[PATCH 06/17] kbuild: add syscall table generation to scripts/Makefile.asm-headers

Arnd Bergmann
2024-07-04T14:37:25Z

From: Arnd Bergmann <arnd@arndb.de>

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 <arnd@arndb.de>
---
Makefile | 2 +-
scripts/Makefile.asm-generic | 58 ---------------------
scripts/Makefile.asm-headers | 98 ++++++++++++++++++++++++++++++++++++
3 files changed, 99 insertions(+), 59 deletions(-)
delete mode 100644 scripts/Makefile.asm-generic
create mode 100644 scripts/Makefile.asm-headers

diff --git a/Makefile b/Makefile
index 06aa6402b385..d62ef2b2c102 100644
--- a/Makefile
+++ b/Makefile
@@ -1219,7 +1219,7 @@ remove-stale-files:
$(Q)$(srctree)/scripts/remove-stale-files

# Support for using generic headers in asm-generic
-asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
+asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj

PHONY += asm-generic uapi-asm-generic
asm-generic: uapi-asm-generic
diff --git a/scripts/Makefile.asm-generic b/scripts/Makefile.asm-generic
deleted file mode 100644
index 69434908930e..000000000000
--- a/scripts/Makefile.asm-generic
+++ /dev/null
@@ -1,58 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0
-# include/asm-generic contains a lot of files that are used
-# verbatim by several architectures.
-#
-# This Makefile reads the file arch/$(SRCARCH)/include/(uapi/)/asm/Kbuild
-# and for each file listed in this file with generic-y creates
-# a small wrapper file in arch/$(SRCARCH)/include/generated/(uapi/)/asm.
-
-PHONY := all
-all:
-
-src := $(srctree)/$(subst /generated,,$(obj))
-
-include $(srctree)/scripts/Kbuild.include
--include $(kbuild-file)
-
-# $(generic)/Kbuild lists mandatory-y. Exclude um since it is a special case.
-ifneq ($(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))
-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) $(generated-y),$(old-headers))
-
-quiet_cmd_wrap = WRAP $@
- cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
-
-quiet_cmd_remove = REMOVE $(unwanted)
- cmd_remove = rm -f $(unwanted)
-
-all: $(generic-y)
- $(if $(unwanted),$(call cmd,remove))
- @:
-
-$(obj)/%.h: $(srctree)/$(generic)/%.h
- $(call cmd,wrap)
-
-# Create output directory. Skip it if at least one old header exists
-# since we know the output directory already exists.
-ifeq ($(old-headers),)
-$(shell mkdir -p $(obj))
-endif
-
-.PHONY: $(PHONY)
diff --git a/scripts/Makefile.asm-headers b/scripts/Makefile.asm-headers
new file mode 100644
index 000000000000..6b8e8318e810
--- /dev/null
+++ b/scripts/Makefile.asm-headers
@@ -0,0 +1,98 @@
+# SPDX-License-Identifier: GPL-2.0
+# include/asm-generic contains a lot of files that are used
+# verbatim by several architectures.
+#
+# This Makefile generates arch/$(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 $@
+ cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
+
+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)
--
2.39.2