Kbuild updates for v4.20

- optimize kallsyms slightly
 
 - remove check for old CFLAGS usage
 
 - add some compiler flags unconditionally instead of evaluating
   $(call cc-option,...)
 
 - fix variable shadowing in host tools
 
 - refactor scripts/mkmakefile
 
 - refactor various makefiles
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Merge tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - optimize kallsyms slightly

 - remove check for old CFLAGS usage

 - add some compiler flags unconditionally instead of evaluating
   $(call cc-option,...)

 - fix variable shadowing in host tools

 - refactor scripts/mkmakefile

 - refactor various makefiles

* tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  modpost: Create macro to avoid variable shadowing
  ASN.1: Remove unnecessary shadowed local variable
  kbuild: use 'else ifeq' for checksrc to improve readability
  kbuild: remove unneeded link_multi_deps
  kbuild: add -Wno-unused-but-set-variable flag unconditionally
  kbuild: add -Wdeclaration-after-statement flag unconditionally
  kbuild: add -Wno-pointer-sign flag unconditionally
  modpost: remove leftover symbol prefix handling for module device table
  kbuild: simplify command line creation in scripts/mkmakefile
  kbuild: do not pass $(objtree) to scripts/mkmakefile
  kbuild: remove user ID check in scripts/mkmakefile
  kbuild: remove VERSION and PATCHLEVEL from $(objtree)/Makefile
  kbuild: add --include-dir flag only for out-of-tree build
  kbuild: remove dead code in cmd_files calculation in top Makefile
  kbuild: hide most of targets when running config or mixed targets
  kbuild: remove old check for CFLAGS use
  kbuild: prefix Makefile.dtbinst path with $(srctree) unconditionally
  kallsyms: remove left-over Blackfin code
  kallsyms: reduce size a little on 64-bit

Makefile

@@ -15,10 +15,9 @@ NAME = "People's Front"
 PHONY := _all
 _all:
 
-# o Do not use make's built-in rules and variables
+# Do not use make's built-in rules and variables
-#   (this increases performance and avoids hard-to-debug behaviour);
+# (this increases performance and avoids hard-to-debug behaviour)
-# o Look for make include files relative to root of kernel src
+MAKEFLAGS += -rR
-MAKEFLAGS += -rR --include-dir=$(CURDIR)
 
 # Avoid funny character set dependencies
 unexport LC_ALL
@@ -136,6 +135,13 @@ KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
 $(if $(KBUILD_OUTPUT),, \
      $(error failed to create output directory "$(saved-output)"))
 
+# Look for make include files relative to root of kernel src
+#
+# This does not become effective immediately because MAKEFLAGS is re-parsed
+# once after the Makefile is read.  It is OK since we are going to invoke
+# 'sub-make' below.
+MAKEFLAGS += --include-dir=$(CURDIR)
+
 PHONY += $(MAKECMDGOALS) sub-make
 
 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
@@ -476,8 +482,7 @@ PHONY += outputmakefile
 outputmakefile:
 ifneq ($(KBUILD_SRC),)
 	$(Q)ln -fsn $(srctree) source
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
-	    $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
 endif
 
 ifeq ($(cc-name),clang)
@@ -713,7 +718,7 @@ else
 
 # These warnings generated too much noise in a regular build.
 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
-KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
+KBUILD_CFLAGS += -Wno-unused-but-set-variable
 endif
 
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
@@ -794,10 +799,10 @@ endif
 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 
 # warn about C99 declaration after statement
-KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
+KBUILD_CFLAGS += -Wdeclaration-after-statement
 
 # disable pointer signed / unsigned warnings in gcc 4.0
-KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
+KBUILD_CFLAGS += -Wno-pointer-sign
 
 # disable stringop warnings in gcc 8+
 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
@@ -1647,9 +1652,6 @@ namespacecheck:
 export_report:
 	$(PERL) $(srctree)/scripts/export_report.pl
 
-endif #ifeq ($(config-targets),1)
-endif #ifeq ($(mixed-targets),1)
-
 PHONY += checkstack kernelrelease kernelversion image_name
 
 # UML needs a little special treatment here.  It wants to use the host
@@ -1756,14 +1758,15 @@ cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
                   $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
 
 # read all saved command lines
-
+cmd_files := $(wildcard .*.cmd)
-cmd_files := $(wildcard .*.cmd $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
 
 ifneq ($(cmd_files),)
   $(cmd_files): ;	# Do not try to update included dependency files
   include $(cmd_files)
 endif
 
+endif   # ifeq ($(config-targets),1)
+endif   # ifeq ($(mixed-targets),1)
 endif	# skip-makefile
 
