[PATCH 2/4] KBUILD: export-type enhancement to modpost.c

[linuxram@us.ibm.com (Ram Pai)]

From: Ram Pai <linuxram@us.ibm.com>

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

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>

 scripts/mod/modpost.c |   59 ++++++++++++++++++++++++++++++++++++--------------
 1 files changed, 43 insertions(+), 16 deletions(-)

Index: linux-2.6.17-rc3/scripts/mod/modpost.c
===================================================================
--- linux-2.6.17-rc3.orig/scripts/mod/modpost.c
+++ linux-2.6.17-rc3/scripts/mod/modpost.c
@@ -18,6 +18,10 @@
 int modversions = 0;
 /* Warn about undefined symbols? (do so if we have vmlinux) */
 int have_vmlinux = 0;
+
+/* elf section number for gpl symbols */
+int ksymtab_gpl;
+
 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
 static int all_versions = 0;
 /* If we are modposting external module set to 1 */
@@ -118,6 +122,7 @@ 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 */
+	int export_type;
 	char name[0];
 };
 
@@ -153,7 +158,8 @@ static struct symbol *alloc_symbol(const
 }
 
 /* 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,
+					int export_type)
 {
 	unsigned int hash;
 	struct symbol *new;
@@ -161,6 +167,7 @@ static struct symbol *new_symbol(const c
 	hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
 	new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
 	new->module = module;
+	new->export_type = export_type;
 	return new;
 }
 
@@ -183,12 +190,13 @@ static struct symbol *find_symbol(const 
  * 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,
+				int export_type)
 {
 	struct symbol *s = find_symbol(name);
 
 	if (!s) {
-		s = new_symbol(name, mod);
+		s = new_symbol(name, mod, export_type);
 	} else {
 		if (!s->preloaded) {
 			warn("%s: '%s' exported twice. Previous export "
@@ -204,12 +212,12 @@ static struct symbol *sym_add_exported(c
 }
 
 static void sym_update_crc(const char *name, struct module *mod,
-			   unsigned int crc)
+			   unsigned int crc, int export_type)
 {
 	struct symbol *s = find_symbol(name);
 
 	if (!s)
-		s = new_symbol(name, mod);
+		s = new_symbol(name, mod, export_type);
 	s->crc = crc;
 	s->crc_valid = 1;
 }
@@ -305,17 +313,23 @@ static void parse_elf(struct elf_info *i
 		sechdrs[i].sh_link   = TO_NATIVE(sechdrs[i].sh_link);
 		sechdrs[i].sh_name   = TO_NATIVE(sechdrs[i].sh_name);
 	}
+
+	ksymtab_gpl = -1;
 	/* Find symbol table. */
 	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_gpl") == 0)
+			ksymtab_gpl = i;
+
 		if (sechdrs[i].sh_type != SHT_SYMTAB)
 			continue;
 
@@ -353,6 +367,7 @@ static void handle_modversions(struct mo
 			       Elf_Sym *sym, const char *symname)
 {
 	unsigned int crc;
+	unsigned int export_type = (sym->st_shndx == ksymtab_gpl);
 
 	switch (sym->st_shndx) {
 	case SHN_COMMON:
@@ -362,7 +377,8 @@ static void handle_modversions(struct mo
 		/* 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_type);
 		}
 		break;
 	case SHN_UNDEF:
@@ -406,7 +422,8 @@ static void handle_modversions(struct mo
 	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_type);
 		}
 		if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 			mod->has_init = 1;
@@ -1103,10 +1120,11 @@ static void read_dump(const char *fname,
 		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;
+		unsigned int export_type = 0;
 
 		if (!(symname = strchr(line, '\t')))
 			goto fail;
@@ -1114,10 +1132,21 @@ static void read_dump(const char *fname,
 		if (!(modname = strchr(symname, '\t')))
 			goto fail;
 		*modname++ = '\0';
-		if (strchr(modname, '\t'))
+		if (!(export = strchr(modname, '\t')))
+			goto fail;
+		*export++ = '\0';
+		if (strchr(export, '\t'))
 			goto fail;
 		crc = strtoul(line, &d, 16);
-		if (*symname == '\0' || *modname == '\0' || *d != '\0')
+		if (*symname == '\0' || *modname == '\0' || *export == '\0' ||
+					*d != '\0')
+			goto fail;
+
+		if ((strcmp(export, "EXPORT_SYMBOL_GPL")))
+			export_type = 1;
+		else if(strcmp(export, "EXPORT_SYMBOL") == 0)
+			export_type = 0;
+		else
 			goto fail;
 
 		if (!(mod = find_module(modname))) {
@@ -1127,10 +1156,10 @@ static void read_dump(const char *fname,
 			mod = new_module(NOFAIL(strdup(modname)));
 			mod->skip = 1;
 		}
-		s = sym_add_exported(symname, mod);
+		s = sym_add_exported(symname, mod, export_type);
 		s->kernel    = kernel;
 		s->preloaded = 1;
-		sym_update_crc(symname, mod, crc);
+		sym_update_crc(symname, mod, crc, export_type);
 	}
 	return;
 fail:
@@ -1160,9 +1189,11 @@ 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,
+					(symbol->export_type?
+					"EXPORT_SYMBOL_GPL" : "EXPORT_SYMBOL"));
 			symbol = symbol->next;
 		}
 	}