Commit 66f4006b authored by Jim Cromie's avatar Jim Cromie Committed by Greg Kroah-Hartman
Browse files

kernel/module: add __dyndbg_classes section 



Add __dyndbg_classes section, using __dyndbg as a model. Use it:

vmlinux.lds.h:

KEEP the new section, which also silences orphan section warning on
loadable modules.  Add (__start_/__stop_)__dyndbg_classes linker
symbols for the c externs (below).

kernel/module/main.c:
- fill new fields in find_module_sections(), using section_objs()
- extend callchain prototypes
  to pass classes, length
  load_module(): pass new info to dynamic_debug_setup()
  dynamic_debug_setup(): new params, pass through to ddebug_add_module()

dynamic_debug.c:
- add externs to the linker symbols.

ddebug_add_module():
- It currently builds a debug_table, and *will* find and attach classes.

dynamic_debug_init():
- add class fields to the _ddebug_info cursor var: di.

Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20220904214134.408619-16-jim.cromie@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent aad0214f

include/asm-generic/vmlinux.lds.h

+3 −0
Original line number Diff line number Diff line
@@ -345,6 +345,9 @@ 
	*(__tracepoints)						\

	/* implement dynamic printk debug */				\

	. = ALIGN(8);							\

	__start___dyndbg_classes = .;					\

	KEEP(*(__dyndbg_classes))					\

	__stop___dyndbg_classes = .;					\

	__start___dyndbg = .;						\

	KEEP(*(__dyndbg))						\

	__stop___dyndbg = .;						\

include/linux/dynamic_debug.h

+2 −0
Original line number Diff line number Diff line
@@ -114,7 +114,9 @@ struct ddebug_class_map { 
/* encapsulate linker provided built-in (or module) dyndbg data */

struct _ddebug_info {

	struct _ddebug *descs;

	struct ddebug_class_map *classes;

	unsigned int num_descs;

	unsigned int num_classes;

};



#if defined(CONFIG_DYNAMIC_DEBUG_CORE)

kernel/module/main.c

+2 −0
Original line number Diff line number Diff line
@@ -2113,6 +2113,8 @@ static int find_module_sections(struct module *mod, struct load_info *info) 


	info->dyndbg.descs = section_objs(info, "__dyndbg",

					sizeof(*info->dyndbg.descs), &info->dyndbg.num_descs);

	info->dyndbg.classes = section_objs(info, "__dyndbg_classes",

					sizeof(*info->dyndbg.classes), &info->dyndbg.num_classes);



	return 0;

}

lib/dynamic_debug.c

+7 −0
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ 


extern struct _ddebug __start___dyndbg[];

extern struct _ddebug __stop___dyndbg[];

extern struct ddebug_class_map __start___dyndbg_classes[];

extern struct ddebug_class_map __stop___dyndbg_classes[];



struct ddebug_table {

	struct list_head link;
@@ -1079,7 +1081,9 @@ static int __init dynamic_debug_init(void) 


	struct _ddebug_info di = {

		.descs = __start___dyndbg,

		.classes = __start___dyndbg_classes,

		.num_descs = __stop___dyndbg - __start___dyndbg,

		.num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,

	};



	if (&__start___dyndbg == &__stop___dyndbg) {
@@ -1122,6 +1126,9 @@ static int __init dynamic_debug_init(void) 
		 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),

		 (int)((i * sizeof(struct _ddebug)) >> 10));



	if (di.num_classes)

		v2pr_info("  %d builtin ddebug class-maps\n", di.num_classes);



	/* now that ddebug tables are loaded, process all boot args

	 * again to find and activate queries given in dyndbg params.

	 * While this has already been done for known boot params, it