Messages in this thread Patch in this message | | | Date | Tue, 18 Feb 2020 17:05:54 +0100 | From | Jessica Yu <> | Subject | Re: [PATCH] modpost: return error if module is missing ns imports and MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=n |
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+++ 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?
>>+ 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 $(KBUILD_MODPOST_WARN),-w)
ifdef MODPOST_VMLINUX Thanks for the review!
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