Commit cd195bc4775a ("kbuild: split adjust_autoksyms.sh in two parts")
split out the code that needs include/config/auto.conf.
This script no longer needs to include include/config/auto.conf.
Bug: 254441685
Fixes: cd195bc4775a ("kbuild: split adjust_autoksyms.sh in two parts")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
(cherry picked from commit 12e9dea6c9766c7403417d00193940cea33ee81a)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I80233c2685728942c9ec37b4f3e1017742018e8f
In order to prepare the ground for a build-time optimization, split
adjust_autoksyms.sh into two scripts: one that generates autoksyms.h
based on all currently available information (whitelist, and .mod
files), and the other to inspect the diff between two versions of
autoksyms.h and trigger appropriate rebuilds.
[ BACKPORT: 60ae1b194b45 not present, sed 3rd line of modules.order ]
Bug: 148277666
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Tested-by: Matthias Maennich <maennich@google.com>
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/lkml/20200218094139.78835-3-qperret@google.com
Change-Id: I7ed4f8f72c0ef9ac98419877efb5ef828d10b0d7
CONFIG_TRIM_UNUSED_KSYMS currently removes all unused exported symbols
from ksymtab. This works really well when using in-tree drivers, but
cannot be used in its current form if some of them are out-of-tree.
Indeed, even if the list of symbols required by out-of-tree drivers is
known at compile time, the only solution today to guarantee these don't
get trimmed is to set CONFIG_TRIM_UNUSED_KSYMS=n. This not only wastes
space, but also makes it difficult to control the ABI usable by vendor
modules in distribution kernels such as Android. Being able to control
the kernel ABI surface is particularly useful to ship a unique Generic
Kernel Image (GKI) for all vendors, which is a first step in the
direction of getting all vendors to contribute their code upstream.
As such, attempt to improve the situation by enabling users to specify a
symbol 'whitelist' at compile time. Any symbol specified in this
whitelist will be kept exported when CONFIG_TRIM_UNUSED_KSYMS is set,
even if it has no in-tree user. The whitelist is defined as a simple
text file, listing symbols, one per line.
[ BACKPORT: 60ae1b194b45 not present, sed 3rd line of modules.order ]
Bug: 148277666
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Tested-by: Matthias Maennich <maennich@google.com>
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/lkml/20200218094139.78835-2-qperret@google.com
Change-Id: Ie9a4bbb8eebb20202623f084859fb89e55a32698
This is essentially a partial backport of b7dca6dd1e59 ("kbuild: create
*.mod with full directory path and remove MODVERDIR") as a full backport
would pull in too many dependencies.
It is necessary to simplify the backport of the TRIM_NONLISTED_KMI
feature.
Bug: 148277666
Change-Id: Ibf85bf864b3961d5bec4965742f08a80e9f234af
Signed-off-by: Quentin Perret <qperret@google.com>
As commit 423a8155fa ("kbuild: Fix reading of .config in
link-vmlinux.sh") addressed, some shells fail to perform '.' if
${KCONFIG_CONFIG} does not contain a slash at all.
Instead, we can source include/config/auto.conf, which obviously
contain slashes, and we do not expect its file path overridden by
a user. Perhaps, the performance might be slightly better since
unset CONFIG options are stripped from include/config/auto.conf.
scripts/setlocalversion already works this way.
Bug: 148277666
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
(cherry picked from commit 94cf8acc38e57caaba1329a255409b6d93936ba7)
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: I414ffbfa92ee202f0c88757f896bf9c8811822d7
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX was selected by BLACKFIN, METAG.
They were removed by commit 4ba66a9760 ("arch: remove blackfin port"),
commit bb6fb6dfcc ("metag: Remove arch/metag/"), respectively.
