From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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 --- Documentation/process/generated-content.rst | 116 ++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 Documentation/process/generated-content.rst (limited to 'Documentation/process/generated-content.rst') diff --git a/Documentation/process/generated-content.rst b/Documentation/process/generated-content.rst new file mode 100644 index 000000000..aad2caad9 --- /dev/null +++ b/Documentation/process/generated-content.rst @@ -0,0 +1,116 @@ +============================================ +Kernel Guidelines for Tool-Generated Content +============================================ + +Purpose +======= + +Kernel contributors have been using tooling to generate contributions +for a long time. These tools can increase the volume of contributions. +At the same time, reviewer and maintainer bandwidth is a scarce +resource. Understanding which portions of a contribution come from +humans versus tools is helpful to maintain those resources and keep +kernel development healthy. + +The goal here is to clarify community expectations around tools. This +lets everyone become more productive while also maintaining high +degrees of trust between submitters and reviewers. + +Out of Scope +============ + +These guidelines do not apply to tools that make trivial tweaks to +preexisting content. Nor do they pertain to tooling that helps with +menial tasks. Some examples: + + - Spelling and grammar fix ups, like rephrasing to imperative voice + - Typing aids like identifier completion, common boilerplate or + trivial pattern completion + - Purely mechanical transformations like variable renaming + - Reformatting, like running Lindent, ``clang-format`` or + ``rust-fmt`` + +Even whenever your tool use is out of scope, you should still always +consider if it would help reviewing your contribution if the reviewer +knows about the tool that you used. + +In Scope +======== + +These guidelines apply when a meaningful amount of content in a kernel +contribution was not written by a person in the Signed-off-by chain, +but was instead created by a tool. + +Detection of a problem and testing the fix for it is also part of the +development process; if a tool was used to find a problem addressed by +a change, that should be noted in the changelog. This not only gives +credit where it is due, it also helps fellow developers find out about +these tools. + +Some examples: + - Any tool-suggested fix such as ``checkpatch.pl --fix`` + - Coccinelle scripts + - A chatbot generated a new function in your patch to sort list entries. + - A .c file in the patch was originally generated by a coding + assistant but cleaned up by hand. + - The changelog was generated by handing the patch to a generative AI + tool and asking it to write the changelog. + - The changelog was translated from another language. + +If in doubt, choose transparency and assume these guidelines apply to +your contribution. + +Guidelines +========== + +First, read the Developer's Certificate of Origin: +Documentation/process/submitting-patches.rst. Its rules are simple +and have been in place for a long time. They have covered many +tool-generated contributions. Ensure that you understand your entire +submission and are prepared to respond to review comments. + +Second, when making a contribution, be transparent about the origin of +content in cover letters and changelogs. You can be more transparent +by adding information like this: + + - What tools were used? + - The input to the tools you used, like the Coccinelle source script. + - If code was largely generated from a single or short set of + prompts, include those prompts. For longer sessions, include a + summary of the prompts and the nature of resulting assistance. + - Which portions of the content were affected by that tool? + - How is the submission tested and what tools were used to test the + fix? + +As with all contributions, individual maintainers have discretion to +choose how they handle the contribution. For example, they might: + + - Treat it just like any other contribution. + - Reject it outright. + - Treat the contribution specially, for example, asking for extra + testing, reviewing with extra scrutiny, or reviewing at a lower + priority than human-generated content. + - Ask for some other special steps, like asking the contributor to + elaborate on how the tool or model was trained. + - Ask the submitter to explain in more detail about the contribution + so that the maintainer can be assured that the submitter fully + understands how the code works. + - Suggest a better prompt instead of suggesting specific code changes. + +If tools permit you to generate a contribution automatically, expect +additional scrutiny in proportion to how much of it was generated. + +As with the output of any tooling, the result may be incorrect or +inappropriate. You are expected to understand and to be able to defend +everything you submit. If you are unable to do so, then do not submit +the resulting changes. + +If you do so anyway, maintainers are entitled to reject your series +without detailed review. + +References +========== + +For specific guidelines on AI coding assistants, see: + +* Documentation/process/coding-assistants.rst -- cgit v1.3.1