 PHONY += FORCE

kernel/kallsyms.c

@@ -37,7 +37,7 @@ extern const u8 kallsyms_names[] __weak;
  * Tell the compiler that the count isn't in the small data section if the arch
  * has one (eg: FRV).
  */
-extern const unsigned long kallsyms_num_syms
+extern const unsigned int kallsyms_num_syms
 __attribute__((weak, section(".rodata")));
 
 extern const unsigned long kallsyms_relative_base
@@ -46,7 +46,7 @@ __attribute__((weak, section(".rodata")));
 extern const u8 kallsyms_token_table[] __weak;
 extern const u16 kallsyms_token_index[] __weak;
 
-extern const unsigned long kallsyms_markers[] __weak;
+extern const unsigned int kallsyms_markers[] __weak;
 
 /*
  * Expand a compressed symbol data into the resulting uncompressed string,

scripts/Kbuild.include

@@ -195,7 +195,7 @@ modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj
 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj=
 # Usage:
 # $(Q)$(MAKE) $(dtbinst)=dir
-dtbinst := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.dtbinst obj
+dtbinst := -f $(srctree)/scripts/Makefile.dtbinst obj
 
 ###
 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=

scripts/Makefile.build

@@ -36,21 +36,11 @@ subdir-ccflags-y :=
 
 include scripts/Kbuild.include
 
-# For backward compatibility check that these variables do not change
-save-cflags := $(CFLAGS)
-
 # The filename Kbuild has precedence over Makefile
 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
 include $(kbuild-file)
 
-# If the save-* variables changed error out
-ifeq ($(KBUILD_NOPEDANTIC),)
-        ifneq ("$(save-cflags)","$(CFLAGS)")
-                $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
-        endif
-endif
-
 include scripts/Makefile.lib
 
 # Do not include host rules unless needed
@@ -83,14 +73,12 @@ __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
 	@:
 
 # Linus' kernel sanity checking tool
-ifneq ($(KBUILD_CHECKSRC),0)
+ifeq ($(KBUILD_CHECKSRC),1)
-  ifeq ($(KBUILD_CHECKSRC),2)
-    quiet_cmd_force_checksrc = CHECK   $<
-          cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
-  else
   quiet_cmd_checksrc       = CHECK   $<
         cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
-  endif
+else ifeq ($(KBUILD_CHECKSRC),2)
+  quiet_cmd_force_checksrc = CHECK   $<
+        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
 endif
 
 ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
@@ -495,28 +483,12 @@ targets += $(obj)/lib-ksyms.o
 
 endif
 
-#
-# Rule to link composite objects
-#
-#  Composite objects are specified in kbuild makefile as follows:
-#    <composite-object>-objs := <list of .o files>
-#  or
-#    <composite-object>-y    := <list of .o files>
-#  or
-#    <composite-object>-m    := <list of .o files>
-#  The -m syntax only works if <composite object> is a module
-link_multi_deps =                     \
-$(filter $(addprefix $(obj)/,         \
-$($(subst $(obj)/,,$(@:.o=-objs)))    \
-$($(subst $(obj)/,,$(@:.o=-y)))       \
-$($(subst $(obj)/,,$(@:.o=-m)))), $^)
-
 quiet_cmd_link_multi-m = LD [M]  $@
-cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
+cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) $(cmd_secanalysis)
 
 $(multi-used-m): FORCE
 	$(call if_changed,link_multi-m)
-	@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
+	@{ echo $(@:.o=.ko); echo $(filter %.o,$^); \
 	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
 

scripts/asn1_compiler.c

@@ -413,7 +413,7 @@ static void tokenise(char *buffer, char *end)
 
 			/* Handle string tokens */
 			if (isalpha(*p)) {
-				const char **dir, *start = p;
+				const char **dir;
 
 				/* Can be a directive, type name or element
 				 * name.  Find the end of the name.

scripts/kallsyms.c

@@ -48,8 +48,6 @@ static unsigned long long relative_base;
 static struct addr_range text_ranges[] = {
 	{ "_stext",     "_etext"     },
 	{ "_sinittext", "_einittext" },
-	{ "_stext_l1",  "_etext_l1"  },	/* Blackfin on-chip L1 inst SRAM */
-	{ "_stext_l2",  "_etext_l2"  },	/* Blackfin on-chip L2 SRAM */
 };
 #define text_range_text     (&text_ranges[0])
 #define text_range_inittext (&text_ranges[1])
@@ -405,7 +403,7 @@ static void write_src(void)
 	}
 
 	output_label("kallsyms_num_syms");
-	printf("\tPTR\t%u\n", table_cnt);
+	printf("\t.long\t%u\n", table_cnt);
 	printf("\n");
 
