From fbb5c0606fa4506e9085e7a62c9e0098e573ce7a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 26 Apr 2024 15:19:48 +0200 Subject: kbuild: add syscall table generation to scripts/Makefile.asm-headers There are 11 copies of arch/*/kernel/syscalls/Makefile that all implement the same basic logic in a somewhat awkward way. I tried out various ways of unifying the existing copies and ended up with something that hooks into the logic for generating the redirections to asm-generic headers. This gives a nicer syntax of being able to list the generated files in $(syscall-y) inside of arch/*/include/asm/Kbuild instead of both $(generated-y) in that place and also in another Makefile. The configuration for which syscall.tbl file to use and which ABIs to enable is now done in arch/*/kernel/Makefile.syscalls. I have done patches for all architectures and made sure that the new generic rules implement a superset of all the architecture specific corner cases. ince the header file is not specific to asm-generic/*.h redirects now, I ended up renaming the file to scripts/Makefile.asm-headers. Signed-off-by: Arnd Bergmann --- scripts/Makefile.asm-headers | 98 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 scripts/Makefile.asm-headers (limited to 'scripts/Makefile.asm-headers') diff --git a/scripts/Makefile.asm-headers b/scripts/Makefile.asm-headers new file mode 100644 index 000000000000..6b8e8318e810 --- /dev/null +++ b/scripts/Makefile.asm-headers @@ -0,0 +1,98 @@ +# SPDX-License-Identifier: GPL-2.0 +# include/asm-generic contains a lot of files that are used +# verbatim by several architectures. +# +# This Makefile generates arch/$(SRCARCH)/include/generated/(uapi/)/asm +# headers from multiple sources: +# - a small wrapper to include the corresponding asm-generic/*.h +# is generated for each file listed as generic-y +# - uapi/asm/unistd_*.h files listed as syscalls-y are generated from +# syscall.tbl with the __NR_* macros +# - Corresponding asm/syscall_table_*.h are generated from the same input + +PHONY := all +all: + +src := $(srctree)/$(subst /generated,,$(obj)) + +syscall_abis_32 += common,32 +syscall_abis_64 += common,64 +syscalltbl := $(srctree)/scripts/syscall.tbl +syshdr-args := --emit-nr + +# let architectures override $(syscall_abis_%) and $(syscalltbl) +-include $(srctree)/arch/$(SRCARCH)/kernel/Makefile.syscalls +include $(srctree)/scripts/Kbuild.include +-include $(kbuild-file) + +syshdr := $(srctree)/scripts/syscallhdr.sh +systbl := $(srctree)/scripts/syscalltbl.sh + +# $(generic)/Kbuild lists mandatory-y. Exclude um since it is a special case. +ifneq ($(SRCARCH),um) +include $(srctree)/$(generic)/Kbuild +endif + +redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y)) +redundant += $(foreach f, $(generic-y), $(if $(wildcard $(src)/$(f)),$(f))) +redundant := $(sort $(redundant)) +$(if $(redundant),\ + $(warning redundant generic-y found in $(src)/Kbuild: $(redundant))) + +# If arch does not implement mandatory headers, fallback to asm-generic ones. +mandatory-y := $(filter-out $(generated-y), $(mandatory-y)) +generic-y += $(foreach f, $(mandatory-y), $(if $(wildcard $(src)/$(f)),,$(f))) + +generic-y := $(addprefix $(obj)/, $(generic-y)) +syscall-y := $(addprefix $(obj)/, $(syscall-y)) +generated-y := $(addprefix $(obj)/, $(generated-y)) + +# Remove stale