linux/init
Eric Dumazet 9c1be1935f net: initialize init_net earlier
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]

f8c46cb390 ("netns: do not call pernet ops for not yet set up init_net namespace")
b5082df801 ("net: Initialise init_net.count to 1")
734b65417b ("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>
2022-02-06 11:04:29 +00:00
..
calibrate.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
do_mounts_initrd.c Merge branch 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 09:40:34 -07:00
do_mounts_rd.c init: add an init_unlink helper 2020-07-31 08:17:52 +02:00
do_mounts.c init: don't panic if mount_nodev_root failed 2021-09-19 22:24:52 -04:00
do_mounts.h init: add an init_mknod helper 2020-07-31 08:17:54 +02:00
init_task.c kcsan: Remove redundant zero-initialization of globals 2021-12-09 16:42:26 -08:00
initramfs.c memblock: use memblock_free for freeing virtual pointers 2021-11-06 13:30:41 -07:00
Kconfig Kbuild updates for v5.17 2022-01-19 11:15:19 +02:00
main.c net: initialize init_net earlier 2022-02-06 11:04:29 +00:00
Makefile kbuild: do not quote string values in include/config/auto.conf 2022-01-08 18:03:57 +09:00
noinitramfs.c init: move usermodehelper_enable() to populate_rootfs() 2021-09-08 11:50:27 -07:00
version.c kbuild: add an elfnote for whether vmlinux is built with lto 2021-04-25 05:25:42 +09:00