fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock

Commit 9c225f26 ("vfs: atomic f_pos accesses as per POSIX") added
locking for file.f_pos access and in particular made concurrent read and
write not possible - now both those functions take f_pos lock for the
whole run, and so if e.g. a read is blocked waiting for data, write will
deadlock waiting for that read to complete.

This caused regression for stream-like files where previously read and
write could run simultaneously, but after that patch could not do so
anymore. See e.g. commit 581d21a2 ("xenbus: fix deadlock on writes
to /proc/xen/xenbus") which fixes such regression for particular case of
/proc/xen/xenbus.

The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
safety for read/write/lseek and added the locking to file descriptors of
all regular files. In 2014 that thread-safety problem was not new as it
was already discussed earlier in 2006.

However even though 2006'th version of Linus's patch was adding f_pos
locking "only for files that are marked seekable with FMODE_LSEEK (thus
avoiding the stream-like objects like pipes and sockets)", the 2014
version - the one that actually made it into the tree as 9c225f26 -
is doing so irregardless of whether a file is seekable or not.

See

    https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/
    https://lwn.net/Articles/180387
    https://lwn.net/Articles/180396

for historic context.

The reason that it did so is, probably, that there are many files that
are marked non-seekable, but e.g. their read implementation actually
depends on knowing current position to correctly handle the read. Some
examples:

	kernel/power/user.c		snapshot_read
	fs/debugfs/file.c		u32_array_read
	fs/fuse/control.c		fuse_conn_waiting_read + ...
	drivers/hwmon/asus_atk0110.c	atk_debugfs_ggrp_read
	arch/s390/hypfs/inode.c		hypfs_read_iter
	...

Despite that, many nonseekable_open users implement read and write with
pure stream semantics - they don't depend on passed ppos at all. And for
those cases where read could wait for something inside, it creates a
situation similar to xenbus - the write could be never made to go until
read is done, and read is waiting for some, potentially external, event,
for potentially unbounded time -> deadlock.

Besides xenbus, there are 14 such places in the kernel that I've found
with semantic patch (see below):

	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
	drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
	drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()

In addition to the cases above another regression caused by f_pos
locking is that now FUSE filesystems that implement open with
FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
stream-like files - for the same reason as above e.g. read can deadlock
write locking on file.f_pos in the kernel.

FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990 ("fuse:
implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
write routines not depending on current position at all, and with both
read and write being potentially blocking operations:

See

    https://github.com/libfuse/osspd
    https://lwn.net/Articles/308445

    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406
    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477
    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510

Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
"somewhat pipe-like files ..." with read handler not using offset.
However that test implements only read without write and cannot exercise
the deadlock scenario:

    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216

I've actually hit the read vs write deadlock for real while implementing
my FUSE filesystem where there is /head/watch file, for which open
creates separate bidirectional socket-like stream in between filesystem
and its user with both read and write being later performed
simultaneously. And there it is semantically not easy to split the
stream into two separate read-only and write-only channels:

    https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169

Let's fix this regression. The plan is:

1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
   doing so would break many in-kernel nonseekable_open users which
   actually use ppos in read/write handlers.

2. Add stream_open() to kernel to open stream-like non-seekable file
   descriptors. Read and write on such file descriptors would never use
   nor change ppos. And with that property on stream-like files read and
   write will be running without taking f_pos lock - i.e. read and write
   could be running simultaneously.

3. With semantic patch search and convert to stream_open all in-kernel
   nonseekable_open users for which read and write actually do not
   depend on ppos and where there is no other methods in file_operations
   which assume @offset access.

4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
   steam_open if that bit is present in filesystem open reply.

   It was tempting to change fs/fuse/ open handler to use stream_open
   instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
   grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
   and in particular GVFS which actually uses offset in its read and
   write handlers

	https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481

   so if we would do such a change it will break a real user.

5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
   from v3.14+ (the kernel where 9c225f26 first appeared).

   This will allow to patch OSSPD and other FUSE filesystems that
   provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
   in their open handler and this way avoid the deadlock on all kernel
   versions. This should work because fs/fuse/ ignores unknown open
   flags returned from a filesystem and so passing FOPEN_STREAM to a
   kernel that is not aware of this flag cannot hurt. In turn the kernel
   that is not aware of FOPEN_STREAM will be < v3.14 where just
   FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
   write deadlock.

This patch adds stream_open, converts /proc/xen/xenbus to it and adds
semantic patch to automatically locate in-kernel places that are either
required to be converted due to read vs write deadlock, or that are just
safe to be converted because read and write do not use ppos and there
are no other funky methods in file_operations.

Regarding semantic patch I've verified each generated change manually -
that it is correct to convert - and each other nonseekable_open instance
left - that it is either not correct to convert there, or that it is not
converted due to current stream_open.cocci limitations.

The script also does not convert files that should be valid to convert,
but that currently have .llseek = noop_llseek or generic_file_llseek for
unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull RTC fixes from Alexandre Belloni:

 - Various alarm fixes for da9063, cros-ec and sh

 - sd3078 manufacturer name fix as this was introduced this cycle

* tag 'rtc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: da9063: set uie_unsupported when relevant
  rtc: sd3078: fix manufacturer name
  rtc: sh: Fix invalid alarm warning for non-enabled alarm
  rtc: cros-ec: Fail suspend/resume if wake IRQ can't be configured

Merge misc fixes from Andrew Morton:
 "14 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kernel/sysctl.c: fix out-of-bounds access when setting file-max
  mm/util.c: fix strndup_user() comment
  sh: fix multiple function definition build errors
  MAINTAINERS: add maintainer and replacing reviewer ARM/NUVOTON NPCM
  MAINTAINERS: fix bad pattern in ARM/NUVOTON NPCM
  mm: writeback: use exact memcg dirty counts
  psi: clarify the units used in pressure files
  mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()
  hugetlbfs: fix memory leak for resv_map
  mm: fix vm_fault_t cast in VM_FAULT_GET_HINDEX()
  lib/lzo: fix bugs for very short or empty input
  include/linux/bitrev.h: fix constant bitrev
  kmemleak: powerpc: skip scanning holes in the .bss section
  lib/string.c: implement a basic bcmp

Commit 32a5ad9c ("sysctl: handle overflow for file-max") hooked up
min/max values for the file-max sysctl parameter via the .extra1 and
.extra2 fields in the corresponding struct ctl_table entry.

