Instead of only accepting "MODULE_${name}", extend it with a comma
separated list of module names and add tail glob support.
That is, something like: "MODULE_foo-*,bar" is now possible.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/module/main.c | 39 ++++++++++++++++++++++++++++++++++-----
scripts/mod/modpost.c | 40 ++++++++++++++++++++++++++++++++++------
2 files changed, 68 insertions(+), 11 deletions(-)
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1061,6 +1061,38 @@ static char *get_modinfo(const struct lo
return get_next_modinfo(info, tag, NULL);
}
+/*
+ * @namespace ~= "MODULE_foo-*,bar", match @modname to 'foo-*' or 'bar'
+ */
+static bool verify_module_namespace(const char *namespace, const char *modname)
+{
+ size_t len, modlen = strlen(modname);
+ const char *sep;
+ bool glob;
+
+ if (strncmp(namespace, "MODULE_", 7) != 0)
+ return false;
+
+ for (namespace += 7; *namespace; namespace = sep) {
+ sep = strchrnul(namespace, ',');
+ len = sep - namespace;
+
+ glob = false;
+ if (sep[-1] == '*') {
+ len--;
+ glob = true;
+ }
+
+ if (*sep)
+ sep++;
+
+ if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+ return true;
+ }
+
+ return false;
+}
+
static int verify_namespace_is_imported(const struct load_info *info,
const struct kernel_symbol *sym,
struct module *mod)
@@ -1070,11 +1102,8 @@ static int verify_namespace_is_imported(
namespace = kernel_symbol_namespace(sym);
if (namespace && namespace[0]) {
- /*
- * Implicitly import MODULE_${mod->name} namespace.
- */
- if (strncmp(namespace, "MODULE_", 7) == 0 &&
- strcmp(namespace+7, mod->name) == 0)
+
+ if (verify_module_namespace(namespace, mod->name))
return 0;
for_each_modinfo_entry(imported_namespace, info, "import_ns") {
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1565,7 +1565,6 @@ static const char *mod_basename(const ch
static void read_symbols(const char *modname)
{
- char module_namespace[MODULE_NAME_LEN + 8];
const char *symname;
char *version;
char *license;
@@ -1601,10 +1600,6 @@ static void read_symbols(const char *mod
namespace = get_next_modinfo(&info, "import_ns", namespace))
add_namespace(&mod->imported_namespaces, namespace);
- snprintf(module_namespace, sizeof(module_namespace), "MODULE_%s",
- mod_basename(mod->name));
- add_namespace(&mod->imported_namespaces, module_namespace);
-
if (extra_warn && !get_modinfo(&info, "description"))
warn("missing MODULE_DESCRIPTION() in %s\n", modname);
}
@@ -1687,6 +1682,38 @@ void buf_write(struct buffer *buf, const
buf->pos += len;
}
+/*
+ * @namespace ~= "MODULE_foo-*,bar", match @modname to 'foo-*' or 'bar'
+ */
+static bool module_namespace(const char *namespace, const char *modname)
+{
+ size_t len, modlen = strlen(modname);
+ const char *sep;
+ bool glob;
+
+ if (strncmp(namespace, "MODULE_", 7) != 0)
+ return false;
+
+ for (namespace += 7; *namespace; namespace = sep) {
+ sep = strchrnul(namespace, ',');
+ len = sep - namespace;
+
+ glob = false;
+ if (sep[-1] == '*') {
+ len--;
+ glob = true;
+ }
+
+ if (*sep)
+ sep++;
+
+ if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+ return true;
+ }
+
+ return false;
+}
+
static void check_exports(struct module *mod)
{
struct symbol *s, *exp;
@@ -1714,7 +1741,8 @@ static void check_exports(struct module
basename = mod_basename(mod->name);
- if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
+ if (!module_namespace(exp->namespace, basename) &&
+ !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
modpost_log(!allow_missing_ns_imports,
"module %s uses symbol %s from namespace %s, but does not import it.\n",
basename, exp->name, exp->namespace);On Tue, Dec 3, 2024 at 12:11 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> Instead of only accepting "MODULE_${name}", extend it with a comma
> separated list of module names and add tail glob support.
