolean and enumeration types in Ada, Pascal */
+
+/* General definitions: */
+
+typedef int One_Thirty;
+typedef int One_Fifty;
+typedef char Capital_Letter;
+typedef int Boolean;
+typedef char Str_30[31];
+typedef int Arr_1_Dim[50];
+typedef int Arr_2_Dim[50][50];
+
+typedef struct record {
+	struct record *Ptr_Comp;
+	Enumeration    Discr;
+	union {
+		struct {
+			Enumeration Enum_Comp;
+			int Int_Comp;
+			char Str_Comp[31];
+		} var_1;
+		struct {
+			Enumeration E_Comp_2;
+			char Str_2_Comp[31];
+		} var_2;
+		struct {
+			char Ch_1_Comp;
+			char Ch_2_Comp;
+		} var_3;
+	} variant;
+} Rec_Type, *Rec_Pointer;
+
+
+extern int Int_Glob;
+extern char Ch_1_Glob;
+
+void Proc_6(Enumeration  Enum_Val_Par, Enumeration *Enum_Ref_Par);
+void Proc_7(One_Fifty Int_1_Par_Val, One_Fifty Int_2_Par_Val,
+	    One_Fifty *Int_Par_Ref);
+void Proc_8(Arr_1_Dim Arr_1_Par_Ref, Arr_2_Dim Arr_2_Par_Ref,
+	    int Int_1_Par_Val, int Int_2_Par_Val);
+Enumeration Func_1(Capital_Letter Ch_1_Par_Val, Capital_Letter Ch_2_Par_Val);
+Boolean Func_2(Str_30 Str_1_Par_Ref, Str_30 Str_2_Par_Ref);
+
+int dhry(int n);