linux-toradex.git/kernel/Makefile, branch v5.9-rc7

all arch: remove system call sys_sysctl

2020-08-15T02:56:56+00:00

Since commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
sys_sysctl is actually unavailable: any input can only return an error.

We have been warning about people using the sysctl system call for years
and believe there are no more users.  Even if there are users of this
interface if they have not complained or fixed their code by now they
probably are not going to, so there is no point in warning them any
longer.

So completely remove sys_sysctl on all architectures.

[nixiaoming@huawei.com: s390: fix build error for sys_call_table_emu]
 Link: http://lkml.kernel.org/r/20200618141426.16884-1-nixiaoming@huawei.com

Signed-off-by: Xiaoming Ni 
Signed-off-by: Andrew Morton 
Acked-by: Will Deacon 		[arm/arm64]
Acked-by: "Eric W. Biederman" 
Cc: Aleksa Sarai 
Cc: Alexander Shishkin 
Cc: Al Viro 
Cc: Andi Kleen 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Arnaldo Carvalho de Melo 
Cc: Arnd Bergmann 
Cc: Benjamin Herrenschmidt 
Cc: Bin Meng 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Catalin Marinas 
Cc: chenzefeng 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Chris Zankel 
Cc: David Howells 
Cc: David S. Miller 
Cc: Diego Elio Pettenò 
Cc: Dmitry Vyukov 
Cc: Dominik Brodowski 
Cc: Fenghua Yu 
Cc: Geert Uytterhoeven 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Iurii Zaikin 
Cc: Ivan Kokshaysky 
Cc: James Bottomley 
Cc: Jens Axboe 
Cc: Jiri Olsa 
Cc: Kars de Jong 
Cc: Kees Cook 
Cc: Krzysztof Kozlowski 
Cc: Luis Chamberlain 
Cc: Marco Elver 
Cc: Mark Rutland 
Cc: Martin K. Petersen 
Cc: Masahiro Yamada 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Miklos Szeredi 
Cc: Minchan Kim 
Cc: Namhyung Kim 
Cc: Naveen N. Rao 
Cc: Nick Piggin 
Cc: Oleg Nesterov 
Cc: Olof Johansson 
Cc: Paul Burton 
Cc: "Paul E. McKenney" 
Cc: Paul Mackerras 
Cc: Peter Zijlstra (Intel) 
Cc: Randy Dunlap 
Cc: Ravi Bangoria 
Cc: Richard Henderson 
Cc: Rich Felker 
Cc: Russell King 
Cc: Sami Tolvanen 
Cc: Sargun Dhillon 
Cc: Stephen Rothwell 
Cc: Sudeep Holla 
Cc: Sven Schnelle 
Cc: Thiago Jung Bauermann 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vasily Gorbik 
Cc: Vlastimil Babka 
Cc: Yoshinori Sato 
Cc: Zhou Yanjie 
Link: http://lkml.kernel.org/r/20200616030734.87257-1-nixiaoming@huawei.com
Signed-off-by: Linus Torvalds

kcov: unconditionally add -fno-stack-protector to compiler options

2020-08-12T17:58:02+00:00

Unconditionally add -fno-stack-protector to KCOV's compiler options, as
all supported compilers support the option.  This saves a compiler
invocation to determine if the option is supported.

Because Clang does not support -fno-conserve-stack, and
-fno-stack-protector was wrapped in the same cc-option, we were missing
-fno-stack-protector with Clang. Unconditionally adding this option
fixes this for Clang.

Suggested-by: Nick Desaulniers 
Signed-off-by: Marco Elver 
Signed-off-by: Andrew Morton 
Reviewed-by: Nick Desaulniers 
Reviewed-by: Andrey Konovalov 
Cc: Dmitry Vyukov 
Cc: Alexander Potapenko 
Link: http://lkml.kernel.org/r/20200615184302.7591-1-elver@google.com
Signed-off-by: Linus Torvalds

Merge branch 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-08-07T16:29:25+00:00

Pull ptrace regset updates from Al Viro:
 "Internal regset API changes:

   - regularize copy_regset_{to,from}_user() callers

   - switch to saner calling conventions for ->get()

   - kill user_regset_copyout()

  The ->put() side of things will have to wait for the next cycle,
  unfortunately.

