[PATCH v3 0/2] rcu: Dump memory object info if callback function is invalid

[thunder.leizhen@huaweicloud.com]

From: Zhen Lei <thunder.leizhen@huawei.com>

v2 --> v3:
1. I made statistics about the source of 'rhp'. kmem_valid_obj() accounts for
   more than 97.5%, and vmalloc accounts for less than 1%. So change call
   mem_dump_obj() to call kmem_dump_obj() can meet debugging requirements and
   avoid the potential deadlock risk of vmalloc_dump_obj().
-		mem_dump_obj(rhp);
+		if (kmem_valid_obj(rhp))
+			kmem_dump_obj(rhp);

   The discussion about vmap_area_lock deadlock in v2:
   https://lkml.org/lkml/2022/11/11/493

2. Provide static inline empty functions for kmem_valid_obj() and kmem_dump_obj()
   when CONFIG_PRINTK=n.

v1 --> v2:
1. Remove condition "(unsigned long)rhp->func & 0x3", it have problems on x86.
2. Paul E. McKenney helped me update the commit message, thanks.

Zhen Lei (2):
  mm: Provide empty function for kmem_dump_obj() when CONFIG_PRINTK=n
  rcu: Dump memory object info if callback function is invalid

 include/linux/slab.h  | 3 +++
 kernel/rcu/rcu.h      | 9 +++++++++
 kernel/rcu/srcutiny.c | 1 +
 kernel/rcu/srcutree.c | 1 +
 kernel/rcu/tasks.h    | 1 +
 kernel/rcu/tiny.c     | 1 +
 kernel/rcu/tree.c     | 1 +
 7 files changed, 17 insertions(+)

-- 
2.34.1