pkgs/os-specific/linux/kernel/gen-kheaders-metadata.patch

   1 From 2cc99c9cdc8fde5e92e34f9655829449cebd3e00 Mon Sep 17 00:00:00 2001
   2 From: Dmitry Goldin <dgoldin+lkml@protonmail.ch>
   3 Date: Fri, 4 Oct 2019 10:40:07 +0000
   4 Subject: kheaders: make headers archive reproducible
   5
   6 In commit 43d8ce9d65a5 ("Provide in-kernel headers to make
   7 extending kernel easier") a new mechanism was introduced, for kernels
   8 >=5.2, which embeds the kernel headers in the kernel image or a module
   9 and exposes them in procfs for use by userland tools.
  10
  11 The archive containing the header files has nondeterminism caused by
  12 header files metadata. This patch normalizes the metadata and utilizes
  13 KBUILD_BUILD_TIMESTAMP if provided and otherwise falls back to the
  14 default behaviour.
  15
  16 In commit f7b101d33046 ("kheaders: Move from proc to sysfs") it was
  17 modified to use sysfs and the script for generation of the archive was
  18 renamed to what is being patched.
  19
  20 Signed-off-by: Dmitry Goldin <dgoldin+lkml@protonmail.ch>
  21 Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22 Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
  23 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
  24
  25 ---
  26
  27 nixos note: This patch is from
  28 https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git/commit/?h=fixes&id=2cc99c9cdc8fde5e92e34f9655829449cebd3e00
  29 I commented out the documentation part here, so that it easily applies
  30 to linux 5.2 and 5.3, which does not ship with the reproducible build
  31 documentation yet, which only was introduced recently.
  32
  33 ---
  34  Documentation/kbuild/reproducible-builds.rst | 13 +++++++++----
  35  kernel/gen_kheaders.sh                       |  5 ++++-
  36  2 files changed, 13 insertions(+), 5 deletions(-)
  37
  38 #diff --git a/Documentation/kbuild/reproducible-builds.rst b/Documentation/kbuild/reproducible-builds.rst
  39 #index ab92e98c89c8..503393854e2e 100644
  40 # --- a/Documentation/kbuild/reproducible-builds.rst
  41 #+++ b/Documentation/kbuild/reproducible-builds.rst
  42 #@@ -16,16 +16,21 @@ the kernel may be unreproducible, and how to avoid them.
  43 # Timestamps
  44 # ----------
  45 #
  46 #-The kernel embeds a timestamp in two places:
  47 #+The kernel embeds timestamps in three places:
  48 #
  49 # * The version string exposed by ``uname()`` and included in
  50 #   ``/proc/version``
  51 #
  52 # * File timestamps in the embedded initramfs
  53 #
  54 #-By default the timestamp is the current time.  This must be overridden
  55 #-using the `KBUILD_BUILD_TIMESTAMP`_ variable.  If you are building
  56 #-from a git commit, you could use its commit date.
  57 #+* If enabled via ``CONFIG_IKHEADERS``, file timestamps of kernel
  58 #+  headers embedded in the kernel or respective module,
  59 #+  exposed via ``/sys/kernel/kheaders.tar.xz``
  60 #+
  61 #+By default the timestamp is the current time and in the case of
  62 #+``kheaders`` the various files' modification times. This must
  63 #+be overridden using the `KBUILD_BUILD_TIMESTAMP`_ variable.
  64 #+If you are building from a git commit, you could use its commit date.
  65 #
  66 # The kernel does *not* use the ``__DATE__`` and ``__TIME__`` macros,
  67 # and enables warnings if they are used.  If you incorporate external
  68 diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh
  69 index 9ff449888d9c..aff79e461fc9 100755
  70 --- a/kernel/gen_kheaders.sh
  71 +++ b/kernel/gen_kheaders.sh
  72 @@ -71,7 +71,10 @@ done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
  73  find $cpio_dir -type f -print0 |
  74         xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
  75
  76 -tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
  77 +# Create archive and try to normalize metadata for reproducibility
  78 +tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
  79 +    --owner=0 --group=0 --sort=name --numeric-owner \
  80 +    -Jcf $tarfile -C $cpio_dir/ . > /dev/null
  81
  82  echo "$src_files_md5" >  kernel/kheaders.md5
  83  echo "$obj_files_md5" >> kernel/kheaders.md5
  84 --
  85 cgit 1.2-0.3.lf.el7
  86