9c1ace066f
[ Upstream commit 9c1be1935fb68b2413796cdc03d019b8cf35ab51 ]
While testing a patch that will follow later
("net: add netns refcount tracker to struct nsproxy")
I found that devtmpfs_init() was called before init_net
was initialized.
This is a bug, because devtmpfs_setup() calls
ksys_unshare(CLONE_NEWNS);
This has the effect of increasing init_net refcount,
which will be later overwritten to 1, as part of setup_net(&init_net)
We had too many prior patches [1] trying to work around the root cause.
Really, make sure init_net is in BSS section, and that net_ns_init()
is called earlier at boot time.
Note that another patch ("vfs: add netns refcount tracker
to struct fs_context") also will need net_ns_init() being called
before vfs_caches_init()
As a bonus, this patch saves around 4KB in .data section.
[1]
f8c46cb39079 ("netns: do not call pernet ops for not yet set up init_net namespace")
b5082df8019a ("net: Initialise init_net.count to 1")
734b65417b24 ("net: Statically initialize init_net.dev_base_head")
v2: fixed a build error reported by kernel build bots (CONFIG_NET=n)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 Restructured Text 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.