ipc/msg: avoid ipc_rcu_alloc()

Instead of using ipc_rcu_alloc() which only performs the refcount bump,
open code it.  This also allows for msg_queue structure layout to be
randomized in the future.

Link: http://lkml.kernel.org/r/20170525185107.12869-12-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/shm: avoid ipc_rcu_alloc()

Instead of using ipc_rcu_alloc() which only performs the refcount bump,
open code it.  This also allows for shmid_kernel structure layout to be
randomized in the future.

Link: http://lkml.kernel.org/r/20170525185107.12869-11-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/sem: avoid ipc_rcu_alloc()

Instead of using ipc_rcu_alloc() which only performs the refcount bump,
open code it to perform better sem-specific checks.  This also allows
for sem_array structure layout to be randomized in the future.

[manfred@colorfullife.com: Rediff, because the memset was temporarily inside ipc_rcu_alloc()]
Link: http://lkml.kernel.org/r/20170525185107.12869-10-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/util: drop ipc_rcu_free()

There are no more callers of ipc_rcu_free(), so remove it.

Link: http://lkml.kernel.org/r/20170525185107.12869-9-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/msg: do not use ipc_rcu_free()

Avoid using ipc_rcu_free, since it just re-finds the original structure
pointer.  For the pre-list-init failure path, there is no RCU needed,
since it was just allocated.  It can be directly freed.

Link: http://lkml.kernel.org/r/20170525185107.12869-8-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/shm: do not use ipc_rcu_free()

Avoid using ipc_rcu_free, since it just re-finds the original structure
pointer.  For the pre-list-init failure path, there is no RCU needed,
since it was just allocated.  It can be directly freed.

Link: http://lkml.kernel.org/r/20170525185107.12869-7-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/sem: do not use ipc_rcu_free()

Avoid using ipc_rcu_free, since it just re-finds the original structure
pointer.  For the pre-list-init failure path, there is no RCU needed,
since it was just allocated.  It can be directly freed.

Link: http://lkml.kernel.org/r/20170525185107.12869-6-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc: drop non-RCU allocation

The only users of ipc_alloc() were ipc_rcu_alloc() and the on-heap
sem_io fall-back memory.  Better to just open-code these to make things
easier to read.

[manfred@colorfullife.com: Rediff due to inclusion of memset() into ipc_rcu_alloc()]
Link: http://lkml.kernel.org/r/20170525185107.12869-5-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/sem.h: correctly document sem_ctime

sem_ctime is initialized to the semget() time and then updated at every
semctl() that changes the array.

Thus it does not represent the time of the last change.

Especially, semop() calls are only stored in sem_otime, not in
sem_ctime.

This is already described in ipc/sem.c, I just overlooked that there is
a comment in include/linux/sem.h and man semctl(2) as well.

So: Correct wrong comments.

Link: http://lkml.kernel.org/r/20170515171912.6298-4-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: <1vier1@web.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc: merge ipc_rcu and kern_ipc_perm

ipc has two management structures that exist for every id:
 - struct kern_ipc_perm, it contains e.g. the permissions.
 - struct ipc_rcu, it contains the rcu head for rcu handling and the
   refcount.

The patch merges both structures.

As a bonus, we may save one cacheline, because both structures are
cacheline aligned.  In addition, it reduces the number of casts, instead
most codepaths can use container_of.

To simplify code, the ipc_rcu_alloc initializes the allocation to 0.

[manfred@colorfullife.com: really include the memset() into ipc_alloc_rcu()]
Link: http://lkml.kernel.org/r/564f8612-0601-b267-514f-a9f650ec9b32@colorfullife.com
Link: http://lkml.kernel.org/r/20170525185107.12869-3-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/sem.c: remove sem_base, embed struct sem

sma->sem_base is initialized with

sma->sem_base = (struct sem *) &sma[1];

The current code has four problems:
 - There is an unnecessary pointer dereference - sem_base is not needed.
 - Alignment for struct sem only works by chance.
 - The current code causes false positive for static code analysis.
 - This is a cast between different non-void types, which the future
   randstruct GCC plugin warns on.

And, as bonus, the code size gets smaller:

  Before:
    0 .text         00003770
  After:
    0 .text         0000374e

[manfred@colorfullife.com: s/[0]/[]/, per hch]
Link: http://lkml.kernel.org/r/20170525185107.12869-2-manfred@colorfullife.com
Link: http://lkml.kernel.org/r/20170515171912.6298-2-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: <1vier1@web.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fault-inject: support systematic fault injection

Add /proc/self/task/<current-tid>/fail-nth file that allows failing
0-th, 1-st, 2-nd and so on calls systematically.
Excerpt from the added documentation:

 "Write to this file of integer N makes N-th call in the current task
  fail (N is 0-based). Read from this file returns a single char 'Y' or
  'N' that says if the fault setup with a previous write to this file
  was injected or not, and disables the fault if it wasn't yet injected.
  Note that this file enables all types of faults (slab, futex, etc).
  This setting takes precedence over all other generic settings like
  probability, interval, times, etc. But per-capability settings (e.g.
  fail_futex/ignore-private) take precedence over it. This feature is
  intended for systematic testing of faults in a single system call. See
  an example below"

Why add a new setting:
1. Existing settings are global rather than per-task.
   So parallel testing is not possible.
2. attr->interval is close but it depends on attr->count
   which is non reset to 0, so interval does not work as expected.
3. Trying to model this with existing settings requires manipulations
   of all of probability, interval, times, space, task-filter and
   unexposed count and per-task make-it-fail files.
4. Existing settings are per-failure-type, and the set of failure
   types is potentially expanding.
5. make-it-fail can't be changed by unprivileged user and aggressive
   stress testing better be done from an unprivileged user.
   Similarly, this would require opening the debugfs files to the
   unprivileged user, as he would need to reopen at least times file
   (not possible to pre-open before dropping privs).

The proposed interface solves all of the above (see the example).

We want to integrate this into syzkaller fuzzer.  A prototype has found
10 bugs in kernel in first day of usage:

  https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance

I've made the current interface work with all types of our sandboxes.
For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to
make /proc entries non-root owned.  So I am fine with the current
version of the code.

[akpm@linux-foundation.org: fix build]
Link: http://lkml.kernel.org/r/20170328130128.101773-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kcmp: fs/epoll: wrap kcmp code with CONFIG_CHECKPOINT_RESTORE

kcmp syscall is build iif CONFIG_CHECKPOINT_RESTORE is selected, so wrap
appropriate helpers in epoll code with the config to build it
conditionally.

Link: http://lkml.kernel.org/r/20170513083456.GG1881@uranus.lan
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reported-by: Andrew Morton <akpm@linuxfoundation.org>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kcmp: add KCMP_EPOLL_TFD mode to compare epoll target files

With current epoll architecture target files are addressed with
file_struct and file descriptor number, where the last is not unique.
Moreover files can be transferred from another process via unix socket,
added into queue and closed then so we won't find this descriptor in the
task fdinfo list.

Thus to checkpoint and restore such processes CRIU needs to find out
where exactly the target file is present to add it into epoll queue.
For this sake one can use kcmp call where some particular target file
from the queue is compared with arbitrary file passed as an argument.

Because epoll target files can have same file descriptor number but
different file_struct a caller should explicitly specify the offset
within.

To test if some particular file is matching entry inside epoll one have
to

 - fill kcmp_epoll_slot structure with epoll file descriptor,
   target file number and target file offset (in case if only
   one target is present then it should be 0)

 - call kcmp as kcmp(pid1, pid2, KCMP_EPOLL_TFD, fd, &kcmp_epoll_slot)
    - the kernel fetch file pointer matching file descriptor @fd of pid1
    - lookups for file struct in epoll queue of pid2 and returns traditional
      0,1,2 result for sorting purpose

Link: http://lkml.kernel.org/r/20170424154423.511592110@gmail.com
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

procfs: fdinfo: extend information about epoll target files

Since it is possbile to have same number in tfd field (say file added,
closed, then nother file dup'ed to same number and added back) it is
imposible to distinguish such target files solely by their numbers.

Strictly speaking regular applications don't need to recognize these
targets at all but for checkpoint/restore sake we need to collect
targets to be able to push them back on restore stage in a proper order.

Thus lets add file position, inode and device number where this target
lays.  This three fields can be used as a primary key for sorting, and
together with kcmp help CRIU can find out an exact file target (from the
whole set of processes being checkpointed).

Link: http://lkml.kernel.org/r/20170424154423.436491881@gmail.com
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kfifo: clean up example to not use page_link

This is a layering violation so we replace the uses with calls to
sg_page().  This is a prep patch for replacing page_link and this is one
of the very few uses outside of scatterlist.h.

Link: http://lkml.kernel.org/r/1495663199-22234-1-git-send-email-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/gdb: lx-dmesg: use explicit encoding=utf8 errors=replace

Use errors=replace because it is never desirable for lx-dmesg to fail on
string decoding errors, not even if the log buffer is corrupt and we
show incorrect info.

The kernel will sometimes print utf8, for example the copyright symbol
from jffs2.  In order to make this work specify 'utf8' everywhere
because python2 otherwise defaults to 'ascii'.

