No description
Find a file
Daniel Xu 0c47383ba3 kernfs: Add option to enable user xattrs
User extended attributes are useful as metadata storage for kernfs
consumers like cgroups. Especially in the case of cgroups, it is useful
to have a central metadata store that multiple processes/services can
use to coordinate actions.

A concrete example is for userspace out of memory killers. We want to
let delegated cgroup subtree owners (running as non-root) to be able to
say "please avoid killing this cgroup". This is especially important for
desktop linux as delegated subtrees owners are less likely to run as
root.

This patch introduces a new flag, KERNFS_ROOT_SUPPORT_USER_XATTR, that
lets kernfs consumers enable user xattr support. An initial limit of 128
entries or 128KB -- whichever is hit first -- is placed per cgroup
because xattrs come from kernel memory and we don't want to let
unprivileged users accidentally eat up too much kernel memory.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-03-16 15:53:47 -04:00
arch Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
block
certs
crypto
Documentation Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
drivers dax fixes 5.6-rc1 2020-02-11 16:52:08 -08:00
fs kernfs: Add option to enable user xattrs 2020-03-16 15:53:47 -04:00
include kernfs: Add option to enable user xattrs 2020-03-16 15:53:47 -04:00
init Various fixes: 2020-02-11 16:39:18 -08:00
ipc
kernel cgroup: Restructure release_agent_path handling 2020-03-12 16:44:35 -04:00
lib Various fixes: 2020-02-11 16:39:18 -08:00
LICENSES
mm kernfs: Add removed_size out param for simple_xattr_set 2020-03-16 15:53:47 -04:00
net Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
samples Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
scripts kbuild: fix mismatch between .version and include/generated/compile.h 2020-02-11 05:18:40 +09:00
security selinux/stable-5.6 PR 20200210 2020-02-10 16:51:35 -08:00
sound
tools selftests/cgroup: add tests for cloning into cgroups 2020-02-12 17:57:51 -05:00
usr Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS fs: New zonefs file system 2020-02-09 15:51:46 -08:00
Makefile Linux 5.6-rc1 2020-02-09 16:08:48 -08:00
README

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.