commit adc589d2a20808fb99d46a78175cd023f2040338 upstream.

Add a linear pipeline logic for the stream control. It's created by
walking backwards on the entity graph. When the stream starts it will
simply loop through the pipeline calling the respective process_frame
function of each entity.

Fixes: f2fe8906 ("vimc: Virtual Media Controller core, capture
and sensor")

Cc: stable@vger.kernel.org # for v4.20
Signed-off-by: NLucas A. M. Magalhães <lucmaga@gmail.com>
Acked-by: NHelen Koike <helen.koike@collabora.com>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: fixed small space-after-tab issue in the patch]
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9dd0627d8d62a7ddb001a75f63942d92b5336561 upstream.

The UVC video driver converts the timestamp from hardware specific unit
to one known by the kernel at the time when the buffer is dequeued. This
is fine in general, but the streamoff operation consists of the
following steps (among other things):

1. uvc_video_clock_cleanup --- the hardware clock sample array is
   released and the pointer to the array is set to NULL,

2. buffers in active state are returned to the user and

3. buf_finish callback is called on buffers that are prepared.
   buf_finish includes calling uvc_video_clock_update that accesses the
   hardware clock sample array.

The above is serialised by a queue specific mutex. Address the problem
by skipping the clock conversion if the hardware clock sample array is
already released.

Fixes: 9c0863b1 ("[media] vb2: call buf_finish from __queue_cancel")
Reported-by: NChiranjeevi Rapolu <chiranjeevi.rapolu@intel.com>
Tested-by: NChiranjeevi Rapolu <chiranjeevi.rapolu@intel.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1b4fd9de6ec7f3722c2b3e08cc5ad171c11f93be upstream.

A typo in code cleanup commit db9c1007 ("media: lgdt330x: do
some cleanups at status logic") broke the FE_HAS_LOCK reporting
for 3303 chips by inadvertently modifying the register mask.

The broken lock status is critial as it prevents video capture
cards from reporting signal strength, scanning for channels,
and capturing video.

Fix regression by reverting mask change.

Cc: stable@vger.kernel.org # Kernel 4.17+
Fixes: db9c1007 ("media: lgdt330x: do some cleanups at status logic")
Signed-off-by: NNick French <naf@ou.edu>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: NAdam Stylinski <kungfujesus06@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a19c22677377b87e4354f7306f46ad99bc982a9f upstream.

Upstream must be stopped immediately after receiving the last EOF and
before disabling the IDMA channel. This can be accomplished by moving
upstream stream off to just after receiving the last EOF completion in
prp_stop(). For symmetry also move upstream stream on to end of
prp_start().

This fixes a complete system hard lockup on the SabreAuto when streaming
from the ADV7180, by repeatedly sending a stream off immediately followed
by stream on:

while true; do v4l2-ctl  -d1 --stream-mmap --stream-count=3; done

Eventually this either causes the system lockup or EOF timeouts at all
subsequent stream on, until a system reset.

The lockup occurs when disabling the IDMA channel at stream off. Stopping
the video data stream entering the IDMA channel before disabling the
channel itself appears to be a reliable fix for the hard lockup.

Fixes: f0d9c892 ("[media] media: imx: Add IC subdev drivers")
Reported-by: NGaël PORTAY <gael.portay@collabora.com>
Tested-by: NGaël PORTAY <gael.portay@collabora.com>
Signed-off-by: NSteve Longerbeam <slongerbeam@gmail.com>
Cc: stable@vger.kernel.org	# for 4.13 and up
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1d1f898df6586c5ea9aeaf349f13089c6fa37903 upstream.

The rcu_gp_kthread_wake() function is invoked when it might be necessary
to wake the RCU grace-period kthread.  Because self-wakeups are normally
a useless waste of CPU cycles, if rcu_gp_kthread_wake() is invoked from
this kthread, it naturally refuses to do the wakeup.

Unfortunately, natural though it might be, this heuristic fails when
rcu_gp_kthread_wake() is invoked from an interrupt or softirq handler
that interrupted the grace-period kthread just after the final check of
the wait-event condition but just before the schedule() call.  In this
case, a wakeup is required, even though the call to rcu_gp_kthread_wake()
is within the RCU grace-period kthread's context.  Failing to provide
this wakeup can result in grace periods failing to start, which in turn
results in out-of-memory conditions.

This race window is quite narrow, but it actually did happen during real
testing.  It would of course need to be fixed even if it was strictly
theoretical in nature.

This patch does not Cc stable because it does not apply cleanly to
earlier kernel versions.