In theory the second errors='replace' is not be required because
everything that can be decoded as utf8 should also be encodable back to
utf8.  But it's better to be extra safe here.  It's worth noting that
this is definitely not true for encoding='ascii', unknown characters are
replaced with U+FFFD REPLACEMENT CHARACTER and they fail to encode back
to ascii.

Link: http://lkml.kernel.org/r/acee067f3345954ed41efb77b80eebdc038619c6.1498481469.git.leonard.crestez@nxp.com
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kieran@ksquared.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/gdb: lx-dmesg: cast log_buf to void* for addr fetch

In some cases it is possible for the str() conversion here to throw
encoding errors because log_buf might not point to valid ascii.  For
example:

  (gdb) python print str(gdb.parse_and_eval("log_buf"))
  Traceback (most recent call last):
    File "<string>", line 1, in <module>
  UnicodeEncodeError: 'ascii' codec can't encode character u'\u0303' in
   position 24: ordinal not in range(128)

Avoid this by explicitly casting to (void *) inside the gdb expression.

Link: http://lkml.kernel.org/r/ba6f85dbb02ca980ebd0e2399b0649423399b565.1498481469.git.leonard.crestez@nxp.com
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kieran@ksquared.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/gdb: add lx-fdtdump command

lx-fdtdump dumps the flattened device tree passed to the kernel from the
bootloader to the filename specified as the command argument.  If no
argument is provided it defaults to fdtdump.dtb.  This then allows
further post processing on the machine running GDB.  The fdt header is
also also printed in the GDB console.  For example:

  (gdb) lx-fdtdump
  fdt_magic:         0xD00DFEED
  fdt_totalsize:     0xC108
  off_dt_struct:     0x38
  off_dt_strings:    0x3804
  off_mem_rsvmap:    0x28
  version:           17
  last_comp_version: 16
  Dumped fdt to fdtdump.dtb

  >fdtdump fdtdump.dtb | less

This command is useful as the bootloader can often re-write parts of the
device tree, and this can sometimes cause the kernel to not boot.

Link: http://lkml.kernel.org/r/1481280065-5336-2-git-send-email-kbingham@kernel.org
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Kieran Bingham <kbingham@kernel.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/Kconfig: kill CONFIG_PERCPU_RWSEM some more

As of commit bf3eac84c42d ("percpu-rwsem: kill CONFIG_PERCPU_RWSEM") we
unconditionally build pcpu-rwsems.  Remove a leftover in for
FILE_LOCKING.

Link: http://lkml.kernel.org/r/20170518180115.2794-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bfs: fix sanity checks for empty files

Mount fails if file system image has empty files because of sanity check
while reading superblock.  For empty files disk offset to end of file
(i_eoffset) is cpu_to_le32(-1).  Sanity check comparison, which compares
disk offset with file system size isn't valid for this value and hence
is ignored with this patch.

Steps to reproduce:

  $  dd if=/dev/zero of=bfs-image count=204800
  $  mkfs.bfs bfs-image
  $  mkdir bfs-mount-point
  $  sudo mount -t bfs -o loop bfs-image bfs-mount-point/
  $  cd bfs-mount-point/
  $  sudo touch a
  $  cd ..
  $  sudo umount bfs-mount-point/
  $  sudo mount -t bfs -o loop bfs-image bfs-mount-point/
  mount: /dev/loop0: can't read superblock

  $  dmesg
  [25526.689580] BFS-fs: bfs_fill_super(): Inode 0x00000003 corrupted

Tigran said:
 "If you had created the filesystem with the proper mkfs under SCO
  UnixWare 7 you (probably) wouldn't encounter this issue. But since
  commercial Unix-es are now part of history and the only proper way is
  the Linux mkfs.bfs utility, your patch is fine"

Link: http://lkml.kernel.org/r/20170505201625.GA3097@hercules.tuxera.com
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Acked-by: Tigran Aivazian <aivazian.tigran@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

random: do not ignore early device randomness

The add_device_randomness() function would ignore incoming bytes if the
crng wasn't ready.  This additionally makes sure to make an early enough
call to add_latent_entropy() to influence the initial stack canary,
which is especially important on non-x86 systems where it stays the same
through the life of the boot.

Link: http://lkml.kernel.org/r/20170626233038.GA48751@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/sysctl_binary.c: check name array length in deprecated_sysctl_warning()

Prevent use of uninitialized memory (originating from the stack frame of
do_sysctl()) by verifying that the name array is filled with sufficient
input data before comparing its specific entries with integer constants.

Through timing measurement or analyzing the kernel debug logs, a
user-mode program could potentially infer the results of comparisons
against the uninitialized memory, and acquire some (very limited)
information about the state of the kernel stack.  The change also
eliminates possible future warnings by tools such as KMSAN and other
code checkers / instrumentations.

Link: http://lkml.kernel.org/r/20170524122139.21333-1-mjurczyk@google.com
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Matthew Whitehead <tedheadster@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: test against int proc_dointvec() array support

Add a few initial respective tests for an array:

  o Echoing values separated by spaces works
  o Echoing only first elements will set first elements
  o Confirm PAGE_SIZE limit still applies even if an array is used

Link: http://lkml.kernel.org/r/20170630224431.17374-7-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add simple proc_douintvec() case

Test against a simple proc_douintvec() case.  While at it, add a test
against UINT_MAX.  Make sure UINT_MAX works, and UINT_MAX+1 will fail
and that negative values are not accepted.

Link: http://lkml.kernel.org/r/20170630224431.17374-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add simple proc_dointvec() case

Test against a simple proc_dointvec() case.  While at it, add a test
against INT_MAX.  Make sure INT_MAX works, and INT_MAX+1 will fail.
Also test negative values work.

Link: http://lkml.kernel.org/r/20170630224431.17374-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: test against PAGE_SIZE for int

Add the following tests to ensure we do not regress:

  o Test using a buffer full of space (PAGE_SIZE-1) followed by a
    single digit works

  o Test using a buffer full of spaces (PAGE_SIZE or over) will fail

As tests increase instead of unloading the module and reloading it we
can just do a shell reset_vals() with a reset to values we know are set
at init on the driver.

Link: http://lkml.kernel.org/r/20170630224431.17374-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add generic script to expand on tests

This adds a generic script to let us more easily add more tests cases.
Since we really have only two types of tests cases just fold them into
the one file.  Each test unit is now identified into its separate
function:

    # ./sysctl.sh -l
  Test ID list:

  TEST_ID x NUM_TEST
  TEST_ID:   Test ID
  NUM_TESTS: Number of recommended times to run the test

  0001 x 1 - tests proc_dointvec_minmax()
  0002 x 1 - tests proc_dostring()

For now we start off with what we had before, and run only each test
once.  We can now watch a test case until it fails:

  ./sysctl.sh -w 0002

We can also run a test case x number of times, say we want to run a test
case 100 times:

  ./sysctl.sh -c 0001 100

To run a test case only once, for example:

  ./sysctl.sh -s 0002

The default settings are specified at the top of sysctl.sh.

Link: http://lkml.kernel.org/r/20170630224431.17374-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add dedicated proc sysctl test driver

The existing tools/testing/selftests/sysctl/ tests include two test
cases, but these use existing production kernel sysctl interfaces.  We
want to expand test coverage but we can't just be looking for random
safe production values to poke at, that's just insane!

Instead just dedicate a test driver for debugging purposes and port the
existing scripts to use it.  This will make it easier for further tests
to be added.

Subsequent patches will extend our test coverage for sysctl.

The stress test driver uses a new license (GPL on Linux, copyleft-next
outside of Linux).  Linus was fine with this [0] and later due to Ted's
and Alans's request ironed out an "or" language clause to use [1] which
is already present upstream.

[0] https://lkml.kernel.org/r/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com
[1] https://lkml.kernel.org/r/1495234558.7848.122.camel@linux.intel.com

Link: http://lkml.kernel.org/r/20170630224431.17374-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: add unsigned int range support

To keep parity with regular int interfaces provide the an unsigned int
proc_douintvec_minmax() which allows you to specify a range of allowed
valid numbers.

Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an
actual user for that.

Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: simplify unsigned int support

Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32
fields") added proc_douintvec() to start help adding support for
unsigned int, this however was only half the work needed.  Two fixes
have come in since then for the following issues:

  o Printing the values shows a negative value, this happens since
    do_proc_dointvec() and this uses proc_put_long()

This was fixed by commit 5380e5644afbba9 ("sysctl: don't print negative
flag for proc_douintvec").

  o We can easily wrap around the int values: UINT_MAX is 4294967295, if
    we echo in 4294967295 + 1 we end up with 0, using 4294967295 + 2 we
    end up with 1.
  o We echo negative values in and they are accepted

This was fixed by commit 425fffd886ba ("sysctl: report EINVAL if value
is larger than UINT_MAX for proc_douintvec").

It still also failed to be added to sysctl_check_table()...  instead of
adding it with the current implementation just provide a proper and
simplified unsigned int support without any array unsigned int support
with no negative support at all.

