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[pull] master from torvalds:master #51

Merged
merged 32 commits into from
Dec 13, 2018
Merged

[pull] master from torvalds:master #51

merged 32 commits into from
Dec 13, 2018

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Created by pull[bot]

amir73il and others added 30 commits November 19, 2018 16:21
Theodore Ts'o reported a v4.19 regression with docker-dropbox:
https://marc.info/?l=linux-fsdevel&m=154070089431116&w=2

"I was rebuilding my dropbox Docker container, and it failed in 4.19
 with the following error:
 ...
 dpkg: error: error creating new backup file \
              '/var/lib/dpkg/status-old': Invalid cross-device link"

The problem did not reproduce with metacopy feature disabled.
The error was caused by insufficient credentials to set
"trusted.overlay.redirect" xattr on link of a metacopy file.

Reproducer:

 echo Y > /sys/module/overlay/parameters/redirect_dir
 echo Y > /sys/module/overlay/parameters/metacopy
 cd /tmp
 mkdir l u w m
 chmod 777 l u
 touch l/foo
 ln l/foo l/link
 chmod 666 l/foo
 mount -t overlay none -olowerdir=l,upperdir=u,workdir=w m
 su fsgqa
 ln m/foo m/bar
 [   21.455823] overlayfs: failed to set redirect (-1)
 ln: failed to create hard link 'm/bar' => 'm/foo':\
     Invalid cross-device link

Reported-by: Theodore Y. Ts'o <tytso@mit.edu>
Reported-by: Maciej Zięba <maciekz82@gmail.com>
Fixes: 4120fe6 ("ovl: Set redirect on upper inode when it is linked")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
When decoding a lower file handle, we first call ovl_check_origin_fh()
with connected=false to get any real lower dentry for overlay inode
cache lookup.

If the real dentry is a disconnected dir dentry, ovl_check_origin_fh()
is called again with connected=true to get a connected real dentry
and find the lower layer the real dentry belongs to.

If the first call returned a connected real dentry, we use it to
lookup an overlay connected dentry, but the first ovl_check_origin_fh()
call with connected=false did not check that the found dentry is under
the root of the layer (see ovl_acceptable()), it only checked that
the found dentry super block matches the uuid of the lower file handle.

In case there are multiple lower layers on the same fs and the found
dentry is not from the top most lower layer, using the layer index
returned from the first ovl_check_origin_fh() is wrong and we end
up failing to decode the file handle.

Fix this by always calling ovl_check_origin_fh() with connected=true
if we got a directory dentry in the first call.

Fixes: 8b58924 ("ovl: lookup in inode cache first when decoding...")
Cc: <stable@vger.kernel.org> # v4.17
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
make_bad_inode() sets inode->i_mode to S_IFREG if I/O error is detected
in fuse_do_getattr()/fuse_do_setattr(). If the inode is not a regular
file, write_files and queued_writes in fuse_inode are not initialized
and have NULL or invalid pointers written by other members in a union.
So, list_empty() returns false in fuse_destroy_inode(). Add
is_bad_inode() to check if make_bad_inode() was called.

Reported-by: syzbot+b9c89b84423073226299@syzkaller.appspotmail.com
Fixes: ab2257e ("fuse: reduce size of struct fuse_inode")
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Commit ab2257e ("fuse: reduce size of struct fuse_inode") moved parts
of fields related to writeback on regular file and to directory caching
into a union.  However fuse_fsync_common() called from fuse_dir_fsync()
touches some writeback related fields, resulting in a crash.

Move writeback related parts from fuse_fsync_common() to fuse_fysnc().

Reported-by: Brett Girton <btgirton@gmail.com>
Tested-by: Brett Girton <btgirton@gmail.com>
Fixes: ab2257e ("fuse: reduce size of struct fuse_inode")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
fuse_invalidate_attr() now sets fi->inval_mask instead of fi->i_time, hence
we need to check the inval mask in fuse_permission() as well.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 2f1e819 ("fuse: allow fine grained attr cache invaldation")
Commit de2bc45 ("media: vsp1: Update LIF buffer thresholds")
updated the LIF buffer thresholds based on the VSP version, but used the
wrong model mask. This resulted in all VSP instances to be treated as a
Gen3 VSPD, breaking operation on all Gen2 platforms as well as on
H3 ES2.0, M3-N, V3M and V3H. Fix it.

Fixes: de2bc45 ("media: vsp1: Update LIF buffer thresholds")

Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
The devm_ioremap_resource() function doesn't return NULL pointers, it
returns error pointers.

Fixes: 50e7615 ("media: platform: Add Cedrus VPU decoder driver")

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
vb2_start_streaming() already rolls back the buffers, so there is no
need to call __vb2_queue_cancel(). Especially since __vb2_queue_cancel()
does too much, such as zeroing the q->queued_count value, causing vb2
to think that no buffers have been queued.

