[PATCH v2 06/26] modpost: traverse unresolved symbols in order

Masahiro Yamada
2022-05-01T08:42:31Z

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>
---

(no changes since v1)

scripts/mod/modpost.c | 20 ++++++++++++++------
scripts/mod/modpost.h | 2 +-
2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index abcdb0677775..c7dda4cfa497 100644
--- 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 d0a8ab60f413..65296eca20a1 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -111,8 +111,8 @@ 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;
--
2.32.0