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, 397 insertions, 0 deletions

diff --git a/tools/docs/kernel-doc b/tools/docs/kernel-doc
new file mode 100755
index 000000000..d9192c3f1
--- /dev/null
+++ b/tools/docs/kernel-doc
@@ -0,0 +1,397 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.
+#
+# pylint: disable=C0103,R0912,R0914,R0915
+#
+# NOTE: While kernel-doc requires at least version 3.6 to run, the
+#       command line should work with Python 3.2+ (tested with 3.4).
+#       The rationale is that it shall fail gracefully during Kernel
+#       compilation with older Kernel versions. Due to that:
+#       - encoding line is needed here;
+#       - f-strings cannot be used in this file.
+#       - libraries that require newer versions can only be included
+#         after the Python version has been checked.
+#
+# Converted from the kernel-doc script originally written in Perl
+# under GPLv2, copyrighted since 1998 by the following authors:
+#
+#    Aditya Srivastava <yashsri421@gmail.com>
+#    Akira Yokosawa <akiyks@gmail.com>
+#    Alexander A. Klimov <grandmaster@al2klimov.de>
+#    Alexander Lobakin <aleksander.lobakin@intel.com>
+#    André Almeida <andrealmeid@igalia.com>
+#    Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+#    Anna-Maria Behnsen <anna-maria@linutronix.de>
+#    Armin Kuster <akuster@mvista.com>
+#    Bart Van Assche <bart.vanassche@sandisk.com>
+#    Ben Hutchings <ben@decadent.org.uk>
+#    Borislav Petkov <bbpetkov@yahoo.de>
+#    Chen-Yu Tsai <wenst@chromium.org>
+#    Coco Li <lixiaoyan@google.com>
+#    Conchúr Navid <conchur@web.de>
+#    Daniel Santos <daniel.santos@pobox.com>
+#    Danilo Cesar Lemes de Paula <danilo.cesar@collabora.co.uk>
+#    Dan Luedtke <mail@danrl.de>
+#    Donald Hunter <donald.hunter@gmail.com>
+#    Gabriel Krisman Bertazi <krisman@collabora.co.uk>
+#    Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+#    Harvey Harrison <harvey.harrison@gmail.com>
+#    Horia Geanta <horia.geanta@freescale.com>
+#    Ilya Dryomov <idryomov@gmail.com>
+#    Jakub Kicinski <kuba@kernel.org>
+#    Jani Nikula <jani.nikula@intel.com>
+#    Jason Baron <jbaron@redhat.com>
+#    Jason Gunthorpe <jgg@nvidia.com>
+#    Jérémy Bobbio <lunar@debian.org>
+#    Johannes Berg <johannes.berg@intel.com>
+#    Johannes Weiner <hannes@cmpxchg.org>
+#    Jonathan Cameron <Jonathan.Cameron@huawei.com>
+#    Jonathan Corbet <corbet@lwn.net>
+#    Jonathan Neuschäfer <j.neuschaefer@gmx.net>
+#    Kamil Rytarowski <n54@gmx.com>
+#    Kees Cook <kees@kernel.org>
+#    Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+#    Levin, Alexander (Sasha Levin) <alexander.levin@verizon.com>
+#    Linus Torvalds <torvalds@linux-foundation.org>
+#    Lucas De Marchi <lucas.demarchi@profusion.mobi>
+#    Mark Rutland <mark.rutland@arm.com>
+#    Markus Heiser <markus.heiser@darmarit.de>
+#    Martin Waitz <tali@admingilde.org>
+#    Masahiro Yamada <masahiroy@kernel.org>
+#    Matthew Wilcox <willy@infradead.org>
+#    Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
+#    Michal Wajdeczko <michal.wajdeczko@intel.com>
+#    Michael Zucchi
+#    Mike Rapoport <rppt@linux.ibm.com>
+#    Niklas Söderlund <niklas.soderlund@corigine.com>
+#    Nishanth Menon <nm@ti.com>
+#    Paolo Bonzini <pbonzini@redhat.com>
+#    Pavan Kumar Linga <pavan.kumar.linga@intel.com>
+#    Pavel Pisa <pisa@cmp.felk.cvut.cz>
+#    Peter Maydell <peter.maydell@linaro.org>
+#    Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
+#    Randy Dunlap <rdunlap@infradead.org>
+#    Richard Kennedy <richard@rsk.demon.co.uk>
+#    Rich Walker <rw@shadow.org.uk>
+#    Rolf Eike Beer <eike-kernel@sf-tec.de>
+#    Sakari Ailus <sakari.ailus@linux.intel.com>
+#    Silvio Fricke <silvio.fricke@gmail.com>
+#    Simon Huggins
+#    Tim Waugh <twaugh@redhat.com>
+#    Tomasz Warniełło <tomasz.warniello@gmail.com>
+#    Utkarsh Tripathi <utripathi2002@gmail.com>
+#    valdis.kletnieks@vt.edu <valdis.kletnieks@vt.edu>
+#    Vegard Nossum <vegard.nossum@oracle.com>
+#    Will Deacon <will.deacon@arm.com>
+#    Yacine Belkadi <yacine.belkadi.1@gmail.com>
+#    Yujie Liu <yujie.liu@intel.com>
+
+"""
+Print formatted kernel documentation to stdout.