Fixes: 48a7639c ("rcu: Make callers awaken grace-period kthread")
Reported-by: N"He, Bo" <bo.he@intel.com>
Co-developed-by: N"Zhang, Jun" <jun.zhang@intel.com>
Co-developed-by: N"He, Bo" <bo.he@intel.com>
Co-developed-by: N"xiao, jin" <jin.xiao@intel.com>
Co-developed-by: NBai, Jie A <jie.a.bai@intel.com>
Signed-off: "Zhang, Jun" <jun.zhang@intel.com>
Signed-off: "He, Bo" <bo.he@intel.com>
Signed-off: "xiao, jin" <jin.xiao@intel.com>
Signed-off: Bai, Jie A <jie.a.bai@intel.com>
Signed-off-by: N"Zhang, Jun" <jun.zhang@intel.com>
[ paulmck: Switch from !in_softirq() to "!in_interrupt() &&
  !in_serving_softirq() to avoid redundant wakeups and to also handle the
  interrupt-handler scenario as well as the softirq-handler scenario that
  actually occurred in testing. ]
Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Link: https://lkml.kernel.org/r/CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX104.ccr.corp.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f5595f5baa30e009bf54d0d7653a9a0cc465be60 upstream.

The send() callback should never return length as it does not in every
driver except tpm_crb in the success case. The reason is that the main
transmit functionality only cares about whether the transmit was
successful or not and ignores the count completely.
Suggested-by: NStefan Berger <stefanb@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Tested-by: NAlexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3d7a850fdc1a2e4d2adbc95cc0fc962974725e88 upstream.

The current approach to read first 6 bytes from the response and then tail
of the response, can cause the 2nd memcpy_fromio() to do an unaligned read
(e.g. read 32-bit word from address aligned to a 16-bits), depending on how
memcpy_fromio() is implemented. If this happens, the read will fail and the
memory controller will fill the read with 1's.

This was triggered by 170d13ca3a2f, which should be probably refined to
check and react to the address alignment. Before that commit, on x86
memcpy_fromio() turned out to be memcpy(). By a luck GCC has done the right
thing (from tpm_crb's perspective) for us so far, but we should not rely on
that. Thus, it makes sense to fix this also in tpm_crb, not least because
the fix can be then backported to stable kernels and make them more robust
when compiled in differing environments.

Cc: stable@vger.kernel.org
Cc: James Morris <jmorris@namei.org>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Fixes: 30fc8d13 ("tpm: TPM 2.0 CRB Interface")
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Acked-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e406f12dde1a8375d77ea02d91f313fb1a9c6aec upstream.

mddev->sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.

Committer node:

Added similar fix to raid5.c, as suggested by Guoqing.

Cc: stable@vger.kernel.org # v3.16+
Acked-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NAditya Pakki <pakki001@umn.edu>
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 076333870c2f5bdd9b6d31e7ca1909cf0c84cbfa upstream.

When TSC is not available, "timeless" decoding is used but a divide by
zero occurs if perf_time_to_tsc() is called.

Ensure the divisor is not zero.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org # v4.9+
Link: https://lkml.kernel.org/n/tip-1i4j0wqoc8vlbkcizqqxpsf4@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8041ffd36f42d8521d66dd1e236feb58cecd68bc upstream.

The client IMC bandwidth events currently return very large values:

  $ perf stat -e uncore_imc/data_reads/ -e uncore_imc/data_writes/ -I 10000 -a

  10.000117222 34,788.76 MiB uncore_imc/data_reads/
  10.000117222 8.26 MiB uncore_imc/data_writes/
  20.000374584 34,842.89 MiB uncore_imc/data_reads/
  20.000374584 10.45 MiB uncore_imc/data_writes/
  30.000633299 37,965.29 MiB uncore_imc/data_reads/
  30.000633299 323.62 MiB uncore_imc/data_writes/
  40.000891548 41,012.88 MiB uncore_imc/data_reads/
  40.000891548 6.98 MiB uncore_imc/data_writes/
  50.001142480 1,125,899,906,621,494.75 MiB uncore_imc/data_reads/
  50.001142480 6.97 MiB uncore_imc/data_writes/

The client IMC events are freerunning counters. They still use the
old event encoding format (0x1 for data_read and 0x2 for data write).
The counter bit width is calculated by common code, which assume that
the standard encoding format is used for the freerunning counters.
Error bit width information is calculated.

The patch intends to convert the old client IMC event encoding to the
standard encoding format.

Current common code uses event->attr.config which directly copy from
user space. We should not implicitly modify it for a converted event.
The event->hw.config is used to replace the event->attr.config in
common code.

For client IMC events, the event->attr.config is used to calculate a
converted event with standard encoding format in the custom
event_init(). The converted event is stored in event->hw.config.
For other events of freerunning counters, they already use the standard
encoding format. The same value as event->attr.config is assigned to
event->hw.config in common event_init().
Reported-by: NJin Yao <yao.jin@linux.intel.com>
Tested-by: NJin Yao <yao.jin@linux.intel.com>
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@kernel.org # v4.18+
Fixes: 9aae1780 ("perf/x86/intel/uncore: Clean up client IMC uncore")
Link: https://lkml.kernel.org/r/20190227165729.1861-1-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5a99d99e3310a565b0cf63f785b347be9ee0da45 upstream.

Auxtrace records might have up to 7 bytes of padding appended. Adjust
the overlap accordingly.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190206103947.15750-3-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c3fcadf0bb765faf45d6d562246e1d08885466df upstream.

Define auxtrace record alignment so that it can be referenced elsewhere.

