modpost: distinguish same module paths from different dump files

Since commit 13b25489b6f8 ("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.

Masahiro Yamada committed 1 year ago

Commit 9435dc71 parent 54956562 files · +11 −9Browse files

Showing the changes to scripts (2 of 2 files). Show all

Unified · Split

2 files

scripts/mod/modpost.c +9 −8
scripts/mod/modpost.h +2 −1

scripts/mod/modpost.c+9−8

@@ -155,12 +155,13 @@ char get_line(char *stringp) · 154 unmodified lines
155	155	/* A list of all modules we processed */
156	156	LIST_HEAD(modules);
157	157
158		−static struct module find_module(const char modname)
	158	+static struct module find_module(const char filename, const char *modname)
159	159	{
160	160	struct module *mod;
161	161
162	162	list_for_each_entry(mod, &modules, list) {
163		− if (strcmp(mod->name, modname) == 0)
	163	+ if (!strcmp(mod->dump_file, filename) &&
	164	+ !strcmp(mod->name, modname))
164	165	return mod;
165	166	}
166	167	return NULL;
@@ -2030,10 +2031,10 @@ static void read_dump(const char *fname) · 1863 unmodified lines
2030	2031	continue;
2031	2032	}
2032	2033
2033		− mod = find_module(modname);
	2034	+ mod = find_module(fname, modname);
2034	2035	if (!mod) {
2035	2036	mod = new_module(modname, strlen(modname));
2036		− mod->from_dump = true;
	2037	+ mod->dump_file = fname;
2037	2038	}
2038	2039	s = sym_add_exported(symname, mod, gpl_only, namespace);
2039	2040	sym_set_crc(s, crc);
@@ -2052,7 +2053,7 @@ static void write_dump(const char *fname) · 12 unmodified lines
2052	2053	struct symbol *sym;
2053	2054
2054	2055	list_for_each_entry(mod, &modules, list) {
2055		− if (mod->from_dump)
	2056	+ if (mod->dump_file)
2056	2057	continue;
2057	2058	list_for_each_entry(sym, &mod->exported_symbols, list) {
2058	2059	if (trim_unused_exports && !sym->used)
@@ -2076,7 +2077,7 @@ static void write_namespace_deps_files(const char *fname) · 17 unmodified lines
2076	2077
2077	2078	list_for_each_entry(mod, &modules, list) {
2078	2079
2079		− if (mod->from_dump \|\| list_empty(&mod->missing_namespaces))
	2080	+ if (mod->dump_file \|\| list_empty(&mod->missing_namespaces))
2080	2081	continue;
2081	2082
2082	2083	buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
@@ -2194,7 +2195,7 @@ int main(int argc, char **argv) · 111 unmodified lines
2194	2195	read_symbols_from_files(files_source);
2195	2196
2196	2197	list_for_each_entry(mod, &modules, list) {
2197		− if (mod->from_dump \|\| mod->is_vmlinux)
	2198	+ if (mod->dump_file \|\| mod->is_vmlinux)
2198	2199	continue;
2199	2200
2200	2201	check_modname_len(mod);
@@ -2205,7 +2206,7 @@ int main(int argc, char **argv) · 4 unmodified lines
2205	2206	handle_white_list_exports(unused_exports_white_list);
2206	2207
2207	2208	list_for_each_entry(mod, &modules, list) {
2208		− if (mod->from_dump)
	2209	+ if (mod->dump_file)
2209	2210	continue;
2210	2211
2211	2212	if (mod->is_vmlinux)

scripts/mod/modpost.h+2−1

@@ -95,14 +95,15 @@ struct module_alias { · 94 unmodified lines
95	95	/**
96	96	* struct module - represent a module (vmlinux or *.ko)
97	97	*
	98	+ * @dump_file: path to the .symvers file if loaded from a file
98	99	* @aliases: list head for module_aliases
99	100	*/
100	101	struct module {
101	102	struct list_head list;
102	103	struct list_head exported_symbols;
103	104	struct list_head unresolved_symbols;
	105	+ const char *dump_file;
104	106	bool is_gpl_compatible;
105		− bool from_dump; /* true if module was loaded from .symvers /
106	107	bool is_vmlinux;
107	108	bool seen;
108	109	bool has_init;