kbuild: Allow to override LINUX_COMPILE_BY and LINUX_COMPILE_HOST macros

Make it possible to override the user@host string displayed during boot
and in /proc/version by the environment variables KBUILD_BUILD_USER and
KBUILD_BUILD_HOST. Several distributions patch scripts/mkcompile_h to
achieve this, so let's provide an official way. Also, document the
KBUILD_BUILD_TIMESTAMP variable while at it.

Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt
index f1431d099fce..f11ebb33e4a6 100644
--- a/Documentation/kbuild/kbuild.txt
+++ b/Documentation/kbuild/kbuild.txt
@@ -201,3 +201,15 @@ KBUILD_ENABLE_EXTRA_GCC_CHECKS
 --------------------------------------------------
 If enabled over the make command line with "W=1", it turns on additional
 gcc -W... options for more extensive build-time checking.
+
+KBUILD_BUILD_TIMESTAMP
+--------------------------------------------------
+Setting this to a date string overrides the timestamp used in the
+UTS_VERSION definition (uname -v in the running kernel). The default value
+is the output of the date command at one point during build.
+
+KBUILD_BUILD_USER, KBUILD_BUILD_HOST
+--------------------------------------------------
+These two variables allow to override the user@host string displayed during
+boot and in /proc/version. The default value is the output of the commands
+whoami and host, respectively.