modpost: traverse unresolved symbols in order

Currently, modpost manages unresolved in a singly linked list; it adds
a new node to the head, and traverses the list from new to old.

Use a doubly linked list to keep the order in the symbol table in the
ELF file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 59d8176..70a66ce 100644 (file)
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -185,6 +185,8 @@ static struct module *new_module(const char *modname)
        mod = NOFAIL(malloc(sizeof(*mod) + strlen(modname) + 1));
        memset(mod, 0, sizeof(*mod));
 
+       INIT_LIST_HEAD(&mod->unresolved_symbols);
+
        strcpy(mod->name, modname);
        mod->is_vmlinux = (strcmp(modname, "vmlinux") == 0);
 
@@ -207,6 +209,7 @@ static struct module *new_module(const char *modname)
 
 struct symbol {
        struct symbol *next;
+       struct list_head list;  /* link to module::unresolved_symbols */
        struct module *module;
        char *namespace;
        unsigned int crc;
@@ -261,8 +264,12 @@ static struct symbol *new_symbol(const char *name, struct module *module,
 
 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 {
-       mod->unres = alloc_symbol(name, mod->unres);
-       mod->unres->weak = weak;
+       struct symbol *sym;
+
+       sym = alloc_symbol(name, NULL);
+       sym->weak = weak;
+
+       list_add_tail(&sym->list, &mod->unresolved_symbols);
 }
 
 static struct symbol *find_symbol(const char *name)
@@ -2156,7 +2163,7 @@ static void check_exports(struct module *mod)
 {
        struct symbol *s, *exp;
 
-       for (s = mod->unres; s; s = s->next) {
+       list_for_each_entry(s, &mod->unresolved_symbols, list) {
                const char *basename;
                exp = find_symbol(s->name);
                if (!exp) {
@@ -2277,7 +2284,7 @@ static void add_versions(struct buffer *b, struct module *mod)
        buf_printf(b, "static const struct modversion_info ____versions[]\n");
        buf_printf(b, "__used __section(\"__versions\") = {\n");
 
-       for (s = mod->unres; s; s = s->next) {
+       list_for_each_entry(s, &mod->unresolved_symbols, list) {
                if (!s->module)
                        continue;
                if (!s->crc_valid) {
@@ -2303,13 +2310,14 @@ static void add_depends(struct buffer *b, struct module *mod)
        int first = 1;
 
        /* Clear ->seen flag of modules that own symbols needed by this. */
-       for (s = mod->unres; s; s = s->next)
+       list_for_each_entry(s, &mod->unresolved_symbols, list) {
                if (s->module)
                        s->module->seen = s->module->is_vmlinux;
+       }
 
        buf_printf(b, "\n");
        buf_printf(b, "MODULE_INFO(depends, \"");
-       for (s = mod->unres; s; s = s->next) {
+       list_for_each_entry(s, &mod->unresolved_symbols, list) {
                const char *p;
                if (!s->module)
                        continue;

diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 69601f3..f06bbd0 100644 (file)
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -113,8 +113,8 @@ buf_write(struct buffer *buf, const char *s, int len);
 
 struct module {
        struct list_head list;
+       struct list_head unresolved_symbols;
        bool is_gpl_compatible;
-       struct symbol *unres;
        bool from_dump;         /* true if module was loaded from *.symvers */
        bool is_vmlinux;
        bool seen;