  The balance is about -1KLoC and replacements for ->get() instances are
  a lot saner"

* 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
  regset: kill user_regset_copyout{,_zero}()
  regset(): kill ->get_size()
  regset: kill ->get()
  csky: switch to ->regset_get()
  xtensa: switch to ->regset_get()
  parisc: switch to ->regset_get()
  nds32: switch to ->regset_get()
  nios2: switch to ->regset_get()
  hexagon: switch to ->regset_get()
  h8300: switch to ->regset_get()
  openrisc: switch to ->regset_get()
  riscv: switch to ->regset_get()
  c6x: switch to ->regset_get()
  ia64: switch to ->regset_get()
  arc: switch to ->regset_get()
  arm: switch to ->regset_get()
  sh: convert to ->regset_get()
  arm64: switch to ->regset_get()
  mips: switch to ->regset_get()
  sparc: switch to ->regset_get()
  ...

Merge tag 'core-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-08-05T04:00:11+00:00

Pull generic kernel entry/exit code from Thomas Gleixner:
 "Generic implementation of common syscall, interrupt and exception
  entry/exit functionality based on the recent X86 effort to ensure
  correctness of entry/exit vs RCU and instrumentation.

  As this functionality and the required entry/exit sequences are not
  architecture specific, sharing them allows other architectures to
  benefit instead of copying the same code over and over again.

  This branch was kept standalone to allow others to work on it. The
  conversion of x86 comes in a seperate pull request which obviously is
  based on this branch"

* tag 'core-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Correct __secure_computing() stub
  entry: Correct 'noinstr' attributes
  entry: Provide infrastructure for work before transitioning to guest mode
  entry: Provide generic interrupt entry/exit code
  entry: Provide generic syscall exit function
  entry: Provide generic syscall entry functionality
  seccomp: Provide stub for __secure_computing()

Merge branch 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2020-08-04T21:27:25+00:00

Pull execve updates from Eric Biederman:
 "During the development of v5.7 I ran into bugs and quality of
  implementation issues related to exec that could not be easily fixed
  because of the way exec is implemented. So I have been diggin into
  exec and cleaning up what I can.

  This cycle I have been looking at different ideas and different
  implementations to see what is possible to improve exec, and cleaning
  the way exec interfaces with in kernel users. Only cleaning up the
  interfaces of exec with rest of the kernel has managed to stabalize
  and make it through review in time for v5.9-rc1 resulting in 2 sets of
  changes this cycle.

   - Implement kernel_execve

   - Make the user mode driver code a better citizen

  With kernel_execve the code size got a little larger as the copying of
  parameters from userspace and copying of parameters from userspace is
  now separate. The good news is kernel threads no longer need to play
  games with set_fs to use exec. Which when combined with the rest of
  Christophs set_fs changes should security bugs with set_fs much more
  difficult"

* 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits)
  exec: Implement kernel_execve
  exec: Factor bprm_stack_limits out of prepare_arg_pages
  exec: Factor bprm_execve out of do_execve_common
  exec: Move bprm_mm_init into alloc_bprm
  exec: Move initialization of bprm->filename into alloc_bprm
  exec: Factor out alloc_bprm
  exec: Remove unnecessary spaces from binfmts.h
  umd: Stop using split_argv
  umd: Remove exit_umh
  bpfilter: Take advantage of the facilities of struct pid
  exit: Factor thread_group_exited out of pidfd_poll
  umd: Track user space drivers with struct pid
  bpfilter: Move bpfilter_umh back into init data
  exec: Remove do_execve_file
  umh: Stop calling do_execve_file
  umd: Transform fork_usermode_blob into fork_usermode_driver
  umd: Rename umd_info.cmdline umd_info.driver_name
  umd: For clarity rename umh_info umd_info
  umh: Separate the user mode driver and the user mode helper support
  umh: Remove call_usermodehelper_setup_file.
  ...

introduction of regset ->get() wrappers, switching ELF coredumps to those

2020-07-27T18:24:50+00:00

Two new helpers: given a process and regset, dump into a buffer.
regset_get() takes a buffer and size, regset_get_alloc() takes size
and allocates a buffer.