Historically sysctl proc helpers have supported arrays, due to the
complexity this adds though we've taken a step back to evaluate array
users to determine if its worth upkeeping for unsigned int.  An
evaluation using Coccinelle has been done to perform a grammatical
search to ask ourselves:

  o How many sysctl proc_dointvec() (int) users exist which likely
    should be moved over to proc_douintvec() (unsigned int) ?
Answer: about 8
- Of these how many are array users ?
Answer: Probably only 1
  o How many sysctl array users exist ?
Answer: about 12

This last question gives us an idea just how popular arrays: they are not.
Array support should probably just be kept for strings.

The identified uint ports are:

  drivers/infiniband/core/ucma.c - max_backlog
  drivers/infiniband/core/iwcm.c - default_backlog
  net/core/sysctl_net_core.c - rps_sock_flow_sysctl()
  net/netfilter/nf_conntrack_timestamp.c - nf_conntrack_timestamp -- bool
  net/netfilter/nf_conntrack_acct.c nf_conntrack_acct -- bool
  net/netfilter/nf_conntrack_ecache.c - nf_conntrack_events -- bool
  net/netfilter/nf_conntrack_helper.c - nf_conntrack_helper -- bool
  net/phonet/sysctl.c proc_local_port_range()

The only possible array users is proc_local_port_range() but it does not
seem worth it to add array support just for this given the range support
works just as well.  Unsigned int support should be desirable more for
when you *need* more than INT_MAX or using int min/max support then does
not suffice for your ranges.

If you forget and by mistake happen to register an unsigned int proc
entry with an array, the driver will fail and you will get something as
follows:

sysctl table check failed: debug/test_sysctl//uint_0002 array now allowed
CPU: 2 PID: 1342 Comm: modprobe Tainted: G        W   E <etc>
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS <etc>
Call Trace:
 dump_stack+0x63/0x81
 __register_sysctl_table+0x350/0x650
 ? kmem_cache_alloc_trace+0x107/0x240
 __register_sysctl_paths+0x1b3/0x1e0
 ? 0xffffffffc005f000
 register_sysctl_table+0x1f/0x30
 test_sysctl_init+0x10/0x1000 [test_sysctl]
 do_one_initcall+0x52/0x1a0
 ? kmem_cache_alloc_trace+0x107/0x240
 do_init_module+0x5f/0x200
 load_module+0x1867/0x1bd0
 ? __symbol_put+0x60/0x60
 SYSC_finit_module+0xdf/0x110
 SyS_finit_module+0xe/0x10
 entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f042b22d119
<etc>

Fixes: e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields")
Link: http://lkml.kernel.org/r/20170519033554.18592-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Liping Zhang <zlpnobody@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: fold sysctl_writes_strict checks into helper

The mode sysctl_writes_strict positional checks keep being copy and pasted
as we add new proc handlers.  Just add a helper to avoid code duplication.

Link: http://lkml.kernel.org/r/20170519033554.18592-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: kdoc'ify sysctl_writes_strict

Document the different sysctl_writes_strict modes in code.

Link: http://lkml.kernel.org/r/20170519033554.18592-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: fix lax sysctl_check_table() sanity check

Patch series "sysctl: few fixes", v5.

I've been working on making kmod more deterministic, and as I did that I
couldn't help but notice a few issues with sysctl.  My end goal was just
to fix unsigned int support, which back then was completely broken.
Liping Zhang has sent up small atomic fixes, however it still missed yet
one more fix and Alexey Dobriyan had also suggested to just drop array
support given its complexity.

I have inspected array support using Coccinelle and indeed its not that
popular, so if in fact we can avoid it for new interfaces, I agree its
best.

I did develop a sysctl stress driver but will hold that off for another
series.

This patch (of 5):

Commit 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks")
improved sanity checks considerbly, however the enhancements on
sysctl_check_table() meant adding a functional change so that only the
last table entry's sanity error is propagated.  It also changed the way
errors were propagated so that each new check reset the err value, this
means only last sanity check computed is used for an error.  This has
been in the kernel since v3.4 days.

Fix this by carrying on errors from previous checks and iterations as we
traverse the table and ensuring we keep any error from previous checks.
We keep iterating on the table even if an error is found so we can
complain for all errors found in one shot.  This works as -EINVAL is
always returned on error anyway, and the check for error is any non-zero
value.

Fixes: 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks")
Link: http://lkml.kernel.org/r/20170519033554.18592-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec/kdump: minor Documentation updates for arm64 and Image

Minor updates in Documentation for arm64 as relocatable kernel.  Also
this patch updates documentation for using uncompressed image "Image"
which is used for ARM64.

Link: http://lkml.kernel.org/r/1495104793-6563-1-git-send-email-Bharat.Bhushan@nxp.com
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Pratyush Anand <panand@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kdump: protect vmcoreinfo data under the crash memory

Currently vmcoreinfo data is updated at boot time subsys_initcall(), it
has the risk of being modified by some wrong code during system is
running.

As a result, vmcore dumped may contain the wrong vmcoreinfo.  Later on,
when using "crash", "makedumpfile", etc utility to parse this vmcore, we
probably will get "Segmentation fault" or other unexpected errors.

E.g.  1) wrong code overwrites vmcoreinfo_data; 2) further crashes the
system; 3) trigger kdump, then we obviously will fail to recognize the
crash context correctly due to the corrupted vmcoreinfo.

Now except for vmcoreinfo, all the crash data is well
protected(including the cpu note which is fully updated in the crash
path, thus its correctness is guaranteed).  Given that vmcoreinfo data
is a large chunk prepared for kdump, we better protect it as well.

To solve this, we relocate and copy vmcoreinfo_data to the crash memory
when kdump is loading via kexec syscalls.  Because the whole crash
memory will be protected by existing arch_kexec_protect_crashkres()
mechanism, we naturally protect vmcoreinfo_data from write(even read)
access under kernel direct mapping after kdump is loaded.

Since kdump is usually loaded at the very early stage after boot, we can
trust the correctness of the vmcoreinfo data copied.

On the other hand, we still need to operate the vmcoreinfo safe copy
when crash happens to generate vmcoreinfo_note again, we rely on vmap()
to map out a new kernel virtual address and update to use this new one
instead in the following crash_save_vmcoreinfo().

BTW, we do not touch vmcoreinfo_note, because it will be fully updated
using the protected vmcoreinfo_data after crash which is surely correct
just like the cpu crash note.

Link: http://lkml.kernel.org/r/1493281021-20737-3-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/fadump: use the correct VMCOREINFO_NOTE_SIZE for phdr

vmcoreinfo_max_size stands for the vmcoreinfo_data, the correct one we
should use is vmcoreinfo_note whose total size is VMCOREINFO_NOTE_SIZE.

Like explained in commit 77019967f06b ("kdump: fix exported size of
vmcoreinfo note"), it should not affect the actual function, but we
better fix it, also this change should be safe and backward compatible.

After this, we can get rid of variable vmcoreinfo_max_size, let's use
the corresponding macros directly, fewer variables means more safety for
vmcoreinfo operation.

[xlpang@redhat.com: fix build warning]
Link: http://lkml.kernel.org/r/1494830606-27736-1-git-send-email-xlpang@redhat.com
Link: http://lkml.kernel.org/r/1493281021-20737-2-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: move vmcoreinfo out of the kernel's .bss section

As Eric said,
 "what we need to do is move the variable vmcoreinfo_note out of the
  kernel's .bss section. And modify the code to regenerate and keep this
  information in something like the control page.

  Definitely something like this needs a page all to itself, and ideally
  far away from any other kernel data structures. I clearly was not
  watching closely the data someone decided to keep this silly thing in
  the kernel's .bss section."

This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.

Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Suggested-by: Eric Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/fork.c: virtually mapped stacks: do not disable interrupts

The reason to disable interrupts seems to be to avoid switching to a
different processor while handling per cpu data using individual loads and
stores.  If we use per cpu RMV primitives we will not have to disable
interrupts.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705171055130.5898@east.gentwo.org
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c: mark create_huge_pmd() inline to prevent build failure

With gcc 4.1.2:

    mm/memory.o: In function `create_huge_pmd':
    memory.c:(.text+0x93e): undefined reference to `do_huge_pmd_anonymous_page'

Interestingly, create_huge_pmd() is emitted in the assembler output, but
never called.

Converting transparent_hugepage_enabled() from a macro to a static
inline function reduced the ability of the compiler to remove unused
code.

Fix this by marking create_huge_pmd() inline.

Fixes: 16981d763501c0e0 ("mm: improve readability of transparent_hugepage_enabled()")
Link: http://lkml.kernel.org/r/1499842660-10665-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel.h: handle pointers to arrays better in container_of()

If the first parameter of container_of() is a pointer to a
non-const-qualified array type (and the third parameter names a
non-const-qualified array member), the local variable __mptr will be
defined with a const-qualified array type.  In ISO C, these types are
incompatible.  They work as expected in GNU C, but some versions will
issue warnings.  For example, GCC 4.9 produces the warning
"initialization from incompatible pointer type".

