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-rw-r--r--Documentation/kbuild/reproducible-builds.rst13
1 files changed, 9 insertions, 4 deletions
diff --git a/Documentation/kbuild/reproducible-builds.rst b/Documentation/kbuild/reproducible-builds.rst
index ab92e98c89c8..503393854e2e 100644
--- a/Documentation/kbuild/reproducible-builds.rst
+++ b/Documentation/kbuild/reproducible-builds.rst
@@ -16,16 +16,21 @@ the kernel may be unreproducible, and how to avoid them.
Timestamps
----------
-The kernel embeds a timestamp in two places:
+The kernel embeds timestamps in three places:
* The version string exposed by ``uname()`` and included in
``/proc/version``
* File timestamps in the embedded initramfs
-By default the timestamp is the current time. This must be overridden
-using the `KBUILD_BUILD_TIMESTAMP`_ variable. If you are building
-from a git commit, you could use its commit date.
+* If enabled via ``CONFIG_IKHEADERS``, file timestamps of kernel
+ headers embedded in the kernel or respective module,
+ exposed via ``/sys/kernel/kheaders.tar.xz``
+
+By default the timestamp is the current time and in the case of
+``kheaders`` the various files' modification times. This must
+be overridden using the `KBUILD_BUILD_TIMESTAMP`_ variable.
+If you are building from a git commit, you could use its commit date.
The kernel does *not* use the ``__DATE__`` and ``__TIME__`` macros,
and enables warnings if they are used. If you incorporate external