Merge tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32

 - ensure to rebuild all objects when the compiler is upgraded

 - exclude system headers from dependency tracking and fixdep processing

 - fix potential bit-size mismatch between the kernel and BPF user-mode
   helper

 - add the new syntax 'userprogs' to build user-space programs for the
   target architecture (the same arch as the kernel)

 - compile user-space sample code under samples/ for the target arch
   instead of the host arch

 - make headers_install fail if a CONFIG option is leaked to user-space

 - sanitize the output format of scripts/checkstack.pl

 - handle ARM 'push' instruction in scripts/checkstack.pl

 - error out before modpost if a module name conflict is found

 - error out when multiple directories are passed to M= because this
   feature is broken for a long time

 - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info

 - a lot of cleanups of modpost

 - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
   second pass of modpost

 - do not run the second pass of modpost if nothing in modules is
   updated

 - install modules.builtin(.modinfo) by 'make install' as well as by
   'make modules_install' because it is useful even when
   CONFIG_MODULES=n

 - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
   to allow users to use alternatives such as pigz, pbzip2, etc.

* tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits)
  kbuild: add variables for compression tools
  Makefile: install modules.builtin even if CONFIG_MODULES=n
  mksysmap: Fix the mismatch of '.L' symbols in System.map
  kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS
  modpost: change elf_info->size to size_t
  modpost: remove is_vmlinux() helper
  modpost: strip .o from modname before calling new_module()
  modpost: set have_vmlinux in new_module()
  modpost: remove mod->skip struct member
  modpost: add mod->is_vmlinux struct member
  modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()
  modpost: remove mod->is_dot_o struct member
  modpost: move -d option in scripts/Makefile.modpost
  modpost: remove -s option
  modpost: remove get_next_text() and make {grab,release_}file static
  modpost: use read_text_file() and get_line() for reading text files
  modpost: avoid false-positive file open error
  modpost: fix potential mmap'ed file overrun in get_src_version()
  modpost: add read_text_file() and get_line() helpers
  modpost: do not call get_modinfo() for vmlinux(.o)
  ...

1 files changed, 53 insertions, 22 deletions

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 957eed6a17a5..3651cbf6ad49 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -43,34 +43,30 @@ __modpost:
 include include/config/auto.conf
 include scripts/Kbuild.include
 
-kernelsymfile := $(objtree)/Module.symvers
-modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
-
 MODPOST = scripts/mod/modpost								\
 	$(if $(CONFIG_MODVERSIONS),-m)							\
 	$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a)					\
-	$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)					\
-	$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS)))			\
-	$(if $(KBUILD_EXTMOD),-o $(modulesymfile))					\
 	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)					\
-	$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) 	\
-	$(if $(KBUILD_MODPOST_WARN),-w)
+	$(if $(KBUILD_MODPOST_WARN),-w) \
+	-o $@
 
 ifdef MODPOST_VMLINUX
 
-quiet_cmd_modpost = MODPOST vmlinux.o
-      cmd_modpost = $(MODPOST) vmlinux.o
+quiet_cmd_modpost = MODPOST $@
+      cmd_modpost = $(MODPOST) $<
 
-__modpost:
+vmlinux.symvers: vmlinux.o
 	$(call cmd,modpost)
 
-else
+__modpost: vmlinux.symvers
 
-MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - \
-	$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS))
+else
 
 ifeq ($(KBUILD_EXTMOD),)
-MODPOST += $(wildcard vmlinux)
+
+input-symdump := vmlinux.symvers
+output-symdump := Module.symvers
+
 else
 
 # set src + obj - they may be used in the modules's Makefile
@@ -80,22 +76,57 @@ src := $(obj)
 # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
 include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
              $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
+
+# modpost option for external modules
+MODPOST += -e
+
+input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS)
+output-symdump := $(KBUILD_EXTMOD)/Module.symvers
+
+endif
+
+# modpost options for modules (both in-kernel and external)
+MODPOST += \
+	$(addprefix -i ,$(wildcard $(input-symdump))) \
+	$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
+	$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)
+
+# 'make -i -k' ignores compile errors, and builds as many modules as possible.
+ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
+MODPOST += -n
 endif
 
-# find all modules listed in modules.order
-modules := $(sort $(shell cat $(MODORDER)))
+# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree).
+VPATH :=
+$(input-symdump):
+	@echo >&2 'WARNING: Symbol version dump "$@" is missing.'
+	@echo >&2 '         Modules may not have dependencies or modversions.'
 
-# Read out modules.order instead of expanding $(modules) to pass in modpost.
+# Read out modules.order to pass in modpost.
 # Otherwise, allmodconfig would fail with "Argument list too long".
-quiet_cmd_modpost = MODPOST $(words $(modules)) modules
-      cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST)
+quiet_cmd_modpost = MODPOST $@
+      cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T -
 
-__modpost:
-	$(call cmd,modpost)
+$(output-symdump): $(MODORDER) $(input-symdump) FORCE
+	$(call if_changed,modpost)
+
+targets += $(output-symdump)
+
+__modpost: $(output-symdump)
 ifneq ($(KBUILD_MODPOST_NOFINAL),1)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
 endif
 
+PHONY += FORCE
+FORCE:
+
+existing-targets := $(wildcard $(sort $(targets)))
+
+-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
+
+PHONY += FORCE
+FORCE:
+
 endif
 
 .PHONY: $(PHONY)