No more architecture enables CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
Clean up the rest of scripts, and remove the Kconfig entry.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Pull Kbuild updates from Masahiro Yamada:
- add a shell script to get Clang version
- improve portability of build scripts
- drop always-enabled CONFIG_THIN_ARCHIVE and remove unused code
- rename built-in.o which is now thin archive to built-in.a
- process clean/build targets one by one to get along with -j option
- simplify ld-option
- improve building with CONFIG_TRIM_UNUSED_KSYMS
- define KBUILD_MODNAME even for objects shared among multiple modules
- avoid linking multiple instances of same objects from composite
objects
- move <linux/compiler_types.h> to c_flags to include it only for C
files
- clean-up various Makefiles
* tag 'kbuild-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (29 commits)
kbuild: get <linux/compiler_types.h> out of <linux/kconfig.h>
kbuild: clean up link rule of composite modules
kbuild: clean up archive rule of built-in.a
kbuild: remove partial section mismatch detection for built-in.a
net: liquidio: clean up Makefile for simpler composite object handling
lib: zstd: clean up Makefile for simpler composite object handling
kbuild: link $(real-obj-y) instead of $(obj-y) into built-in.a
kbuild: rename real-objs-y/m to real-obj-y/m
kbuild: move modname and modname-multi close to modname_flags
kbuild: simplify modname calculation
kbuild: fix modname for composite modules
kbuild: define KBUILD_MODNAME even if multiple modules share objects
kbuild: remove unnecessary $(subst $(obj)/, , ...) in modname-multi
kbuild: Use ls(1) instead of stat(1) to obtain file size
kbuild: link vmlinux only once for CONFIG_TRIM_UNUSED_KSYMS
kbuild: move include/config/ksym/* to include/ksym/*
kbuild: move CONFIG_TRIM_UNUSED_KSYMS code unneeded for external module
kbuild: restore autoksyms.h touch to the top Makefile
kbuild: move 'scripts' target below
kbuild: remove wrong 'touch' in adjust_autoksyms.sh
...
The idea of using fixdep was inspired by Kconfig, but autoksyms
belongs to a different group. So, I want to move those touched
files under include/config/ksym/ to include/ksym/.
The directory include/ksym/ can be removed by 'make clean' because
it is meaningless for the external module building.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
The comment mentions it creates autoksyms.h in case it is missing,
but the actual code touches it when it does exists.
The build system creates it anyway because <linux/export.h> and
<asm-generic/export.h> need it.
The code would not have worked as intended, and people have not
noticed it. This is a proof that we can simply remove it.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
* Use BREs where EREs aren't necessary.
* Pass -E instead of -r to use EREs. This will be standardized in the
next POSIX revision[0]. GNU sed supports this since 4.2 (May 2009),
and busybox since 1.22.0 (Jan 2014).
* Use the [:space:] character class instead of ` \t` in bracket
expressions. In bracket expressions, POSIX says that <backslash> loses
its special meaning, so a conforming implementation cannot expand \t
to <tab>[1].
* In BREs, use interval expressions (\{n,m\}) instead of non-standard
features like \+ and \?.
* Use a loop instead of -s flag.
There are still plenty of other cases of non-standard sed invocations
(use of ERE features in BREs, in-place editing), but this fixes some
core ones.
[0] http://austingroupbugs.net/view.php?id=528
[1] http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03_05
Signed-off-by: Michael Forney <forney@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Some filesystems have timestamps with coarse precision that may allow
for a recently built object file to have the same timestamp as the
updated time on one of its dependency files. When that happens, the
object file doesn't get rebuilt as it should.
This is especially the case on filesystems that don't have sub-second
time precision, such as ext3 or Ext4 with 128B inodes.
Let's prevent that by making sure updated dependency files have a newer
timestamp than the first file we created (i.e. autoksyms.h.tmpnew).
Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
When CONFIG_TRIM_UNUSED_KSYMS=y and no modules are actually selected,
the adjust_autoksyms.sh script fails with:
sed: can't read .tmp_versions/*.mod: No such file or directory
Let's cope with that case gracefully.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
When only one symbol was listed and therefore the line didn't contain
any space to separate multiple symbols, that symbol got ignored.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
Given the list of exported symbols needed by all modules, we can create
a header file containing preprocessor defines for each of those symbols.
Also, when some symbols are added and/or removed from the list, we can
update the time on the corresponding files used as build dependencies for
those symbols. And finally, if any symbol did change state, the
corresponding source files must be rebuilt.
The insertion or removal of an EXPORT_SYMBOL() entry within a module may
create or remove the need for another exported symbol. This is why this
operation has to be repeated until the list of needed exported symbols
becomes stable. Only then the final kernel and modules link take place.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