It appears that this call to __vb2_queue_cancel() is a left-over from
before commit b3379c6.

Fixes: b3379c6 ('vb2: only call start_streaming if sufficient buffers are queued')

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <stable@vger.kernel.org>      # for v4.16 and up
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
VIDIOC_PREPARE_BUF should ignore V4L2_BUF_FLAG_REQUEST_FD since it isn't
doing anything with requests. So inform vb2_queue_or_prepare_buf whether
it is called from vb2_prepare_buf or vb2_qbuf and just return 0 in the
first case.

This was found when adding new v4l2-compliance checks.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
When vb2_buffer_done is called the buffer is unbound from the
request and put. The media_request_object_put also 'put's the
request reference. If the application has already closed the
request fd, then that means that the request reference at that
point goes to 0 and the whole request is released.

This means that the control handler associated with the request is
also freed and that causes this kernel oops:

[174705.995401] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908
[174705.995411] in_atomic(): 1, irqs_disabled(): 1, pid: 28071, name: vivid-000-vid-o
[174705.995416] 2 locks held by vivid-000-vid-o/28071:
[174705.995420]  #0: 000000001ea3a232 (&dev->mutex#3){....}, at: vivid_thread_vid_out+0x3f5/0x550 [vivid]
[174705.995447]  #1: 00000000e30a0d1e (&(&q->done_lock)->rlock){....}, at: vb2_buffer_done+0x92/0x1d0 [videobuf2_common]
[174705.995460] Preemption disabled at:
[174705.995461] [<0000000000000000>]           (null)
[174705.995472] CPU: 11 PID: 28071 Comm: vivid-000-vid-o Tainted: G        W         4.20.0-rc1-test-no #88
[174705.995476] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
[174705.995481] Call Trace:
[174705.995500]  dump_stack+0x46/0x60
[174705.995512]  ___might_sleep.cold.79+0xe1/0xf1
[174705.995523]  __mutex_lock+0x50/0x8f0
[174705.995531]  ? find_held_lock+0x2d/0x90
[174705.995536]  ? find_held_lock+0x2d/0x90
[174705.995542]  ? find_held_lock+0x2d/0x90
[174705.995564]  ? v4l2_ctrl_handler_free.part.13+0x44/0x1d0 [videodev]
[174705.995576]  v4l2_ctrl_handler_free.part.13+0x44/0x1d0 [videodev]
[174705.995590]  v4l2_ctrl_request_release+0x1c/0x30 [videodev]
[174705.995600]  media_request_clean+0x64/0xe0 [media]
[174705.995609]  media_request_release+0x19/0x40 [media]
[174705.995617]  vb2_buffer_done+0xef/0x1d0 [videobuf2_common]
[174705.995630]  vivid_thread_vid_out+0x2c1/0x550 [vivid]
[174705.995645]  ? vivid_stop_generating_vid_cap+0x1c0/0x1c0 [vivid]
[174705.995653]  kthread+0x113/0x130
[174705.995659]  ? kthread_park+0x80/0x80
[174705.995667]  ret_from_fork+0x35/0x40

The vb2_buffer_done function can be called from interrupt context, so
anything that sleeps is not allowed.

The solution is to increment the request refcount when the buffer is
queued and decrement it when the buffer is dequeued. Releasing the
request is fine if that happens from VIDIOC_DQBUF.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
When a buffer is returned to state QUEUED (that happens when
start_streaming fails), then do not unbind and put the object
from the request. Nothing has changed yet, so just keep it as
is.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
If start_streaming() fails and all queued buffers are returned to
vb2, then do not call v4l2_ctrl_request_complete(). Nothing happened
to the request and the state should remain as it was before
start_streaming was called.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
The state structure contains the resolution expected by the decoder
and encoder. For an encoder that resolution should be taken from the
OUTPUT format, and for a decoder from the CAPTURE format.

If the wrong format is picked, a buffer overrun can occur if there is
a mismatch between the CAPTURE and OUTPUT formats.

The real fix would be to correctly implement the stateful codec
specification, but that will take more time. For now just prevent the
buffer overrun.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This reverts commit 007ea44.

The commit broke some selinux-testsuite cases, and it looks like there's no
straightforward fix keeping the direction of this patch, so revert for now.

The original patch was trying to fix the consistency of permission checks, and
not an observed bug.  So reverting should be safe.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The MPEG2 state controls for the cedrus stateless MPEG2 driver are
not yet stable. Move them out of the public headers into media/mpeg2-ctrls.h.

Eventually, once this has stabilized, they will be moved back to the
public headers.

Unfortunately I had to cast the control type to a u32 in two switch
statements to prevent a compiler warning about a control type define
not being part of the enum.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Add a note mentioning that these two controls are not part of the
public API while they still stabilizing.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
The Request API is now merged to the kernel but the confidence on the
stability of that API is not great, especially regarding the interaction
with V4L2.