 	/* table of offset markers, that give the offset in the compressed stream
@@ -434,7 +432,7 @@ static void write_src(void)
 
 	output_label("kallsyms_markers");
 	for (i = 0; i < ((table_cnt + 255) >> 8); i++)
-		printf("\tPTR\t%d\n", markers[i]);
+		printf("\t.long\t%u\n", markers[i]);
 	printf("\n");
 
 	free(markers);

scripts/mkmakefile

@@ -6,31 +6,20 @@
 
 # Usage
 # $1 - Kernel src directory
-# $2 - Output directory
-# $3 - version
-# $4 - patchlevel
 
-
-test ! -r $2/Makefile -o -O $2/Makefile || exit 0
 # Only overwrite automatically generated Makefiles
 # (so we do not overwrite kernel Makefile)
-if test -e $2/Makefile && ! grep -q Automatically $2/Makefile
+if test -e Makefile && ! grep -q Automatically Makefile
 then
 	exit 0
 fi
 if [ "${quiet}" != "silent_" ]; then
-	echo "  GEN     $2/Makefile"
+	echo "  GEN     Makefile"
 fi
 
-cat << EOF > $2/Makefile
+cat << EOF > Makefile
 # Automatically generated by $0: don't edit
 
-VERSION = $3
-PATCHLEVEL = $4
-
-lastword = \$(word \$(words \$(1)),\$(1))
-makedir := \$(dir \$(call lastword,\$(MAKEFILE_LIST)))
-
 ifeq ("\$(origin V)", "command line")
 VERBOSE := \$(V)
 endif
@@ -38,15 +27,12 @@ ifneq (\$(VERBOSE),1)
 Q := @
 endif
 
-MAKEARGS := -C $1
-MAKEARGS += O=\$(if \$(patsubst /%,,\$(makedir)),\$(CURDIR)/)\$(patsubst %/,%,\$(makedir))
-
 MAKEFLAGS += --no-print-directory
 
 .PHONY: __sub-make \$(MAKECMDGOALS)
 
 __sub-make:
-	\$(Q)\$(MAKE) \$(MAKEARGS) \$(MAKECMDGOALS)
+	\$(Q)\$(MAKE) -C $1 O=\$(CURDIR) \$(MAKECMDGOALS)
 
 \$(filter-out __sub-make, \$(MAKECMDGOALS)): __sub-make
 	@:

scripts/mod/file2alias.c

@@ -95,12 +95,20 @@ extern struct devtable *__start___devtable[], *__stop___devtable[];
  */
 #define DEF_FIELD(m, devid, f) \
 	typeof(((struct devid *)0)->f) f = TO_NATIVE(*(typeof(f) *)((m) + OFF_##devid##_##f))
+
+/* Define a variable v that holds the address of field f of struct devid
+ * based at address m.  Due to the way typeof works, for a field of type
+ * T[N] the variable has type T(*)[N], _not_ T*.
+ */
+#define DEF_FIELD_ADDR_VAR(m, devid, f, v) \
+	typeof(((struct devid *)0)->f) *v = ((m) + OFF_##devid##_##f)
+
 /* Define a variable f that holds the address of field f of struct devid
  * based at address m.  Due to the way typeof works, for a field of type
  * T[N] the variable has type T(*)[N], _not_ T*.
  */
 #define DEF_FIELD_ADDR(m, devid, f) \
-	typeof(((struct devid *)0)->f) *f = ((m) + OFF_##devid##_##f)
+	DEF_FIELD_ADDR_VAR(m, devid, f, f)
 
 /* Add a table entry.  We test function type matches while we're here. */
 #define ADD_TO_DEVTABLE(device_id, type, function) \
@@ -656,10 +664,13 @@ static void do_pnp_card_entries(void *symval, unsigned long size,
 
 			/* find duplicate, already added value */
 			for (i2 = 0; i2 < i && !dup; i2++) {
-				DEF_FIELD_ADDR(symval + i2*id_size, pnp_card_device_id, devs);
+				DEF_FIELD_ADDR_VAR(symval + i2 * id_size,
+						   pnp_card_device_id,
+						   devs, devs_dup);
 
 				for (j2 = 0; j2 < PNP_MAX_DEVICES; j2++) {
-					const char *id2 = (char *)(*devs)[j2].id;
+					const char *id2 =
+						(char *)(*devs_dup)[j2].id;
 
 					if (!id2[0])
 						break;
@@ -1415,11 +1426,10 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
 	if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
 		return;
 
-	/* All our symbols are of form <prefix>__mod_<name>__<identifier>_device_table. */
+	/* All our symbols are of form __mod_<name>__<identifier>_device_table. */
-	name = strstr(symname, "__mod_");
+	if (strncmp(symname, "__mod_", strlen("__mod_")))
-	if (!name)
 		return;
-	name += strlen("__mod_");
+	name = symname + strlen("__mod_");
 	namelen = strlen(name);
 	if (namelen < strlen("_device_table"))
 		return;