>
> That is, something like: "MODULE_foo-*,bar" is now possible.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> kernel/module/main.c | 39 ++++++++++++++++++++++++++++++++++-----
> scripts/mod/modpost.c | 40 ++++++++++++++++++++++++++++++++++------
> 2 files changed, 68 insertions(+), 11 deletions(-)
>
> static void check_exports(struct module *mod)
> {
> struct symbol *s, *exp;
> @@ -1714,7 +1741,8 @@ static void check_exports(struct module
>
> basename = mod_basename(mod->name);
>
> - if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
> + if (!module_namespace(exp->namespace, basename) &&
> + !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
> modpost_log(!allow_missing_ns_imports,
> "module %s uses symbol %s from namespace %s, but does not import it.\n",
> basename, exp->name, exp->namespace);
>
When module_namespace() fails, the following error message is shown:
ERROR: modpost: module bar uses symbol foo from namespace
MODULE_kvm, but does not import it.
We get a hint from this error message, but the solution
is not MODULE_IMPORT_NS();
'make nsdeps' will try to solve this by adding
MODULE_IMPORT_NS("MODULE_kvm");
Apparently, this does not work.
Not sure if you want to solve the issue.
--
Best Regards
Masahiro Yamada
On Sat, Feb 08, 2025 at 12:45:21AM +0900, Masahiro Yamada wrote:
> On Tue, Dec 3, 2024 at 12:11 AM Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > Instead of only accepting "MODULE_${name}", extend it with a comma
> > separated list of module names and add tail glob support.
> >
> > That is, something like: "MODULE_foo-*,bar" is now possible.
> >
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > ---
> > kernel/module/main.c | 39 ++++++++++++++++++++++++++++++++++-----
> > scripts/mod/modpost.c | 40 ++++++++++++++++++++++++++++++++++------
> > 2 files changed, 68 insertions(+), 11 deletions(-)
> >
>
> > static void check_exports(struct module *mod)
> > {
> > struct symbol *s, *exp;
> > @@ -1714,7 +1741,8 @@ static void check_exports(struct module
> >
> > basename = mod_basename(mod->name);
> >
> > - if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
> > + if (!module_namespace(exp->namespace, basename) &&
> > + !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
> > modpost_log(!allow_missing_ns_imports,
> > "module %s uses symbol %s from namespace %s, but does not import it.\n",
> > basename, exp->name, exp->namespace);
> >
>
> When module_namespace() fails, the following error message is shown:
>
> ERROR: modpost: module bar uses symbol foo from namespace
> MODULE_kvm, but does not import it.
>
>
> We get a hint from this error message, but the solution
> is not MODULE_IMPORT_NS();
>
> 'make nsdeps' will try to solve this by adding
>
> MODULE_IMPORT_NS("MODULE_kvm");
>
> Apparently, this does not work.
>
> Not sure if you want to solve the issue.
Seems unsolvable by construction; so no.
On Tue, Dec 3, 2024 at 12:11 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> Instead of only accepting "MODULE_${name}", extend it with a comma
> separated list of module names and add tail glob support.
>
> That is, something like: "MODULE_foo-*,bar" is now possible.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> kernel/module/main.c | 39 ++++++++++++++++++++++++++++++++++-----
> scripts/mod/modpost.c | 40 ++++++++++++++++++++++++++++++++++------
> 2 files changed, 68 insertions(+), 11 deletions(-)
>
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -1061,6 +1061,38 @@ static char *get_modinfo(const struct lo
> return get_next_modinfo(info, tag, NULL);
> }
>
> +/*
> + * @namespace ~= "MODULE_foo-*,bar", match @modname to 'foo-*' or 'bar'
Please add a proper kdoc style comment block.
Rather than an underscore, I prefer a colon, which rarely appears in file names.
How about "module:foo-*,bar" instead of "MODULE_foo-*,bar" ?
> + */
> +static bool verify_module_namespace(const char *namespace, const char *modname)
> +{
> + size_t len, modlen = strlen(modname);
> + const char *sep;
> + bool glob;
> +
> + if (strncmp(namespace, "MODULE_", 7) != 0)
> + return false;
> +
> + for (namespace += 7; *namespace; namespace = sep) {
> + sep = strchrnul(namespace, ',');
> + len = sep - namespace;
> +
> + glob = false;
> + if (sep[-1] == '*') {
> + len--;
> + glob = true;
> + }
Why only limited to the trailing wildcard?
Did you consider using glob_match()?