Return value in both cases is the amount of data actually dumped in
case of success or -E...  on error.

In both cases the size is capped by regset->n * regset->size, so
->get() is called with offset 0 and size no more than what regset
expects.

binfmt_elf.c callers of ->get() are switched to using those; the other
caller (copy_regset_to_user()) will need some preparations to switch.

Signed-off-by: Al Viro

entry: Provide generic syscall entry functionality

2020-07-24T12:59:03+00:00

On syscall entry certain work needs to be done:

   - Establish state (lockdep, context tracking, tracing)
   - Conditional work (ptrace, seccomp, audit...)

This code is needlessly duplicated and  different in all
architectures.

Provide a generic version based on the x86 implementation which has all the
RCU and instrumentation bits right.

As interrupt/exception entry from user space needs parts of the same
functionality, provide a function for this as well.

syscall_enter_from_user_mode() and irqentry_enter_from_user_mode() must be
called right after the low level ASM entry. The calling code must be
non-instrumentable. After the functions returns state is correct and the
subsequent functions can be instrumented.

Signed-off-by: Thomas Gleixner 
Acked-by: Kees Cook 
Link: https://lkml.kernel.org/r/20200722220519.513463269@linutronix.de

umh: Separate the user mode driver and the user mode helper support

2020-07-04T14:34:32+00:00

This makes it clear which code is part of the core user mode
helper support and which code is needed to implement user mode
drivers.

This makes the kernel smaller for everyone who does not use a usermode
driver.

v1: https://lkml.kernel.org/r/87tuyyf0ln.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87imf963s6.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-5-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman 
Acked-by: Alexei Starovoitov 
Tested-by: Alexei Starovoitov 
Signed-off-by: "Eric W. Biederman"

gcc-plugins/stackleak: Don't instrument itself

2020-06-24T14:48:13+00:00

There is no need to try instrumenting functions in kernel/stackleak.c.
Otherwise that can cause issues if the cleanup pass of stackleak gcc plugin
is disabled.

Signed-off-by: Alexander Popov 
Link: https://lore.kernel.org/r/20200624123330.83226-2-alex.popov@linux.com
Signed-off-by: Kees Cook

Merge tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

2020-06-13T16:56:21+00:00

Pull notification queue from David Howells:
"This adds a general notification queue concept and adds an event
source for keys/keyrings, such as linking and unlinking keys and
changing their attributes.

Thanks to Debarshi Ray, we do have a pull request to use this to fix a
problem with gnome-online-accounts - as mentioned last time:

https://gitlab.gnome.org/GNOME/gnome-online-accounts/merge_requests/47

Without this, g-o-a has to constantly poll a keyring-based kerberos
cache to find out if kinit has changed anything.

[ There are other notification pending: mount/sb fsinfo notifications
for libmount that Karel Zak and Ian Kent have been working on, and
Christian Brauner would like to use them in lxc, but let's see how
this one works first ]

LSM hooks are included:

- A set of hooks are provided that allow an LSM to rule on whether or
not a watch may be set. Each of these hooks takes a different
"watched object" parameter, so they're not really shareable. The
LSM should use current's credentials. [Wanted by SELinux & Smack]

- A hook is provided to allow an LSM to rule on whether or not a
particular message may be posted to a particular queue. This is
given the credentials from the event generator (which may be the
system) and the watch setter. [Wanted by Smack]

I've provided SELinux and Smack with implementations of some of these
hooks.

WHY
===

Key/keyring notifications are desirable because if you have your
kerberos tickets in a file/directory, your Gnome desktop will monitor
that using something like fanotify and tell you if your credentials
cache changes.

However, we also have the ability to cache your kerberos tickets in
the session, user or persistent keyring so that it isn't left around
on disk across a reboot or logout. Keyrings, however, cannot currently
be monitored asynchronously, so the desktop has to poll for it - not
so good on a laptop. This facility will allow the desktop to avoid the
need to poll.

