scripts/Makefile.modsign is a subset of scripts/Makefile.modinst,
and duplicates the code. Let's merge them.
By the way, you do not need to run 'make modules_sign' explicitly
because modules are signed as a part of 'make modules_install' when
CONFIG_MODULE_SIG_ALL=y. If CONFIG_MODULE_SIG_ALL=n, mod_sign_cmd is
set to 'true', so 'make modules_sign' is not functional.
In my understanding, the reason of still keeping this is to handle
corner cases like commit 64178cb62c ("builddeb: fix stripped module
signatures if CONFIG_DEBUG_INFO and CONFIG_MODULE_SIG_ALL are set").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Both mod_strip_cmd and mod_compress_cmd are only used in
scripts/Makefile.modinst, hence there is no good reason to define them
in the top Makefile. Move the relevant code to scripts/Makefile.modinst.
Also, show separate log messages for each of install, strip, sign, and
compress.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
scripts/Makefile.modinst is ugly and weird in multiple ways; it
specifies real files $(modules) as phony, makes directory manipulation
needlessly too complicated.
Clean up the Makefile code, and show the full path of installed modules
in the log.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
If there are multiple modules with the same name in the same external
module tree, there is ambiguity about which one will be loaded, and
very likely something odd is happening.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Nathan reports that the mips defconfig emits the following warning:
WARNING: modpost: Symbol info of vmlinux is missing. Unresolved symbol check will be entirely skipped.
This false-positive happens when CONFIG_TRIM_UNUSED_KSYMS is enabled,
but no CONFIG option is set to 'm'.
Commit a0590473c5 ("nfs: fix PNFS_FLEXFILE_LAYOUT Kconfig default")
turned the last 'm' into 'y' for the mips defconfig, and uncovered
this issue.
In this case, the module feature itself is enabled, but we have no
module to build. As a result, CONFIG_TRIM_UNUSED_KSYMS drops all the
instances of EXPORT_SYMBOL. Then, modpost wrongly assumes vmlinux is
missing because vmlinux.symvers is empty. (As another false-positive
case, you can create a module that does not use any symbol of vmlinux).
The current behavior is to entirely suppress the unresolved symbol
warnings when vmlinux is missing just because there are too many.
I found the origin of this code in the historical git tree. [1]
If this is a matter of noisiness, I think modpost can display the
first 10 warnings, and the number of suppressed warnings at the end.
You will get a bit noisier logs when you run 'make modules' without
vmlinux, but such warnings are better to show because you never know
the resulting modules are actually loadable or not.
This commit changes the following:
- If any of input *.symver files is missing, pass -w option to let
the module build keep going with warnings instead of errors.
- If there are too many (10+) unresolved symbol warnings, show only
the first 10, and also the number of suppressed warnings.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=1cc0e0529569bf6a94f6d49770aa6d4b599d2c46
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The -w option is meaningless for the first pass of modpost (vmlinux.o).
We know there are unresolved symbols in vmlinux.o, hence we skip
check_exports() and other checks when mod->is_vmlinux is set.
See the following part in the for-loop.
if (mod->is_vmlinux || mod->from_dump)
continue;
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The external module build shows the following warning if Module.symvers
is missing in the kernel tree.
WARNING: Symbol version dump "Module.symvers" is missing.
Modules may not have dependencies or modversions.
I think this is an important heads-up because the resulting modules may
not work as expected. This happens when you did not build the entire
kernel tree, for example, you might have prepared the minimal setups
for external modules by 'make defconfig && make modules_preapre'.
A problem is that 'make modules' creates Module.symvers even without
vmlinux. In this case, that warning is suppressed since Module.symvers
already exists in spite of its incomplete content.
The incomplete (i.e. invalid) Module.symvers should not be created.
This commit changes the second pass of modpost to dump symbols into
modules-only.symvers. The final Module.symvers is created by
concatenating vmlinux.symvers and modules-only.symvers if both exist.
Module.symvers is supposed to collect symbols from both vmlinux and
modules. It might be a bit confusing, and I am not quite sure if it
is an official interface, but presumably it is difficult to rename it
because some tools (e.g. kmod) parse it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The test code in scripts/test_dwarf5_support.sh is somewhat difficult
to understand, but after all, we want to check binutils >= 2.35.2
From the former discussion, the requirement for generating DWARF v5 from
C code is as follows:
- gcc + gnu as -> requires gcc 5.0+ (but 7.0+ for full support)
- clang + gnu as -> requires binutils 2.35.2+
- clang + integrated as -> OK
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Documentation/process/changes.rst defines the minimum assembler version
(binutils version), but we have never checked it in the build time.