Add a Kconfig option for the API, with a scary-looking warning.

The patch itself disables request creation as well as does not advertise
them as buffer flags. The driver requiring requests (cedrus) now depends
on the Kconfig option as well.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
…te_dirty()

Otherwise dm_bitset_cursor_begin() return -ENODATA.  Other calls to
dm_bitset_cursor_begin() have similar negative checks.

Fixes inability to create a cache in passthrough mode (even though doing
so makes no sense).

Fixes: 0d963b6 ("dm cache metadata: fix metadata2 format's blocks_are_clean_separate_dirty")
Cc: stable@vger.kernel.org
Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Otherwise the incoming bios, of various types, won't be shaped based on
the DM device's advertised limits.

Depends-on: af67c31 ("blk: remove bio_set arg from blk_queue_split()")
Fixes: 744889b ("block: don't deal with discard limit in blkdev_issue_discard()")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
struct bioctx includes the ref refcount_t to track the number of I/O
fragments used to process a target BIO as well as ensure that the zone
of the BIO is kept in the active state throughout the lifetime of the
BIO. However, since decrementing of this reference count is done in the
target .end_io method, the function bio_endio() must be called multiple
times for read and write target BIOs, which causes problems with the
value of the __bi_remaining struct bio field for chained BIOs (e.g. the
clone BIO passed by dm core is large and splits into fragments by the
block layer), resulting in incorrect values and inconsistencies with the
BIO_CHAIN flag setting. This is turn triggers the BUG_ON() call:

BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);

in bio_remaining_done() called from bio_endio().

Fix this ensuring that bio_endio() is called only once for any target
BIO by always using internal clone BIOs for processing any read or
write target BIO. This allows reference counting using the target BIO
context counter to trigger the target BIO completion bio_endio() call
once all data, metadata and other zone work triggered by the BIO
complete.

Overall, this simplifies the code too as the target .end_io becomes
unnecessary and differences between read and write BIO issuing and
completion processing disappear.

Fixes: 3b1a94c ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When ntfs is unmounted, the following leak is
reported by kmemleak.

kmemleak report:

unreferenced object 0xffff880052bf4400 (size 4096):
  comm "mount.ntfs", pid 16530, jiffies 4294861127 (age 3215.836s)
  hex dump (first 32 bytes):
    00 44 bf 52 00 88 ff ff 00 44 bf 52 00 88 ff ff  .D.R.....D.R....
    10 44 bf 52 00 88 ff ff 10 44 bf 52 00 88 ff ff  .D.R.....D.R....
  backtrace:
    [<00000000bf4a2f8d>] fuse_fill_super+0xb22/0x1da0 [fuse]
    [<000000004dde0f0c>] mount_bdev+0x263/0x320
    [<0000000025aebc66>] mount_fs+0x82/0x2bf
    [<0000000042c5a6be>] vfs_kern_mount.part.33+0xbf/0x480
    [<00000000ed10cd5b>] do_mount+0x3de/0x2ad0
    [<00000000d59ff068>] ksys_mount+0xba/0xd0
    [<000000001bda1bcc>] __x64_sys_mount+0xba/0x150
    [<00000000ebe26304>] do_syscall_64+0x151/0x490
    [<00000000d25f2b42>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
    [<000000002e0abd2c>] 0xffffffffffffffff

fuse_dev_alloc() allocate fud->pq.processing.
But this hash table is not freed.

Fix this by freeing fud->pq.processing.

Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: be2ff42 ("fuse: Use hash table to link processing request")
The create_filter() calls create_filter_start() which allocates a
"parse_error" descriptor, but fails to call create_filter_finish() that
frees it.

The op_stack and inverts in predicate_parse() were also not freed.

Found by kmemleak detector.

Cc: stable@vger.kernel.org
Fixes: 8076559 ("tracing: Rewrite filter logic to be simpler and faster")
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When create_event_filter() fails in set_trigger_filter(), the filter may
still be allocated and needs to be freed. The caller expects the
data->filter to be updated with the new filter, even if the new filter
failed (we could add an error message by setting set_str parameter of
create_event_filter(), but that's another update).

But because the error would just exit, filter was left hanging and
nothing could free it.

Found by kmemleak detector.

Cc: stable@vger.kernel.org
Fixes: bac5fb9 ("tracing: Add and use generic set_trigger_filter() implementation")
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The following commands will cause a memory leak:

 # cd /sys/kernel/tracing
 # mkdir instances/foo
 # echo schedule > instance/foo/set_ftrace_filter
 # rmdir instances/foo

The reason is that the hashes that hold the filters to set_ftrace_filter and
set_ftrace_notrace are not freed if they contain any data on the instance
and the instance is removed.

Found by kmemleak detector.

Cc: stable@vger.kernel.org
Fixes: 591dffd ("ftrace: Allow for function tracing instance to filter functions")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Sending a DM event before a thin-pool state change is about to happen is
a bug.  It wasn't realized until it became clear that userspace response
to the event raced with the actual state change that the event was
meant to notify about.

