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A single fix for debugobjects:

Browse Source 
The recent fix to ensure atomicity of lookup and allocation inadvertently
   broke the pool refill mechanism, so that debugobject OOMs now in certain
   situations. The reason is that the functions which got updated no longer
   invoke debug_objecs_init(), which is now the only place to care about
   refilling the tracking object pool.
 
   Restore the original behaviour by adding explicit refill opportunities to
   those places.
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Merge tag 'core-debugobjects-2023-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull debugobjects fix from Thomas Gleixner:
 "A single fix for debugobjects:

  The recent fix to ensure atomicity of lookup and allocation
  inadvertently broke the pool refill mechanism, so that debugobject
  OOMs now in certain situations. The reason is that the functions which
  got updated no longer invoke debug_objecs_init(), which is now the
  only place to care about refilling the tracking object pool.

  Restore the original behaviour by adding explicit refill opportunities
  to those places"

* tag 'core-debugobjects-2023-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  debugobject: Ensure pool refill (again)
This commit is contained in:
Linus Torvalds 2023-05-07 11:04:26 -07:00
commit 17784de648
1 changed files with 15 additions and 6 deletions
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21
lib/debugobjects.c
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@ -587,6 +587,16 @@ static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket
return NULL;
}
static void debug_objects_fill_pool(void)
{
/*
* On RT enabled kernels the pool refill must happen in preemptible
* context:
*/
if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible())
fill_pool();
}
static void
__debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack)
{
@ -595,12 +605,7 @@ __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack
struct debug_obj *obj;
unsigned long flags;
/*
* On RT enabled kernels the pool refill must happen in preemptible
* context:
*/
if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible())
fill_pool();
debug_objects_fill_pool();
db = get_bucket((unsigned long) addr);
@ -685,6 +690,8 @@ int debug_object_activate(void *addr, const struct debug_obj_descr *descr)
if (!debug_objects_enabled)
return 0;
debug_objects_fill_pool();
db = get_bucket((unsigned long) addr);
raw_spin_lock_irqsave(&db->lock, flags);
@ -894,6 +901,8 @@ void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr)
if (!debug_objects_enabled)
return;
debug_objects_fill_pool();
db = get_bucket((unsigned long) addr);
raw_spin_lock_irqsave(&db->lock, flags);