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, 109 insertions, 0 deletions

diff --git a/Documentation/process/contribution-maturity-model.rst b/Documentation/process/contribution-maturity-model.rst
new file mode 100644
index 000000000..b87ab34de
--- /dev/null
+++ b/Documentation/process/contribution-maturity-model.rst
@@ -0,0 +1,109 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========================================
+Linux Kernel Contribution Maturity Model
+========================================
+
+
+Background
+==========
+
+As a part of the 2021 Linux Kernel Maintainers’ Summit, there was a
+`discussion <https://lwn.net/Articles/870581/>`_ about the challenges in
+recruiting kernel maintainers as well as maintainer succession.  Some of
+the conclusions from that discussion included that companies which are a
+part of the Linux Kernel community need to allow engineers to be
+maintainers as part of their job, so they can grow into becoming
+respected leaders and eventually, kernel maintainers.  To support a
+strong talent pipeline, developers should be allowed and encouraged to
+take on upstream contributions such as reviewing other people’s patches,
+refactoring kernel infrastructure, and writing documentation.
+
+To that end, the Linux Foundation Technical Advisory Board (TAB)
+proposes this Linux Kernel Contribution Maturity Model. These common
+expectations for upstream community engagement aim to increase the
+influence of individual developers, increase the collaboration of
+organizations, and improve the overall health of the Linux Kernel
+ecosystem.
+
+The TAB urges organizations to continuously evaluate their Open Source
+maturity model and commit to improvements to align with this model.  To
+be effective, this evaluation should incorporate feedback from across
+the organization, including management and developers at all seniority
+levels.  In the spirit of Open Source, we encourage organizations to
+publish their evaluations and plans to improve their engagement with the
+upstream community.
+
+Level 0
+=======
+
+* Software Engineers are not allowed to contribute patches to the Linux
+  kernel.
+
+
+Level 1
+=======
+
+* Software Engineers are allowed to contribute patches to the Linux
+  kernel, either as part of their job responsibilities or on their own
+  time.
+
+Level 2
+=======
+
+* Software Engineers are expected to contribute to the Linux Kernel as
+  part of their job responsibilities.
+* Software Engineers will be supported to attend Linux-related
+  conferences as a part of their job.
+* A Software Engineer’s upstream code contributions will be considered
+  in promotion and performance reviews.
+
+Level 3
+=======
+
+* Software Engineers are expected to review patches (including patches
+  authored by engineers from other companies) as part of their job
+  responsibilities
+* Contributing presentations or papers to Linux-related or academic
+  conferences (such those organized by the Linux Foundation, Usenix,
+  ACM, etc.), are considered part of an engineer’s work.
+* A Software Engineer’s community contributions will be considered in
+  promotion and performance reviews.
+* Organizations will regularly report metrics of their open source
+  contributions and track these metrics over time.  These metrics may be
+  published only internally within the organization, or at the
+  organization’s discretion, some or all may be published externally.
+  Metrics that are strongly suggested include:
+
+  * The number of upstream kernel contributions by team or organization
+    (e.g., all people reporting up to a manager, director, or VP).
+  * The percentage of kernel developers who have made upstream
+    contributions relative to the total kernel developers in the
+    organization.
+  * The time interval between kernels used in the organization’s servers
+    and/or products, and the publication date of the upstream kernel
+    upon which the internal kernel is based.
+  * The number of out-of-tree commits present in internal kernels.
+
+Level 4
+=======
+
+* Software Engineers are encouraged to spend a portion of their work
+  time focused on Upstream Work, which is defined as reviewing patches,
+  serving on program committees, improving core project infrastructure
+  such as writing or maintaining tests, upstream tech debt reduction,
+  writing documentation, etc.
+* Software Engineers are supported in helping to organize Linux-related
+  conferences.
+* Organizations will consider community member feedback in official
+  performance reviews.
+
+Level 5
+=======
+
+* Upstream kernel development is considered a formal job position, with
+  at least a third of the engineer’s time spent doing Upstream Work.
+* Organizations will actively seek out community member feedback as a
+  factor in official performance reviews.
+* Organizations will regularly report internally on the ratio of
+  Upstream Work to work focused on directly pursuing business goals.