Merge tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - add modpost warn exported symbols marked as 'static' because 'static'
   and EXPORT_SYMBOL is an odd combination

 - break the build early if gold linker is used

 - optimize the Bison rule to produce .c and .h files by a single
   pattern rule

 - handle PREEMPT_RT in the module vermagic and UTS_VERSION

 - warn CONFIG options leaked to the user-space except existing ones

 - make single targets work properly

 - rebuild modules when module linker scripts are updated

 - split the module final link stage into scripts/Makefile.modfinal

 - fix the missed error code in merge_config.sh

 - improve the error message displayed on the attempt of the O= build in
   unclean source tree

 - remove 'clean-dirs' syntax

 - disable -Wimplicit-fallthrough warning for Clang

 - add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC

 - remove ARCH_{CPP,A,C}FLAGS variables

 - add $(BASH) to run bash scripts

 - change *CFLAGS_<basetarget>.o to take the relative path to $(obj)
   instead of the basename

 - stop suppressing Clang's -Wunused-function warnings when W=1

 - fix linux/export.h to avoid genksyms calculating CRC of trimmed
   exported symbols

 - misc cleanups

* tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits)
  genksyms: convert to SPDX License Identifier for lex.l and parse.y
  modpost: use __section in the output to *.mod.c
  modpost: use MODULE_INFO() for __module_depends
  export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols
  export.h: remove defined(__KERNEL__), which is no longer needed
  kbuild: allow Clang to find unused static inline functions for W=1 build
  kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN
  kbuild: refactor scripts/Makefile.extrawarn
  merge_config.sh: ignore unwanted grep errors
  kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)
  modpost: add NOFAIL to strndup
  modpost: add guid_t type definition
  kbuild: add $(BASH) to run scripts with bash-extension
  kbuild: remove ARCH_{CPP,A,C}FLAGS
  kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC
  kbuild: Do not enable -Wimplicit-fallthrough for clang for now
  kbuild: clean up subdir-ymn calculation in Makefile.clean
  kbuild: remove unneeded '+' marker from cmd_clean
  kbuild: remove clean-dirs syntax
  kbuild: check clean srctree even earlier
  ...

1 files changed, 38 insertions, 10 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index f277e116e0eb..820eed87fb43 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -169,6 +169,7 @@ struct symbol {
 	unsigned int kernel:1;     /* 1 if symbol is from kernel
 				    *  (only for external modules) **/
 	unsigned int preloaded:1;  /* 1 if symbol from Module.symvers, or crc */
+	unsigned int is_static:1;  /* 1 if symbol is not global */
 	enum export  export;       /* Type of export */
 	char name[0];
 };
@@ -201,6 +202,7 @@ static struct symbol *alloc_symbol(const char *name, unsigned int weak,
 	strcpy(s->name, name);
 	s->weak = weak;
 	s->next = next;
+	s->is_static = 1;
 	return s;
 }
 
@@ -795,9 +797,9 @@ static int match(const char *sym, const char * const pat[])
 
 		/* "*foo*" */
 		if (*p == '*' && *endp == '*') {
-			char *here, *bare = strndup(p + 1, strlen(p) - 2);
+			char *bare = NOFAIL(strndup(p + 1, strlen(p) - 2));
+			char *here = strstr(sym, bare);
 
-			here = strstr(sym, bare);
 			free(bare);
 			if (here != NULL)
 				return 1;
@@ -1980,6 +1982,21 @@ static void read_symbols(const char *modname)
 		handle_modversions(mod, &info, sym, symname);
 		handle_moddevtable(mod, &info, sym, symname);
 	}
+
+	// check for static EXPORT_SYMBOL_* functions && global vars
+	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
+		unsigned char bind = ELF_ST_BIND(sym->st_info);
+
+		if (bind == STB_GLOBAL || bind == STB_WEAK) {
+			struct symbol *s =
+				find_symbol(remove_dot(info.strtab +
+						       sym->st_name));
+
+			if (s)
+				s->is_static = 0;
+		}
+	}
+
 	if (!is_vmlinux(modname) || vmlinux_section_warnings)
 		check_sec_ref(mod, modname, &info);
 
@@ -2159,7 +2176,7 @@ static void add_header(struct buffer *b, struct module *mod)
 	buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
 	buf_printf(b, "\n");
 	buf_printf(b, "__visible struct module __this_module\n");
-	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
+	buf_printf(b, "__section(.gnu.linkonce.this_module) = {\n");
 	buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
 	if (mod->has_init)
 		buf_printf(b, "\t.init = init_module,\n");
@@ -2213,8 +2230,7 @@ static int add_versions(struct buffer *b, struct module *mod)
 
 	buf_printf(b, "\n");
 	buf_printf(b, "static const struct modversion_info ____versions[]\n");
-	buf_printf(b, "__used\n");
-	buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
+	buf_printf(b, "__used __section(__versions) = {\n");
 
 	for (s = mod->unres; s; s = s->next) {
 		if (!s->module)
@@ -2250,10 +2266,7 @@ static void add_depends(struct buffer *b, struct module *mod)
 			s->module->seen = is_vmlinux(s->module->name);
 
 	buf_printf(b, "\n");
-	buf_printf(b, "static const char __module_depends[]\n");
-	buf_printf(b, "__used\n");
-	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
-	buf_printf(b, "\"depends=");
+	buf_printf(b, "MODULE_INFO(depends, \"");
 	for (s = mod->unres; s; s = s->next) {
 		const char *p;
 		if (!s->module)
@@ -2271,7 +2284,7 @@ static void add_depends(struct buffer *b, struct module *mod)
 		buf_printf(b, "%s%s", first ? "" : ",", p);
 		first = 0;
 	}
-	buf_printf(b, "\";\n");
+	buf_printf(b, "\");\n");
 }
 
 static void add_srcversion(struct buffer *b, struct module *mod)
@@ -2369,6 +2382,7 @@ static void read_dump(const char *fname, unsigned int kernel)
 		s = sym_add_exported(symname, mod, export_no(export));
 		s->kernel    = kernel;
 		s->preloaded = 1;
+		s->is_static = 0;
 		sym_update_crc(symname, mod, crc, export_no(export));
 	}
 	release_file(file, size);
@@ -2425,6 +2439,7 @@ int main(int argc, char **argv)
 	char *dump_write = NULL, *files_source = NULL;
 	int opt;
 	int err;
+	int n;
 	struct ext_sym_list *extsym_iter;
 	struct ext_sym_list *extsym_start = NULL;
 
@@ -2520,6 +2535,19 @@ int main(int argc, char **argv)
 	if (sec_mismatch_count && sec_mismatch_fatal)
 		fatal("modpost: Section mismatches detected.\n"
 		      "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
+	for (n = 0; n < SYMBOL_HASH_SIZE; n++) {
+		struct symbol *s = symbolhash[n];
+
+		while (s) {
+			if (s->is_static)
+				warn("\"%s\" [%s] is a static %s\n",
+				     s->name, s->module->name,
+				     export_str(s->export));
+
+			s = s->next;
+		}
+	}
+
 	free(buf.p);
 
 	return err;