[RFC PATCH 2/2] Documentation: dev-tools: add kconfirm

[Julian Braha]

Add usage documentation and a brief description for kconfirm to
Documentation/dev-tools/

Signed-off-by: Julian Braha <julianbraha@xxxxxxxxx>
---
 Documentation/dev-tools/index.rst    |   1 +
 Documentation/dev-tools/kconfirm.rst | 147 +++++++++++++++++++++++++++
 2 files changed, 148 insertions(+)
 create mode 100644 Documentation/dev-tools/kconfirm.rst

diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst
index 59cbb77b33ff..130ebc0d7282 100644
--- a/Documentation/dev-tools/index.rst
+++ b/Documentation/dev-tools/index.rst
@@ -40,3 +40,4 @@ Documentation/process/debugging/index.rst
    autofdo
    propeller
    container
+   kconfirm
diff --git a/Documentation/dev-tools/kconfirm.rst b/Documentation/dev-tools/kconfirm.rst
new file mode 100644
index 000000000000..6ad02de15031
--- /dev/null
+++ b/Documentation/dev-tools/kconfirm.rst
@@ -0,0 +1,147 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+.. Copyright (C) 2026 Julian Braha <julianbraha@xxxxxxxxx>
+
+========
+kconfirm
+========
+
+kconfirm is a static analysis tool for the kernel's Kconfig system.  It
+checks the entire tree-wide Kconfig, and reports misusage like
+dead code.  In the case of dead default statements, these can be a
+significant code smell.
+
+kconfirm has an optional check for dead links in the Kconfig help texts.
+Since this has a high potential for false positives (due to websites
+blocking bots) and slows down runtime signficantly, it is disabled by
+default.  However, an example of how to enable it is included below.
+
+kconfirm is written in Rust and lives in ``scripts/kconfirm``.  Other
+than the dead link checks, kconfirm aims for zero false positives.
+
+**NOTE**: kconfirm does not modify or compile the source tree; it is
+strictly a static checker.
+
+
+Getting Started
+===============
+
+
+kconfirm's Minimum Supported Rust Version (MSRV) is v1.85.0, because
+it uses Rust edition 2024, and this is the earliest supported version.
+
+kconfirm also requires the Cargo package manager and an internet
+connection for compilation of its dependencies.
+
+If Cargo is available, kconfirm can be built and run from the top of the
+kernel source tree::
+
+    make kconfirm
+
+The compiled ``kconfirm-linux`` binary will be available in
+``scripts/kconfirm/target/release/``.
+
+The default checks currently cover dead code analysis.  ``dead_links``
+must be turned on explicitly with ``--enable``; conversely, any default
+check can be turned off with ``--disable``.  Both options accept
+either a comma-separated list or repeated flags, so the following
+two invocations are equivalent::
+
+  kconfirm-linux --linux-path . --enable dead_defaults,dead_links
+  kconfirm-linux --linux-path . --enable dead_defaults --enable dead_links
+
+
+
+Options
+=======
+
+**NOTE**: kconfirm's arguments must be provided in the ``KCONFIRM_ARGS``
+environment variable if running with ``make``. See `Examples`_.
+
+Available options:
+
+``--linux-path PATH``
+    The path to the linux source tree to analyze. ``make`` uses this
+    option to pass the current linux tree, but this option can be used
+    when running the tool directly with another source tree.
+    See `Examples`_.
+
+``--enable CHECK[,CHECK...]``
+
+    Enable one or more checks in addition to the default set.  May be
+    given multiple times, or as a single comma-separated list.  See
+    `Available checks`_ below for valid names.
+
+``--disable CHECK[,CHECK...]``
+
+    Disable one or more checks from the default set.  May be given
+    multiple times, or as a single comma-separated list.
+
+``-h, --help``
+
+    Show the help message and exit.
+
+``-V, --version``
+
+    Show version information and exit.
+
+
+Available checks
+================
+
+Each check has a string name that is accepted by ``--enable`` and
+``--disable``.  Checks marked *(default)* are enabled unless turned off
+explicitly.
+
+``duplicate_dependency`` *(default)*
+
+    Reports duplicated ``depends on`` entries on a single Kconfig symbol.
+
+``duplicate_range`` *(default)*
+
+    Reports duplicated ``range`` entries on a single Kconfig symbol.
+
+``duplicate_select`` *(default)*
+
+    Reports duplicated ``select`` entries on a single Kconfig symbol.
+
+``duplicate_default`` *(default)*
+
+    Reports duplicated ``default`` entries on a single Kconfig symbol.
+
+``dead_default`` *(default)*
+
+    Reports ``default`` entries that can never be selected, for example
+    because their condition is unsatisfiable.
+
+``dead_links``
+
+    Reports broken URLs found in Kconfig help text.  Because this
+    performs network requests it can be quite slow, and is disabled by
+    default. May also have false positives.
+
+``style``
+
+    Reports opinionated style issues in Kconfig files.  Disabled by
+    default.
+
+
+Examples
+========
+
+Compile (as needed) and run on the current tree::
+
+    make kconfirm
+
+To additionally enable dead-link checking::
+
+    make kconfirm KCONFIRM_ARGS="--enable dead_links"
+
+To disable a check (here, ``duplicate_dependency``) while keeping the
+rest of the default set::
+
+    make kconfirm KCONFIRM_ARGS="--disable duplicate_dependency"
+
+To run the default checks against a kernel tree separate from the
+current directory, such as ``~/repos/linux``::
+
+    scripts/kconfirm/target/release/kconfirm-linux --linux-path ~/repos/linux
-- 
2.53.0