On Thu, Dec 19, 2024 at 7:48 PM Jon Hunter <jonathanh@xxxxxxxxxx> wrote:
>
>
> On 12/12/2024 20:17, Jon Hunter wrote:
> >
> > On 12/12/2024 15:46, Masahiro Yamada wrote:
> >> 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 is 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: 13b25489b6f8 ("kbuild: change working directory to external
> >> module directory with M=")
> >> Reported-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> >> Closes: https://lore.kernel.org/all/eb21a546-a19c-40df-b821-
> >> bbba80f19a3d@xxxxxxxxxx/
> >> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> >> ---
> >>
> >> scripts/mod/modpost.c | 17 +++++++++--------
> >> scripts/mod/modpost.h | 3 ++-
> >> 2 files changed, 11 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> >> index fb787a5715f5..94ee49207a45 100644
> >> --- a/scripts/mod/modpost.c
> >> +++ b/scripts/mod/modpost.c
> >> @@ -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)
> >> diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
> >> index 49848fcbe2a1..8b72c227ebf4 100644
> >> --- a/scripts/mod/modpost.h
> >> +++ b/scripts/mod/modpost.h
> >> @@ -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;
> >
> >
> > Thanks for fixing!
> >
> > Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
>
>
> I have not seen this land in -next yet. Would be great to get this applied.
>
Now applied to linux-kbuild/fixes.
--
Best Regards
Masahiro Yamada