Kbuild never invokes 'as' directly because all assembly files in the
kernel tree are *.S, hence must be preprocessed. I do not expect
raw assembly source files (*.s) would be added to the kernel tree.
Therefore, we always use $(CC) as the assembler driver, and commit
aa824e0c96 ("kbuild: remove AS variable") removed 'AS'. However,
we are still interested in the version of the assembler acting behind.
As usual, the --version option prints the version string.
$ as --version | head -n 1
GNU assembler (GNU Binutils for Ubuntu) 2.35.1
But, we do not have $(AS). So, we can add the -Wa prefix so that
$(CC) passes --version down to the backing assembler.
$ gcc -Wa,--version | head -n 1
gcc: fatal error: no input files
compilation terminated.
OK, we need to input something to satisfy gcc.
$ gcc -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1
GNU assembler (GNU Binutils for Ubuntu) 2.35.1
The combination of Clang and GNU assembler works in the same way:
$ clang -no-integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1
GNU assembler (GNU Binutils for Ubuntu) 2.35.1
Clang with the integrated assembler fails like this:
$ clang -integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1
clang: error: unsupported argument '--version' to option 'Wa,'
For the last case, checking the error message is fragile. If the
proposal for -Wa,--version support [1] is accepted, this may not be
even an error in the future.
One easy way is to check if -integrated-as is present in the passed
arguments. We did not pass -integrated-as to CLANG_FLAGS before, but
we can make it explicit.
Nathan pointed out -integrated-as is the default for all of the
architectures/targets that the kernel cares about, but it goes
along with "explicit is better than implicit" policy. [2]
With all this in my mind, I implemented scripts/as-version.sh to
check the assembler version in Kconfig time.
$ scripts/as-version.sh gcc
GNU 23501
$ scripts/as-version.sh clang -no-integrated-as
GNU 23501
$ scripts/as-version.sh clang -integrated-as
LLVM 0
[1]: https://github.com/ClangBuiltLinux/linux/issues/1320
[2]: https://lore.kernel.org/linux-kbuild/20210307044253.v3h47ucq6ng25iay@archlinux-ax161/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
The kernel build uses various tools, many of which are provided by the
same software suite, for example, LLVM and Binutils.
When you raise the minimum version of Clang/LLVM, you need to update
clang_min_version in scripts/cc-version.sh and also lld_min_version in
scripts/ld-version.sh.
Kbuild can handle CC=clang and LD=ld.lld independently, but it does not
make much sense to maintain their versions separately.
Let's create a central place of minimum tool versions so you do not need
to touch multiple files. scripts/min-tool-version.sh prints the minimum
version of the given tool.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Move $(strip ...) to the callee from the callers of suffix-search. It
shortens the code slightly. Adding a space after a comma will not be
a matter. I also dropped parentheses from single character variables.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
I think multi-obj-* is clearer, and more consistent with real-obj-*.
Rename as follows:
multi-used-y -> multi-obj-y
multi-used-m -> multi-obj-m
multi-used -> multi-obj-ym
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The patch adding CONFIG_VMLINUX_MAP revealed a small defect in the
build system: link-vmlinux.sh takes decisions based on CONFIG_*
options, but changing one of those does not always lead to vmlinux
being linked again.
For most of the CONFIG_* knobs referenced previously, this has
probably been hidden by those knobs also affecting some object file,
hence indirectly also vmlinux.
But CONFIG_VMLINUX_MAP is only handled inside link-vmlinux.sh, and
changing CONFIG_VMLINUX_MAP=n to CONFIG_VMLINUX_MAP=y does not cause
the build system to re-link (and hence have vmlinux.map
emitted). Since that map file is mostly a debugging aid, this is
merely a nuisance which is easily worked around by just deleting
vmlinux and building again.
But one could imagine other (possibly future) CONFIG options that
actually do affect the vmlinux binary but which are not captured
through some object file dependency.
To fix this, make link-vmlinux.sh emit a .vmlinux.d file in the same
format as the dependency files generated by gcc, and apply the fixdep
logic to that. I've tested that this correctly works with both in-tree
and out-of-tree builds.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
It can be quite useful to have ld emit a link map file, in order to
debug or verify that special sections end up where they are supposed
to, and to see what LD_DEAD_CODE_DATA_ELIMINATION manages to get rid
of.
The only reason I'm not just adding this unconditionally is that the
.map file can be rather large (several MB), and that's a waste of
space when one isn't interested in these things. Also make it depend
on CONFIG_EXPERT.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
scripts/Kbuild.include is included everywhere, but macros such as
cc-option are needed by build targets only.
For example, when 'make clean' traverses the tree, it does not need
to evaluate $(call cc-option,).
