kbuild: export-type enhancement to modpost.c

This patch provides the ability to identify the export-type of each
exported symbols in Module.symvers.

NOTE: It updates the Module.symvers file with the additional
information as shown below.

0x0f8b92af      platform_device_add_resources   vmlinux EXPORT_SYMBOL_GPL
0xcf7efb2a      ethtool_op_set_tx_csum          vmlinux EXPORT_SYMBOL

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Avantika Mathur <mathur@us.ibm.com>
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

2 files changed, 80 insertions, 16 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index a70f5ddb705c..ba2e4fc2af20 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -22,6 +22,8 @@ int have_vmlinux = 0;
 static int all_versions = 0;
 /* If we are modposting external module set to 1 */
 static int external_module = 0;
+/* How a symbol is exported */
+enum export {export_plain, export_gpl, export_gpl_future, export_unknown};
 
 void fatal(const char *fmt, ...)
 {
@@ -118,6 +120,7 @@ struct symbol {
         unsigned int kernel:1;     /* 1 if symbol is from kernel
                                     *  (only for external modules) **/
         unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
+        enum export  export;       /* Type of export */
         char name[0];
 };
 
@@ -153,7 +156,8 @@ static struct symbol *alloc_symbol(const char *name, unsigned int weak,
 }
 
 /* For the hash of exported symbols */
-static struct symbol *new_symbol(const char *name, struct module *module)
+static struct symbol *new_symbol(const char *name, struct module *module,
+                                 enum export export)
 {
         unsigned int hash;
         struct symbol *new;
@@ -161,6 +165,7 @@ static struct symbol *new_symbol(const char *name, struct module *module)
         hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
         new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
         new->module = module;
+        new->export = export;
         return new;
 }
 
@@ -179,16 +184,55 @@ static struct symbol *find_symbol(const char *name)
         return NULL;
 }
 
+static struct {
+        const char *str;
+        enum export export;
+} export_list[] = {
+        { .str = "EXPORT_SYMBOL",            .export = export_plain },
+        { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
+        { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
+        { .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;
+        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 enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
+{
+        if (sec == elf->export_sec)
+                return export_plain;
+        else if (sec == elf->export_gpl_sec)
+                return export_gpl;
+        else if (sec == elf->export_gpl_future_sec)
+                return export_gpl_future;
+        else
+                return export_unknown;
+}
+
 /**
  * Add an exported symbol - it may have already been added without a
  * CRC, in this case just update the CRC
  **/
-static struct symbol *sym_add_exported(const char *name, struct module *mod)
+static struct symbol *sym_add_exported(const char *name, struct module *mod,
+                                       enum export export)
 {
         struct symbol *s = find_symbol(name);
 
         if (!s) {
-                s = new_symbol(name, mod);
+                s = new_symbol(name, mod, export);
         } else {
                 if (!s->preloaded) {
                         warn("%s: '%s' exported twice. Previous export "
@@ -200,16 +244,17 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod)
         s->preloaded = 0;
         s->vmlinux   = is_vmlinux(mod->name);
         s->kernel    = 0;
+        s->export    = export;
         return s;
 }
 
 static void sym_update_crc(const char *name, struct module *mod,
-                           unsigned int crc)
+                           unsigned int crc, enum export export)
 {
         struct symbol *s = find_symbol(name);
 
         if (!s)
-                s = new_symbol(name, mod);
+                s = new_symbol(name, mod, export);
         s->crc = crc;
         s->crc_valid = 1;
 }
@@ -309,13 +354,21 @@ static void parse_elf(struct elf_info *info, const char *filename)
         for (i = 1; i < hdr->e_shnum; i++) {
                 const char *secstrings
                         = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+                const char *secname;
 
                 if (sechdrs[i].sh_offset > info->size)
                         goto truncated;
-                if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) {
+                secname = secstrings + sechdrs[i].sh_name;
+                if (strcmp(secname, ".modinfo") == 0) {
                         info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
                         info->modinfo_len = sechdrs[i].sh_size;
-                }
+                } else if (strcmp(secname, "__ksymtab") == 0)
+                        info->export_sec = i;
+                else if (strcmp(secname, "__ksymtab_gpl") == 0)
+                        info->export_gpl_sec = i;
+                else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
+                        info->export_gpl_future_sec = i;
+
                 if (sechdrs[i].sh_type != SHT_SYMTAB)
                         continue;
 