Note this is preparation for patch "perf intel-pt: Fix overlap calculation
for padding"
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190206103947.15750-2-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d6d457451eb94fa747dc202765592eb8885a7352 upstream.

Kallsyms symbols do not have a size, so the size becomes the distance to
the next symbol.

Consequently the recently added trampoline symbols end up with large
sizes because the trampolines are some distance from one another and the
main kernel map.

However, symbols that end outside their map can disrupt the symbol tree
because, after mapping, it can appear incorrectly that they overlap
other symbols.

Add logic to truncate symbol size to the end of the corresponding map.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Fixes: d83212d5 ("kallsyms, x86: Export addresses of PTI entry trampolines")
Link: http://lkml.kernel.org/r/20190109091835.5570-2-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 03997612904866abe7cdcc992784ef65cb3a4b81 upstream.

CYC packet timestamp calculation depends upon CBR which was being
cleared upon overflow (OVF). That can cause errors due to failing to
synchronize with sideband events. Even if a CBR change has been lost,
the old CBR is still a better estimate than zero. So remove the clearing
of CBR.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190206103947.15750-4-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f76a16adc485699f95bb71fce114f97c832fe664 upstream.

The .orc_unwind section is a packed array of 6-byte structs.  It's
currently aligned to 6 bytes, which is causing warnings in the LLD
linker.

Six isn't a power of two, so it's not a valid alignment value.  The
actual alignment doesn't matter much because it's an array of packed
structs.  An alignment of two is sufficient.  In reality it always gets
aligned to four bytes because it comes immediately after the
4-byte-aligned .orc_unwind_ip section.

Fixes: ee9f8fce ("x86/unwind: Add the ORC unwinder")
Reported-by: NNick Desaulniers <ndesaulniers@google.com>
Reported-by: NDmitry Golovin <dima@golovin.in>
Reported-by: NSedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NSedat Dilek <sedat.dilek@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/218
Link: https://lkml.kernel.org/r/d55027ee95fe73e952dcd8be90aebd31b0095c45.1551892041.git.jpoimboe@redhat.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a6dbe442755999960ca54a9b8ecfd9606be0ea75 upstream.

Commit 4b4ecd9c ("vt: Perform safe console erase only once") removed
what appeared to be an extra call to scr_memsetw(). This missed the fact
that set_origin() must be called before clearing the screen otherwise
old screen content gets restored on the screen when using vgacon. Let's
fix that by moving all the scrollback handling to flush_scrollback()
where it logically belongs, and invoking it before the actual screen
clearing in csi_J(), making the code simpler in the end.
Reported-by: NMatthew Whitehead <tedheadster@gmail.com>
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NMatthew Whitehead <tedheadster@gmail.com>
Fixes: 4b4ecd9c ("vt: Perform safe console erase only once")
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a41e8f25fa8f8f67360d88eb0eebbabe95a64bdf upstream.

The networking maintainer keeps a public list of the patches being
queued up for the next round of stable releases.  Be sure to check there
before asking for a patch to be applied so that you do not waste
people's time.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9951379b0ca88c95876ad9778b9099e19a95d566 upstream.

Some users see panics like the following when performing fstrim on a
bcached volume:

[  529.803060] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[  530.183928] #PF error: [normal kernel read fault]
[  530.412392] PGD 8000001f42163067 P4D 8000001f42163067 PUD 1f42168067 PMD 0
[  530.750887] Oops: 0000 [#1] SMP PTI
[  530.920869] CPU: 10 PID: 4167 Comm: fstrim Kdump: loaded Not tainted 5.0.0-rc1+ #3
[  531.290204] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015
[  531.693137] RIP: 0010:blk_queue_split+0x148/0x620
[  531.922205] Code: 60 38 89 55 a0 45 31 db 45 31 f6 45 31 c9 31 ff 89 4d 98 85 db 0f 84 7f 04 00 00 44 8b 6d 98 4c 89 ee 48 c1 e6 04 49 03 70 78 <8b> 46 08 44 8b 56 0c 48
8b 16 44 29 e0 39 d8 48 89 55 a8 0f 47 c3
[  532.838634] RSP: 0018:ffffb9b708df39b0 EFLAGS: 00010246
[  533.093571] RAX: 00000000ffffffff RBX: 0000000000046000 RCX: 0000000000000000
[  533.441865] RDX: 0000000000000200 RSI: 0000000000000000 RDI: 0000000000000000
[  533.789922] RBP: ffffb9b708df3a48 R08: ffff940d3b3fdd20 R09: 0000000000000000
[  534.137512] R10: ffffb9b708df3958 R11: 0000000000000000 R12: 0000000000000000
[  534.485329] R13: 0000000000000000 R14: 0000000000000000 R15: ffff940d39212020
[  534.833319] FS:  00007efec26e3840(0000) GS:ffff940d1f480000(0000) knlGS:0000000000000000
[  535.224098] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  535.504318] CR2: 0000000000000008 CR3: 0000001f4e256004 CR4: 00000000001606e0
[  535.851759] Call Trace:
[  535.970308]  ? mempool_alloc_slab+0x15/0x20
[  536.174152]  ? bch_data_insert+0x42/0xd0 [bcache]
[  536.403399]  blk_mq_make_request+0x97/0x4f0
[  536.607036]  generic_make_request+0x1e2/0x410
[  536.819164]  submit_bio+0x73/0x150
[  536.980168]  ? submit_bio+0x73/0x150
[  537.149731]  ? bio_associate_blkg_from_css+0x3b/0x60
[  537.391595]  ? _cond_resched+0x1a/0x50
[  537.573774]  submit_bio_wait+0x59/0x90
[  537.756105]  blkdev_issue_discard+0x80/0xd0
[  537.959590]  ext4_trim_fs+0x4a9/0x9e0
[  538.137636]  ? ext4_trim_fs+0x4a9/0x9e0
[  538.324087]  ext4_ioctl+0xea4/0x1530
[  538.497712]  ? _copy_to_user+0x2a/0x40
[  538.679632]  do_vfs_ioctl+0xa6/0x600
[  538.853127]  ? __do_sys_newfstat+0x44/0x70
[  539.051951]  ksys_ioctl+0x6d/0x80
[  539.212785]  __x64_sys_ioctl+0x1a/0x20
[  539.394918]  do_syscall_64+0x5a/0x110
[  539.568674]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