+
+Read C language source or header FILEs, extract embedded
+documentation comments, and print formatted documentation
+to standard output.
+
+The documentation comments are identified by the ``/**``
+opening comment mark.
+
+See Documentation/doc-guide/kernel-doc.rst for the
+documentation comment syntax.
+"""
+
+import argparse
+import logging
+import os
+import sys
+
+# Import Python modules
+
+LIB_DIR = "../lib/python"
+SRC_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))
+
+WERROR_RETURN_CODE = 3
+
+DESC = """
+Read C language source or header FILEs, extract embedded documentation comments,
+and print formatted documentation to standard output.
+
+The documentation comments are identified by the "/**" opening comment mark.
+
+See Documentation/doc-guide/kernel-doc.rst for the documentation comment syntax.
+"""
+
+EXPORT_FILE_DESC = """
+Specify an additional FILE in which to look for EXPORT_SYMBOL information.
+
+May be used multiple times.
+"""
+
+EXPORT_DESC = """
+Only output documentation for symbols that have been
+exported using EXPORT_SYMBOL() and related macros in any input
+FILE or -export-file FILE.
+"""
+
+INTERNAL_DESC = """
+Only output documentation for symbols that have NOT been
+exported using EXPORT_SYMBOL() and related macros in any input
+FILE or -export-file FILE.
+"""
+
+FUNCTION_DESC = """
+Only output documentation for the given function or DOC: section
+title. All other functions and DOC: sections are ignored.
+
+May be used multiple times.
+"""
+
+NOSYMBOL_DESC = """
+Exclude the specified symbol from the output documentation.
+
+May be used multiple times.
+"""
+
+FILES_DESC = """
+Header and C source files to be parsed.
+"""
+
+WARN_CONTENTS_BEFORE_SECTIONS_DESC = """
+Warn if there are contents before sections (deprecated).
+
+This option is kept just for backward-compatibility, but it does nothing,
+neither here nor at the original Perl script.
+"""
+
+EPILOG = """
+The return value is:
+
+- 0: success or Python version is not compatible with
+kernel-doc.  If -Werror is not used, it will also
+return 0 if there are issues at kernel-doc markups;
+
+- 1: an abnormal condition happened;
+
+- 2: argparse issued an error;
+
+- 3: When -Werror is used, it means that one or more unfiltered parse
+     warnings happened.
+"""
+
+class MsgFormatter(logging.Formatter):
+    """
+    Helper class to capitalize errors and warnings, the same way
+    the venerable (now retired) kernel-doc.pl used to do.
+    """
+
+    def format(self, record):
+        record.levelname = record.levelname.capitalize()
+        return logging.Formatter.format(self, record)
+
+def main():
+    """
+    Main program.
+
+    """
+
+    parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter,
+                                     description=DESC, epilog=EPILOG)
+
+    #
+    # Normal arguments
+    #
+    parser.add_argument("-v", "-verbose", "--verbose", action="store_true",
+                        help="Verbose output, more warnings and other information.")
+
+    parser.add_argument("-d", "-debug", "--debug", action="store_true",
+                        help="Enable debug messages")
+
+    parser.add_argument("-M", "-modulename", "--modulename",
+                        help="Allow setting a module name at the output.")
+
+    parser.add_argument("-l", "-enable-lineno", "--enable_lineno",
+                        action="store_true",
+                        help="Enable line number output (only in ReST mode)")
+
+    #
+    # Arguments to control the warning behavior
+    #
+    parser.add_argument("-Wreturn", "--wreturn", action="store_true",
+                        help="Warns about the lack of a return markup on functions.")
+
+    parser.add_argument("-Wshort-desc", "-Wshort-description", "--wshort-desc",
+                        action="store_true",
+                        help="Warns if initial short description is missing")
+
+    parser.add_argument("-Wcontents-before-sections",
+                        "--wcontents-before-sections", action="store_true",
+                        help=WARN_CONTENTS_BEFORE_SECTIONS_DESC)
+
+    parser.add_argument("-Wall", "--wall", action="store_true",
+                        help="Enable all types of warnings")
+
+    parser.add_argument("-Werror", "--werror", action="store_true",
+                        help="Treat warnings as errors.")
+
+    parser.add_argument("-export-file", "--export-file", action='append',
+                        help=EXPORT_FILE_DESC)
+
+    #
+    # Output format
+    #
+    out_fmt = parser.add_argument_group("Output format selection (mutually exclusive)")
+
+    out_fmt.add_argument("-m", "-man", "--man", action="store_true",
+                         help="Output troff manual page format.")
+    out_fmt.add_argument("-r", "-rst", "--rst", action="store_true",
+                         help="Output reStructuredText format (default).")
