user/sven/linux.git/scripts/Makefile.modpost, branch v6.1.13

kbuild: fix typo in modpost

2022-10-27T15:19:40Z

Commit f73edc8951b2 ("kbuild: unify two modpost invocations") introduced a typo (moudle.symvers-if-present) which results in the kernel's Module.symvers to not be included as a prerequisite for $(KBUILD_EXTMOD)/Module.symvers. Fix the typo to restore the intended functionality. Fixes: f73edc8951b2 ("kbuild: unify two modpost invocations") Signed-off-by: Will McVicker Signed-off-by: Masahiro Yamada

modpost: put modpost options before argument

2022-10-14T13:32:52Z

The musl implementation of getopt stops looking for options after the first non-option argument. Put the options before the non-option argument so environments using musl can still build the kernel and modules. Fixes: f73edc8951b2 ("kbuild: unify two modpost invocations") Link: https://git.musl-libc.org/cgit/musl/tree/src/misc/getopt.c?h=dc9285ad1dc19349c407072cc48ba70dab86de45#n44 Signed-off-by: Richard Acayan Signed-off-by: Masahiro Yamada

kbuild: use obj-y instead extra-y for objects placed at the head

2022-10-02T09:04:05Z

The objects placed at the head of vmlinux need special treatments: - arch/$(SRCARCH)/Makefile adds them to head-y in order to place them before other archives in the linker command line. - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of obj-y to avoid them going into built-in.a. This commit gets rid of the latter. Create vmlinux.a to collect all the objects that are unconditionally linked to vmlinux. The objects listed in head-y are moved to the head of vmlinux.a by using 'ar m'. With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y for builtin objects. There is no *.o that is directly linked to vmlinux. Drop unneeded code in scripts/clang-tools/gen_compile_commands.py. $(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested by Nathan Chancellor [1]. [1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/ Signed-off-by: Masahiro Yamada Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier

kbuild: re-run modpost when it is updated

2022-09-28T21:08:18Z

Modpost generates .vmlinux.export.c and *.mod.c, which are prerequisites of vmlinux and modules, respectively. The modpost stage should be re-run when the modpost code is updated. Signed-off-by: Masahiro Yamada

kbuild: unify two modpost invocations

2022-09-28T21:07:58Z

Currently, modpost is executed twice; first for vmlinux, second for modules. This commit merges them. Current build flow ================== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux 4) link vmlinux 5) modpost for modules 6) link modules (*.ko) The build steps 1) through 6) are serialized, that is, modules are built after vmlinux. You do not get benefits of parallel builds when scripts/link-vmlinux.sh is being run. New build flow ============== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux and modules 4a) link vmlinux 4b) link modules (*.ko) In the new build flow, modpost is invoked just once. vmlinux and modules are built in parallel. One exception is CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux. Signed-off-by: Masahiro Yamada Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier

kbuild: move .vmlinux.objs rule to Makefile.modpost

2022-09-28T19:42:00Z

.vmlinux.objs is used by modpost, so scripts/Makefile.modpost is a better place to generate it. It is used only when CONFIG_MODVERSIONS=y. It should be guarded by "ifdef CONFIG_MODVERSIONS". Signed-off-by: Masahiro Yamada Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier

kbuild: do not create *.prelink.o for Clang LTO or IBT

2022-05-29T09:39:35Z

When CONFIG_LTO_CLANG=y, additional intermediate *.prelink.o is created for each module. Also, objtool is postponed until LLVM IR is converted to ELF. CONFIG_X86_KERNEL_IBT works in a similar way to postpone objtool until objects are merged together. This commit stops generating *.prelink.o, so the build flow will look similar with/without LTO. The following figures show how the LTO build currently works, and how this commit is changing it. Current build flow ================== [1] single-object module $(LD) $(CC) +objtool $(LD) foo.c --------------------> foo.o -----> foo.prelink.o -----> foo.ko (LLVM IR) (ELF) | (ELF) | foo.mod.o --/ (LLVM IR) [2] multi-object module $(LD) $(CC) $(AR) +objtool $(LD) foo1.c -----> foo1.o -----> foo.o -----> foo.prelink.o -----> foo.ko | (archive) (ELF) | (ELF) foo2.c -----> foo2.o --/ | (LLVM IR) foo.mod.o --/ (LLVM IR) One confusion is that foo.o in multi-object module is an archive despite of its suffix. New build flow ============== [1] single-object module Since there is only one object, there is no need to keep the LLVM IR. Use $(CC)+$(LD) to generate an ELF object in one build rule. When LTO is disabled, $(LD) is unneeded because $(CC) produces an ELF object. $(CC)+$(LD)+objtool $(LD) foo.c ----------------------------> foo.o ---------> foo.ko (ELF) | (ELF) | foo.mod.o --/ (LLVM IR) [2] multi-object module Previously, $(AR) was used to combine LLVM IR files into an archive, but there was no technical reason to do so. Use $(LD) to merge them into a single ELF object. $(LD) $(CC) +objtool $(LD) foo1.c ---------> foo1.o ---------> foo.o ---------> foo.ko | (ELF) | (ELF) foo2.c ---------> foo2.o ----/ | (LLVM IR) foo.mod.o --/ (LLVM IR) Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor Reviewed-by: Sami Tolvanen Tested-by: Sedat Dilek # LLVM-14 (x86-64) Acked-by: Josh Poimboeuf

kbuild: replace $(if A,A,B) with $(or A,B) in scripts/Makefile.modpost

2022-05-27T07:17:43Z

Similar cleanup to commit 5c8166419acf ("kbuild: replace $(if A,A,B) with $(or A,B)"). Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers

kbuild: Fix include path in scripts/Makefile.modpost

2022-05-27T06:51:48Z

When building an external module, if users don't need to separate the compilation output and source code, they run the following command: "make -C $(LINUX_SRC_DIR) M=$(PWD)". At this point, "$(KBUILD_EXTMOD)" and "$(src)" are the same. If they need to separate them, they run "make -C $(KERNEL_SRC_DIR) O=$(KERNEL_OUT_DIR) M=$(OUT_DIR) src=$(PWD)". Before running the command, they need to copy "Kbuild" or "Makefile" to "$(OUT_DIR)" to prevent compilation failure. So the kernel should change the included path to avoid the copy operation. Signed-off-by: Jing Leng [masahiro: I do not think "M=$(OUT_DIR) src=$(PWD)" is the official way, but this patch is a nice clean up anyway.] Signed-off-by: Masahiro Yamada

kbuild: Fix comment typo in scripts/Makefile.modpost

2021-09-19T01:14:19Z

Change comment "create one .mod.c file pr. module" to "create one .mod.c file per module" Signed-off-by: Ramji Jiyani Signed-off-by: Masahiro Yamada