Changes in v4:
  - Rebase again because I dropped
     https://patchwork.kernel.org/project/linux-kbuild/patch/20220501084032.1025918-11-masahiroy@kernel.org/
  - Remove warning message because I plan to change this hunk again in a later commit
  - Remove orphan comment

Changes in v3:
  - New patch

 scripts/mod/modpost.c | 108 ++++++++++++------------------------------
 1 file changed, 30 insertions(+), 78 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index d9efbd5b31a6..a78b75f0eeb0 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c

@@ -30,7 +30,7 @@ static bool all_versions;
 static bool external_module;
 /* Only warn about unresolved symbols */
 static bool warn_unresolved;
-/* How a symbol is exported */
+
 static int sec_mismatch_count;
 static bool sec_mismatch_warn_only = true;
 /* ignore missing files */

@@ -47,12 +47,6 @@ static bool error_occurred;
 #define MAX_UNRESOLVED_REPORTS 10
 static unsigned int nr_unresolved;

-enum export {
-       export_plain,
-       export_gpl,
-       export_unknown
-};
-
 /* In kernel, this size is defined in linux/module.h;
  * here we use Elf_Addr instead of long for covering cross-compile
  */

@@ -219,7 +213,7 @@ struct symbol {
        bool crc_valid;
        bool weak;
        bool is_static;         /* true if symbol is not global */
-       enum export  export;       /* Type of export */
+       bool is_gpl_only;       /* exported by EXPORT_SYMBOL_GPL */
        char name[];
 };

@@ -316,34 +310,6 @@ static void add_namespace(struct list_head *head, const char *namespace)
        }
 }

-static const struct {
-       const char *str;
-       enum export export;
-} export_list[] = {
-       { .str = "EXPORT_SYMBOL",            .export = export_plain },
-       { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
-       { .str = "(unknown)",                .export = export_unknown },
-};
-
-
-static const char *export_str(enum export ex)
-{
-       return export_list[ex].str;
-}
-
-static enum export export_no(const char *s)
-{
-       int i;
-
-       if (!s)
-               return export_unknown;
-       for (i = 0; export_list[i].export != export_unknown; i++) {
-               if (strcmp(export_list[i].str, s) == 0)
-                       return export_list[i].export;
-       }
-       return export_unknown;
-}
-
 static void *sym_get_data_by_offset(const struct elf_info *info,
                                    unsigned int secindex, unsigned long offset)
 {

@@ -374,18 +340,6 @@ static const char *sec_name(const struct elf_info *info, int secindex)

 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)

-static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
-{
-       const char *secname = sec_name(elf, sec);
-
-       if (strstarts(secname, "___ksymtab+"))
-               return export_plain;
-       else if (strstarts(secname, "___ksymtab_gpl+"))
-               return export_gpl;
-       else
-               return export_unknown;
-}
-
 static void sym_update_namespace(const char *symname, const char *namespace)
 {
        struct symbol *s = find_symbol(symname);

@@ -405,7 +359,7 @@ static void sym_update_namespace(const char *symname, const char *namespace)
 }

 static struct symbol *sym_add_exported(const char *name, struct module *mod,
-                                      enum export export)
+                                      bool gpl_only)
 {
        struct symbol *s = find_symbol(name);

@@ -417,7 +371,7 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod,

        s = alloc_symbol(name);
        s->module = mod;
-       s->export    = export;
+       s->is_gpl_only = gpl_only;
        list_add_tail(&s->list, &mod->exported_symbols);
        hash_add_symbol(s);

@@ -689,8 +643,6 @@ static void handle_modversion(const struct module *mod,
 static void handle_symbol(struct module *mod, struct elf_info *info,
                          const Elf_Sym *sym, const char *symname)
 {
-       const char *name;
-
        switch (sym->st_shndx) {
        case SHN_COMMON:
                if (strstarts(symname, "__gnu_lto_")) {

@@ -724,12 +676,15 @@ static void handle_symbol(struct module *mod, struct elf_info *info,
        default:
                /* All exported symbols */
                if (strstarts(symname, "__ksymtab_")) {
-                       enum export export;
+                       const char *name, *secname;

                        name = symname + strlen("__ksymtab_");
-                       export = export_from_secname(info,
-                                                    get_secindex(info, sym));
-                       sym_add_exported(name, mod, export);
+                       secname = sec_name(info, get_secindex(info, sym));
+
+                       if (strstarts(secname, "___ksymtab_gpl+"))
+                               sym_add_exported(name, mod, true);
+                       else if (strstarts(secname, "___ksymtab+"))
+                               sym_add_exported(name, mod, false);
                }
                if (strcmp(symname, "init_module") == 0)
                        mod->has_init = true;

@@ -2140,20 +2095,6 @@ void buf_write(struct buffer *buf, const char *s, int len)
        buf->pos += len;
 }

-static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
-{
-       switch (exp) {
-       case export_gpl:
-               error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
-                     m, s);
-               break;
-       case export_plain:
-       case export_unknown:
-               /* ignore */
-               break;
-       }
-}
-
 static void check_exports(struct module *mod)
 {
        struct symbol *s, *exp;

@@ -2192,8 +2133,9 @@ static void check_exports(struct module *mod)
                        add_namespace(&mod->missing_namespaces, exp->namespace);
                }

-               if (!mod->is_gpl_compatible)
-                       check_for_gpl_usage(exp->export, basename, exp->name);
+               if (!mod->is_gpl_compatible && exp->is_gpl_only)
+                       error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
+                             basename, exp->name);
        }
 }

@@ -2437,6 +2379,7 @@ static void read_dump(const char *fname)
                unsigned int crc;
                struct module *mod;
                struct symbol *s;
+               bool gpl_only;

                if (!(symname = strchr(line, '\t')))
                        goto fail;

@@ -2454,12 +2397,22 @@ static void read_dump(const char *fname)
                crc = strtoul(line, &d, 16);
                if (*symname == '\0' || *modname == '\0' || *d != '\0')
                        goto fail;
+
+               if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
+                       gpl_only = true;
+               } else if (!strcmp(export, "EXPORT_SYMBOL")) {
+                       gpl_only = false;
+               } else {
+                       error("%s: unknown license %s. skip", symname, export);
+                       continue;
+               }
+
                mod = find_module(modname);
                if (!mod) {
                        mod = new_module(modname);
                        mod->from_dump = true;
                }
-               s = sym_add_exported(symname, mod, export_no(export));
+               s = sym_add_exported(symname, mod, gpl_only);
                s->is_static = false;
                sym_set_crc(symname, crc);
                sym_update_namespace(symname, namespace);

@@ -2481,9 +2434,9 @@ static void write_dump(const char *fname)
                if (mod->from_dump)
                        continue;
                list_for_each_entry(sym, &mod->exported_symbols, list) {
-                       buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n",
+                       buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
                                   sym->crc, sym->name, mod->name,
-                                  export_str(sym->export),
+                                  sym->is_gpl_only ? "_GPL" : "",
                                   sym->namespace ?: "");
                }
        }

@@ -2604,9 +2557,8 @@ int main(int argc, char **argv)

                for (s = symbolhash[n]; s; s = s->next) {
                        if (s->is_static)
-                               error("\"%s\" [%s] is a static %s\n",
-                                     s->name, s->module->name,
-                                     export_str(s->export));
+                               error("\"%s\" [%s] is a static EXPORT_SYMBOL\n",
+                                     s->name, s->module->name);
                }
        }

--

2.32.0

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