mainlining shenanigans
Go to file
Eric W. Biederman a0d4a14175 Proc mount option handling is broken, and it has been since I
accidentally broke it in the middle 2016.

The problem is that because we perform an internal mount of proc
before user space mounts proc all of the mount options that user
specifies when mounting proc are ignored.

You can set those mount options with a remount but that is rather
surprising.

This most directly affects android which is using hidpid=2 by default.

Now that the sysctl system call support has been removed, and we have
settled on way of flushing proc dentries when a process exits without
using proc_mnt, there is an simple and easy fix.

a) Give UML mconsole it's own private mount of proc to use.
b) Stop creating the internal mount of proc

We still need Alexey Gladkov's full patch to get proc mount options to
work inside of UML, and to be generally useful.  This set of changes
is just enough to get them working as well as they have in the past.

If anyone sees any problem with this code please let me know.

Otherwise I plan to merge these set of fixes through my tree.

Link: https://lore.kernel.org/lkml/87r21tuulj.fsf@x220.int.ebiederm.org/
Link: https://lore.kernel.org/lkml/871rqk2brn.fsf_-_@x220.int.ebiederm.org/
Link: https://lore.kernel.org/lkml/20200210150519.538333-1-gladkov.alexey@gmail.com/
Link: https://lore.kernel.org/lkml/20180611195744.154962-1-astrachan@google.com/
Fixes: e94591d0d9 ("proc: Convert proc_mount to use mount_ns.")

Eric W. Biederman (4):
      uml: Don't consult current to find the proc_mnt in mconsole_proc
      uml: Create a private mount of proc for mconsole
      proc: Remove the now unnecessary internal mount of proc
      pid: Improve the comment about waiting in zap_pid_ns_processes

 arch/um/drivers/mconsole_kern.c | 28 +++++++++++++++++++++++++++-
 fs/proc/root.c                  | 36 ------------------------------------
 include/linux/pid_namespace.h   |  2 --
 include/linux/proc_ns.h         |  5 -----
 kernel/pid.c                    |  8 --------
 kernel/pid_namespace.c          | 38 +++++++++++++++++++-------------------
 6 files changed, 46 insertions(+), 71 deletions(-)
2020-03-02 16:00:33 -06:00
arch uml: Create a private mount of proc for mconsole 2020-02-28 12:04:33 -06:00
block block-5.6-2020-02-05 2020-02-06 06:15:23 +00:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto s390 updates for 5.6-rc2 2020-02-15 13:10:38 -08:00
Documentation Minor bug fixes for IPMI 2020-02-16 13:05:46 -08:00
drivers Minor bug fixes for IPMI 2020-02-16 13:05:46 -08:00
fs proc: Remove the now unnecessary internal mount of proc 2020-02-28 12:06:14 -06:00
include proc: Remove the now unnecessary internal mount of proc 2020-02-28 12:06:14 -06:00
init Various fixes: 2020-02-11 16:39:18 -08:00
ipc proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
kernel pid: Improve the comment about waiting in zap_pid_ns_processes 2020-02-28 16:29:12 -06:00
lib Various fixes: 2020-02-11 16:39:18 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
net NFS Client Bugfixes for Linux 5.6-rc2 2020-02-14 14:46:11 -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 ALSA: pcm: Fix double hw_free calls 2020-02-13 16:30:22 +01:00
tools Bugfixes and improvements to selftests. On top of this, Mauro converted the 2020-02-16 13:01:42 -08:00
usr Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
virt KVM: Disable preemption in kvm_get_running_vcpu() 2020-02-12 12:19:35 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS open: introduce openat2(2) syscall 2020-01-18 09:19:18 -05:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: Sort entries in database for GPIO 2020-02-10 10:55:18 +01:00
Makefile Linux 5.6-rc2 2020-02-16 13:16:59 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.