We have observed it where both:
1) LVM/devmapper is involved (bcache backing device is LVM volume) and
2) writeback cache is involved (bcache cache_mode is writeback)

On one machine, we can reliably reproduce it with:

 # echo writeback > /sys/block/bcache0/bcache/cache_mode
   (not sure whether above line is required)
 # mount /dev/bcache0 /test
 # for i in {0..10}; do
	file="$(mktemp /test/zero.XXX)"
	dd if=/dev/zero of="$file" bs=1M count=256
	sync
	rm $file
    done
  # fstrim -v /test

Observing this with tracepoints on, we see the following writes:

fstrim-18019 [022] .... 91107.302026: bcache_write: 73f95583-561c-408f-a93a-4cbd2498f5c8 inode 0  DS 4260112 + 196352 hit 0 bypass 1
fstrim-18019 [022] .... 91107.302050: bcache_write: 73f95583-561c-408f-a93a-4cbd2498f5c8 inode 0  DS 4456464 + 262144 hit 0 bypass 1
fstrim-18019 [022] .... 91107.302075: bcache_write: 73f95583-561c-408f-a93a-4cbd2498f5c8 inode 0  DS 4718608 + 81920 hit 0 bypass 1
fstrim-18019 [022] .... 91107.302094: bcache_write: 73f95583-561c-408f-a93a-4cbd2498f5c8 inode 0  DS 5324816 + 180224 hit 0 bypass 1
fstrim-18019 [022] .... 91107.302121: bcache_write: 73f95583-561c-408f-a93a-4cbd2498f5c8 inode 0  DS 5505040 + 262144 hit 0 bypass 1
fstrim-18019 [022] .... 91107.302145: bcache_write: 73f95583-561c-408f-a93a-4cbd2498f5c8 inode 0  DS 5767184 + 81920 hit 0 bypass 1
fstrim-18019 [022] .... 91107.308777: bcache_write: 73f95583-561c-408f-a93a-4cbd2498f5c8 inode 0  DS 6373392 + 180224 hit 1 bypass 0
<crash>

Note the final one has different hit/bypass flags.

This is because in should_writeback(), we were hitting a case where
the partial stripe condition was returning true and so
should_writeback() was returning true early.

If that hadn't been the case, it would have hit the would_skip test, and
as would_skip == s->iop.bypass == true, should_writeback() would have
returned false.

Looking at the git history from 'commit 72c27061 ("bcache: Write out
full stripes")', it looks like the idea was to optimise for raid5/6:

       * If a stripe is already dirty, force writes to that stripe to
	 writeback mode - to help build up full stripes of dirty data

To fix this issue, make sure that should_writeback() on a discard op
never returns true.

More details of debugging:
https://www.spinics.net/lists/linux-bcache/msg06996.html

Previous reports:
 - https://bugzilla.kernel.org/show_bug.cgi?id=201051
 - https://bugzilla.kernel.org/show_bug.cgi?id=196103
 - https://www.spinics.net/lists/linux-bcache/msg06885.html

(Coly Li: minor modification to follow maximum 75 chars per line rule)

Cc: Kent Overstreet <koverstreet@google.com>
Cc: stable@vger.kernel.org
Fixes: 72c27061 ("bcache: Write out full stripes")
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1fad17fb1bbcd73159c2b992668a6957ecc5af8a upstream.

If wakeup_source_add() is called right after wakeup_source_remove()
for the same wakeup source, timer_setup() may be called for a
potentially scheduled timer which is incorrect.

To avoid that, move the wakeup source timer cancellation from
wakeup_source_drop() to wakeup_source_remove().

Moreover, make wakeup_source_remove() clear the timer function after
canceling the timer to let wakeup_source_not_registered() treat
unregistered wakeup sources in the same way as the ones that have
never been registered.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
[ rjw: Subject, changelog, merged two patches together ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b7e5034cbecf5a65b7bfdc2b20a8378039577706 upstream.