Unfortunately, the minimum value points at the global 'zero' variable,
which is an int.  This results in a KASAN splat when accessed as a long
by proc_doulongvec_minmax on 64-bit architectures:

  | BUG: KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax+0x5d8/0x6a0
  | Read of size 8 at addr ffff2000133d1c20 by task systemd/1
  |
  | CPU: 0 PID: 1 Comm: systemd Not tainted 5.1.0-rc3-00012-g40b114779944 #2
  | Hardware name: linux,dummy-virt (DT)
  | Call trace:
  |  dump_backtrace+0x0/0x228
  |  show_stack+0x14/0x20
  |  dump_stack+0xe8/0x124
  |  print_address_description+0x60/0x258
  |  kasan_report+0x140/0x1a0
  |  __asan_report_load8_noabort+0x18/0x20
  |  __do_proc_doulongvec_minmax+0x5d8/0x6a0
  |  proc_doulongvec_minmax+0x4c/0x78
  |  proc_sys_call_handler.isra.19+0x144/0x1d8
  |  proc_sys_write+0x34/0x58
  |  __vfs_write+0x54/0xe8
  |  vfs_write+0x124/0x3c0
  |  ksys_write+0xbc/0x168
  |  __arm64_sys_write+0x68/0x98
  |  el0_svc_common+0x100/0x258
  |  el0_svc_handler+0x48/0xc0
  |  el0_svc+0x8/0xc
  |
  | The buggy address belongs to the variable:
  |  zero+0x0/0x40
  |
  | Memory state around the buggy address:
  |  ffff2000133d1b00: 00 00 00 00 00 00 00 00 fa fa fa fa 04 fa fa fa
  |  ffff2000133d1b80: fa fa fa fa 04 fa fa fa fa fa fa fa 04 fa fa fa
  | >ffff2000133d1c00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
  |                                ^
  |  ffff2000133d1c80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
  |  ffff2000133d1d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Fix the splat by introducing a unsigned long 'zero_ul' and using that
instead.

Link: http://lkml.kernel.org/r/20190403153409.17307-1-will.deacon@arm.com
Fixes: 32a5ad9c ("sysctl: handle overflow for file-max")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Christian Brauner <christian@brauner.io>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The kerneldoc misdescribes strndup_user()'s return value.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Timur Tabi <timur@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Many of the sh CPU-types have their own plat_irq_setup() and
arch_init_clk_ops() functions, so these same (empty) functions in
arch/sh/boards/of-generic.c are not needed and cause build errors.

If there is some case where these empty functions are needed, they can
be retained by marking them as "__weak" while at the same time making
builds that do not need them succeed.

Fixes these build errors:

arch/sh/boards/of-generic.o: In function `plat_irq_setup':
(.init.text+0x134): multiple definition of `plat_irq_setup'
arch/sh/kernel/cpu/sh2/setup-sh7619.o:(.init.text+0x30): first defined here
arch/sh/boards/of-generic.o: In function `arch_init_clk_ops':
(.init.text+0x118): multiple definition of `arch_init_clk_ops'
arch/sh/kernel/cpu/sh2/clock-sh7619.o:(.init.text+0x0): first defined here

Link: http://lkml.kernel.org/r/9ee4e0c5-f100-86a2-bd4d-1d3287ceab31@infradead.orgSigned-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add Tali Perry as Nuvoton NPCM maintainer, replace Brendan Higgins
Nuvoton NPCM reviewer with Benjamin Fair.

Link: http://lkml.kernel.org/r/20190328235752.334462-2-tmaimon77@gmail.comSigned-off-by: Tomer Maimon <tmaimon77@gmail.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Benjamin Fair <benjaminfair@google.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Joe Perches <joe@perches.com>
Cc: Avi Fishman <avifishman70@gmail.com>
Cc: Patrick Venture <venture@google.com>
Cc: Nancy Yuen <yuenn@google.com>
Cc: Tali Perry <tali.perry1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In the process of upstreaming architecture support for ARM/NUVOTON NPCM
include/dt-bindings/clock/nuvoton,npcm7xx-clks.h was renamed
include/dt-bindings/clock/nuvoton,npcm7xx-clock.h without updating
MAINTAINERS.  This updates the MAINTAINERS pattern to match the new name
of this file.

Link: http://lkml.kernel.org/r/20190328235752.334462-1-tmaimon77@gmail.com
Fixes: 6a498e06 ("MAINTAINERS: Add entry for the Nuvoton NPCM architecture")
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Reported-by: Joe Perches <joe@perches.com>
Reviewed-by: Benjamin Fair <benjaminfair@google.com>
Cc: Avi Fishman <avifishman70@gmail.com>
Cc: Mukesh Ojha <mojha@codeaurora.org>
Cc: Nancy Yuen <yuenn@google.com>
Cc: Patrick Venture <venture@google.com>
Cc: Tali Perry <tali.perry1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since commit a983b5eb ("mm: memcontrol: fix excessive complexity in
memory.stat reporting") memcg dirty and writeback counters are managed
as:

 1) per-memcg per-cpu values in range of [-32..32]

 2) per-memcg atomic counter

When a per-cpu counter cannot fit in [-32..32] it's flushed to the
atomic.  Stat readers only check the atomic.  Thus readers such as
balance_dirty_pages() may see a nontrivial error margin: 32 pages per
cpu.

Assuming 100 cpus:
   4k x86 page_size:  13 MiB error per memcg
  64k ppc page_size: 200 MiB error per memcg

Considering that dirty+writeback are used together for some decisions the
errors double.

This inaccuracy can lead to undeserved oom kills.  One nasty case is
when all per-cpu counters hold positive values offsetting an atomic
negative value (i.e.  per_cpu[*]=32, atomic=n_cpu*-32).
balance_dirty_pages() only consults the atomic and does not consider
throttling the next n_cpu*32 dirty pages.  If the file_lru is in the
13..200 MiB range then there's absolutely no dirty throttling, which
burdens vmscan with only dirty+writeback pages thus resorting to oom
kill.