+    out_fmt.add_argument("-N", "-none", "--none", action="store_true",
+                         help="Do not output documentation, only warnings.")
+
+    out_fmt.add_argument("-y", "--yaml-file", "--yaml",
+                         help="Stores kernel-doc output on a yaml file.")
+    out_fmt.add_argument("-k", "--kdoc-item", "--kdoc", action="store_true",
+                         help="Store KdocItem inside yaml file. Ued together with --yaml.")
+
+
+    #
+    # Output selection mutually-exclusive group
+    #
+    sel_group = parser.add_argument_group("Output selection (mutually exclusive)")
+    sel_mut = sel_group.add_mutually_exclusive_group()
+
+    sel_mut.add_argument("-e", "-export", "--export", action='store_true',
+                         help=EXPORT_DESC)
+
+    sel_mut.add_argument("-i", "-internal", "--internal", action='store_true',
+                         help=INTERNAL_DESC)
+
+    sel_mut.add_argument("-s", "-function", "--symbol", action='append',
+                         help=FUNCTION_DESC)
+
+    #
+    # Those are valid for all 3 types of filter
+    #
+    parser.add_argument("-n", "-nosymbol", "--nosymbol", action='append',
+                        help=NOSYMBOL_DESC)
+
+    parser.add_argument("-D", "-no-doc-sections", "--no-doc-sections",
+                        action='store_true', help="Don't output DOC sections")
+
+    parser.add_argument("files", metavar="FILE",
+                        nargs="+", help=FILES_DESC)
+
+    args = parser.parse_args()
+
+    if args.wall:
+        args.wreturn = True
+        args.wshort_desc = True
+        args.wcontents_before_sections = True
+
+    logger = logging.getLogger()
+
+    if not args.debug:
+        logger.setLevel(logging.INFO)
+    else:
+        logger.setLevel(logging.DEBUG)
+
+    formatter = MsgFormatter('%(levelname)s: %(message)s')
+
+    handler = logging.StreamHandler()
+    handler.setFormatter(formatter)
+
+    logger.addHandler(handler)
+
+    python_ver = sys.version_info[:2]
+    if python_ver < (3,6):
+        #
+        # Depending on the Kernel configuration, kernel-doc --none is called at
+        # build time. As we don't want to break compilation due to the
+        # usage of an old Python version, return 0 here.
+        #
+        if args.none:
+            logger.error("Python 3.6 or later is required by kernel-doc. Skipping checks")
+            sys.exit(0)
+
+        sys.exit("Python 3.6 or later is required by kernel-doc. Aborting.")
+
+    if python_ver < (3,7):
+        logger.warning("Python 3.7 or later is required for correct results")
+
+    #
+    # Import kernel-doc libraries only after checking the Python version
+    #
+    from kdoc.kdoc_files import KernelFiles             # pylint: disable=C0415
+    from kdoc.kdoc_output import RestFormat, ManFormat  # pylint: disable=C0415
+
+    yaml_content = set()
+    if args.yaml_file:
+        out_style = None
+
+        if args.man:
+            yaml_content |= {"man"}
+
+        if args.rst:
+            yaml_content |= {"rst"}
+
+        if args.kdoc_item or not yaml_content:
+            yaml_content |= {"KdocItem"}
+
+    else:
+        n_outputs = 0
+
+        if args.man:
+            out_style = ManFormat(modulename=args.modulename)
+            n_outputs += 1
+
+        if args.none:
+            out_style = None
+            n_outputs += 1
+
+        if  args.rst or n_outputs == 0:
+            n_outputs += 1
+            out_style = RestFormat()
+
+        if n_outputs > 1:
+             parser.error("Those arguments are muttually exclusive: --man, --rst, --none, except when generating a YAML file.")
+
+        elif not n_outputs:
+            out_style = RestFormat()
+
+    kfiles = KernelFiles(verbose=args.verbose,
+                         yaml_file=args.yaml_file, yaml_content=yaml_content,
+                         out_style=out_style, werror=args.werror,
+                         wreturn=args.wreturn, wshort_desc=args.wshort_desc,
+                         wcontents_before_sections=args.wcontents_before_sections)
+
+    kfiles.parse(args.files, export_file=args.export_file)
+
+    for t in kfiles.msg(enable_lineno=args.enable_lineno, export=args.export,
+                        internal=args.internal, symbol=args.symbol,
+                        nosymbol=args.nosymbol, export_file=args.export_file,
+                        no_doc_sections=args.no_doc_sections):
+        msg = t[1]
+        if msg:
+            print(msg)
+
+    error_count = kfiles.errors
+    if not error_count:
+        sys.exit(0)
+
+    if args.werror:
+        print("%s warnings as errors" % error_count)    # pylint: disable=C0209
+        sys.exit(WERROR_RETURN_CODE)
+
+    if args.verbose:
+        print("%s errors" % error_count)                # pylint: disable=C0209
+
+    sys.exit(0)
+
+#
+# Call main method
+#
+if __name__ == "__main__":
+    main()