James Pearson found that an NFS server stopped responding to UDP
requests if started with more than 1017 threads.

sv_max_mesg is about 2^20, so that is probably where the calculation
performed by

	svc_sock_setbufsize(svsk->sk_sock,
                            (serv->sv_nrthreads+3) * serv->sv_max_mesg,
                            (serv->sv_nrthreads+3) * serv->sv_max_mesg);

starts to overflow an int.
Reported-by: NJames Pearson <jcpearson@gmail.com>
Tested-by: NJames Pearson <jcpearson@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c1dffe0bf7f9c3d57d9f237a7cb2a81e62babd2b upstream.

If we have to retransmit a request, we should ensure that we reinitialise
the sequence results structure, since in the event of a signal
we need to treat the request as if it had not been sent.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit dd838821f0a29781b185cd8fb8e48d5c177bd838 upstream.

Commit 62a063b8e7d1 "nfsd4: fix crash on writing v4_end_grace before
nfsd startup" is trying to fix a NULL dereference issue, but it
mistakenly checks if the nfsd server is started. So fix it.

Fixes: 62a063b8e7d1 "nfsd4: fix crash on writing v4_end_grace before nfsd startup"
Cc: stable@vger.kernel.org
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: NYihao Wu <wuyihao@linux.alibaba.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b602345da6cbb135ba68cf042df8ec9a73da7981 upstream.

If the result of an NFSv3 readdir{,plus} request results in the
"offset" on one entry having to be split across 2 pages, and is sized
so that the next directory entry doesn't fit in the requested size,
then memory corruption can happen.

When encode_entry() is called after encoding the last entry that fits,
it notices that ->offset and ->offset1 are set, and so stores the
offset value in the two pages as required.  It clears ->offset1 but
*does not* clear ->offset.

Normally this omission doesn't matter as encode_entry_baggage() will
be called, and will set ->offset to a suitable value (not on a page
boundary).
But in the case where cd->buflen < elen and nfserr_toosmall is
returned, ->offset is not reset.

This means that nfsd3proc_readdirplus will see ->offset with a value 4
bytes before the end of a page, and ->offset1 set to NULL.
It will try to write 8bytes to ->offset.
If we are lucky, the next page will be read-only, and the system will
  BUG: unable to handle kernel paging request at...

If we are unlucky, some innocent page will have the first 4 bytes
corrupted.

nfsd3proc_readdir() doesn't even check for ->offset1, it just blindly
writes 8 bytes to the offset wherever it is.

Fix this by clearing ->offset after it is used, and copying the
->offset handling code from nfsd3_proc_readdirplus into
nfsd3_proc_readdir.

(Note that the commit hash in the Fixes tag is from the 'history'
 tree - this bug predates git).

Fixes: 0b1d57cf7654 ("[PATCH] kNFSd: Fix nfs3 dentry encoding")
Fixes-URL: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=0b1d57cf7654
Cc: stable@vger.kernel.org (v2.6.12+)
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c54f24e338ed2a35218f117a4a1afb5f9e2b4e64 upstream.

We're unintentionally limiting the number of slots per nfsv4.1 session
to 10.  Often more than 10 simultaneous RPCs are needed for the best
performance.

This calculation was meant to prevent any one client from using up more
than a third of the limit we set for total memory use across all clients
and sessions.  Instead, it's limiting the client to a third of the
maximum for a single session.

Fix this.
Reported-by: NChris Tracy <ctracy@engr.scu.edu>
Cc: stable@vger.kernel.org
Fixes: de766e57 "nfsd: give out fewer session slots as limit approaches"
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8127d82705998568b52ac724e28e00941538083d upstream.

If the I/O completion failed with a fatal error, then we should just
exit nfs_pageio_complete_mirror() rather than try to recoalesce.

Fixes: a7d42ddb ("nfs: add mirroring support to pgio layer")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 4d91969ed4dbcefd0e78f77494f0cb8fada9048a upstream.

Whether we need to exit early, or just reprocess the list, we
must not lost track of the request which failed to get recoalesced.

Fixes: 03d5eb65 ("NFS: Fix a memory leak in nfs_do_recoalesce")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f57dcf4c72113c745d83f1c65f7291299f65c14f upstream.

When we fail to add the request to the I/O queue, we currently leave it
to the caller to free the failed request. However since some of the
requests that fail are actually created by nfs_pageio_add_request()
itself, and are not passed back the caller, this leads to a leakage
issue, which can again cause page locks to leak.

This commit addresses the leakage by freeing the created requests on
error, using desc->pg_completion_ops->error_cleanup()
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Fixes: a7d42ddb ("nfs: add mirroring support to pgio layer")
Cc: stable@vger.kernel.org # v4.0: c18b96a1: nfs: clean up rest of reqs
Cc: stable@vger.kernel.org # v4.0: d600ad1f: NFS41: pop some layoutget
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit fd10606f93a149a9f3d37574e5385b083b4a7b32 upstream.