It could be argued that tiny containers are not supported, but it's more
subtle.  It's the amount the space available for file lru that matters.
If a container has memory.max-200MiB of non reclaimable memory, then it
will also suffer such oom kills on a 100 cpu machine.

The following test reliably ooms without this patch.  This patch avoids
oom kills.

  $ cat test
  mount -t cgroup2 none /dev/cgroup
  cd /dev/cgroup
  echo +io +memory > cgroup.subtree_control
  mkdir test
  cd test
  echo 10M > memory.max
  (echo $BASHPID > cgroup.procs && exec /memcg-writeback-stress /foo)
  (echo $BASHPID > cgroup.procs && exec dd if=/dev/zero of=/foo bs=2M count=100)

  $ cat memcg-writeback-stress.c
  /*
   * Dirty pages from all but one cpu.
   * Clean pages from the non dirtying cpu.
   * This is to stress per cpu counter imbalance.
   * On a 100 cpu machine:
   * - per memcg per cpu dirty count is 32 pages for each of 99 cpus
   * - per memcg atomic is -99*32 pages
   * - thus the complete dirty limit: sum of all counters 0
   * - balance_dirty_pages() only sees atomic count -99*32 pages, which
   *   it max()s to 0.
   * - So a workload can dirty -99*32 pages before balance_dirty_pages()
   *   cares.
   */
  #define _GNU_SOURCE
  #include <err.h>
  #include <fcntl.h>
  #include <sched.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <sys/stat.h>
  #include <sys/sysinfo.h>
  #include <sys/types.h>
  #include <unistd.h>

  static char *buf;
  static int bufSize;

  static void set_affinity(int cpu)
  {
  	cpu_set_t affinity;

  	CPU_ZERO(&affinity);
  	CPU_SET(cpu, &affinity);
  	if (sched_setaffinity(0, sizeof(affinity), &affinity))
  		err(1, "sched_setaffinity");
  }

  static void dirty_on(int output_fd, int cpu)
  {
  	int i, wrote;

  	set_affinity(cpu);
  	for (i = 0; i < 32; i++) {
  		for (wrote = 0; wrote < bufSize; ) {
  			int ret = write(output_fd, buf+wrote, bufSize-wrote);
  			if (ret == -1)
  				err(1, "write");
  			wrote += ret;
  		}
  	}
  }

  int main(int argc, char **argv)
  {
  	int cpu, flush_cpu = 1, output_fd;
  	const char *output;

  	if (argc != 2)
  		errx(1, "usage: output_file");

  	output = argv[1];
  	bufSize = getpagesize();
  	buf = malloc(getpagesize());
  	if (buf == NULL)
  		errx(1, "malloc failed");

  	output_fd = open(output, O_CREAT|O_RDWR);
  	if (output_fd == -1)
  		err(1, "open(%s)", output);

  	for (cpu = 0; cpu < get_nprocs(); cpu++) {
  		if (cpu != flush_cpu)
  			dirty_on(output_fd, cpu);
  	}

  	set_affinity(flush_cpu);
  	if (fsync(output_fd))
  		err(1, "fsync(%s)", output);
  	if (close(output_fd))
  		err(1, "close(%s)", output);
  	free(buf);
  }

Make balance_dirty_pages() and wb_over_bg_thresh() work harder to
collect exact per memcg counters.  This avoids the aforementioned oom
kills.

This does not affect the overhead of memory.stat, which still reads the
single atomic counter.

Why not use percpu_counter? memcg already handles cpus going offline, so
no need for that overhead from percpu_counter.  And the percpu_counter
spinlocks are more heavyweight than is required.

It probably also makes sense to use exact dirty and writeback counters
in memcg oom reports.  But that is saved for later.

Link: http://lkml.kernel.org/r/20190329174609.164344-1-gthelen@google.comSigned-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>	[4.16+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The output of the PSI files show a bunch of numbers with no unit.  The
psi.txt documentation file also does not indicate what units are used.
One can only find out by looking at the source code.  The units are
percentage for the averages and useconds for the total.  Make the
information easier to find by documenting the units in psi.txt.

Link: http://lkml.kernel.org/r/20190402193810.3450-1-longman@redhat.comSigned-off-by: Waiman Long <longman@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With some architectures like ppc64, set_pmd_at() cannot cope with a
situation where there is already some (different) valid entry present.

Use pmdp_set_access_flags() instead to modify the pfn which is built to
deal with modifying existing PMD entries.

This is similar to commit cae85cb8 ("mm/memory.c: fix modifying of
page protection by insert_pfn()")

We also do similar update w.r.t insert_pfn_pud eventhough ppc64 don't
support pud pfn entries now.

Without this patch we also see the below message in kernel log "BUG:
non-zero pgtables_bytes on freeing mm:"

Link: http://lkml.kernel.org/r/20190402115125.18803-1-aneesh.kumar@linux.ibm.comSigned-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reported-by: Chandan Rajendra <chandan@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When mknod is used to create a block special file in hugetlbfs, it will
allocate an inode and kmalloc a 'struct resv_map' via resv_map_alloc().
inode->i_mapping->private_data will point the newly allocated resv_map.
However, when the device special file is opened bd_acquire() will set
inode->i_mapping to bd_inode->i_mapping.  Thus the pointer to the
allocated resv_map is lost and the structure is leaked.

Programs to reproduce:
        mount -t hugetlbfs nodev hugetlbfs
        mknod hugetlbfs/dev b 0 0
        exec 30<> hugetlbfs/dev
        umount hugetlbfs/

resv_map structures are only needed for inodes which can have associated
page allocations.  To fix the leak, only allocate resv_map for those
inodes which could possibly be associated with page allocations.

Link: http://lkml.kernel.org/r/20190401213101.16476-1-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Yufen Yu <yuyufen@huawei.com>
Suggested-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Symmetrically to VM_FAULT_SET_HINDEX(), we need a force-cast in
VM_FAULT_GET_HINDEX() to tell sparse that this is intentional.