wrappers when the corresponding files are removed from generic-y +old-headers := $(wildcard $(obj)/*.h) +unwanted := $(filter-out $(generic-y) $(generated-y) $(syscall-y),$(old-headers)) + +quiet_cmd_wrap = WRAP $@ + cmd_wrap = echo "\#include " > $@ + +quiet_cmd_remove = REMOVE $(unwanted) + cmd_remove = rm -f $(unwanted) + +quiet_cmd_syshdr = SYSHDR $@ + cmd_syshdr = $(CONFIG_SHELL) $(syshdr) \ + $(if $(syshdr-args-$*),$(syshdr-args-$*),$(syshdr-args)) \ + $(if $(syscall_compat),--prefix "compat$*_") \ + --abis $(subst $(space),$(comma),$(strip $(syscall_abis_$*))) \ + $< $@ + +quiet_cmd_systbl = SYSTBL $@ + cmd_systbl = $(CONFIG_SHELL) $(systbl) \ + $(if $(systbl-args-$*),$(systbl-args-$*),$(systbl-args)) \ + --abis $(subst $(space),$(comma),$(strip $(syscall_abis_$*))) \ + $< $@ + +all: $(generic-y) $(syscall-y) + $(if $(unwanted),$(call cmd,remove)) + @: + +$(obj)/%.h: $(srctree)/$(generic)/%.h + $(call cmd,wrap) + +$(obj)/unistd_%.h: $(syscalltbl) $(syshdr) FORCE + $(call if_changed,syshdr) + +$(obj)/unistd_compat_%.h: syscall_compat:=1 +$(obj)/unistd_compat_%.h: $(syscalltbl) $(syshdr) FORCE + $(call if_changed,syshdr) + +$(obj)/syscall_table_%.h: $(syscalltbl) $(systbl) FORCE + $(call if_changed,systbl) + +# Create output directory. Skip it if at least one old header exists +# since we know the output directory already exists. +ifeq ($(old-headers),) +$(shell mkdir -p $(obj)) +endif + +FORCE: + +.PHONY: $(PHONY) -- cgit v1.2.3 From 49208b67585d18521225bf72bf842593cea711f8 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 18 Jul 2024 01:24:20 +0900 Subject: kbuild: fix rebuild of generic syscall headers Commit fbb5c0606fa4 ("kbuild: add syscall table generation to scripts/Makefile.asm-headers") started to generate syscall headers for architectures using generic syscalls. However, these headers are always rebuilt using GNU Make 4.4.1 or newer. When using GNU Make 4.4 or older, these headers are not rebuilt when the command to generate them is changed, despite the use of the if_changed macro. scripts/Makefile.asm-headers now uses FORCE, but it is not marked as .PHONY. To handle the command line change correctly, .*.cmd files must be included. Fixes: fbb5c0606fa4 ("kbuild: add syscall table generation to scripts/Makefile.asm-headers") Reported-by: Linus Torvalds Closes: https://lore.kernel.org/lkml/CAHk-=wibB7SvXnUftBgAt+4-3vEKRpvEgBeDEH=i=j2GvDitoA@mail.gmail.com/ Signed-off-by: Masahiro Yamada Tested-by: Arnd Bergmann Signed-off-by: Linus Torvalds --- scripts/Makefile.asm-headers | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'scripts/Makefile.asm-headers') diff --git a/scripts/Makefile.asm-headers b/scripts/Makefile.asm-headers index 6b8e8318e810..8a4856e74180 100644 --- a/scripts/Makefile.asm-headers +++ b/scripts/Makefile.asm-headers @@ -87,12 +87,20 @@ $(obj)/unistd_compat_%.h: $(syscalltbl) $(syshdr) FORCE $(obj)/syscall_table_%.h: $(syscalltbl) $(systbl) FORCE $(call if_changed,systbl) +targets := $(syscall-y) + # Create output directory. Skip it if at least one old header exists # since we know the output directory already exists. ifeq ($(old-headers),) $(shell mkdir -p $(obj)) endif +PHONY += FORCE + FORCE: +existing-targets := $(wildcard $(sort $(targets))) + +-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) + .PHONY: $(PHONY) -- cgit v1.2.3