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authorLinus Torvalds <torvalds@linux-foundation.org>2019-10-05 12:56:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-10-05 12:56:59 -0700
commit2d00aee21a5d4966e086d98f9d710afb92fb14e8 (patch)
tree7e35b06f7834c4cdca1e1c320d3d9097c97ff85f /Documentation
parent126195c972a2adba8cae12a65cdee155440a4525 (diff)
parent86cdd2fdc4e39c388d39c7ba2396d1a9dfd66226 (diff)
Merge tag 'kbuild-fixes-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada: - remove unneeded ar-option and KBUILD_ARFLAGS - remove long-deprecated SUBDIRS - fix modpost to suppress false-positive warnings for UML builds - fix namespace.pl to handle relative paths to ${objtree}, ${srctree} - make setlocalversion work for /bin/sh - make header archive reproducible - fix some Makefiles and documents * tag 'kbuild-fixes-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kheaders: make headers archive reproducible kbuild: update compile-test header list for v5.4-rc2 kbuild: two minor updates for Documentation/kbuild/modules.rst scripts/setlocalversion: clear local variable to make it work for sh namespace: fix namespace.pl script to support relative paths video/logo: do not generate unneeded logo C files video/logo: remove unneeded *.o pattern from clean-files integrity: remove pointless subdir-$(CONFIG_...) integrity: remove unneeded, broken attempt to add -fshort-wchar modpost: fix static EXPORT_SYMBOL warnings for UML build kbuild: correct formatting of header in kbuild module docs kbuild: remove SUBDIRS support kbuild: remove ar-option and KBUILD_ARFLAGS
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kbuild/makefiles.rst5
-rw-r--r--Documentation/kbuild/modules.rst7
-rw-r--r--Documentation/kbuild/reproducible-builds.rst13
3 files changed, 13 insertions, 12 deletions
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 6ba9d5365ff3..b89c88168d6a 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -954,11 +954,6 @@ When kbuild executes, the following steps are followed (roughly):
From commandline LDFLAGS_MODULE shall be used (see kbuild.txt).
- KBUILD_ARFLAGS Options for $(AR) when creating archives
-
- $(KBUILD_ARFLAGS) set by the top level Makefile to "D" (deterministic
- mode) if this option is supported by $(AR).
-
KBUILD_LDS
The linker script with full path. Assigned by the top-level Makefile.
diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst
index d2ae799237fd..774a998dcf37 100644
--- a/Documentation/kbuild/modules.rst
+++ b/Documentation/kbuild/modules.rst
@@ -498,10 +498,11 @@ build.
will be written containing all exported symbols that were not
defined in the kernel.
---- 6.3 Symbols From Another External Module
+6.3 Symbols From Another External Module
+----------------------------------------
Sometimes, an external module uses exported symbols from
- another external module. kbuild needs to have full knowledge of
+ another external module. Kbuild needs to have full knowledge of
all symbols to avoid spitting out warnings about undefined
symbols. Three solutions exist for this situation.
@@ -521,7 +522,7 @@ build.
The top-level kbuild file would then look like::
#./Kbuild (or ./Makefile):
- obj-y := foo/ bar/
+ obj-m := foo/ bar/
And executing::
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