Sparse complains about the current code when building a kernel with
CONFIG_MEMORY_FAILURE:

  arch/x86/mm/fault.c:1058:53: warning: restricted vm_fault_t degrades to integer

Link: http://lkml.kernel.org/r/20190327204117.35215-1-jannh@google.com
Fixes: 3d353901 ("mm: create the new vm_fault_t type")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

For very short input data (0 - 1 bytes), lzo-rle was not behaving
correctly.  Fix this behaviour and update documentation accordingly.

For zero-length input, lzo v0 outputs an end-of-stream marker only,
which was misinterpreted by lzo-rle as a bitstream version number.
Ensure bitstream versions > 0 require a minimum stream length of 5.

Also fixes a bug in handling the tail for very short inputs when a
bitstream version is present.

Link: http://lkml.kernel.org/r/20190326165857.34613-1-dave.rodgman@arm.comSigned-off-by: Dave Rodgman <dave.rodgman@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

clang points out with hundreds of warnings that the bitrev macros have a
problem with constant input:

  drivers/hwmon/sht15.c:187:11: error: variable '__x' is uninitialized when used within its own initialization
        [-Werror,-Wuninitialized]
          u8 crc = bitrev8(data->val_status & 0x0F);
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  include/linux/bitrev.h:102:21: note: expanded from macro 'bitrev8'
          __constant_bitrev8(__x) :                       \
          ~~~~~~~~~~~~~~~~~~~^~~~
  include/linux/bitrev.h:67:11: note: expanded from macro '__constant_bitrev8'
          u8 __x = x;                     \
             ~~~   ^

Both the bitrev and the __constant_bitrev macros use an internal
variable named __x, which goes horribly wrong when passing one to the
other.

The obvious fix is to rename one of the variables, so this adds an extra
'_'.

It seems we got away with this because

 - there are only a few drivers using bitrev macros

 - usually there are no constant arguments to those

 - when they are constant, they tend to be either 0 or (unsigned)-1
   (drivers/isdn/i4l/isdnhdlc.o, drivers/iio/amplifiers/ad8366.c) and
   give the correct result by pure chance.

In fact, the only driver that I could find that gets different results
with this is drivers/net/wan/slic_ds26522.c, which in turn is a driver
for fairly rare hardware (adding the maintainer to Cc for testing).

Link: http://lkml.kernel.org/r/20190322140503.123580-1-arnd@arndb.de
Fixes: 556d2f05 ("ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Zhao Qiang <qiang.zhao@nxp.com>
Cc: Yalin Wang <yalin.wang@sonymobile.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 2d4f5671 ("KVM: PPC: Introduce kvm_tmp framework") adds
kvm_tmp[] into the .bss section and then free the rest of unused spaces
back to the page allocator.

kernel_init
  kvm_guest_init
    kvm_free_tmp
      free_reserved_area
        free_unref_page
          free_unref_page_prepare

With DEBUG_PAGEALLOC=y, it will unmap those pages from kernel.  As the
result, kmemleak scan will trigger a panic when it scans the .bss
section with unmapped pages.

This patch creates dedicated kmemleak objects for the .data, .bss and
potentially .data..ro_after_init sections to allow partial freeing via
the kmemleak_free_part() in the powerpc kvm_free_tmp() function.

Link: http://lkml.kernel.org/r/20190321171917.62049-1-catalin.marinas@arm.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Qian Cai <cai@lca.pw>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Qian Cai <cai@lca.pw>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A recent optimization in Clang (r355672) lowers comparisons of the
return value of memcmp against zero to comparisons of the return value
of bcmp against zero.  This helps some platforms that implement bcmp
more efficiently than memcmp.  glibc simply aliases bcmp to memcmp, but
an optimized implementation is in the works.

This results in linkage failures for all targets with Clang due to the
undefined symbol.  For now, just implement bcmp as a tailcail to memcmp
to unbreak the build.  This routine can be further optimized in the
future.

Other ideas discussed:

 * A weak alias was discussed, but breaks for architectures that define
   their own implementations of memcmp since aliases to declarations are
   not permitted (only definitions). Arch-specific memcmp
   implementations typically declare memcmp in C headers, but implement
   them in assembly.

 * -ffreestanding also is used sporadically throughout the kernel.

 * -fno-builtin-bcmp doesn't work when doing LTO.

Link: https://bugs.llvm.org/show_bug.cgi?id=41035
Link: https://code.woboq.org/userspace/glibc/string/memcmp.c.html#bcmp
Link: https://github.com/llvm/llvm-project/commit/8e16d73346f8091461319a7dfc4ddd18eedcff13
Link: https://github.com/ClangBuiltLinux/linux/issues/416
Link: http://lkml.kernel.org/r/20190313211335.165605-1-ndesaulniers@google.comSigned-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reported-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: James Y Knight <jyknight@google.com>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'for-5.1/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Two queue_limits stacking fixes: disable discards if underlying
   driver does. And propagate BDI_CAP_STABLE_WRITES to fix sporadic
   checksum errors.

 - Fix that reverts a DM core limit that wasn't needed given that
   dm-crypt was already updated to impose an equivalent limit.

 - Fix dm-init to properly establish 'const' for __initconst array.

 - Fix deadlock in DM integrity target that occurs when overlapping IO
   is being issued to it. And two smaller fixes to the DM integrity
   target.

