[v4,0/3] kernel/notifier.c: intercepting duplicate registrations to avoid infinite loops

Message

Xiaoming Ni Sept. 19, 2019, 2:58 a.m. UTC

Registering the same notifier to a hook repeatedly can cause the hook
list to form a ring or lose other members of the list.
so, need add a check in in notifier_chain_register(),
intercepting duplicate registrations to avoid infinite loops


v1:
* use notifier_chain_cond_register replace notifier_chain_register

v2:
* Add a check in notifier_chain_register() to avoid duplicate registration
* remove notifier_chain_cond_register() to avoid duplicate code 
* remove blocking_notifier_chain_cond_register() to avoid duplicate code

v3:
* Add a cover letter.

v4:
* Add Reviewed-by and adjust the title.

Xiaoming Ni (3):
  kernel/notifier.c: intercepting duplicate registrations to avoid
    infinite loops
  kernel/notifier.c: remove notifier_chain_cond_register()
  kernel/notifier.c: remove blocking_notifier_chain_cond_register()

 include/linux/notifier.h |  4 ----
 kernel/notifier.c        | 41 +++--------------------------------------
 net/sunrpc/rpc_pipe.c    |  2 +-
 3 files changed, 4 insertions(+), 43 deletions(-)