DESIGN DECISIONS
================

- The notification queue is built on top of a standard pipe. Messages
are effectively spliced in. The pipe is opened with a special flag:

pipe2(fds, O_NOTIFICATION_PIPE);

The special flag has the same value as O_EXCL (which doesn't seem
like it will ever be applicable in this context)[?]. It is given up
front to make it a lot easier to prohibit splice&co from accessing
the pipe.

[?] Should this be done some other way? I'd rather not use up a new
O_* flag if I can avoid it - should I add a pipe3() system call
instead?

The pipe is then configured::

ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, queue_depth);
ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter);

Messages are then read out of the pipe using read().

- It should be possible to allow write() to insert data into the
notification pipes too, but this is currently disabled as the
kernel has to be able to insert messages into the pipe *without*
holding pipe->mutex and the code to make this work needs careful
auditing.

- sendfile(), splice() and vmsplice() are disabled on notification
pipes because of the pipe->mutex issue and also because they
sometimes want to revert what they just did - but one or more
notification messages might've been interleaved in the ring.

- The kernel inserts messages with the wait queue spinlock held. This
means that pipe_read() and pipe_write() have to take the spinlock
to update the queue pointers.

- Records in the buffer are binary, typed and have a length so that
they can be of varying size.

This allows multiple heterogeneous sources to share a common
buffer; there are 16 million types available, of which I've used
just a few, so there is scope for others to be used. Tags may be
specified when a watchpoint is created to help distinguish the
sources.

- Records are filterable as types have up to 256 subtypes that can be
individually filtered. Other filtration is also available.

- Notification pipes don't interfere with each other; each may be
bound to a different set of watches. Any particular notification
will be copied to all the queues that are currently watching for it
- and only those that are watching for it.

- When recording a notification, the kernel will not sleep, but will
rather mark a queue as having lost a message if there's
insufficient space. read() will fabricate a loss notification
message at an appropriate point later.

- The notification pipe is created and then watchpoints are attached
to it, using one of:

keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01);
watch_mount(AT_FDCWD, "/", 0, fd, 0x02);
watch_sb(AT_FDCWD, "/mnt", 0, fd, 0x03);

where in both cases, fd indicates the queue and the number after is
a tag between 0 and 255.

- Watches are removed if either the notification pipe is destroyed or
the watched object is destroyed. In the latter case, a message will
be generated indicating the enforced watch removal.

Things I want to avoid:

- Introducing features that make the core VFS dependent on the
network stack or networking namespaces (ie. usage of netlink).

- Dumping all this stuff into dmesg and having a daemon that sits
there parsing the output and distributing it as this then puts the
responsibility for security into userspace and makes handling
namespaces tricky. Further, dmesg might not exist or might be
inaccessible inside a container.

- Letting users see events they shouldn't be able to see.

TESTING AND MANPAGES
====================

- The keyutils tree has a pipe-watch branch that has keyctl commands
for making use of notifications. Proposed manual pages can also be
found on this branch, though a couple of them really need to go to
the main manpages repository instead.

If the kernel supports the watching of keys, then running "make
test" on that branch will cause the testing infrastructure to spawn
a monitoring process on the side that monitors a notifications pipe
for all the key/keyring changes induced by the tests and they'll
all be checked off to make sure they happened.

https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log/?h=pipe-watch

- A test program is provided (samples/watch_queue/watch_test) that
can be used to monitor for keyrings, mount and superblock events.
Information on the notifications is simply logged to stdout"

* tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
smack: Implement the watch_key and post_notification hooks
selinux: Implement the watch_key security hook
keys: Make the KEY_NEED_* perms an enum rather than a mask
pipe: Add notification lossage handling
pipe: Allow buffers to be marked read-whole-or-error for notifications
Add sample notification program
watch_queue: Add a key/keyring notification facility
security: Add hooks to rule on setting a watch
pipe: Add general notification queue support
pipe: Add O_NOTIFICATION_PIPE
security: Add a hook for the point of notification insertion
uapi: General notification queue definitions