[PATCH v2 23/59] dyndbg: move .mod_name from/to structs ddebug_table/_ddebug_info

[Jim Cromie <jim.cromie@gmail.com>]

struct _ddebug_info already has almost all dyndbg's info for a module,
so finish the encapsulation.  This puts the datum closer to where its
needed, improving the chance that we can obsolete the _ddebug.modame
field with a desc_modname(dp) accessor fn.

In static ddebug_add_module(&_ddebug_info_cursor..), force the
cursor-model by dropping the modname arg, and setting it explicitly
into the cursor before the 3 calls to it.

struct ddebug_table only uses .mod_name when applying >control
changes, and it has a _ddebug_info member anyway, so it keeps access
to the field, just with a different offset.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h |  1 +
 lib/dynamic_debug.c           | 41 ++++++++++++++++++-----------------
 2 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 03a83a83b621..8043966a0fd6 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -198,6 +198,7 @@ struct _ddebug_class_users {
 } __packed;
 
 struct _ddebug_info {
+	const char *mod_name;
 	struct _ddebug_descs descs;
 	struct _ddebug_class_maps maps;
 	struct _ddebug_class_users users;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 3c9fb8324ad6..cd3eec5bb81c 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -49,7 +49,6 @@ extern struct _ddebug_class_user __stop___dyndbg_class_users[];
 
 struct ddebug_table {
 	struct list_head link;
-	const char *mod_name;
 	struct _ddebug_info info;
 };
 
@@ -166,7 +165,7 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 #define vpr_dt_info(dt_p, msg_p, ...) ({				\
 	struct ddebug_table const *_dt = dt_p;				\
 	v2pr_info(msg_p " module:%s nd:%d nc:%d nu:%d\n", ##__VA_ARGS__, \
-		  _dt->mod_name, _dt->info.descs.len, _dt->info.maps.len, \
+		  _dt->info.mod_name, _dt->info.descs.len, _dt->info.maps.len, \
 		  _dt->info.users.len);					\
 	})
 
@@ -215,7 +214,7 @@ static int ddebug_change(const struct ddebug_query *query, struct flag_settings
 
 		/* match against the module name */
 		if (query->module &&
-		    !match_wildcard(query->module, dt->mod_name))
+		    !match_wildcard(query->module, dt->info.mod_name))
 			continue;
 
 		if (query->class_string) {
@@ -283,7 +282,7 @@ static int ddebug_change(const struct ddebug_query *query, struct flag_settings
 #endif
 			v4pr_info("changed %s:%d [%s]%s %s => %s\n",
 				  trim_prefix(dp->filename), dp->lineno,
-				  dt->mod_name, dp->function,
+				  dt->info.mod_name, dp->function,
 				  ddebug_describe_flags(dp->flags, &fbuf),
 				  ddebug_describe_flags(newflags, &nbuf));
 			dp->flags = newflags;
@@ -1123,7 +1122,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 
 	seq_printf(m, "%s:%u [%s]%s =%s \"",
 		   trim_prefix(dp->filename), dp->lineno,
-		   iter->table->mod_name, dp->function,
+		   iter->table->info.mod_name, dp->function,
 		   ddebug_describe_flags(dp->flags, &flags));
 	seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
 	seq_putc(m, '"');
@@ -1283,7 +1282,7 @@ static void ddebug_apply_class_users(const struct ddebug_table *dt)
 #define dd_mark_vector_subrange(_i, _dst, _sp, _box, _vec) ({	\
 	int nc = 0;							\
 	for_subvec(_i, _sp, _box, _vec) {				\
-		if (!strcmp((_sp)->mod_name, (_dst)->mod_name)) {	\
+		if (!strcmp((_sp)->mod_name, (_dst)->info.mod_name)) {	\
 			if (!nc++)					\
 				(_dst)->info._vec.start = (_sp);	\
 		} else {						\
@@ -1314,7 +1313,7 @@ ddebug_class_range_overlap(struct _ddebug_class_map *cm,
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
  */
-static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
+static int ddebug_add_module(struct _ddebug_info *di)
 {
 	struct ddebug_table *dt;
 	struct _ddebug_class_map *cm;
@@ -1325,20 +1324,19 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	if (!di->descs.len)
 		return 0;
 
-	v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
+	v3pr_info("add-module: %s %d sites\n", di->mod_name, di->descs.len);
 
 	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 	if (dt == NULL) {
-		pr_err("error adding module: %s\n", modname);
+		pr_err("error adding module: %s\n", di->mod_name);
 		return -ENOMEM;
 	}
 	/*
-	 * For built-in modules, name lives in .rodata and is
-	 * immortal. For loaded modules, name points at the name[]
-	 * member of struct module, which lives at least as long as
-	 * this struct ddebug_table.
+	 * For built-in modules, name (as supplied in di by its
+	 * callers) lives in .rodata and is immortal. For loaded
+	 * modules, name points at the name[] member of struct module,
+	 * which lives at least as long as this struct ddebug_table.
 	 */
-	dt->mod_name = modname;
 	dt->info = *di;
 
 	INIT_LIST_HEAD(&dt->link);
@@ -1368,10 +1366,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	if (dt->info.users.len)
 		ddebug_apply_class_users(dt);
 
-	vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
+	vpr_info("%3u debug prints in module %s\n", di->descs.len, di->mod_name);
 	return 0;
 cleanup:
-	WARN_ONCE("dyndbg multi-classmap conflict in %s\n", modname);
+	WARN_ONCE("dyndbg multi-classmap conflict in %s\n", di->mod_name);
 	kfree(dt);
 	return -EINVAL;
 
@@ -1436,7 +1434,7 @@ static int ddebug_remove_module(const char *mod_name)
 
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
-		if (dt->mod_name == mod_name) {
+		if (dt->info.mod_name == mod_name) {
 			ddebug_table_free(dt);
 			ret = 0;
 			break;
@@ -1456,7 +1454,8 @@ static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
 
 	switch (val) {
 	case MODULE_STATE_COMING:
-		ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
+		mod->dyndbg_info.mod_name = mod->name;
+		ret = ddebug_add_module(&mod->dyndbg_info);
 		if (ret)
 			WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
 		break;
@@ -1556,7 +1555,8 @@ static int __init dynamic_debug_init(void)
 			mod_ct++;
 			di.descs.len = mod_sites;
 			di.descs.start = iter_mod_start;
-			ret = ddebug_add_module(&di, modname);
+			di.mod_name = modname;
+			ret = ddebug_add_module(&di);
 			if (ret)
 				goto out_err;
 
@@ -1567,7 +1567,8 @@ static int __init dynamic_debug_init(void)
 	}
 	di.descs.len = mod_sites;
 	di.descs.start = iter_mod_start;
-	ret = ddebug_add_module(&di, modname);
+	di.mod_name = modname;
+	ret = ddebug_add_module(&di);
 	if (ret)
 		goto out_err;
 
-- 
2.49.0