Here is an example of where the problem occurs:

-------------------------------------------------------
   #include <linux/kernel.h>
   #include <linux/module.h>

  MODULE_LICENSE("GPL");

  struct st {
   int a;
   char b[16];
  };

  static int __init example_init(void) {
   struct st t = { .a = 101, .b = "hello" };
   char (*p)[16] = &t.b;
   struct st *x = container_of(p, struct st, b);
   printk(KERN_DEBUG "%p %p\n", (void *)&t, (void *)x);
   return 0;
  }

  static void __exit example_exit(void) {
  }

  module_init(example_init);
  module_exit(example_exit);
-------------------------------------------------------

Building the module with gcc-4.9 results in these warnings (where '{m}'
is the module source and '{k}' is the kernel source):

-------------------------------------------------------
  In file included from {m}/example.c:1:0:
  {m}/example.c: In function `example_init':
  {k}/include/linux/kernel.h:854:48: warning: initialization from incompatible pointer type
    const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                                  ^
  {m}/example.c:14:17: note: in expansion of macro `container_of'
    struct st *x = container_of(p, struct st, b);
                   ^
  {k}/include/linux/kernel.h:854:48: warning: (near initialization for `x')
    const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                                  ^
  {m}/example.c:14:17: note: in expansion of macro `container_of'
    struct st *x = container_of(p, struct st, b);
                   ^
-------------------------------------------------------

Replace the type checking performed by the macro to avoid these
warnings.  Make sure `*(ptr)` either has type compatible with the
member, or has type compatible with `void`, ignoring qualifiers.  Raise
compiler errors if this is not true.  This is stronger than the previous
behaviour, which only resulted in compiler warnings for a type mismatch.

[arnd@arndb.de: fix new warnings for container_of()]
Link: http://lkml.kernel.org/r/20170620200940.90557-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170525120316.24473-7-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/dcache.h: use unsigned chars in struct name_snapshot

"kernel.h: handle pointers to arrays better in container_of()" triggers:

In file included from include/uapi/linux/stddef.h:1:0,
                 from include/linux/stddef.h:4,
                 from include/uapi/linux/posix_types.h:4,
                 from include/uapi/linux/types.h:13,
                 from include/linux/types.h:5,
                 from include/linux/syscalls.h:71,
                 from fs/dcache.c:17:
fs/dcache.c: In function 'release_dentry_name_snapshot':
include/linux/compiler.h:542:38: error: call to '__compiletime_assert_305' declared with attribute error: pointer type mismatch in container_of()
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
                                      ^
include/linux/compiler.h:525:4: note: in definition of macro '__compiletime_assert'
    prefix ## suffix();    \
    ^
include/linux/compiler.h:542:2: note: in expansion of macro '_compiletime_assert'
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
  ^
include/linux/build_bug.h:46:37: note: in expansion of macro 'compiletime_assert'
 #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                     ^
include/linux/kernel.h:860:2: note: in expansion of macro 'BUILD_BUG_ON_MSG'
  BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
  ^
fs/dcache.c:305:7: note: in expansion of macro 'container_of'
   p = container_of(name->name, struct external_name, name[0]);

Switch name_snapshot to use unsigned chars, matching struct qstr and
struct external_name.

Link: http://lkml.kernel.org/r/20170710152134.0f78c1e6@canb.auug.org.au
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'i2c/for-4.13' of git://git./linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "This pull request contains:

   - i2c core reorganization. One source file became too monolithic. It
     is now split up, yet we still have the same named object as the
     final output. This should ease maintenance.

   - new drivers: ZTE ZX2967 family, ASPEED 24XX/25XX

   - designware driver gained slave mode support

   - xgene-slimpro driver gained ACPI support

   - bigger overhaul for pca-platform driver

   - the algo-bit module now supports messages with enforced STOP

   - slightly bigger than usual set of driver updates and improvements

  and with much appreciated quality assurance from Andy Shevchenko"

* 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (51 commits)
  i2c: Provide a stub for i2c_detect_slave_mode()
  i2c: designware: Let slave adapter support be optional
  i2c: designware: Make HW init functions static
  i2c: designware: fix spelling mistakes
  i2c: pca-platform: propagate error from i2c_pca_add_numbered_bus
  i2c: pca-platform: correctly set algo_data.reset_chip
  i2c: acpi: Do not create i2c-clients for LNXVIDEO ACPI devices
  i2c: designware: enable SLAVE in platform module
  i2c: designware: add SLAVE mode functions
  i2c: zx2967: drop COMPILE_TEST dependency
  i2c: zx2967: always use the same device when printing errors
  i2c: pca-platform: use dev_warn/dev_info instead of printk
  i2c: pca-platform: use device managed allocations
  i2c: pca-platform: add devicetree awareness
  i2c: pca-platform: switch to struct gpio_desc
  dt-bindings: add bindings for i2c-pca-platform
  i2c: cadance: fix ctrl/addr reg write order
  i2c: zx2967: add i2c controller driver for ZTE's zx2967 family
  dt: bindings: add documentation for zx2967 family i2c controller
  i2c: algo-bit: add support for I2C_M_STOP
  ...

Merge tag 'iommu-updates-v4.13' of git://git./linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
 "This update comes with:

   - Support for lockless operation in the ARM io-pgtable code.

     This is an important step to solve the scalability problems in the
     common dma-iommu code for ARM

   - Some Errata workarounds for ARM SMMU implemenations

   - Rewrite of the deferred IO/TLB flush code in the AMD IOMMU driver.

     The code suffered from very high flush rates, with the new
     implementation the flush rate is down to ~1% of what it was before

   - Support for amd_iommu=off when booting with kexec.

     The problem here was that the IOMMU driver bailed out early without
     disabling the iommu hardware, if it was enabled in the old kernel

   - The Rockchip IOMMU driver is now available on ARM64

   - Align the return value of the iommu_ops->device_group call-backs to
     not miss error values

   - Preempt-disable optimizations in the Intel VT-d and common IOVA
     code to help Linux-RT

   - Various other small cleanups and fixes"

* tag 'iommu-updates-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (60 commits)
  iommu/vt-d: Constify intel_dma_ops
  iommu: Warn once when device_group callback returns NULL
  iommu/omap: Return ERR_PTR in device_group call-back
  iommu: Return ERR_PTR() values from device_group call-backs
  iommu/s390: Use iommu_group_get_for_dev() in s390_iommu_add_device()
  iommu/vt-d: Don't disable preemption while accessing deferred_flush()
  iommu/iova: Don't disable preempt around this_cpu_ptr()
  iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126
  iommu/arm-smmu-v3: Enable ACPI based HiSilicon CMD_PREFETCH quirk(erratum 161010701)
  iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74
  ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3 model
  iommu/arm-smmu-v3, acpi: Add temporary Cavium SMMU-V3 IORT model number definitions
  iommu/io-pgtable-arm: Use dma_wmb() instead of wmb() when publishing table
  iommu/io-pgtable: depend on !GENERIC_ATOMIC64 when using COMPILE_TEST with LPAE
  iommu/arm-smmu-v3: Remove io-pgtable spinlock
  iommu/arm-smmu: Remove io-pgtable spinlock
  iommu/io-pgtable-arm-v7s: Support lockless operation
  iommu/io-pgtable-arm: Support lockless operation
  iommu/io-pgtable: Introduce explicit coherency
  iommu/io-pgtable-arm-v7s: Refactor split_blk_unmap
  ...

Merge branch 'overlayfs-linus' of git://git./linux/kernel/git/mszeredi/vfs

Pull overlayfs updates from Miklos Szeredi:
 "This work from Amir introduces the inodes index feature, which
  provides:

   - hardlinks are not broken on copy up

   - infrastructure for overlayfs NFS export

  This also fixes constant st_ino for samefs case for lower hardlinks"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (33 commits)
  ovl: mark parent impure and restore timestamp on ovl_link_up()
  ovl: document copying layers restrictions with inodes index
  ovl: cleanup orphan index entries
  ovl: persistent overlay inode nlink for indexed inodes
  ovl: implement index dir copy up
  ovl: move copy up lock out
  ovl: rearrange copy up
  ovl: add flag for upper in ovl_entry
  ovl: use struct copy_up_ctx as function argument
  ovl: base tmpfile in workdir too
  ovl: factor out ovl_copy_up_inode() helper
  ovl: extract helper to get temp file in copy up
  ovl: defer upper dir lock to tempfile link
  ovl: hash overlay non-dir inodes by copy up origin
  ovl: cleanup bad and stale index entries on mount
  ovl: lookup index entry for copy up origin
  ovl: verify index dir matches upper dir
  ovl: verify upper root dir matches lower root dir
  ovl: introduce the inodes index dir feature
  ovl: generalize ovl_create_workdir()
  ...

fix a braino in compat_sys_getrlimit()

Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Fixes: commit d9e968cb9f84 "getrlimit()/setrlimit(): move compat to native"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge git://git./linux/kernel/git/davem/sparc

Pull sparc fixes from David Miller:

 - Fix symbol version generation for assembler on sparc, from
   Nagarathnam Muthusamy.