Fix this by first updating internal thin-pool state to reflect what the
DM event is being issued about.  This fixes a long-standing racey/buggy
userspace device-mapper-test-suite 'resize_io' test that would get an
event but not find the state it was looking for -- so it would just go
on to hang because no other events caused the test to reevaluate the
thin-pool's state.

Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When FUSE_OPEN returns ENOSYS, the no_open bit is set on the connection.

Because the FUSE_RELEASE and FUSE_RELEASEDIR paths share code, this
incorrectly caused the FUSE_RELEASEDIR request to be dropped and never sent
to userspace.

Pass an isdir bool to distinguish between FUSE_RELEASE and FUSE_RELEASEDIR
inside of fuse_file_put.

Fixes: 7678ac5 ("fuse: support clients that don't implement 'open'")
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: Chad Austin <chadaustin@fb.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Decoupled version bump from commit f6c3675 ("dm thin: send event
about thin-pool state change _after_ making it") because version bumps
just create conflicts when backporting to the stable trees.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
…nel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "While running various ftrace tests on new development code, the
  kmemleak detector found some allocations that were not freed
  correctly.

  This fixes a couple of leaks in the event trigger code as well as in
  adding function trace filters in trace instances"

* tag 'trace-v4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix memory leak of instance function hash filters
  tracing: Fix memory leak in set_trigger_filter()
  tracing: Fix memory leak in create_filter()
…/kernel/git/mszeredi/fuse

Pull fuse fixes from Miklos Szeredi:
 "There's one patch fixing a minor but long lived bug, the others are
  fixing regressions introduced in this cycle"

* tag 'fuse-fixes-4.20-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: continue to send FUSE_RELEASEDIR when FUSE_OPEN returns ENOSYS
  fuse: Fix memory leak in fuse_dev_free()
  fuse: fix revalidation of attributes for permission check
  fuse: fix fsync on directory
  fuse: Add bad inode check in fuse_destroy_inode()
…kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:
 "Needed to revert a patch, because it possibly introduces a security
  hole. Since the patch is basically a conceptual cleanup, not a bug
  fix, it's safe to revert. I'm not giving up on this, and discussions
  seemed to have reached an agreement over how to move forward, but that
  can wait 'till the next release.

  The other two patches are fixes for bugs introduced in recent
  releases"

* tag 'ovl-fixes-4.20-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  Revert "ovl: relax permission checking on underlying layers"
  ovl: fix decode of dir file handle with multi lower layers
  ovl: fix missing override creds in link of a metacopy upper
…l/git/mchehab/linux-media

Pull media fixes from Mauro Carvalho Chehab:

 - one regression at vsp1 driver

 - some last time changes for the upcoming request API logic and for
   stateless codec support. As the stateless codec "cedrus" driver is at
   staging, don't apply the MPEG controls as part of the main V4L2 API,
   as those may not be ready for production yet.

* tag 'media/v4.20-5' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: Add a Kconfig option for the Request API
  media: extended-controls.rst: add note to the MPEG2 state controls
  media: mpeg2-ctrls.h: move MPEG2 state controls to non-public header
  media: vicodec: set state resolution from raw format
  media: vivid: drop v4l2_ctrl_request_complete() from start_streaming
  media: vb2: don't unbind/put the object when going to state QUEUED
  media: vb2: keep a reference to the request until dqbuf
  media: vb2: skip request checks for VIDIOC_PREPARE_BUF
  media: vb2: don't call __vb2_queue_cancel if vb2_start_streaming failed
  media: cedrus: Fix a NULL vs IS_ERR() check
  media: vsp1: Fix LIF buffer thresholds
…ernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix DM cache metadata to verify that a cache has block before trying
   to continue with operation that requires them.

 - Fix bio-based DM core's dm_make_request() to properly impose device
   limits on individual bios by making use of blk_queue_split().

 - Fix long-standing race with how DM thinp notified userspace of
   thin-pool mode state changes before they were actually made.

 - Fix the zoned target's bio completion handling; this is a fairly
   invassive fix at this stage but it is localized to the zoned target.
   Any zoned target users will benefit from this fix.

* tag 'for-4.20/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: bump target version
  dm thin: send event about thin-pool state change _after_ making it
  dm zoned: Fix target BIO completion handling
  dm: call blk_queue_split() to impose device limits on bios
  dm cache metadata: verify cache has blocks in blocks_are_clean_separate_dirty()
@pull pull bot added the ⤵️ pull label Dec 13, 2018
@pull pull bot merged commit 67f2a93 into lokeshbv:master Dec 13, 2018
pull bot pushed a commit that referenced this pull request Jan 20, 2019
Since commit b89d82e ("arm64: kpti: Avoid rewriting early page
tables when KASLR is enabled"), a kernel built with CONFIG_RANDOMIZE_BASE
can decide early whether to use non-global mappings by checking the
kaslr_offset().

