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081efd1832
We will get rid of RTNL from RTM_NEWROUTE and SIOCADDRT. Then, we may be going to add a route tied to a dying nexthop. The nexthop itself is not freed during the RCU grace period, but if we link a route after __remove_nexthop_fib() is called for the nexthop, the route will be leaked. To avoid the race between IPv6 route addition under RCU vs nexthop deletion under RTNL, let's add a dead flag and protect it and nh->f6i_list with a spinlock. __remove_nexthop_fib() acquires the nexthop's spinlock and sets false to nh->dead, then calls ip6_del_rt() for the linked route one by one without the spinlock because fib6_purge_rt() acquires it later. While adding an IPv6 route, fib6_add() acquires the nexthop lock and checks the dead flag just before inserting the route. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250418000443.43734-15-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.