@@ -353,6 +406,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
                                Elf_Sym *sym, const char *symname)
 {
         unsigned int crc;
+        enum export export = export_from_sec(info, sym->st_shndx);
 
         switch (sym->st_shndx) {
         case SHN_COMMON:
@@ -362,7 +416,8 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
                 /* CRC'd symbol */
                 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
                         crc = (unsigned int) sym->st_value;
-                        sym_update_crc(symname + strlen(CRC_PFX), mod, crc);
+                        sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
+                                        export);
                 }
                 break;
         case SHN_UNDEF:
@@ -406,7 +461,8 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
         default:
                 /* All exported symbols */
                 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
-                        sym_add_exported(symname + strlen(KSYMTAB_PFX), mod);
+                        sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
+                                        export);
                 }
                 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
                         mod->has_init = 1;
@@ -1146,6 +1202,9 @@ static void write_if_changed(struct buffer *b, const char *fname)
         fclose(file);
 }
 
+/* parse Module.symvers file. line format:
+ * 0x12345678<tab>symbol<tab>module[<tab>export]
+ **/
 static void read_dump(const char *fname, unsigned int kernel)
 {
         unsigned long size, pos = 0;
@@ -1157,7 +1216,7 @@ static void read_dump(const char *fname, unsigned int kernel)
                 return;
 
         while ((line = get_next_line(&pos, file, size))) {
-                char *symname, *modname, *d;
+                char *symname, *modname, *d, *export;
                 unsigned int crc;
                 struct module *mod;
                 struct symbol *s;
@@ -1168,8 +1227,9 @@ static void read_dump(const char *fname, unsigned int kernel)
                 if (!(modname = strchr(symname, '\t')))
                         goto fail;
                 *modname++ = '\0';
-                if (strchr(modname, '\t'))
-                        goto fail;
+                if (!(export = strchr(modname, '\t')))
+                        *export++ = '\0';
+
                 crc = strtoul(line, &d, 16);
                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
                         goto fail;
@@ -1181,10 +1241,10 @@ static void read_dump(const char *fname, unsigned int kernel)
                         mod = new_module(NOFAIL(strdup(modname)));
                         mod->skip = 1;
                 }
-                s = sym_add_exported(symname, mod);
+                s = sym_add_exported(symname, mod, export_no(export));
                 s->kernel    = kernel;
                 s->preloaded = 1;
-                sym_update_crc(symname, mod, crc);
+                sym_update_crc(symname, mod, crc, export_no(export));
         }
         return;
 fail:
@@ -1214,9 +1274,10 @@ static void write_dump(const char *fname)
                 symbol = symbolhash[n];
                 while (symbol) {
                         if (dump_sym(symbol))
-                                buf_printf(&buf, "0x%08x\t%s\t%s\n",
+                                buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
                                         symbol->crc, symbol->name,
-                                        symbol->module->name);
+                                        symbol->module->name,
+                                        export_str(symbol->export));
                         symbol = symbol->next;
                 }
         }
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 861d866fcd83..f7ee3a3fde14 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -115,6 +115,9 @@ struct elf_info {
         Elf_Shdr     *sechdrs;
         Elf_Sym      *symtab_start;
         Elf_Sym      *symtab_stop;
+        Elf_Section  export_sec;
+        Elf_Section  export_gpl_sec;
+        Elf_Section  export_gpl_future_sec;
         const char   *strtab;
         char         *modinfo;
         unsigned int modinfo_len;