I missed explanation.
All the code protected by this rwlock is KERNEL_LOCK()’ed. The context
switches which can be caused by memory allocation or NET_LOCK() dances
within pppx_add_session() and pppx_if_destroy() are not under acquired
pppx_if_lk. So there is no concurrent access to structures it’s
It protects nothing.
Index: sys/net/if_pppx.c
===
RCS file: /cvs/src/sys/net/if_pppx.c,v
retrieving revision 1.83
diff -u -p -r1.83 if_pppx.c
--- sys/net/if_pppx.c 10 Apr 2020 07:36:52 - 1.83
+++ sys/net/if_pppx.c 11 Apr