path: root/include/linux/debugobjects.h
diff options
authorDu, Changbin <>2016-05-19 17:09:41 -0700
committerLinus Torvalds <>2016-05-19 19:12:14 -0700
commitb9fdac7f660609abb157500e468d2165b3c9cf08 (patch)
tree37d3b704f52b46dfb6d9ebb24611870dbb2b93be /include/linux/debugobjects.h
parent8bad1cd0e1edd124c0f05f925762ef84e6047586 (diff)
debugobjects: insulate non-fixup logic related to static obj from fixup callbacks
When activating a static object we need make sure that the object is tracked in the object tracker. If it is a non-static object then the activation is illegal. In previous implementation, each subsystem need take care of this in their fixup callbacks. Actually we can put it into debugobjects core. Thus we can save duplicated code, and have *pure* fixup callbacks. To achieve this, a new callback "is_static_object" is introduced to let the type specific code decide whether a object is static or not. If yes, we take it into object tracker, otherwise give warning and invoke fixup callback. This change has paassed debugobjects selftest, and I also do some test with all debugobjects supports enabled. At last, I have a concern about the fixups that can it change the object which is in incorrect state on fixup? Because the 'addr' may not point to any valid object if a non-static object is not tracked. Then Change such object can overwrite someone's memory and cause unexpected behaviour. For example, the timer_fixup_activate bind timer to function stub_timer. Link: [ improve code comments where invoke the new is_static_object callback] Link: Signed-off-by: Du, Changbin <> Cc: Jonathan Corbet <> Cc: Josh Triplett <> Cc: Steven Rostedt <> Cc: Thomas Gleixner <> Cc: Tejun Heo <> Cc: Christian Borntraeger <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'include/linux/debugobjects.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/debugobjects.h b/include/linux/debugobjects.h
index a899f10c9365..46056cb161fc 100644
--- a/include/linux/debugobjects.h
+++ b/include/linux/debugobjects.h
@@ -38,6 +38,7 @@ struct debug_obj {
* @name: name of the object typee
* @debug_hint: function returning address, which have associated
* kernel symbol, to allow identify the object
+ * @is_static_object return true if the obj is static, otherwise return false
* @fixup_init: fixup function, which is called when the init check
* fails. All fixup functions must return true if fixup
* was successful, otherwise return false
@@ -53,6 +54,7 @@ struct debug_obj {
struct debug_obj_descr {
const char *name;
void *(*debug_hint)(void *addr);
+ bool (*is_static_object)(void *addr);
bool (*fixup_init)(void *addr, enum debug_obj_state state);
bool (*fixup_activate)(void *addr, enum debug_obj_state state);
bool (*fixup_destroy)(void *addr, enum debug_obj_state state);