 - Fix compound page handling in gup_huge_pmd(), from Nitin Gupta.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix gup_huge_pmd
  Adding the type of exported symbols
  sed regex in Makefile.build requires line break between exported symbols
  Adding asm-prototypes.h for genksyms to generate crc

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
 "This is a followup for block changes, that didn't make the initial
  pull request. It's a bit of a mixed bag, this contains:

   - A followup pull request from Sagi for NVMe. Outside of fixups for
     NVMe, it also includes a series for ensuring that we properly
     quiesce hardware queues when browsing live tags.

   - Set of integrity fixes from Dmitry (mostly), fixing various issues
     for folks using DIF/DIX.

   - Fix for a bug introduced in cciss, with the req init changes. From
     Christoph.

   - Fix for a bug in BFQ, from Paolo.

   - Two followup fixes for lightnvm/pblk from Javier.

   - Depth fix from Ming for blk-mq-sched.

   - Also from Ming, performance fix for mtip32xx that was introduced
     with the dynamic initialization of commands"

* 'for-linus' of git://git.kernel.dk/linux-block: (44 commits)
  block: call bio_uninit in bio_endio
  nvmet: avoid unneeded assignment of submit_bio return value
  nvme-pci: add module parameter for io queue depth
  nvme-pci: compile warnings in nvme_alloc_host_mem()
  nvmet_fc: Accept variable pad lengths on Create Association LS
  nvme_fc/nvmet_fc: revise Create Association descriptor length
  lightnvm: pblk: remove unnecessary checks
  lightnvm: pblk: control I/O flow also on tear down
  cciss: initialize struct scsi_req
  null_blk: fix error flow for shared tags during module_init
  block: Fix __blkdev_issue_zeroout loop
  nvme-rdma: unconditionally recycle the request mr
  nvme: split nvme_uninit_ctrl into stop and uninit
  virtio_blk: quiesce/unquiesce live IO when entering PM states
  mtip32xx: quiesce request queues to make sure no submissions are inflight
  nbd: quiesce request queues to make sure no submissions are inflight
  nvme: kick requeue list when requeueing a request instead of when starting the queues
  nvme-pci: quiesce/unquiesce admin_q instead of start/stop its hw queues
  nvme-loop: quiesce/unquiesce admin_q instead of start/stop its hw queues
  nvme-fc: quiesce/unquiesce admin_q instead of start/stop its hw queues
  ...

Merge tag 'smb3-security-fixes-for-4.13' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes and sane default from Steve French:
 "Upgrade default dialect to more secure SMB3 from older cifs dialect"

* tag 'smb3-security-fixes-for-4.13' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Clean up unused variables in smb2pdu.c
  [SMB3] Improve security, move default dialect to SMB3 from old CIFS
  [SMB3] Remove ifdef since SMB3 (and later) now STRONGLY preferred
  CIFS: Reconnect expired SMB sessions
  CIFS: Display SMB2 error codes in the hex format
  cifs: Use smb 2 - 3 and cifsacl mount options setacl function
  cifs: prototype declaration and definition to set acl for smb 2 - 3 and cifsacl mount options

Merge tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-client

Pull ceph updates from Ilya Dryomov:
 "The main item here is support for v12.y.z ("Luminous") clusters:
  RESEND_ON_SPLIT, RADOS_BACKOFF, OSDMAP_PG_UPMAP and CRUSH_CHOOSE_ARGS
  feature bits, and various other changes in the RADOS client protocol.

  On top of that we have a new fsc mount option to allow supplying
  fscache uniquifier (similar to NFS) and the usual pile of filesystem
  fixes from Zheng"

* tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-client: (44 commits)
  libceph: advertise support for NEW_OSDOP_ENCODING and SERVER_LUMINOUS
  libceph: osd_state is 32 bits wide in luminous
  crush: remove an obsolete comment
  crush: crush_init_workspace starts with struct crush_work
  libceph, crush: per-pool crush_choose_arg_map for crush_do_rule()
  crush: implement weight and id overrides for straw2
  libceph: apply_upmap()
  libceph: compute actual pgid in ceph_pg_to_up_acting_osds()
  libceph: pg_upmap[_items] infrastructure
  libceph: ceph_decode_skip_* helpers
  libceph: kill __{insert,lookup,remove}_pg_mapping()
  libceph: introduce and switch to decode_pg_mapping()
  libceph: don't pass pgid by value
  libceph: respect RADOS_BACKOFF backoffs
  libceph: make DEFINE_RB_* helpers more general
  libceph: avoid unnecessary pi lookups in calc_target()
  libceph: use target pi for calc_target() calculations
  libceph: always populate t->target_{oid,oloc} in calc_target()
  libceph: make sure need_resend targets reflect latest map
  libceph: delete from need_resend_linger before check_linger_pool_dne()
  ...

Merge git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - Add Renesas RZ/A WDT Watchdog driver

 - STM32 Independent WatchDoG (IWDG) support

 - UniPhier watchdog support

 - Add F71868 support

 - Add support for NCT6793D and NCT6795D

 - dw_wdt: add reset lines support

 - core: add option to avoid early handling of watchdog

 - core: introduce watchdog_worker_should_ping helper

 - Cleanups and improvements for sama5d4, intel-mid_wdt, s3c2410_wdt,
   orion_wdt, gpio_wdt, it87_wdt, meson_wdt, davinci_wdt, bcm47xx_wdt,
   zx2967_wdt, cadence_wdt

* git://www.linux-watchdog.org/linux-watchdog: (32 commits)
  watchdog: introduce watchdog_worker_should_ping helper
  watchdog: uniphier: add UniPhier watchdog driver
  dt-bindings: watchdog: add description for UniPhier WDT controller
  watchdog: cadence_wdt: make of_device_ids const.
  watchdog: zx2967: constify zx2967_wdt_ops.
  watchdog: bcm47xx_wdt: constify bcm47xx_wdt_hard_ops and bcm47xx_wdt_soft_ops
  watchdog: davinci: Add missing clk_disable_unprepare().
  watchdog: davinci: Handle return value of clk_prepare_enable
  watchdog: meson: Handle return value of clk_prepare_enable
  watchdog: it87: Add support for various Super-IO chips
  watchdog: it87: Use infrastructure to stop watchdog on reboot
  watchdog: it87: Drop support for resetting watchdog though CIR and Game port
  watchdog: it87: Convert to use watchdog core infrastructure
  watchdog: it87: Drop FSF mailing address
  watchdog: dw_wdt: get reset lines from dt
  watchdog: bindings: dw_wdt: add reset lines
  watchdog: w83627hf: Add support for NCT6793D and NCT6795D
  watchdog: core: add option to avoid early handling of watchdog
  watchdog: f71808e_wdt: Add F71868 support
  watchdog: Add STM32 IWDG driver
  ...

Merge tag 'chrome-platform-for-linus-4.13' of git://git./linux/kernel/git/bleung/chrome-platform

Pull chrome platform updates from Benson Leung:
 "Changes in this pull request are around catching up cros_ec with the
  internal chromeos-kernel versions of cros_ec, cros_ec_lpc, and
  cros_ec_lightbar.

  Also, switching maintainership from olof to bleung"

* tag 'chrome-platform-for-linus-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform:
  platform/chrome : Add myself as Maintainer
  platform/chrome: cros_ec_lightbar - hide unused PM functions
  cros_ec: Don't signal wake event for non-wake host events
  cros_ec: Fix deadlock when EC is not responsive at probe
  cros_ec: Don't return error when checking command version
  platform/chrome: cros_ec_lightbar - Avoid I2C xfer to EC during suspend
  platform/chrome: cros_ec_lightbar - Add userspace lightbar control bit to EC
  platform/chrome: cros_ec_lightbar - Control of suspend/resume lightbar sequence
  platform/chrome: cros_ec_lightbar - Add lightbar program feature to sysfs
  platform/chrome: cros_ec_lpc: Add MKBP events support over ACPI
  platform/chrome: cros_ec_lpc: Add power management ops
  platform/chrome: cros_ec_lpc: Add support for GOOG004 ACPI device
  platform/chrome: cros_ec_lpc: Add support for mec1322 EC
  platform/chrome: cros_ec_lpc: Add R/W helpers to LPC protocol variants
  mfd: cros_ec: Add support for dumping panic information
  cros_ec_debugfs: Pass proper struct sizes to cros_ec_cmd_xfer()
  mfd: cros_ec: add debugfs, console log file
  mfd: cros_ec: Add EC console read structures definitions
  mfd: cros_ec: Add helper for event notifier.