A kernel built without CONFIG_RANDOMIZE_BASE, instead checks the
cpufeature static-key.

This leaves a gap where CONFIG_RANDOMIZE_BASE was enabled, no
kaslr seed was provided, but kpti was forced on using the cmdline
option.

When the decision is made late, kpti_install_ng_mappings() will re-write
the page tables, but arm64_kernel_use_ng_mappings()'s value does not
change as it only tests the cpufeature static-key if
CONFIG_RANDOMIZE_BASE is disabled.
This function influences PROT_DEFAULT via PTE_MAYBE_NG, and causes
pgattr_change_is_safe() to catch nG->G transitions when the unchanged
PROT_DEFAULT is used as part of PAGE_KERNEL_RO:
[    1.942255] alternatives: patching kernel code
[    1.998288] ------------[ cut here ]------------
[    2.000693] kernel BUG at arch/arm64/mm/mmu.c:165!
[    2.019215] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[    2.020257] Modules linked in:
[    2.020807] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2 #51
[    2.021917] Hardware name: linux,dummy-virt (DT)
[    2.022790] pstate: 40000005 (nZcv daif -PAN -UAO)
[    2.023742] pc : __create_pgd_mapping+0x508/0x6d0
[    2.024671] lr : __create_pgd_mapping+0x500/0x6d0

[    2.058059] Process swapper/0 (pid: 1, stack limit = 0x(____ptrval____))
[    2.059369] Call trace:
[    2.059845]  __create_pgd_mapping+0x508/0x6d0
[    2.060684]  update_mapping_prot+0x48/0xd0
[    2.061477]  mark_linear_text_alias_ro+0xdc/0xe4
[    2.070502]  smp_cpus_done+0x90/0x98
[    2.071216]  smp_init+0x100/0x114
[    2.071878]  kernel_init_freeable+0xd4/0x220
[    2.072750]  kernel_init+0x10/0x100
[    2.073455]  ret_from_fork+0x10/0x18

[    2.075414] ---[ end trace 3572f3a7782292de ]---
[    2.076389] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

If arm64_kernel_unmapped_at_el0() is true, arm64_kernel_use_ng_mappings()
should also be true.

Signed-off-by: James Morse <james.morse@arm.com>
CC: Ard Biesheuvel <ard.biesheuvel@linaro.org>
CC: John Garry <john.garry@huawei.com>
CC: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
pull bot pushed a commit that referenced this pull request Feb 15, 2019
Due to quadratic behavior of x25_new_lci(), syzbot was able
to trigger an rcu stall.

Fix this by not blocking BH for the whole duration of
the function, and inserting a reschedule point when possible.

If we care enough, using a bitmap could get rid of the quadratic
behavior.

syzbot report :

