Messages in this thread | | | From | Masahiro Yamada <> | Date | Wed, 19 Feb 2020 04:27:09 +0900 | Subject | Re: [PATCH] modpost: return error if module is missing ns imports and MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=n |
| |
On Wed, Feb 19, 2020 at 1:06 AM Jessica Yu <jeyu@kernel.org> wrote: > > +++ Matthias Maennich [17/02/20 14:56 +0000]: > >Hi Jessica! > > > >On Fri, Feb 14, 2020 at 03:37:09PM +0100, Jessica Yu wrote: > >>Currently when CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=n, modpost only warns > >>when a module is missing namespace imports. Under this configuration, such a module > >>cannot be loaded into the kernel anyway, as the module loader would reject it. > >>We might as well return a build error when a module is missing namespace imports > >>under CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=n, so that the build > >>warning does not go ignored/unnoticed. > > > >I generally agree with the idea of the patch. Thanks for working on > >this! I also can't remember any reason why I did not write it like this > >initially. Probably just because I introduced this configuration option > >quite late in the development process of the initial patches. > > > >> > >>Signed-off-by: Jessica Yu <jeyu@kernel.org> > >>--- > >>scripts/Makefile.modpost | 1 + > >>scripts/mod/modpost.c | 19 +++++++++++++++---- > >>2 files changed, 16 insertions(+), 4 deletions(-) > >> > >>diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost > >>index b4d3f2d122ac..a53660f910a9 100644 > >>--- a/scripts/Makefile.modpost > >>+++ b/scripts/Makefile.modpost > >>@@ -53,6 +53,7 @@ MODPOST = scripts/mod/modpost \ > >> $(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \ > >> $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ > >> $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ > >>+ $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS),,-N) \ > >> $(if $(KBUILD_MODPOST_WARN),-w) > >> > >>ifdef MODPOST_VMLINUX > >>diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > >>index 7edfdb2f4497..53e966f7d557 100644 > >>--- a/scripts/mod/modpost.c > >>+++ b/scripts/mod/modpost.c > >>@@ -39,6 +39,8 @@ static int sec_mismatch_count = 0; > >>static int sec_mismatch_fatal = 0; > >>/* ignore missing files */ > >>static int ignore_missing_files; > >>+/* Return an error when there are missing namespace imports */ > >>+static int missing_ns_import_error = 0; > > > >A more suitable name is maybe missing_ns_import_is_error or follow the > >naming of the config option: allow_missing_ns_imports (with default = 1). > > > >> > >>enum export { > >> export_plain, export_unused, export_gpl, > >>@@ -2216,9 +2218,15 @@ static int check_exports(struct module *mod) > >> > >> if (exp->namespace && > >> !module_imports_namespace(mod, exp->namespace)) { > >>- warn("module %s uses symbol %s from namespace %s, but does not import it.\n", > >>- basename, exp->name, exp->namespace); > >>- add_namespace(&mod->missing_namespaces, exp->namespace); > >>+ if (missing_ns_import_error) { > >>+ merror("module %s uses symbol %s from namespace %s, but does not import it.\n", > >>+ basename, exp->name, exp->namespace); > > > >I would like to avoid the code duplication here. The string literal is > >identical for both cases. > > Hm, but one is a call to merror() and the other to warn(). The > previous if (warn_unresolved) block does the same thing. I am not sure > how to simplify it to one call without introducing macro magic or > overcomplicating things. Or were you thinking of something else?
I would not say this is a horrible duplication, but if you avoid repeating the same string, maybe you could do like this:
PRINTF log(enum loglevel loglevel, const char *fmt, ...)
BTW, you accidentally changed the indentation of add_namespace(&mod->missing_namespaces, exp->namespace);
> >>+ err = 1; > > > >Also, if we fail here, we might as well help the user to fix it by > >suggesting to run `make nsdeps` (once per failed modpost run). Speaking > >of which, `make nsdeps` is currently broken by this patch as it relies > >on a successful (yet warning-full) build of the modules. So, in case of > >`make nsdeps`, we probably have to omit the -N flag again when invoking > >modpost. > > Good catch! Since KBUILD_NSDEPS is set when running `make nsdeps`, > maybe we can do something like: > > diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost > index a53660f910a9..145703ef8d3a 100644 > --- a/scripts/Makefile.modpost > +++ b/scripts/Makefile.modpost > @@ -53,7 +53,7 @@ MODPOST = scripts/mod/modpost \ > $(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \ > $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ > $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ > - $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS),,-N) \ > + $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS),,$(if $(KBUILD_NSDEPS),,-N)) \
If you follow Matthias' suggestion "follow the naming of the config option: allow_missing_ns_imports (with default = 1)." the option is inverted, and you can write it more simply:
$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-n) \
-- Best Regards Masahiro Yamada
| |