Merge branch 'for-next' of git://git./linux/kernel/git/gerg/m68knommu

Pull x86nommu update from Greg Ungerer:
 "Only a single change, to remove old Kconfig options from defconfigs"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: defconfig: Cleanup from old Kconfig options

Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - most of the rest of MM

 - KASAN updates

 - lib/ updates

 - checkpatch updates

 - some binfmt_elf changes

 - various misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (115 commits)
  kernel/exit.c: avoid undefined behaviour when calling wait4()
  kernel/signal.c: avoid undefined behaviour in kill_something_info
  binfmt_elf: safely increment argv pointers
  s390: reduce ELF_ET_DYN_BASE
  powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm64: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm: move ELF_ET_DYN_BASE to 4MB
  binfmt_elf: use ELF_ET_DYN_BASE only for PIE
  fs, epoll: short circuit fetching events if thread has been killed
  checkpatch: improve multi-line alignment test
  checkpatch: improve macro reuse test
  checkpatch: change format of --color argument to --color[=WHEN]
  checkpatch: silence perl 5.26.0 unescaped left brace warnings
  checkpatch: improve tests for multiple line function definitions
  checkpatch: remove false warning for commit reference
  checkpatch: fix stepping through statements with $stat and ctx_statement_block
  checkpatch: [HLP]LIST_HEAD is also declaration
  checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\t
  checkpatch: improve the unnecessary OOM message test
  lib/bsearch.c: micro-optimize pivot position calculation
  ...

kernel/exit.c: avoid undefined behaviour when calling wait4()

wait4(-2147483648, 0x20, 0, 0xdd0000) triggers:
UBSAN: Undefined behaviour in kernel/exit.c:1651:9

The related calltrace is as follows:

  negation of -2147483648 cannot be represented in type 'int':
  CPU: 9 PID: 16482 Comm: zj Tainted: G    B          ---- -------   3.10.0-327.53.58.71.x86_64+ #66
  Hardware name: Huawei Technologies Co., Ltd. Tecal RH2285          /BC11BTSA              , BIOS CTSAV036 04/27/2011
  Call Trace:
    dump_stack+0x19/0x1b
    ubsan_epilogue+0xd/0x50
    __ubsan_handle_negate_overflow+0x109/0x14e
    SyS_wait4+0x1cb/0x1e0
    system_call_fastpath+0x16/0x1b

Exclude the overflow to avoid the UBSAN warning.

Link: http://lkml.kernel.org/r/1497264618-20212-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhongjiang <zhongjiang@huawei.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/signal.c: avoid undefined behaviour in kill_something_info

When running kill(72057458746458112, 0) in userspace I hit the following
issue.

  UBSAN: Undefined behaviour in kernel/signal.c:1462:11
  negation of -2147483648 cannot be represented in type 'int':
  CPU: 226 PID: 9849 Comm: test Tainted: G    B          ---- -------   3.10.0-327.53.58.70.x86_64_ubsan+ #116
  Hardware name: Huawei Technologies Co., Ltd. RH8100 V3/BC61PBIA, BIOS BLHSV028 11/11/2014
  Call Trace:
    dump_stack+0x19/0x1b
    ubsan_epilogue+0xd/0x50
    __ubsan_handle_negate_overflow+0x109/0x14e
    SYSC_kill+0x43e/0x4d0
    SyS_kill+0xe/0x10
    system_call_fastpath+0x16/0x1b

Add code to avoid the UBSAN detection.

[akpm@linux-foundation.org: tweak comment]
Link: http://lkml.kernel.org/r/1496670008-59084-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhongjiang <zhongjiang@huawei.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

binfmt_elf: safely increment argv pointers

When building the argv/envp pointers, the envp is needlessly
pre-incremented instead of just continuing after the argv pointers are
finished.  In some (likely impossible) race where the strings could be
changed from userspace between copy_strings() and here, it might be
possible to confuse the envp position.  Instead, just use sp like
everything else.

Link: http://lkml.kernel.org/r/20170622173838.GA43308@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390: reduce ELF_ET_DYN_BASE

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers.  On 32-bit use 4MB, which is the
traditional x86 minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided).  For s390 the
position could be 0x10000, but that is needlessly close to the NULL
address.

Link: http://lkml.kernel.org/r/1498154792-49952-5-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers.  On 32-bit use 4MB, which is the
traditional x86 minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided).

Link: http://lkml.kernel.org/r/1498154792-49952-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm64: move ELF_ET_DYN_BASE to 4GB / 4MB

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers.  On 32-bit use 4MB, to match ARM.
This could be 0x8000, the standard ET_EXEC load address, but that is
needlessly close to the NULL address, and anyone running arm compat PIE
will have an MMU, so the tight mapping is not needed.

Link: http://lkml.kernel.org/r/1498251600-132458-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm: move ELF_ET_DYN_BASE to 4MB

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

4MB is chosen here mainly to have parity with x86, where this is the
traditional minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided).

For ARM the position could be 0x8000, the standard ET_EXEC load address,
but that is needlessly close to the NULL address, and anyone running PIE
on 32-bit ARM will have an MMU, so the tight mapping is not needed.

Link: http://lkml.kernel.org/r/1498154792-49952-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

binfmt_elf: use ELF_ET_DYN_BASE only for PIE

The ELF_ET_DYN_BASE position was originally intended to keep loaders
away from ET_EXEC binaries.  (For example, running "/lib/ld-linux.so.2
/bin/cat" might cause the subsequent load of /bin/cat into where the
loader had been loaded.)

With the advent of PIE (ET_DYN binaries with an INTERP Program Header),
ELF_ET_DYN_BASE continued to be used since the kernel was only looking
at ET_DYN.  However, since ELF_ET_DYN_BASE is traditionally set at the
top 1/3rd of the TASK_SIZE, a substantial portion of the address space
is unused.

For 32-bit tasks when RLIMIT_STACK is set to RLIM_INFINITY, programs are
loaded above the mmap region.  This means they can be made to collide
(CVE-2017-1000370) or nearly collide (CVE-2017-1000371) with
pathological stack regions.

Lowering ELF_ET_DYN_BASE solves both by moving programs below the mmap
region in all cases, and will now additionally avoid programs falling
back to the mmap region by enforcing MAP_FIXED for program loads (i.e.
if it would have collided with the stack, now it will fail to load
instead of falling back to the mmap region).

To allow for a lower ELF_ET_DYN_BASE, loaders (ET_DYN without INTERP)
are loaded into the mmap region, leaving space available for either an
ET_EXEC binary with a fixed location or PIE being loaded into mmap by
the loader.  Only PIE programs are loaded offset from ELF_ET_DYN_BASE,
which means architectures can now safely lower their values without risk
of loaders colliding with their subsequently loaded programs.

For 64-bit, ELF_ET_DYN_BASE is best set to 4GB to allow runtimes to use
the entire 32-bit address space for 32-bit pointers.

Thanks to PaX Team, Daniel Micay, and Rik van Riel for inspiration and
suggestions on how to implement this solution.

Fixes: d1fd836dcf00 ("mm: split ET_DYN ASLR from mmap ASLR")
Link: http://lkml.kernel.org/r/20170621173201.GA114489@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs, epoll: short circuit fetching events if thread has been killed

We've encountered zombies that are waiting for a thread to exit that are
looping in ep_poll() almost endlessly although there is a pending
SIGKILL as a result of a group exit.

This happens because we always find ep_events_available() and fetch more
events and never are able to check for signal_pending() that would break
from the loop and return -EINTR.

Special case fatal signals and break immediately to guarantee that we
loop to fetch more events and delay making a timely exit.

It would also be possible to simply move the check for signal_pending()
higher than checking for ep_events_available(), but there have been no
reports of delayed signal handling other than SIGKILL preventing zombies
from exiting that would be fixed by this.

It fixes an issue for us where we have witnessed zombies sticking around
for at least O(minutes), but considering the code has been like this
forever and nobody else has complained that I have found, I would simply
queue it up for 4.12.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705031722350.76784@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve multi-line alignment test

The current test fails to warn about improper alignment with code like

foo->bar = func(arg1,
arg2);

because foo->bar is not a single identifier.

Convert the $Ident to $Lval which allows for multiple dereferences.

Link: http://lkml.kernel.org/r/01c35b9b6a12a415e57746d45d589bfaad39952a.1498841563.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve macro reuse test

checkpatch reports a false positive when using token pasting argument
multiple times in a macro.

Fix it.

Miscellanea:

o Make the $tmp variable name used in the macro argument tests
  a bit more descriptive

Link: http://lkml.kernel.org/r/cf434ae7602838388c7cb49d42bca93ab88527e7.1498483044.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: change format of --color argument to --color[=WHEN]

The boolean --color argument did not offer the ability to force
colourized output even if stdout is not a terminal.  Change the format
of the argument to the familiar --color[=WHEN] construct as seen in
common Linux utilities such as git, ls and dmesg, which allows the user
to specify whether to colourize output "always", "never", or "auto" when
the output is a terminal.  The default is "auto".

The old command-line uses of --color and --no-color are unchanged.

Link: http://lkml.kernel.org/r/efe43bdbad400f39ba691ae663044462493b0773.1496799721.git.joe@perches.com
Signed-off-by: John Brooks <john@fastquake.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: silence perl 5.26.0 unescaped left brace warnings

As of perl 5, version 26, subversion 0 (v5.26.0) some new warnings have
occurred when running checkpatch.

Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){
<-- HERE \s*/ at scripts/checkpatch.pl line 3544.

Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){
<-- HERE \s*/ at scripts/checkpatch.pl line 3885.

Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in
m/^(\+.*(?:do|\))){ <-- HERE / at scripts/checkpatch.pl line 4374.

It seems perfectly reasonable to do as the warning suggests and simply
escape the left brace in these three locations.