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu:    0-...!: (10500 ticks this GP) idle=4fa/1/0x4000000000000002 softirq=283376/283376 fqs=0
rcu:     (t=10501 jiffies g=383105 q=136)
rcu: rcu_preempt kthread starved for 10502 jiffies! g383105 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I28928    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2844 [inline]
 __schedule+0x817/0x1cc0 kernel/sched/core.c:3485
 schedule+0x92/0x180 kernel/sched/core.c:3529
 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803
 rcu_gp_fqs_loop kernel/rcu/tree.c:1948 [inline]
 rcu_gp_kthread+0x956/0x17a0 kernel/rcu/tree.c:2105
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 8759 Comm: syz-executor2 Not tainted 5.0.0-rc4+ #51
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1211
 print_cpu_stall kernel/rcu/tree.c:1348 [inline]
 check_cpu_stall kernel/rcu/tree.c:1422 [inline]
 rcu_pending kernel/rcu/tree.c:3018 [inline]
 rcu_check_callbacks.cold+0x500/0xa4a kernel/rcu/tree.c:2521
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
RIP: 0010:queued_write_lock_slowpath+0x13e/0x290 kernel/locking/qrwlock.c:86
Code: 00 00 fc ff df 4c 8d 2c 01 41 83 c7 03 41 0f b6 45 00 41 38 c7 7c 08 84 c0 0f 85 0c 01 00 00 8b 03 3d 00 01 00 00 74 1a f3 90 <41> 0f b6 55 00 41 38 d7 7c eb 84 d2 74 e7 48 89 df e8 6c 0f 4f 00
RSP: 0018:ffff88805f117bd8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000300 RBX: ffffffff89413ba0 RCX: 1ffffffff1282774
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff89413ba0
RBP: ffff88805f117c70 R08: 1ffffffff1282774 R09: fffffbfff1282775
R10: fffffbfff1282774 R11: ffffffff89413ba3 R12: 00000000000000ff
R13: fffffbfff1282774 R14: 1ffff1100be22f7d R15: 0000000000000003
 queued_write_lock include/asm-generic/qrwlock.h:104 [inline]
 do_raw_write_lock+0x1d6/0x290 kernel/locking/spinlock_debug.c:203
 __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline]
 _raw_write_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:312
 x25_insert_socket+0x21/0xe0 net/x25/af_x25.c:267
 x25_bind+0x273/0x340 net/x25/af_x25.c:705
 __sys_bind+0x23f/0x290 net/socket.c:1505
 __do_sys_bind net/socket.c:1516 [inline]
 __se_sys_bind net/socket.c:1514 [inline]
 __x64_sys_bind+0x73/0xb0 net/socket.c:1514
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457e39
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fafccd0dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39
RDX: 0000000000000012 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fafccd0e6d4
R13: 00000000004bdf8b R14: 00000000004ce4b8 R15: 00000000ffffffff
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8752 Comm: syz-executor4 Not tainted 5.0.0-rc4+ #51
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__x25_find_socket+0x78/0x120 net/x25/af_x25.c:328
Code: 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 a6 00 00 00 4d 8b 64 24 68 4d 85 e4 74 7f e8 03 97 3d fb 49 83 ec 68 74 74 e8 f8 96 3d fb <49> 8d bc 24 88 04 00 00 48 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 74
RSP: 0018:ffff8880639efc58 EFLAGS: 00000246
RAX: 0000000000040000 RBX: dffffc0000000000 RCX: ffffc9000e677000
RDX: 0000000000040000 RSI: ffffffff863244b8 RDI: ffff88806a764628
RBP: ffff8880639efc80 R08: ffff8880a80d05c0 R09: fffffbfff1282775
R10: fffffbfff1282774 R11: ffffffff89413ba3 R12: ffff88806a7645c0
R13: 0000000000000001 R14: ffff88809f29ac00 R15: 0000000000000000
FS:  00007fe8d0c58700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32823000 CR3: 00000000672eb000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 x25_new_lci net/x25/af_x25.c:357 [inline]
 x25_connect+0x374/0xdf0 net/x25/af_x25.c:786
 __sys_connect+0x266/0x330 net/socket.c:1686
 __do_sys_connect net/socket.c:1697 [inline]
 __se_sys_connect net/socket.c:1694 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1694
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457e39
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe8d0c57c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39
RDX: 0000000000000012 RSI: 0000000020000200 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe8d0c586d4
R13: 00000000004be378 R14: 00000000004ceb00 R15: 00000000ffffffff

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: linux-x25@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
pull bot pushed a commit that referenced this pull request Mar 6, 2019
LTP testcase mtest06 [1] can trigger a crash on s390x running 5.0.0-rc8.
This is a stress test, where one thread mmaps/writes/munmaps memory area
and other thread is trying to read from it:

  CPU: 0 PID: 2611 Comm: mmap1 Not tainted 5.0.0-rc8+ #51
  Hardware name: IBM 2964 N63 400 (z/VM 6.4.0)
  Krnl PSW : 0404e00180000000 00000000001ac8d8 (__lock_acquire+0x7/0x7a8)
  Call Trace:
  ([<0000000000000000>]           (null))
   [<00000000001adae4>] lock_acquire+0xec/0x258
   [<000000000080d1ac>] _raw_spin_lock_bh+0x5c/0x98
   [<000000000012a780>] page_table_free+0x48/0x1a8
   [<00000000002f6e54>] do_fault+0xdc/0x670
   [<00000000002fadae>] __handle_mm_fault+0x416/0x5f0
   [<00000000002fb138>] handle_mm_fault+0x1b0/0x320
   [<00000000001248cc>] do_dat_exception+0x19c/0x2c8
   [<000000000080e5ee>] pgm_check_handler+0x19e/0x200

page_table_free() is called with NULL mm parameter, but because "0" is a
valid address on s390 (see S390_lowcore), it keeps going until it
eventually crashes in lockdep's lock_acquire.  This crash is
reproducible at least since 4.14.

Problem is that "vmf->vma" used in do_fault() can become stale.  Because
mmap_sem may be released, other threads can come in, call munmap() and
cause "vma" be returned to kmem cache, and get zeroed/re-initialized and
re-used:

handle_mm_fault                           |
  __handle_mm_fault                       |
    do_fault                              |
      vma = vmf->vma                      |
      do_read_fault                       |
        __do_fault                        |
          vma->vm_ops->fault(vmf);        |
            mmap_sem is released          |
                                          |
                                          | do_munmap()
                                          |   remove_vma_list()
                                          |     remove_vma()
                                          |       vm_area_free()
                                          |         # vma is released
                                          | ...
                                          | # same vma is allocated
                                          | # from kmem cache
                                          | do_mmap()
                                          |   vm_area_alloc()
                                          |     memset(vma, 0, ...)
                                          |
      pte_free(vma->vm_mm, ...);          |
        page_table_free                   |
          spin_lock_bh(&mm->context.lock);|
            <crash>                       |

Cache mm_struct to avoid using potentially stale "vma".