* tag 'for-5.1/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm integrity: fix deadlock with overlapping I/O
  dm: disable DISCARD if the underlying storage no longer supports it
  dm table: propagate BDI_CAP_STABLE_WRITES to fix sporadic checksum errors
  dm: revert 8f50e358 ("dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE")
  dm init: fix const confusion for dm_allowed_targets array
  dm integrity: make dm_integrity_init and dm_integrity_exit static
  dm integrity: change memcmp to strncmp in dm_integrity_ctr

Pull VFIO fixes from Alex Williamson:

 - Fix clang printk format errors (Louis Taylor)

 - Declare structure static to fix sparse warning (Wang Hai)

 - Limit user DMA mappings per container (CVE-2019-3882) (Alex
   Williamson)

* tag 'vfio-v5.1-rc4' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Limit DMA mappings per container
  vfio/spapr_tce: Make symbol 'tce_iommu_driver_ops' static
  vfio/pci: use correct format characters

Pull kvm fixes from Paolo Bonzini:
 "x86 fixes for overflows and other nastiness"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: nVMX: fix x2APIC VTPR read intercept
  KVM: x86: nVMX: close leak of L0's x2APIC MSRs (CVE-2019-3887)
  KVM: SVM: prevent DBG_DECRYPT and DBG_ENCRYPT overflow
  kvm: svm: fix potential get_num_contig_pages overflow

Pull arm64 fix from Catalin Marinas:
 "Fix unwind_frame() in the context of pseudo NMI"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: fix wrong check of on_sdei_stack in nmi context

Pull syscall-get-arguments cleanup and fixes from Steven Rostedt:
 "Andy Lutomirski approached me to tell me that the
  syscall_get_arguments() implementation in x86 was horrible and gcc
  certainly gets it wrong.

  He said that since the tracepoints only pass in 0 and 6 for i and n
  repectively, it should be optimized for that case. Inspecting the
  kernel, I discovered that all users pass in 0 for i and only one file
  passing in something other than 6 for the number of arguments. That
  code happens to be my own code used for the special syscall tracing.

  That can easily be converted to just using 0 and 6 as well, and only
  copying what is needed. Which is probably the faster path anyway for
  that case.

  Along the way, a couple of real fixes came from this as the
  syscall_get_arguments() function was incorrect for csky and riscv.

  x86 has been optimized to for the new interface that removes the
  variable number of arguments, but the other architectures could still
  use some loving and take more advantage of the simpler interface"

* tag 'trace-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  syscalls: Remove start and number from syscall_set_arguments() args
  syscalls: Remove start and number from syscall_get_arguments() args
  csky: Fix syscall_get_arguments() and syscall_set_arguments()
  riscv: Fix syscall_get_arguments() and syscall_set_arguments()
  tracing/syscalls: Pass in hardcoded 6 into syscall_get_arguments()
  ptrace: Remove maxargs from task_current_syscall()

dm-integrity will deadlock if overlapping I/O is issued to it, the bug
was introduced by commit 724376a0 ("dm integrity: implement fair
range locks").  Users rarely use overlapping I/O so this bug went
undetected until now.

Fix this bug by correcting, likely cut-n-paste, typos in
ranges_overlap() and also remove a flawed ranges_overlap() check in
remove_range_unlocked().  This condition could leave unprocessed bios
hanging on wait_list forever.

Cc: stable@vger.kernel.org # v4.19+
Fixes: 724376a0 ("dm integrity: implement fair range locks")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Referring to the "VIRTUALIZING MSR-BASED APIC ACCESSES" chapter of the
SDM, when "virtualize x2APIC mode" is 1 and "APIC-register
virtualization" is 0, a RDMSR of 808H should return the VTPR from the
virtual APIC page.

However, for nested, KVM currently fails to disable the read intercept
for this MSR. This means that a RDMSR exit takes precedence over
"virtualize x2APIC mode", and KVM passes through L1's TPR to L2,
instead of sourcing the value from L2's virtual APIC page.

This patch fixes the issue by disabling the read intercept, in VMCS02,
for the VTPR when "APIC-register virtualization" is 0.

The issue described above and fix prescribed here, were verified with
a related patch in kvm-unit-tests titled "Test VMX's virtualize x2APIC
mode w/ nested".
Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Fixes: c992384b ("KVM: vmx: speed up MSR bitmap merge")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The nested_vmx_prepare_msr_bitmap() function doesn't directly guard the
x2APIC MSR intercepts with the "virtualize x2APIC mode" MSR. As a
result, we discovered the potential for a buggy or malicious L1 to get
access to L0's x2APIC MSRs, via an L2, as follows.

1. L1 executes WRMSR(IA32_SPEC_CTRL, 1). This causes the spec_ctrl
variable, in nested_vmx_prepare_msr_bitmap() to become true.
2. L1 disables "virtualize x2APIC mode" in VMCS12.
3. L1 enables "APIC-register virtualization" in VMCS12.

Now, KVM will set VMCS02's x2APIC MSR intercepts from VMCS12, and then
set "virtualize x2APIC mode" to 0 in VMCS02. Oops.

This patch closes the leak by explicitly guarding VMCS02's x2APIC MSR
intercepts with VMCS12's "virtualize x2APIC mode" control.

The scenario outlined above and fix prescribed here, were verified with
a related patch in kvm-unit-tests titled "Add leak scenario to
virt_x2apic_mode_test".

Note, it looks like this issue may have been introduced inadvertently
during a merge---see 15303ba5.
Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This ensures that the address and length provided to DBG_DECRYPT and
DBG_ENCRYPT do not cause an overflow.

At the same time, pass the actual number of pages pinned in memory to
sev_unpin_memory() as a cleanup.
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

get_num_contig_pages() could potentially overflow int so make its type
consistent with its usage.
Reported-by: Cfir Cohen <cfir@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull mm/compaction fixes from Mel Gorman:
 "The merge window for 5.1 introduced a number of compaction-related
  patches. with intermittent reports of corruption and functional
  issues. The bugs are due to sloopy checking of zone boundaries and a
  corner case where invalid indexes are used to access the free lists.

  Reports are not common but at least two users and 0-day have tripped
  over them. There is a chance that one of the syzbot reports are
  related but it has not been confirmed properly.

  The normal submission path is with Andrew but there have been some
  delays and I consider them urgent enough that they should be picked up
  before RC4 to avoid duplicate reports.

  All of these have been successfully tested on older RC windows. This
  will make this branch look like a rebase but in fact, they've simply
  been lifted again from Andrew's tree and placed on a fresh branch.
  I've no reason to believe that this has invalidated the testing given
  the lack of change in compaction and the nature of the fixes"

* tag 'mm-compaction-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux:
  mm/compaction.c: abort search if isolation fails
  mm/compaction.c: correct zone boundary handling when resetting pageblock skip hints

The n_r3964 line discipline driver was written in a different time, when
SMP machines were rare, and users were trusted to do the right thing.
Since then, the world has moved on but not this code, it has stayed
rooted in the past with its lovely hand-crafted list structures and
loads of "interesting" race conditions all over the place.