Link: http://lkml.kernel.org/r/20170607060135.17384-1-cyrilbur@gmail.com
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve tests for multiple line function definitions

Add a block that identifies multiple line function definitions.

Save the function name into $context_function to improve the embedded
function name test.

Look for misplaced open brace on the function definition.
Emit an OPEN_BRACE error when the function definition is similar to

     void foo(int arg1,
              int arg2) {

Miscellanea:

o Remove the $realfile test in function declaration w/o named arguments test
o Comment the function declaration w/o named arguments test

Link: http://lkml.kernel.org/r/de620ed6ebab75fdfa323741ada2134a0f545892.1496835238.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: remove false warning for commit reference

Checkpatch warns of an incorrect commit reference style for any
hexadecimal number of 12 digits and more.

Numbers of 12 digits are not necessarily commit ids.

For an example provoking the problem see
  https://patchwork.kernel.org/patch/9170897/

Checkpatch should only warn if the number refers to an existing commit.

Link: http://lkml.kernel.org/r/20170607184008.5869-1-xypron.glpk@gmx.de
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix stepping through statements with $stat and ctx_statement_block

Fix the off-by-one in the suppression of lines in a statement block.

This means that for multiple line statements like

foo(bar,
    baz,
    qux);

$stat has been inspected first correctly for the entire statement,
and subsequently incorrectly just for

    qux);

This fix will help make tracking appropriate indentation a little easier.

Link: http://lkml.kernel.org/r/71b25979c90412133c717084036c9851cd2b7bcb.1496862585.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: [HLP]LIST_HEAD is also declaration

Fixes the following false warning among others for LLIST_HEAD and
PLIST_HEAD:

    WARNING: Missing a blank line after declarations
    #71: FILE: drivers/s390/scsi/zfcp_fsf.c:422:
    + struct hlist_node *tmp;
    + HLIST_HEAD(remove_queue);

Link: http://lkml.kernel.org/r/20170614133512.89425-1-maier@linux.vnet.ibm.com
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\t

For consistency, MAINTAINERS entries should be an upper case letter,
then a colon, then a tab, then the value.

Warn when an entry doesn't have this form.  --fix it too.

Link: http://lkml.kernel.org/r/9aaaf03ec10adf3888b5e98dd2176b7fe9b5fad8.1496343345.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve the unnecessary OOM message test

Use the context around a patch to avoid missing some candidates.

Link: http://lkml.kernel.org/r/865e874fbae5decc331a849bd8d71c325db6bc80.1496343345.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/bsearch.c: micro-optimize pivot position calculation

There is a slightly faster way (in terms of the number of instructions
being used) to calculate the position of a middle element, preserving
integer overflow safeness.

./scripts/bloat-o-meter lib/bsearch.o.old lib/bsearch.o.new
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-24 (-24)
function                                     old     new   delta
bsearch                                      122      98     -24

TEST

INT array of size 100001, elements [0..100000]. gcc 7.1, Os, x86_64.

a) bsearch() of existing key "100001 - 2":

BASE
====

$ perf stat ./a.out

 Performance counter stats for './a.out':

        619.445196      task-clock:u (msec)       #    0.999 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               133      page-faults:u             #    0.215 K/sec
     1,949,517,279      cycles:u                  #    3.147 GHz                      (83.06%)
       181,017,938      stalled-cycles-frontend:u #    9.29% frontend cycles idle     (83.05%)
        82,959,265      stalled-cycles-backend:u  #    4.26% backend cycles idle      (67.02%)
     4,355,706,383      instructions:u            #    2.23  insn per cycle
                                                  #    0.04  stalled cycles per insn  (83.54%)
     1,051,539,242      branches:u                # 1697.550 M/sec                    (83.54%)
        15,263,381      branch-misses:u           #    1.45% of all branches          (83.43%)

       0.620082548 seconds time elapsed

PATCHED
=======

$ perf stat ./a.out

 Performance counter stats for './a.out':

        475.097316      task-clock:u (msec)       #    0.999 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               135      page-faults:u             #    0.284 K/sec
     1,487,467,717      cycles:u                  #    3.131 GHz                      (82.95%)
       186,537,162      stalled-cycles-frontend:u #   12.54% frontend cycles idle     (82.93%)
        28,797,869      stalled-cycles-backend:u  #    1.94% backend cycles idle      (67.10%)
     3,807,564,203      instructions:u            #    2.56  insn per cycle
                                                  #    0.05  stalled cycles per insn  (83.57%)
     1,049,344,291      branches:u                # 2208.693 M/sec                    (83.60%)
             5,485      branch-misses:u           #    0.00% of all branches          (83.58%)

       0.475760235 seconds time elapsed

b) bsearch() of un-existing key "100001 + 2":

BASE
====

$ perf stat ./a.out

 Performance counter stats for './a.out':

        499.244480      task-clock:u (msec)       #    0.999 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               132      page-faults:u             #    0.264 K/sec
     1,571,194,855      cycles:u                  #    3.147 GHz                      (83.18%)
        13,450,980      stalled-cycles-frontend:u #    0.86% frontend cycles idle     (83.18%)
        21,256,072      stalled-cycles-backend:u  #    1.35% backend cycles idle      (66.78%)
     4,171,197,909      instructions:u            #    2.65  insn per cycle
                                                  #    0.01  stalled cycles per insn  (83.68%)
     1,009,175,281      branches:u                # 2021.405 M/sec                    (83.79%)
             3,122      branch-misses:u           #    0.00% of all branches          (83.37%)

       0.499871144 seconds time elapsed

PATCHED
=======

$ perf stat ./a.out

 Performance counter stats for './a.out':

        399.023499      task-clock:u (msec)       #    0.998 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               134      page-faults:u             #    0.336 K/sec
     1,245,793,991      cycles:u                  #    3.122 GHz                      (83.39%)
        11,529,273      stalled-cycles-frontend:u #    0.93% frontend cycles idle     (83.46%)
        12,116,311      stalled-cycles-backend:u  #    0.97% backend cycles idle      (66.92%)
     3,679,710,005      instructions:u            #    2.95  insn per cycle
                                                  #    0.00  stalled cycles per insn  (83.47%)
     1,009,792,625      branches:u                # 2530.660 M/sec                    (83.46%)
             2,590      branch-misses:u           #    0.00% of all branches          (83.12%)

       0.399733539 seconds time elapsed

Link: http://lkml.kernel.org/r/20170607150457.5905-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/extable.c: use bsearch() library function in search_extable()

[thomas@m3y3r.de: v3: fix arch specific implementations]
Link: http://lkml.kernel.org/r/1497890858.12931.7.camel@m3y3r.de
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/rhashtable.c: use kvzalloc() in bucket_table_alloc() when possible

bucket_table_alloc() can be currently called with GFP_KERNEL or
GFP_ATOMIC.  For the former we basically have an open coded kvzalloc()
while the later only uses kzalloc().  Let's simplify the code a bit by
the dropping the open coded path and replace it with kvzalloc().

Link: http://lkml.kernel.org/r/20170531155145.17111-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: allow full tree search

...  such that a user can specify visiting all the nodes in the tree
(intersects with the world).  This is a nice opposite from the very
basic default query which is a single point.

Link: http://lkml.kernel.org/r/20170518174936.20265-5-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: allow users to limit scope of endpoint

Add a 'max_endpoint' parameter such that users may easily limit the size
of the intervals that are randomly generated.

Link: http://lkml.kernel.org/r/20170518174936.20265-4-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: make test options module parameters

Allows for more flexible debugging.

Link: http://lkml.kernel.org/r/20170518174936.20265-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: allow the module to be compiled-in

Patch series "lib/interval_tree_test: some debugging improvements".

Here are some patches that update the interval_tree_test module allowing
users to pass finer grained options to run the actual test.

This patch (of 4):

It is a tristate after all, and also serves well for quick debugging.

Link: http://lkml.kernel.org/r/20170518174936.20265-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/kstrtox.c: use "unsigned int" more

gcc does generates stupid code sign extending data back and forth.  Help
by using "unsigned int".

add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-61 (-61)
function                                     old     new   delta
_parse_integer                               128     123      -5

It _still_ does generate useless MOVSX but I don't know how to delete it:

0000000000000070 <_parse_integer>:
...
  a0:   89 c2                   mov    edx,eax
  a2:   83 e8 30                sub    eax,0x30
  a5:   83 f8 09                cmp    eax,0x9
  a8:   76 11                   jbe    bb <_parse_integer+0x4b>
  aa:   83 ca 20                or     edx,0x20
  ad:   0f be c2      ===>      movsx  eax,dl         <===
useless
  b0:   8d 50 9f                lea    edx,[rax-0x61]
  b3:   83 fa 05                cmp    edx,0x5

Patch also helps on embedded archs which generally only like "int".  On
arm "and 0xff" is generated which is waste because all values used in
comparisons are positive.

Link: http://lkml.kernel.org/r/20170514194720.GB32563@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/kstrtox.c: delete end-of-string test

Standard "while (*s)" test is unnecessary because NUL won't pass
valid-digit test anyway.  Save one branch per parsed character.