Split cc-option, ld-option, etc. to scripts/Makefile.compiler, which
is only included from the top Makefile and scripts/Makefile.build.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
VPATH is used in Kbuild to make pattern rules search for prerequisites
in both $(objtree) and $(srctree). Some of *.c, *.S files are not real
sources, but generated by tools such as flex, bison, perl.
In contrast, I doubt the benefit of --include-dir=$(abs_srctree) because
it is always clear which Makefiles are real sources, and which are not.
So, my hope is to add $(srctree)/ prefix to all check-in Makefiles,
then remove --include-dir=$(abs_srctree) flag in the future.
I am touching only some Kbuild core parts for now. Treewide fixes will
be needed to achieve this goal.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
ld-version.sh checks the output from $(LD) --version, but it has a
problem on some locales.
For example, in Italian:
$ LC_MESSAGES=it_IT.UTF-8 ld --version | head -n 1
ld di GNU (GNU Binutils for Debian) 2.35.2
This makes ld-version.sh fail because it expects "GNU ld" for the
BFD linker case.
Add LC_ALL=C to override the user's locale.
BTW, setting LC_MESSAGES=C (or LANG=C) is not enough because it is
ineffective if LC_ALL is set on the user's environment.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=212105
Reported-by: Marco Scardovi
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Recensito-da: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
This is a remnant of commit 78046fabe6 ("kbuild: determine the output
format of DTC by the target suffix").
The parameter "yaml" is meaningless because cmd_dtc no loner takes $(2).
Reported-by: Rob Herring <robh@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This piece of code converts the target suffix to the dtc -O option:
*.dtb -> -O dtb
*.dt.yaml -> -O yaml
Commit ce88c9c794 ("kbuild: Add support to build overlays (%.dtbo)")
added the third case:
*.dtbo -> -O dtbo
This works thanks to commit 163f0469bf2e ("dtc: Allow overlays to have
.dtbo extension") in the upstream DTC, which has already been pulled in
the kernel.
However, I think it is a bit odd because "dtbo" is not a format name.
At least, it does not show up in the help message of dtc.
$ scripts/dtc/dtc --help
[ snip ]
-O, --out-format <arg>
Output formats are:
dts - device tree source text
dtb - device tree blob
yaml - device tree encoded as YAML
asm - assembler source
So, I am not a big fan of the second hunk of that change:
} else if (streq(outform, "dtbo")) {
dt_to_blob(outf, dti, outversion);
Anyway, we did not need to do this in Makefile in the first place.
guess_type_by_name() had already understood ".yaml" before commit
4f0e3a57d6 ("kbuild: Add support for DT binding schema checks"),
and now does ".dtbo" as well.
Makefile does not need to duplicate the same logic. Let's leave it
to dtc.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Commit aec6c60a01 ("kbuild: check the minimum compiler version in
Kconfig") changed how the script detects the compiler version.
Get 'make CROSS_COMPILE=scripts/dummy-tools/' back working again.
Fixes: aec6c60a01 ("kbuild: check the minimum compiler version in Kconfig")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
ppc64le checks for -mprofile-kernel to define MPROFILE_KERNEL Kconfig.
Kconfig calls arch/powerpc/tools/gcc-check-mprofile-kernel.sh for that
purpose. This script performs two checks:
1) build with -mprofile-kernel should contain "_mcount"
2) build with -mprofile-kernel with a function marked as "notrace"
should not produce "_mcount"
So support this in dummy-tools' gcc, so that we have MPROFILE_KERNEL
always true.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Linus reported a build error due to the GCC plugin incompatibility
when the compiler is upgraded. [1]
GCC plugins are tied to a particular GCC version. So, they must be
rebuilt when the compiler is upgraded.
This seems to be a long-standing flaw since the initial support of
GCC plugins.
Extend commit 8b59cd81dc ("kbuild: ensure full rebuild when the
compiler is updated"), so that GCC plugins are covered by the
compiler upgrade detection.
[1]: https://lore.kernel.org/lkml/CAHk-=wieoN5ttOy7SnsGwZv+Fni3R6m-Ut=oxih6bbZ28G+4dw@mail.gmail.com/
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
If LLD was built with -DLLD_VENDOR="xyz", ld.lld --version output
will prefix LLD_VENDOR. Since LLD_VENDOR can contain spaces, the
LLD identifier isn't guaranteed to be $2 either.
Adjust the version checker to handle such versions of lld.
Link: https://lore.kernel.org/lkml/20210302221211.1620858-1-bero@lindev.ch/
Signed-off-by: Bernhard Rosenkränzer <bero@lindev.ch>
[masahiro yamada: refactor the code]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Piotr Gorski
Masahiro Yamada
Bhaskar Chowdhury
Rasmus Villemoes
Jiri Slaby
Bernhard Rosenkränzer