> +
> + if (*sep)
> + sep++;
> +
> + if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
> + return true;
> + }
> +
> + return false;
> +}
> +
> static int verify_namespace_is_imported(const struct load_info *info,
> const struct kernel_symbol *sym,
> struct module *mod)
> @@ -1070,11 +1102,8 @@ static int verify_namespace_is_imported(
>
> namespace = kernel_symbol_namespace(sym);
> if (namespace && namespace[0]) {
> - /*
> - * Implicitly import MODULE_${mod->name} namespace.
> - */
> - if (strncmp(namespace, "MODULE_", 7) == 0 &&
> - strcmp(namespace+7, mod->name) == 0)
> +
> + if (verify_module_namespace(namespace, mod->name))
> return 0;
>
> for_each_modinfo_entry(imported_namespace, info, "import_ns") {
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -1565,7 +1565,6 @@ static const char *mod_basename(const ch
>
> static void read_symbols(const char *modname)
> {
> - char module_namespace[MODULE_NAME_LEN + 8];
> const char *symname;
> char *version;
> char *license;
> @@ -1601,10 +1600,6 @@ static void read_symbols(const char *mod
> namespace = get_next_modinfo(&info, "import_ns", namespace))
> add_namespace(&mod->imported_namespaces, namespace);
>
> - snprintf(module_namespace, sizeof(module_namespace), "MODULE_%s",
> - mod_basename(mod->name));
> - add_namespace(&mod->imported_namespaces, module_namespace);
> -
> if (extra_warn && !get_modinfo(&info, "description"))
> warn("missing MODULE_DESCRIPTION() in %s\n", modname);
> }
> @@ -1687,6 +1682,38 @@ void buf_write(struct buffer *buf, const
> buf->pos += len;
> }
>
> +/*
> + * @namespace ~= "MODULE_foo-*,bar", match @modname to 'foo-*' or 'bar'
Same comment as in kernel/module/main.c
> + */
> +static bool module_namespace(const char *namespace, const char *modname)
> +{
> + size_t len, modlen = strlen(modname);
> + const char *sep;
> + bool glob;
> +
> + if (strncmp(namespace, "MODULE_", 7) != 0)
> + return false;
If you see the existing code closely, strstarts() helper is used everywhere.
I would write like this:
static const char *prefix = "module:";
if (!strstarts(namespace, prefix))
return false;
> +
> + for (namespace += 7; *namespace; namespace = sep) {
I tend to avoid the magic number, 7.
Just like this:
https://github.com/torvalds/linux/blob/v6.14-rc1/scripts/mod/file2alias.c#L1494
> + sep = strchrnul(namespace, ',');
> + len = sep - namespace;
> +
> + glob = false;
> + if (sep[-1] == '*') {
> + len--;
> + glob = true;
> + }
> +
> + if (*sep)
> + sep++;
> +
> + if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
> + return true;
> + }
Same as kernel/module/main.c.
If you see around line 700 in this file,
you will find fnmatch() is already used for glob matching.
> +
> + return false;
> +}
> +
> static void check_exports(struct module *mod)
> {
> struct symbol *s, *exp;
> @@ -1714,7 +1741,8 @@ static void check_exports(struct module
>
> basename = mod_basename(mod->name);
>
> - if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
> + if (!module_namespace(exp->namespace, basename) &&
> + !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
> modpost_log(!allow_missing_ns_imports,
> "module %s uses symbol %s from namespace %s, but does not import it.\n",
> basename, exp->name, exp->namespace);
>
>
--
Best Regards
Masahiro Yamada
On Fri, Feb 07, 2025 at 05:41:54PM +0900, Masahiro Yamada wrote:
> > +static bool verify_module_namespace(const char *namespace, const char *modname)
> > +{
> > + size_t len, modlen = strlen(modname);
> > + const char *sep;
> > + bool glob;
> > +
> > + if (strncmp(namespace, "MODULE_", 7) != 0)
> > + return false;
> > +
> > + for (namespace += 7; *namespace; namespace = sep) {
> > + sep = strchrnul(namespace, ',');
> > + len = sep - namespace;
> > +
> > + glob = false;
> > + if (sep[-1] == '*') {
> > + len--;
> > + glob = true;
> > + }
>
>
> Why only limited to the trailing wildcard?
Because its simple and easy.
> Did you consider using glob_match()?
I had not, because I didn't know we had that in-kernel. Looking at that,
using it is a bit of a pain, since it needs the pattern as a C string,
which means I need to strdup() the thing because I can't modify the
original.
That in turn means we need to deal with malloc failure.
Is that all worth it?
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