After attempting to clean up most of the issues, I just gave up and am
now marking the driver as BROKEN so that hopefully someone who has this
hardware will show up out of the woodwork (I know you are out there!)
and will help with debugging a raft of changes that I had laying around
for the code, but was too afraid to commit as odds are they would break
things.

Many thanks to Jann and Linus for pointing out the initial problems in
this codebase, as well as many reviews of my attempts to fix the issues.
It was a case of whack-a-mole, and as you can see, the mole won.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After removing the start and count arguments of syscall_get_arguments() it
seems reasonable to remove them from syscall_set_arguments(). Note, as of
today, there are no users of syscall_set_arguments(). But we are told that
there will be soon. But for now, at least make it consistent with
syscall_get_arguments().

Link: http://lkml.kernel.org/r/20190327222014.GA32540@altlinux.org

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Dave Martin <dave.martin@arm.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes
Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits
Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

At Linux Plumbers, Andy Lutomirski approached me and pointed out that the
function call syscall_get_arguments() implemented in x86 was horribly
written and not optimized for the standard case of passing in 0 and 6 for
the starting index and the number of system calls to get. When looking at
all the users of this function, I discovered that all instances pass in only
0 and 6 for these arguments. Instead of having this function handle
different cases that are never used, simply rewrite it to return the first 6
arguments of a system call.

This should help out the performance of tracing system calls by ptrace,
ftrace and perf.

Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Dave Martin <dave.martin@arm.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes
Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits
Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Pull drm fixes from Dave Airlie:
 "Pretty quiet week, just some amdgpu and i915 fixes.

  i915:
   - deadlock fix
   - gvt fixes

  amdgpu:
   - PCIE dpm feature fix
   - Powerplay fixes"

* tag 'drm-fixes-2019-04-05' of git://anongit.freedesktop.org/drm/drm:
  drm/i915/gvt: Fix kerneldoc typo for intel_vgpu_emulate_hotplug
  drm/i915/gvt: Correct the calculation of plane size
  drm/amdgpu: remove unnecessary rlc reset function on gfx9
  drm/i915: Always backoff after a drm_modeset_lock() deadlock
  drm/i915/gvt: do not let pin count of shadow mm go negative
  drm/i915/gvt: do not deliver a workload if its creation fails
  drm/amd/display: VBIOS can't be light up HDMI when restart system
  drm/amd/powerplay: fix possible hang with 3+ 4K monitors
  drm/amd/powerplay: correct data type to avoid overflow
  drm/amd/powerplay: add ECC feature bit
  drm/amd/amdgpu: fix PCIe dpm feature issue (v3)

Pull networking fixes from David Miller:

 1) Several hash table refcount fixes in batman-adv, from Sven
    Eckelmann.

 2) Use after free in bpf_evict_inode(), from Daniel Borkmann.

 3) Fix mdio bus registration in ixgbe, from Ivan Vecera.

 4) Unbounded loop in __skb_try_recv_datagram(), from Paolo Abeni.

 5) ila rhashtable corruption fix from Herbert Xu.

 6) Don't allow upper-devices to be added to vrf devices, from Sabrina
    Dubroca.

 7) Add qmi_wwan device ID for Olicard 600, from Bjørn Mork.

 8) Don't leave skb->next poisoned in __netif_receive_skb_list_ptype,
    from Alexander Lobakin.

 9) Missing IDR checks in mlx5 driver, from Aditya Pakki.

10) Fix false connection termination in ktls, from Jakub Kicinski.

11) Work around some ASPM issues with r8169 by disabling rx interrupt
    coalescing on certain chips. From Heiner Kallweit.

12) Properly use per-cpu qstat values on NOLOCK qdiscs, from Paolo
    Abeni.

13) Fully initialize sockaddr_in structures in SCTP, from Xin Long.

14) Various BPF flow dissector fixes from Stanislav Fomichev.

15) Divide by zero in act_sample, from Davide Caratti.

16) Fix bridging multicast regression introduced by rhashtable
    conversion, from Nikolay Aleksandrov.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (106 commits)
  ibmvnic: Fix completion structure initialization
  ipv6: sit: reset ip header pointer in ipip6_rcv
  net: bridge: always clear mcast matching struct on reports and leaves
  libcxgb: fix incorrect ppmax calculation
  vlan: conditional inclusion of FCoE hooks to match netdevice.h and bnx2x
  sch_cake: Make sure we can write the IP header before changing DSCP bits
  sch_cake: Use tc_skb_protocol() helper for getting packet protocol
  tcp: Ensure DCTCP reacts to losses
  net/sched: act_sample: fix divide by zero in the traffic path
  net: thunderx: fix NULL pointer dereference in nicvf_open/nicvf_stop
  net: hns: Fix sparse: some warnings in HNS drivers
  net: hns: Fix WARNING when remove HNS driver with SMMU enabled
  net: hns: fix ICMP6 neighbor solicitation messages discard problem
  net: hns: Fix probabilistic memory overwrite when HNS driver initialized
  net: hns: Use NAPI_POLL_WEIGHT for hns driver
  net: hns: fix KASAN: use-after-free in hns_nic_net_xmit_hw()
  flow_dissector: rst'ify documentation
  ipv6: Fix dangling pointer when ipv6 fragment
  net-gro: Fix GRO flush when receiving a GSO packet.
  flow_dissector: document BPF flow dissector environment
  ...