Link: http://lkml.kernel.org/r/20170514193756.GA32563@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitmap: use memcmp optimisation in more situations

Commit 7dd968163f7c ("bitmap: bitmap_equal memcmp optimization") was
rather more restrictive than necessary; we can use memcmp() to implement
bitmap_equal() as long as the number of bits can be proved to be a
multiple of 8.  And architectures other than s390 may be able to make
good use of this optimisation.

[arnd@arndb.de: fix build: add a memcmp() declaration]
Link: http://lkml.kernel.org/r/20170630153908.3439707-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170628153221.11322-5-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/bitmap.h: turn bitmap_set and bitmap_clear into memset when possible

Several callers have constant 'start' and an 'nbits' that is a multiple
of 8, so we can turn them into calls to memset.  We don't need the
entirety of 'start' and 'nbits' to be constant, we just need to know
whether they're divisible by 8.

Link: http://lkml.kernel.org/r/20170628153221.11322-4-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitmap: optimise bitmap_set and bitmap_clear of a single bit

We have eight users calling bitmap_clear for a single bit and seventeen
calling bitmap_set for a single bit.  Rather than fix all of them to
call __clear_bit or __set_bit, turn bitmap_clear and bitmap_set into
inline functions and make this special case efficient.

Link: http://lkml.kernel.org/r/20170628153221.11322-3-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_bitmap.c: add optimisation tests

Patch series "Bitmap optimisations", v2.

These three bitmap patches use more efficient specialisations when the
compiler can figure out that it's safe to do so.  Thanks to Rasmus's
eagle eyes, a nasty bug in v1 was avoided, and I've added a test case
which would have caught it.

This patch (of 4):

This version of the test is actually a no-op; the next patch will enable
it.

Link: http://lkml.kernel.org/r/20170628153221.11322-2-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: give proc sysctl some maintainer love

We poke at proc sysctl enough that really we should declare it
maintained.  We'll just be Cc'd and sending updates / ACK'ing changes
through akpm's tree.

Link: http://lkml.kernel.org/r/20170524231305.8649-1-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/kallsyms.c: replace all_var with IS_ENABLED(CONFIG_KALLSYMS_ALL)

'all_var' looks like a variable, but is actually a macro.  Use
IS_ENABLED(CONFIG_KALLSYMS_ALL) for clarification.

Link: http://lkml.kernel.org/r/1497577591-3434-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/groups.c: use sort library function

setgroups is not exactly a hot path, so we might as well use the library
function instead of open-coding the sorting.  Saves ~150 bytes.

Link: http://lkml.kernel.org/r/1497301378-22739-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/ksysfs.c: constify attribute_group structures.

attribute_groups are not supposed to change at runtime.  All functions
working with attribute_groups provided by <linux/sysfs.h> work with
const attribute_group.  So mark the non-const structs as const.

File size before:
   text    data     bss     dec     hex filename
   1120     544      16    1680     690 kernel/ksysfs.o

File size After adding 'const':
   text    data     bss     dec     hex filename
   1160     480      16    1656     678 kernel/ksysfs.o

Link: http://lkml.kernel.org/r/aa224b3cc923fdbb3edd0c41b2c639c85408c9e8.1498737347.git.arvind.yadav.cs@gmail.com
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ARM: fix rd_size declaration

The global variable 'rd_size' is declared as 'int' in source file
arch/arm/kernel/atags_parse.c and as 'unsigned long' in
drivers/block/brd.c.  Fix this inconsistency.

Additionally, remove the declarations of rd_image_start, rd_prompt and
rd_doload from parse_tag_ramdisk() since these duplicate existing
declarations in <linux/initrd.h>.

Link: http://lkml.kernel.org/r/20170627065024.12347-1-bart.vanassche@wdc.com
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Yan <yanaijie@huawei.com>
Cc: Zhaohongjiang <zhaohongjiang@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: split BUILD_BUG stuff out into <linux/build_bug.h>

Including <linux/bug.h> pulls in a lot of bloat from <asm/bug.h> and
<asm-generic/bug.h> that is not needed to call the BUILD_BUG() family of
macros.  Split them out into their own header, <linux/build_bug.h>.

Also correct some checkpatch.pl errors for the BUILD_BUG_ON_ZERO() and
BUILD_BUG_ON_NULL() macros by adding parentheses around the bitfield
widths that begin with a minus sign.

Link: http://lkml.kernel.org/r/20170525120316.24473-6-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

linux/bug.h: correct "space required before that '-'"

Correct these checkpatch.pl errors:

|ERROR: space required before that '-' (ctx:OxO)
|#37: FILE: include/linux/bug.h:37:
|+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))

|ERROR: space required before that '-' (ctx:OxO)
|#38: FILE: include/linux/bug.h:38:
|+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

I decided to wrap the bitfield expressions that begin with minus signs
in parentheses rather than insert spaces before the minus signs.

Link: http://lkml.kernel.org/r/20170525120316.24473-5-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

linux/bug.h: correct "(foo*)" should be "(foo *)"

Correct this checkpatch.pl error:

|ERROR: "(foo*)" should be "(foo *)"
|#19: FILE: include/linux/bug.h:19:
|+#define BUILD_BUG_ON_NULL(e) ((void*)0)

Link: http://lkml.kernel.org/r/20170525120316.24473-4-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

linux/bug.h: correct formatting of block comment

Correct these checkpatch.pl warnings:

|WARNING: Block comments use * on subsequent lines
|#34: FILE: include/linux/bug.h:34:
|+/* Force a compilation error if condition is true, but also produce a
|+   result (of value 0 and type size_t), so the expression can be used

|WARNING: Block comments use a trailing */ on a separate line
|#36: FILE: include/linux/bug.h:36:
|+   aren't permitted). */

Link: http://lkml.kernel.org/r/20170525120316.24473-3-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

asm-generic/bug.h: declare struct pt_regs; before function prototype

This series of patches splits BUILD_BUG related macros out of
"include/linux/bug.h" into new file "include/linux/build_bug.h" (patch
5), and changes the pointer type checking in the `container_of()` macro
to deal with pointers of array type better (patch 6).  Patches 1 to 4
are prerequisites.

Patches 2, 3, 4, and 5 have been inserted since the previous version of
this patch series.  Patch 6 here corresponds to v3 and v4's patch 2.

Patch 1 was a prerequisite in v3 of this series to avoid a lot of
warnings when <linux/bug.h> was included by <linux/kernel.h>.  That is
no longer relevant for v5 of the series, but I left it in because it was
acked by a Arnd Bergmann and Michal Nazarewicz.

Patches 2, 3, and 4 are some checkpatch clean-ups on
"include/linux/bug.h" before splitting out the BUILD_BUG stuff in patch
5.

Patch 5 splits the BUILD_BUG related macros out of "include/linux/bug.h"
into new file "include/linux/build_bug.h" because including
<linux/bug.h> in "include/linux/kernel.h" would result in build failures
due to circular dependencies.

Patch 6 changes the pointer type checking by `container_of()` to avoid
some incompatible pointer warnings when the dereferenced pointer has
array type.

1) asm-generic/bug.h: declare struct pt_regs; before function prototype
2) linux/bug.h: correct formatting of block comment
3) linux/bug.h: correct "(foo*)" should be "(foo *)"
4) linux/bug.h: correct "space required before that '-'"
5) bug: split BUILD_BUG stuff out into <linux/build_bug.h>
6) kernel.h: handle pointers to arrays better in container_of()

This patch (of 6):

The declaration of `__warn()` has `struct pt_regs *regs` as one of its
parameters.  This can result in compiler warnings if `struct regs` is not
already declared.  Add an empty declaration of `struct pt_regs` to avoid
the warnings.

Link: http://lkml.kernel.org/r/20170525120316.24473-2-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/generic.c: switch to ida_simple_get/remove

The code can be much simplified by switching to ida_simple_get/remove.

Link: http://lkml.kernel.org/r/8d1cc9f7-5115-c9dc-028e-c0770b6bfe1f@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

frv: cmpxchg: implement cmpxchg64()

FRV supports 64-bit cmpxchg, which is provided by the arch code as
__cmpxchg_64 and subsequently used to implement atomic64_cmpxchg.

This patch hooks up the generic cmpxchg64 API using the same function,
which also provides default definitions of the relaxed, acquire and
release variants.  This fixes the build when COMPILE_TEST=y and
IOMMU_IO_PGTABLE_LPAE=y.

Link: http://lkml.kernel.org/r/1499084670-6996-1-git-send-email-will.deacon@arm.com
Signed-off-by: Will Deacon <will.deacon@arm.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

frv: use generic fb.h

The arch uses a verbatim copy of the asm-generic version and does not
add any own implementations to the header, so use asm-generic/fb.h
instead of duplicating code.

Link: http://lkml.kernel.org/r/20170517083307.1697-1-tklauser@distanz.ch
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

frv: remove wrapper header for asm/device.h

frv's asm/device.h is merely including asm-generic/device.h.  Thus, the
arch specific header can be omitted and the generic header can be used
directly.

Link: http://lkml.kernel.org/r/20170517124915.26904-1-tklauser@distanz.ch
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>