The driver doesn't generate uevents on charger connect/disconnect.
This leads to UPower not detecting when AC is on or off... and that is
bad.

Reported by Arthur D. on github (
https://github.com/maemo-leste/bugtracker/issues/206 ), thanks to
Merlijn Wajer for suggesting a fix.

Cc: stable@kernel.org
Signed-off-by: NPavel Machek <pavel@ucw.cz>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ae7b8eda27b33b1f688dfdebe4d46f690a8f9162 upstream.

There is a potential NULL pointer dereference in case devm_kzalloc()
fails and returns NULL.

Fix this by adding a NULL check on *lookup*

This bug was detected with the help of Coccinelle.

Fixes: b2e63555 ("i2c: gpio: Convert to use descriptors")
Cc: stable@vger.kernel.org
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 225557446856448039a9e495da37b72c20071ef2 upstream.

When using dm-integrity underneath md-raid, some tests with raid
auto-correction trigger large amounts of integrity failures - and all
these failures print an error message. These messages can bring the
system to a halt if the system is using serial console.

Fix this by limiting the rate of error messages - it improves the speed
of raid recovery and avoids the hang.

Fixes: 7eada909 ("dm: add integrity target")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0bdb50c531f7377a9da80d3ce2d61f389c84cb30 upstream.

A dm-raid array with devices larger than 4GB won't assemble on
a 32 bit host since _check_data_dev_sectors() was added in 4.16.
This is because to_sector() treats its argument as an "unsigned long"
which is 32bits (4GB) on a 32bit host.  Using "unsigned long long"
is more correct.

Kernels as early as 4.2 can have other problems due to to_sector()
being used on the size of a device.

Fixes: 0cf45031 ("dm raid: add support for the MD RAID0 personality")
cc: stable@vger.kernel.org (v4.2+)
Reported-and-tested-by: NGuillaume Perréal <gperreal@free.fr>
Signed-off-by: NNeilBrown <neil@brown.name>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 401e7e88d4ef80188ffa07095ac00456f901b8c4 upstream.

When we excute the following commands, we got oops
rmmod ipmi_si
cat /proc/ioports

[ 1623.482380] Unable to handle kernel paging request at virtual address ffff00000901d478
[ 1623.482382] Mem abort info:
[ 1623.482383]   ESR = 0x96000007
[ 1623.482385]   Exception class = DABT (current EL), IL = 32 bits
[ 1623.482386]   SET = 0, FnV = 0
[ 1623.482387]   EA = 0, S1PTW = 0
[ 1623.482388] Data abort info:
[ 1623.482389]   ISV = 0, ISS = 0x00000007
[ 1623.482390]   CM = 0, WnR = 0
[ 1623.482393] swapper pgtable: 4k pages, 48-bit VAs, pgdp = 00000000d7d94a66
[ 1623.482395] [ffff00000901d478] pgd=000000dffbfff003, pud=000000dffbffe003, pmd=0000003f5d06e003, pte=0000000000000000
[ 1623.482399] Internal error: Oops: 96000007 [#1] SMP
[ 1623.487407] Modules linked in: ipmi_si(E) nls_utf8 isofs rpcrdma ib_iser ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_umad rdma_cm ib_cm dm_mirror dm_region_hash dm_log iw_cm dm_mod aes_ce_blk crypto_simd cryptd aes_ce_cipher ses ghash_ce sha2_ce enclosure sha256_arm64 sg sha1_ce hisi_sas_v2_hw hibmc_drm sbsa_gwdt hisi_sas_main ip_tables mlx5_ib ib_uverbs marvell ib_core mlx5_core ixgbe mdio hns_dsaf ipmi_devintf hns_enet_drv ipmi_msghandler hns_mdio [last unloaded: ipmi_si]
[ 1623.532410] CPU: 30 PID: 11438 Comm: cat Kdump: loaded Tainted: G            E     5.0.0-rc3+ #168
[ 1623.541498] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.37 11/21/2017
[ 1623.548822] pstate: a0000005 (NzCv daif -PAN -UAO)
[ 1623.553684] pc : string+0x28/0x98
[ 1623.557040] lr : vsnprintf+0x368/0x5e8
[ 1623.560837] sp : ffff000013213a80
[ 1623.564191] x29: ffff000013213a80 x28: ffff00001138abb5
[ 1623.569577] x27: ffff000013213c18 x26: ffff805f67d06049
[ 1623.574963] x25: 0000000000000000 x24: ffff00001138abb5
[ 1623.580349] x23: 0000000000000fb7 x22: ffff0000117ed000
[ 1623.585734] x21: ffff000011188fd8 x20: ffff805f67d07000
[ 1623.591119] x19: ffff805f67d06061 x18: ffffffffffffffff
[ 1623.596505] x17: 0000000000000200 x16: 0000000000000000
[ 1623.601890] x15: ffff0000117ed748 x14: ffff805f67d07000
[ 1623.607276] x13: ffff805f67d0605e x12: 0000000000000000
[ 1623.612661] x11: 0000000000000000 x10: 0000000000000000
[ 1623.618046] x9 : 0000000000000000 x8 : 000000000000000f
[ 1623.623432] x7 : ffff805f67d06061 x6 : fffffffffffffffe
[ 1623.628817] x5 : 0000000000000012 x4 : ffff00000901d478
[ 1623.634203] x3 : ffff0a00ffffff04 x2 : ffff805f67d07000
[ 1623.639588] x1 : ffff805f67d07000 x0 : ffffffffffffffff
[ 1623.644974] Process cat (pid: 11438, stack limit = 0x000000008d4cbc10)
[ 1623.651592] Call trace:
[ 1623.654068]  string+0x28/0x98
[ 1623.657071]  vsnprintf+0x368/0x5e8
[ 1623.660517]  seq_vprintf+0x70/0x98
[ 1623.668009]  seq_printf+0x7c/0xa0
[ 1623.675530]  r_show+0xc8/0xf8
[ 1623.682558]  seq_read+0x330/0x440
[ 1623.689877]  proc_reg_read+0x78/0xd0
[ 1623.697346]  __vfs_read+0x60/0x1a0
[ 1623.704564]  vfs_read+0x94/0x150
[ 1623.711339]  ksys_read+0x6c/0xd8
[ 1623.717939]  __arm64_sys_read+0x24/0x30
[ 1623.725077]  el0_svc_common+0x120/0x148
[ 1623.732035]  el0_svc_handler+0x30/0x40
[ 1623.738757]  el0_svc+0x8/0xc
[ 1623.744520] Code: d1000406 aa0103e2 54000149 b4000080 (39400085)
[ 1623.753441] ---[ end trace f91b6a4937de9835 ]---
[ 1623.760871] Kernel panic - not syncing: Fatal exception
[ 1623.768935] SMP: stopping secondary CPUs
[ 1623.775718] Kernel Offset: disabled
[ 1623.781998] CPU features: 0x002,21006008
[ 1623.788777] Memory Limit: none
[ 1623.798329] Starting crashdump kernel...
[ 1623.805202] Bye!