Fix device initialization completion handling for vNIC adapters.
Initialize the completion structure on probe and reinitialize when needed.
This also fixes a race condition during kdump where the driver can attempt
to access the completion struct before it is initialized:

Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc0000000081acbe0
Oops: Kernel access of bad area, sig: 11 [#1]
LE SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: ibmvnic(+) ibmveth sunrpc overlay squashfs loop
CPU: 19 PID: 301 Comm: systemd-udevd Not tainted 4.18.0-64.el8.ppc64le #1
NIP:  c0000000081acbe0 LR: c0000000081ad964 CTR: c0000000081ad900
REGS: c000000027f3f990 TRAP: 0300   Not tainted  (4.18.0-64.el8.ppc64le)
MSR:  800000010280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 28228288  XER: 00000006
CFAR: c000000008008934 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 1
GPR00: c0000000081ad964 c000000027f3fc10 c0000000095b5800 c0000000221b4e58
GPR04: 0000000000000003 0000000000000001 000049a086918581 00000000000000d4
GPR08: 0000000000000007 0000000000000000 ffffffffffffffe8 d0000000014dde28
GPR12: c0000000081ad900 c000000009a00c00 0000000000000001 0000000000000100
GPR16: 0000000000000038 0000000000000007 c0000000095e2230 0000000000000006
GPR20: 0000000000400140 0000000000000001 c00000000910c880 0000000000000000
GPR24: 0000000000000000 0000000000000006 0000000000000000 0000000000000003
GPR28: 0000000000000001 0000000000000001 c0000000221b4e60 c0000000221b4e58
NIP [c0000000081acbe0] __wake_up_locked+0x50/0x100
LR [c0000000081ad964] complete+0x64/0xa0
Call Trace:
[c000000027f3fc10] [c000000027f3fc60] 0xc000000027f3fc60 (unreliable)
[c000000027f3fc60] [c0000000081ad964] complete+0x64/0xa0
[c000000027f3fca0] [d0000000014dad58] ibmvnic_handle_crq+0xce0/0x1160 [ibmvnic]
[c000000027f3fd50] [d0000000014db270] ibmvnic_tasklet+0x98/0x130 [ibmvnic]
[c000000027f3fda0] [c00000000813f334] tasklet_action_common.isra.3+0xc4/0x1a0
[c000000027f3fe00] [c000000008cd13f4] __do_softirq+0x164/0x400
[c000000027f3fef0] [c00000000813ed64] irq_exit+0x184/0x1c0
[c000000027f3ff20] [c0000000080188e8] __do_irq+0xb8/0x210
[c000000027f3ff90] [c00000000802d0a4] call_do_irq+0x14/0x24
[c000000026a5b010] [c000000008018adc] do_IRQ+0x9c/0x130
[c000000026a5b060] [c000000008008ce4] hardware_interrupt_common+0x114/0x120
Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipip6 tunnels run iptunnel_pull_header on received skbs. This can
determine the following use-after-free accessing iph pointer since
the packet will be 'uncloned' running pskb_expand_head if it is a
cloned gso skb (e.g if the packet has been sent though a veth device)

[  706.369655] BUG: KASAN: use-after-free in ipip6_rcv+0x1678/0x16e0 [sit]
[  706.449056] Read of size 1 at addr ffffe01b6bd855f5 by task ksoftirqd/1/=
[  706.669494] Hardware name: HPE ProLiant m400 Server/ProLiant m400 Server, BIOS U02 08/19/2016
[  706.771839] Call trace:
[  706.801159]  dump_backtrace+0x0/0x2f8
[  706.845079]  show_stack+0x24/0x30
[  706.884833]  dump_stack+0xe0/0x11c
[  706.925629]  print_address_description+0x68/0x260
[  706.982070]  kasan_report+0x178/0x340
[  707.025995]  __asan_report_load1_noabort+0x30/0x40
[  707.083481]  ipip6_rcv+0x1678/0x16e0 [sit]
[  707.132623]  tunnel64_rcv+0xd4/0x200 [tunnel4]
[  707.185940]  ip_local_deliver_finish+0x3b8/0x988
[  707.241338]  ip_local_deliver+0x144/0x470
[  707.289436]  ip_rcv_finish+0x43c/0x14b0
[  707.335447]  ip_rcv+0x628/0x1138
[  707.374151]  __netif_receive_skb_core+0x1670/0x2600
[  707.432680]  __netif_receive_skb+0x28/0x190
[  707.482859]  process_backlog+0x1d0/0x610
[  707.529913]  net_rx_action+0x37c/0xf68
[  707.574882]  __do_softirq+0x288/0x1018
[  707.619852]  run_ksoftirqd+0x70/0xa8
[  707.662734]  smpboot_thread_fn+0x3a4/0x9e8
[  707.711875]  kthread+0x2c8/0x350
[  707.750583]  ret_from_fork+0x10/0x18

[  707.811302] Allocated by task 16982:
[  707.854182]  kasan_kmalloc.part.1+0x40/0x108
[  707.905405]  kasan_kmalloc+0xb4/0xc8
[  707.948291]  kasan_slab_alloc+0x14/0x20
[  707.994309]  __kmalloc_node_track_caller+0x158/0x5e0
[  708.053902]  __kmalloc_reserve.isra.8+0x54/0xe0
[  708.108280]  __alloc_skb+0xd8/0x400
[  708.150139]  sk_stream_alloc_skb+0xa4/0x638
[  708.200346]  tcp_sendmsg_locked+0x818/0x2b90
[  708.251581]  tcp_sendmsg+0x40/0x60
[  708.292376]  inet_sendmsg+0xf0/0x520
[  708.335259]  sock_sendmsg+0xac/0xf8
[  708.377096]  sock_write_iter+0x1c0/0x2c0
[  708.424154]  new_sync_write+0x358/0x4a8
[  708.470162]  __vfs_write+0xc4/0xf8
[  708.510950]  vfs_write+0x12c/0x3d0
[  708.551739]  ksys_write+0xcc/0x178
[  708.592533]  __arm64_sys_write+0x70/0xa0
[  708.639593]  el0_svc_handler+0x13c/0x298
[  708.686646]  el0_svc+0x8/0xc

