Commit 9435dc77 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

modpost: distinguish same module paths from different dump files 



Since commit 13b25489 ("kbuild: change working directory to external
module directory with M="), module paths are always relative to the top
of the external module tree.

The module paths recorded in Module.symvers are no longer globally unique
when they are passed via KBUILD_EXTRA_SYMBOLS for building other external
modules, which may result in false-positive "exported twice" errors.
Such errors should not occur because external modules should be able to
override in-tree modules.

To address this, record the dump file path in struct module and check it
when searching for a module.

Fixes: 13b25489 ("kbuild: change working directory to external module directory with M=")
Reported-by: default avatarJon Hunter <jonathanh@nvidia.com>
Closes: https://lore.kernel.org/all/eb21a546-a19c-40df-b821-bbba80f19a3d@nvidia.com/


Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Tested-by: default avatarJon Hunter <jonathanh@nvidia.com>
parent 54956567

scripts/mod/modpost.c

+9 −8
Original line number Diff line number Diff line
@@ -155,12 +155,13 @@ char *get_line(char **stringp) 
/* A list of all modules we processed */

LIST_HEAD(modules);



static struct module *find_module(const char *modname)

static struct module *find_module(const char *filename, const char *modname)

{

	struct module *mod;



	list_for_each_entry(mod, &modules, list) {

		if (strcmp(mod->name, modname) == 0)

		if (!strcmp(mod->dump_file, filename) &&

		    !strcmp(mod->name, modname))

			return mod;

	}

	return NULL;
@@ -2030,10 +2031,10 @@ static void read_dump(const char *fname) 
			continue;

		}



		mod = find_module(modname);

		mod = find_module(fname, modname);

		if (!mod) {

			mod = new_module(modname, strlen(modname));

			mod->from_dump = true;

			mod->dump_file = fname;

		}

		s = sym_add_exported(symname, mod, gpl_only, namespace);

		sym_set_crc(s, crc);
@@ -2052,7 +2053,7 @@ static void write_dump(const char *fname) 
	struct symbol *sym;



	list_for_each_entry(mod, &modules, list) {

		if (mod->from_dump)

		if (mod->dump_file)

			continue;

		list_for_each_entry(sym, &mod->exported_symbols, list) {

			if (trim_unused_exports && !sym->used)
@@ -2076,7 +2077,7 @@ static void write_namespace_deps_files(const char *fname) 


	list_for_each_entry(mod, &modules, list) {



		if (mod->from_dump || list_empty(&mod->missing_namespaces))

		if (mod->dump_file || list_empty(&mod->missing_namespaces))

			continue;



		buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
@@ -2194,7 +2195,7 @@ int main(int argc, char **argv) 
		read_symbols_from_files(files_source);



	list_for_each_entry(mod, &modules, list) {

		if (mod->from_dump || mod->is_vmlinux)

		if (mod->dump_file || mod->is_vmlinux)

			continue;



		check_modname_len(mod);
@@ -2205,7 +2206,7 @@ int main(int argc, char **argv) 
		handle_white_list_exports(unused_exports_white_list);



	list_for_each_entry(mod, &modules, list) {

		if (mod->from_dump)

		if (mod->dump_file)

			continue;



		if (mod->is_vmlinux)

scripts/mod/modpost.h

+2 −1
Original line number Diff line number Diff line
@@ -95,14 +95,15 @@ struct module_alias { 
/**

 * struct module - represent a module (vmlinux or *.ko)

 *

 * @dump_file: path to the .symvers file if loaded from a file

 * @aliases: list head for module_aliases

 */

struct module {

	struct list_head list;

	struct list_head exported_symbols;

	struct list_head unresolved_symbols;

	const char *dump_file;

	bool is_gpl_compatible;

	bool from_dump;		/* true if module was loaded from *.symvers */

	bool is_vmlinux;

	bool seen;

	bool has_init;