From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- Documentation/trace/index.rst | 110 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 Documentation/trace/index.rst (limited to 'Documentation/trace/index.rst') diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst new file mode 100644 index 000000000..5d9bf4694 --- /dev/null +++ b/Documentation/trace/index.rst @@ -0,0 +1,110 @@ +================================ +Linux Tracing Technologies Guide +================================ + +Tracing in the Linux kernel is a powerful mechanism that allows +developers and system administrators to analyze and debug system +behavior. This guide provides documentation on various tracing +frameworks and tools available in the Linux kernel. + +Introduction to Tracing +----------------------- + +This section provides an overview of Linux tracing mechanisms +and debugging approaches. + +.. toctree:: + :maxdepth: 1 + + debugging + tracepoints + tracepoint-analysis + ring-buffer-map + +Core Tracing Frameworks +----------------------- + +The following are the primary tracing frameworks integrated into +the Linux kernel. + +.. toctree:: + :maxdepth: 1 + + ftrace + ftrace-design + ftrace-uses + kprobes + kprobetrace + fprobetrace + eprobetrace + fprobe + ring-buffer-design + +Event Tracing and Analysis +-------------------------- + +A detailed explanation of event tracing mechanisms and their +applications. + +.. toctree:: + :maxdepth: 1 + + events + events-kmem + events-power + events-nmi + events-msr + events-pci + events-pci-controller + boottime-trace + histogram + histogram-design + +Hardware and Performance Tracing +-------------------------------- + +This section covers tracing features that monitor hardware +interactions and system performance. + +.. toctree:: + :maxdepth: 1 + + intel_th + stm + sys-t + coresight/index + rv/index + hisi-ptt + mmiotrace + hwlat_detector + osnoise-tracer + timerlat-tracer + +User-Space Tracing +------------------ + +These tools allow tracing user-space applications and +interactions. + +.. toctree:: + :maxdepth: 1 + + user_events + uprobetracer + +Remote Tracing +-------------- + +This section covers the framework to read compatible ring-buffers, written by +entities outside of the kernel (most likely firmware or hypervisor) + +.. toctree:: + :maxdepth: 1 + + remotes + +Additional Resources +-------------------- + +For more details, refer to the respective documentation of each +tracing tool and framework. -- cgit v1.3.1