[  708.739019] Freed by task 17:
[  708.774597]  __kasan_slab_free+0x114/0x228
[  708.823736]  kasan_slab_free+0x10/0x18
[  708.868703]  kfree+0x100/0x3d8
[  708.905320]  skb_free_head+0x7c/0x98
[  708.948204]  skb_release_data+0x320/0x490
[  708.996301]  pskb_expand_head+0x60c/0x970
[  709.044399]  __iptunnel_pull_header+0x3b8/0x5d0
[  709.098770]  ipip6_rcv+0x41c/0x16e0 [sit]
[  709.146873]  tunnel64_rcv+0xd4/0x200 [tunnel4]
[  709.200195]  ip_local_deliver_finish+0x3b8/0x988
[  709.255596]  ip_local_deliver+0x144/0x470
[  709.303692]  ip_rcv_finish+0x43c/0x14b0
[  709.349705]  ip_rcv+0x628/0x1138
[  709.388413]  __netif_receive_skb_core+0x1670/0x2600
[  709.446943]  __netif_receive_skb+0x28/0x190
[  709.497120]  process_backlog+0x1d0/0x610
[  709.544169]  net_rx_action+0x37c/0xf68
[  709.589131]  __do_softirq+0x288/0x1018

[  709.651938] The buggy address belongs to the object at ffffe01b6bd85580
                which belongs to the cache kmalloc-1024 of size 1024
[  709.804356] The buggy address is located 117 bytes inside of
                1024-byte region [ffffe01b6bd85580, ffffe01b6bd85980)
[  709.946340] The buggy address belongs to the page:
[  710.003824] page:ffff7ff806daf600 count:1 mapcount:0 mapping:ffffe01c4001f600 index:0x0
[  710.099914] flags: 0xfffff8000000100(slab)
[  710.149059] raw: 0fffff8000000100 dead000000000100 dead000000000200 ffffe01c4001f600
[  710.242011] raw: 0000000000000000 0000000000380038 00000001ffffffff 0000000000000000
[  710.334966] page dumped because: kasan: bad access detected

Fix it resetting iph pointer after iptunnel_pull_header

Fixes: a09a4c8d ("tunnels: Remove encapsulation offloads on decap")
Tested-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'riscv-for-linus-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V fixes from Palmer Dabbelt:
 "I dropped the ball a bit here: these patches should all probably have
  been part of rc2, but I wanted to get around to properly testing them
  in the various configurations (qemu32, qeum64, unleashed) first.

  Unfortunately I've been traveling and didn't have time to actually do
  that, but since these fix concrete bugs and pass my old set of tests I
  don't want to delay the fixes any longer.

  There are four independent fixes here:

   - A fix for the rv32 port that corrects the 64-bit user accesor's
     fixup label address.

   - A fix for a regression introduced during the merge window that
     broke medlow configurations at run time. This patch also includes a
     fix that disables ftrace for the same set of functions, which was
     found by inspection at the same time.

   - A modification of the memory map to avoid overlapping the FIXMAP
     and VMALLOC regions on systems with small memory maps.

   - A fix to the module handling code to use the correct syntax for
     probing Kconfig entries.

  These have passed my standard test flow, but I didn't have time to
  expand that testing like I said I would"

* tag 'riscv-for-linus-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  RISC-V: Use IS_ENABLED(CONFIG_CMODEL_MEDLOW)
  RISC-V: Fix FIXMAP_TOP to avoid overlap with VMALLOC area
  RISC-V: Always compile mm/init.c with cmodel=medany and notrace
  riscv: fix accessing 8-byte variable from RV32

We need to be careful and always zero the whole br_ip struct when it is
used for matching since the rhashtable change. This patch fixes all the
places which didn't properly clear it which in turn might've caused
mismatches.

Thanks for the great bug report with reproducing steps and bisection.

Steps to reproduce (from the bug report):
ip link add br0 type bridge mcast_querier 1
ip link set br0 up

ip link add v2 type veth peer name v3
ip link set v2 master br0
ip link set v2 up
ip link set v3 up
ip addr add 3.0.0.2/24 dev v3

ip netns add test
ip link add v1 type veth peer name v1 netns test
ip link set v1 master br0
ip link set v1 up
ip -n test link set v1 up
ip -n test addr add 3.0.0.1/24 dev v1

# Multicast receiver
ip netns exec test socat
UDP4-RECVFROM:5588,ip-add-membership=224.224.224.224:3.0.0.1,fork -

# Multicast sender
echo hello | nc -u -s 3.0.0.2 224.224.224.224 5588

Reported-by: liam.mcbirnie@boeing.com
Fixes: 19e3a9c9 ("net: bridge: convert multicast to generic rhashtable")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull power management fixes from Rafael Wysocki:
 "These fix up the intel_pstate driver after recent changes to prevent
  it from printing pointless messages and update the turbostat utility
  (mostly fixes and new hardware support).

  Specifics:

   - Make intel_pstate only load on Intel processors and prevent it from
     printing pointless failure messages (Borislav Petkov).

   - Update the turbostat utility:
      * Assorted fixes (Ben Hutchings, Len Brown, Prarit Bhargava).
      * Support for AMD Fam 17h (Zen) RAPL and package power (Calvin
        Walton).
      * Support for Intel Icelake and for systems with more than one die
        per package (Len Brown).
      * Cleanups (Len Brown)"

* tag 'pm-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq/intel_pstate: Load only on Intel hardware
  tools/power turbostat: update version number
  tools/power turbostat: Warn on bad ACPI LPIT data
  tools/power turbostat: Add checks for failure of fgets() and fscanf()
  tools/power turbostat: Also read package power on AMD F17h (Zen)
  tools/power turbostat: Add support for AMD Fam 17h (Zen) RAPL
  tools/power turbostat: Do not display an error on systems without a cpufreq driver
  tools/power turbostat: Add Die column
  tools/power turbostat: Add Icelake support
  tools/power turbostat: Cleanup CNL-specific code
  tools/power turbostat: Cleanup CC3-skip code
  tools/power turbostat: Restore ability to execute in topology-order

Pull ACPI fix from Rafael Wysocki:
 "Prevent stale GPE events from triggering spurious system wakeups from
  suspend-to-idle (Furquan Shaikh)"

* tag 'acpi-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPICA: Clear status of GPEs before enabling them

Merge tag 'drm-intel-fixes-2019-04-04' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

Only one fix for DSC (backoff after drm_modeset_lock deadlock)
and GVT's fixes including vGPU display plane size calculation,
shadow mm pin count, error recovery path for workload create
and one kerneldoc fix.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190404161116.GA14522@intel.com