If io_setup is called successful in try_smi_init() but try_smi_init()
goes out_err before calling ipmi_register_smi(), so ipmi_unregister_smi()
will not be called while removing module. It leads to the resource that
allocated in io_setup() can not be freed, but the name(DEVICE_NAME) of
resource is freed while removing the module. It causes use-after-free
when cat /proc/ioports.

Fix this by calling io_cleanup() while try_smi_init() goes to out_err.
and don't call io_cleanup() until io_setup() returns successful to avoid
warning prints.

Fixes: 93c303d2 ("ipmi_si: Clean up shutdown a bit")
Cc: stable@vger.kernel.org
Reported-by: NNuoHan Qiao <qiaonuohan@huawei.com>
Suggested-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c88b093693ccbe41991ef2e9b1d251945e6e54ed upstream.

Due to what looks like a typo dating back to the original addition
of FPEXC32_EL2 handling, KVM currently initialises this register to
an architecturally invalid value.

As a result, the VECITR field (RES1) in bits [10:8] is initialised
with 0, and the two reserved (RES0) bits [6:5] are initialised with
1.  (In the Common VFP Subarchitecture as specified by ARMv7-A,
these two bits were IMP DEF.  ARMv8-A removes them.)

This patch changes the reset value from 0x70 to 0x700, which
reflects the architectural constraints and is presumably what was
originally intended.

Cc: <stable@vger.kernel.org> # 4.12.x-
Cc: Christoffer Dall <christoffer.dall@arm.com>
Fixes: 62a89c44 ("arm64: KVM: 32bit handling of coprocessor traps")
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6bd288569b50bc89fa5513031086746968f585cb upstream.

Debug exception handlers may be called for exceptions generated both by
user and kernel code. In many cases, this is checked explicitly, but
in other cases things either happen to work by happy accident or they
go slightly wrong. For example, executing 'brk #4' from userspace will
enter the kprobes code and be ignored, but the instruction will be
retried forever in userspace instead of delivering a SIGTRAP.

Fix this issue in the most stable-friendly fashion by simply adding
explicit checks of the triggering exception level to all of our debug
exception handlers.

Cc: <stable@vger.kernel.org>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5870970b9a828d8693aa6d15742573289d7dbcd0 upstream.

When using VHE, the host needs to clear HCR_EL2.TGE bit in order
to interact with guest TLBs, switching from EL2&0 translation regime
to EL1&0.

However, some non-maskable asynchronous event could happen while TGE is
cleared like SDEI. Because of this address translation operations
relying on EL2&0 translation regime could fail (tlb invalidation,
userspace access, ...).

Fix this by properly setting HCR_EL2.TGE when entering NMI context and
clear it if necessary when returning to the interrupted context.
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Suggested-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NJames Morse <james.morse@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e2477233145f2156434afb799583bccd878f3e9f upstream.

Fix boolean expressions by using logical AND operator '&&' instead of
bitwise operator '&'.

This issue was detected with the help of Coccinelle.

