depmod: separate symbol lookup and dependency calculation

The new load_dep_syms() operation in moduleops returns a string table of
symbols on which a module depends. calculate_deps() is moved to depmod.

Remaining depmod callbacks in moduleops are removed.

Signed-off-by: Andreas Robinson <andr345@gmail.com>

4 files changed, 48 insertions, 21 deletions

diff --git a/depmod.c b/depmod.c
index da4ff44..a42fed5 100644
--- a/depmod.c
+++ b/depmod.c
@@ -667,6 +667,40 @@ static struct module *sort_modules(const char *dirname, struct module *list)
 	return tlist;
 }
 
+/* Calculate the dependencies for this module */
+static void calculate_deps(struct module *module)
+{
+	unsigned int i;
+	struct string_table *symnames;
+	struct string_table *symtypes;
+
+	module->num_deps = 0;
+	module->deps = NULL;
+
+	symnames = module->ops->load_dep_syms(module, &symtypes);
+	if (!symnames || !symtypes)
+		return;
+
+	for (i = 0; i < symnames->cnt; i++) {
+		const char *name;
+		struct module *owner;
+		int weak;
+
+		name = symnames->str[i];
+		weak = (*(symtypes->str[i]) == 'W');
+		owner = find_symbol(name, module->pathname, weak);
+		if (owner) {
+			info("%s needs \"%s\": %s\n",
+			       module->pathname, name,
+			       owner->pathname);
+			add_dep(module, owner);
+		}
+	}
+
+	free(symnames);
+	free(symtypes);
+}
+
 static struct module *parse_modules(struct module *list)
 {
 	struct module *i;
@@ -684,7 +718,7 @@ static struct module *parse_modules(struct module *list)
 	}
 	
 	for (i = list; i; i = i->next)
-		i->ops->calculate_deps(i);
+		calculate_deps(i);
 	
 	/* Strip out modules with dependency loops. */
  again:
diff --git a/depmod.h b/depmod.h
index 4d92c98..089acdd 100644
--- a/depmod.h
+++ b/depmod.h
@@ -4,10 +4,6 @@
 
 struct module;
 
-/* Functions provided by depmod.c */
-struct module *find_symbol(const char *name, const char *modname, int weak);
-void add_dep(struct module *mod, struct module *depends_on);
-
 struct module
 {
 	/* Next module in list of all modules */
diff --git a/moduleops.h b/moduleops.h
index 55e2320..2624fa7 100644
--- a/moduleops.h
+++ b/moduleops.h
@@ -17,7 +17,8 @@ struct kernel_symbol64 {
 struct module_ops
 {
 	struct string_table *(*load_symbols)(struct module *module);
-	void (*calculate_deps)(struct module *module);
+	struct string_table *(*load_dep_syms)(struct module *module,
+		struct string_table **types);
 	void (*fetch_tables)(struct module *module);
 	char *(*get_aliases)(struct module *module, unsigned long *size);
 	char *(*get_modinfo)(struct module *module, unsigned long *size);
diff --git a/moduleops_core.c b/moduleops_core.c
index 2454199..ea9b110 100644
--- a/moduleops_core.c
+++ b/moduleops_core.c
@@ -73,8 +73,8 @@ static char *PERBIT(get_modinfo)(struct module *module, unsigned long *size)
 #define STT_REGISTER    13              /* Global register reserved to app. */
 #endif
 
-/* Calculate the dependencies for this module */
-static void PERBIT(calculate_deps)(struct module *module)
+static struct string_table *PERBIT(load_dep_syms)(struct module *module,
+						  struct string_table **types)
 {
 	unsigned int i;
 	unsigned long size;
@@ -82,19 +82,20 @@ static void PERBIT(calculate_deps)(struct module *module)
 	ElfPERBIT(Sym) *syms;
 	ElfPERBIT(Ehdr) *hdr;
 	int handle_register_symbols;
+	struct string_table *names;
+
+	names = NULL;
+	*types = NULL;
 
 	strings = PERBIT(load_section)(module->data, ".strtab", &size,
 				       module->conv);
 	syms = PERBIT(load_section)(module->data, ".symtab", &size,
 				    module->conv);
 
-	module->num_deps = 0;
-	module->deps = NULL;
-
 	if (!strings || !syms) {
 		warn("Couldn't find symtab and strtab in module %s\n",
 		     module->pathname);
-		return;
+		return NULL;
 	}
 
 	hdr = module->data;
@@ -107,7 +108,6 @@ static void PERBIT(calculate_deps)(struct module *module)
 		if (END(syms[i].st_shndx, module->conv) == SHN_UNDEF) {
 			/* Look for symbol */
 			const char *name;
-			struct module *owner;
 			int weak;
 
 			name = strings + END(syms[i].st_name, module->conv);
@@ -125,15 +125,11 @@ static void PERBIT(calculate_deps)(struct module *module)
 			weak = (ELFPERBIT(ST_BIND)(END(syms[i].st_info,
 						       module->conv))
 				== STB_WEAK);
-			owner = find_symbol(name, module->pathname, weak);
-			if (owner) {
-				info("%s needs \"%s\": %s\n",
-				       module->pathname, name,
-				       owner->pathname);
-				add_dep(module, owner);
-			}
+			names = strtbl_add(name, names);
+			*types = strtbl_add(weak ? "W" : "U", *types);
 		}
 	}
+	return names;
 }
 
 static void *PERBIT(deref_sym)(ElfPERBIT(Ehdr) *hdr,
@@ -239,7 +235,7 @@ static void PERBIT(fetch_tables)(struct module *module)
 
 struct module_ops PERBIT(mod_ops) = {
 	.load_symbols	= PERBIT(load_symbols),
-	.calculate_deps	= PERBIT(calculate_deps),
+	.load_dep_syms	= PERBIT(load_dep_syms),
 	.fetch_tables	= PERBIT(fetch_tables),
 	.get_aliases	= PERBIT(get_aliases),
 	.get_modinfo	= PERBIT(get_modinfo),