Fixes: 4fa084af ("ARM: OSIRIS: DVS (Dynamic Voltage Scaling) supoort.")
Cc: stable@vger.kernel.org
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
[krzk: Fix -Wparentheses warning]
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9bf3d3c4e4fd82c7174f4856df372ab2a71005b9 upstream.

Today's message is useless:

  [   42.253267] Kernel stack overflow in process (ptrval), r1=c65500b0

This patch fixes it:

  [   66.905235] Kernel stack overflow in process sh[356], r1=c65560b0

Fixes: ad67b74d ("printk: hash addresses printed with %p")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
[mpe: Use task_pid_nr()]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0bbea75c476b77fa7d7811d6be911cc7583e640f upstream.

Looks like book3s/32 doesn't set RI on machine check, so
checking RI before calling die() will always be fatal
allthought this is not an issue in most cases.

Fixes: b96672dd ("powerpc: Machine check interrupt is a non-maskable interrupt")
Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts")
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Cc: stable@vger.kernel.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 35f2806b481f5b9207f25e1886cba5d1c4d12cc7 upstream.

We added runtime allocation of 16G pages in commit 4ae279c2
("powerpc/mm/hugetlb: Allow runtime allocation of 16G.") That was done
to enable 16G allocation on PowerNV and KVM config. In case of KVM
config, we mostly would have the entire guest RAM backed by 16G
hugetlb pages for this to work. PAPR do support partial backing of
guest RAM with hugepages via ibm,expected#pages node of memory node in
the device tree. This means rest of the guest RAM won't be backed by
16G contiguous pages in the host and hence a hash page table insertion
can fail in such case.

An example error message will look like

  hash-mmu: mm: Hashing failure ! EA=0x7efc00000000 access=0x8000000000000006 current=readback
  hash-mmu:     trap=0x300 vsid=0x67af789 ssize=1 base psize=14 psize 14 pte=0xc000000400000386
  readback[12260]: unhandled signal 7 at 00007efc00000000 nip 00000000100012d0 lr 000000001000127c code 2

This patch address that by preventing runtime allocation of 16G
hugepages in LPAR config. To allocate 16G hugetlb one need to kernel
command line hugepagesz=16G hugepages=<number of 16G pages>

With radix translation mode we don't run into this issue.

This change will prevent runtime allocation of 16G hugetlb pages on
kvm with hash translation mode. However, with the current upstream it
was observed that 16G hugetlbfs backed guest doesn't boot at all.

We observe boot failure with the below message:
  [131354.647546] KVM: map_vrma at 0 failed, ret=-4

That means this patch is not resulting in an observable regression.
Once we fix the boot issue with 16G hugetlb backed memory, we need to
use ibm,expected#pages memory node attribute to indicate 16G page
reservation to the guest. This will also enable partial backing of
guest RAM with 16G pages.

Fixes: 4ae279c2 ("powerpc/mm/hugetlb: Allow runtime allocation of 16G.")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ca6d5149d2ad0a8d2f9c28cbe379802260a0a5e0 upstream.

GCC 8 warns about the logic in vr_get/set(), which with -Werror breaks
the build:

  In function ‘user_regset_copyin’,
      inlined from ‘vr_set’ at arch/powerpc/kernel/ptrace.c:628:9:
  include/linux/regset.h:295:4: error: ‘memcpy’ offset [-527, -529] is
  out of the bounds [0, 16] of object ‘vrsave’ with type ‘union
  <anonymous>’ [-Werror=array-bounds]
  arch/powerpc/kernel/ptrace.c: In function ‘vr_set’:
  arch/powerpc/kernel/ptrace.c:623:5: note: ‘vrsave’ declared here
     } vrsave;

This has been identified as a regression in GCC, see GCC bug 88273.

However we can avoid the warning and also simplify the logic and make
it more robust.

Currently we pass -1 as end_pos to user_regset_copyout(). This says
"copy up to the end of the regset".

The definition of the regset is:
	[REGSET_VMX] = {
		.core_note_type = NT_PPC_VMX, .n = 34,
		.size = sizeof(vector128), .align = sizeof(vector128),
		.active = vr_active, .get = vr_get, .set = vr_set
	},

The end is calculated as (n * size), ie. 34 * sizeof(vector128).

In vr_get/set() we pass start_pos as 33 * sizeof(vector128), meaning
we can copy up to sizeof(vector128) into/out-of vrsave.

The on-stack vrsave is defined as:
  union {
	  elf_vrreg_t reg;
	  u32 word;
  } vrsave;

And elf_vrreg_t is:
  typedef __vector128 elf_vrreg_t;

So there is no bug, but we rely on all those sizes lining up,
otherwise we would have a kernel stack exposure/overwrite on our
hands.

Rather than relying on that we can pass an explict end_pos based on
the sizeof(vrsave). The result should be exactly the same but it's
more obviously not over-reading/writing the stack and it avoids the
compiler warning.
Reported-by: NMeelis Roos <mroos@linux.ee>
Reported-by: NMathieu Malaterre <malat@debian.org>
Cc: stable@vger.kernel.org
Tested-by: NMathieu Malaterre <malat@debian.org>
Tested-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>