[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/mem/mtest06/mmap1.c

Link: http://lkml.kernel.org/r/5b3fdf19e2a5be460a384b936f5b56e13733f1b8.1551595137.git.jstancek@redhat.com
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Rafael Aquini <aquini@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Mar 15, 2019
Merge the left-over patches from Andrew Morton.

This merges the remaining two patches from Andrew's pile of "little bit
more MM".  I mulled it over, and we emailed back and forth with Josef,
and he pointed out where I was wrong.

Rule #51 of kernel maintenance: when somebody makes it clear that they
know the code better than you did, stop arguing and just apply the damn
patch.

Add a third patch by me to add a comment for the case that I had thought
was buggy and Josef corrected me on.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  filemap: add a comment about FAULT_FLAG_RETRY_NOWAIT behavior
  filemap: drop the mmap_sem for all blocking operations
  filemap: kill page_cache_read usage in filemap_fault
pull bot pushed a commit that referenced this pull request Jul 12, 2019
With architectures allowing the kernel to be placed almost arbitrarily
in memory (e.g.: ARM64), it is possible to have the kernel resides at
physical addresses above 4GB, resulting in neither the default CMA area,
nor the atomic pool from successfully allocating. This does not prevent
specific peripherals from working though, one example is XHCI, which
still operates correctly.

Trouble comes when the XHCI driver gets suspended and resumed, since we
can now trigger the following NPD:

[   12.664170] usb usb1: root hub lost power or was reset
[   12.669387] usb usb2: root hub lost power or was reset
[   12.674662] Unable to handle kernel NULL pointer dereference at virtual address 00000008
[   12.682896] pgd = ffffffc1365a7000
[   12.686386] [00000008] *pgd=0000000136500003, *pud=0000000136500003, *pmd=0000000000000000
[   12.694897] Internal error: Oops: 96000006 [#1] SMP
[   12.699843] Modules linked in:
[   12.702980] CPU: 0 PID: 1499 Comm: pml Not tainted 4.9.135-1.13pre #51
[   12.709577] Hardware name: BCM97268DV (DT)
[   12.713736] task: ffffffc136bb6540 task.stack: ffffffc1366cc000
[   12.719740] PC is at addr_in_gen_pool+0x4/0x48
[   12.724253] LR is at __dma_free+0x64/0xbc
[   12.728325] pc : [<ffffff80083c0df8>] lr : [<ffffff80080979e0>] pstate: 60000145
[   12.735825] sp : ffffffc1366cf990
[   12.739196] x29: ffffffc1366cf990 x28: ffffffc1366cc000
[   12.744608] x27: 0000000000000000 x26: ffffffc13a8568c8
[   12.750020] x25: 0000000000000000 x24: ffffff80098f9000
[   12.755433] x23: 000000013a5ff000 x22: ffffff8009c57000
[   12.760844] x21: ffffffc13a856810 x20: 0000000000000000
[   12.766255] x19: 0000000000001000 x18: 000000000000000a
[   12.771667] x17: 0000007f917553e0 x16: 0000000000001002
[   12.777078] x15: 00000000000a36cb x14: ffffff80898feb77
[   12.782490] x13: ffffffffffffffff x12: 0000000000000030
[   12.787899] x11: 00000000fffffffe x10: ffffff80098feb7f
[   12.793311] x9 : 0000000005f5e0ff x8 : 65776f702074736f
[   12.798723] x7 : 6c2062756820746f x6 : ffffff80098febb1
[   12.804134] x5 : ffffff800809797c x4 : 0000000000000000
[   12.809545] x3 : 000000013a5ff000 x2 : 0000000000000fff
[   12.814955] x1 : ffffff8009c57000 x0 : 0000000000000000
[   12.820363]
[   12.821907] Process pml (pid: 1499, stack limit = 0xffffffc1366cc020)
[   12.828421] Stack: (0xffffffc1366cf990 to 0xffffffc1366d0000)
[   12.834240] f980:                                   ffffffc1366cf9e0 ffffff80086004d0
[   12.842186] f9a0: ffffffc13ab08238 0000000000000010 ffffff80097c2218 ffffffc13a856810
[   12.850131] f9c0: ffffff8009c57000 000000013a5ff000 0000000000000008 000000013a5ff000
[   12.858076] f9e0: ffffffc1366cfa50 ffffff80085f9250 ffffffc13ab08238 0000000000000004
[   12.866021] fa00: ffffffc13ab08000 ffffff80097b6000 ffffffc13ab08130 0000000000000001
[   12.873966] fa20: 0000000000000008 ffffffc13a8568c8 0000000000000000 ffffffc1366cc000
[   12.881911] fa40: ffffffc13ab08130 0000000000000001 ffffffc1366cfa90 ffffff80085e3de8
[   12.889856] fa60: ffffffc13ab08238 0000000000000000 ffffffc136b75b00 0000000000000000
[   12.897801] fa80: 0000000000000010 ffffff80089ccb92 ffffffc1366cfac0 ffffff80084ad040
[   12.905746] faa0: ffffffc13a856810 0000000000000000 ffffff80084ad004 ffffff80084b91a8
[   12.913691] fac0: ffffffc1366cfae0 ffffff80084b91b4 ffffffc13a856810 ffffff80080db5cc
[   12.921636] fae0: ffffffc1366cfb20 ffffff80084b96bc ffffffc13a856810 0000000000000010
[   12.929581] fb00: ffffffc13a856870 0000000000000000 ffffffc13a856810 ffffff800984d2b8
[   12.937526] fb20: ffffffc1366cfb50 ffffff80084baa70 ffffff8009932ad0 ffffff800984d260
[   12.945471] fb40: 0000000000000010 00000002eff0a065 ffffffc1366cfbb0 ffffff80084bafbc
[   12.953415] fb60: 0000000000000010 0000000000000003 ffffff80098fe000 0000000000000000
[   12.961360] fb80: ffffff80097b6000 ffffff80097b6dc8 ffffff80098c12b8 ffffff80098c12f8
[   12.969306] fba0: ffffff8008842000 ffffff80097b6dc8 ffffffc1366cfbd0 ffffff80080e0d88
[   12.977251] fbc0: 00000000fffffffb ffffff80080e10bc ffffffc1366cfc60 ffffff80080e16a8
[   12.985196] fbe0: 0000000000000000 0000000000000003 ffffff80097b6000 ffffff80098fe9f0
[   12.993140] fc00: ffffff80097d4000 ffffff8008983802 0000000000000123 0000000000000040
[   13.001085] fc20: ffffff8008842000 ffffffc1366cc000 ffffff80089803c2 00000000ffffffff
[   13.009029] fc40: 0000000000000000 0000000000000000 ffffffc1366cfc60 0000000000040987
[   13.016974] fc60: ffffffc1366cfcc0 ffffff80080dfd08 0000000000000003 0000000000000004
[   13.024919] fc80: 0000000000000003 ffffff80098fea08 ffffffc136577ec0 ffffff80089803c2
[   13.032864] fca0: 0000000000000123 0000000000000001 0000000500000002 0000000000040987
[   13.040809] fcc0: ffffffc1366cfd00 ffffff80083a89d4 0000000000000004 ffffffc136577ec0
[   13.048754] fce0: ffffffc136610cc0 ffffffffffffffea ffffffc1366cfeb0 ffffffc136610cd8
[   13.056700] fd00: ffffffc1366cfd10 ffffff800822a614 ffffffc1366cfd40 ffffff80082295d4
[   13.064645] fd20: 0000000000000004 ffffffc136577ec0 ffffffc136610cc0 0000000021670570
[   13.072590] fd40: ffffffc1366cfd80 ffffff80081b5d10 ffffff80097b6000 ffffffc13aae4200
[   13.080536] fd60: ffffffc1366cfeb0 0000000000000004 0000000021670570 0000000000000004
[   13.088481] fd80: ffffffc1366cfe30 ffffff80081b6b20 ffffffc13aae4200 0000000000000000
[   13.096427] fda0: 0000000000000004 0000000021670570 ffffffc1366cfeb0 ffffffc13a838200
[   13.104371] fdc0: 0000000000000000 000000000000000a ffffff80097b6000 0000000000040987
[   13.112316] fde0: ffffffc1366cfe20 ffffff80081b3af0 ffffffc13a838200 0000000000000000
[   13.120261] fe00: ffffffc1366cfe30 ffffff80081b6b0c ffffffc13aae4200 0000000000000000
[   13.128206] fe20: 0000000000000004 0000000000040987 ffffffc1366cfe70 ffffff80081b7dd8
[   13.136151] fe40: ffffff80097b6000 ffffffc13aae4200 ffffffc13aae4200 fffffffffffffff7
[   13.144096] fe60: 0000000021670570 ffffffc13a8c63c0 0000000000000000 ffffff8008083180
[   13.152042] fe80: ffffffffffffff1d 0000000021670570 ffffffffffffffff 0000007f917ad9b8
[   13.159986] fea0: 0000000020000000 0000000000000015 0000000000000000 0000000000040987
[   13.167930] fec0: 0000000000000001 0000000021670570 0000000000000004 0000000000000000
[   13.175874] fee0: 0000000000000888 0000440110000000 000000000000006d 0000000000000003
[   13.183819] ff00: 0000000000000040 ffffff80ffffffc8 0000000000000000 0000000000000020
[   13.191762] ff20: 0000000000000000 0000000000000000 0000000000000001 0000000000000000
[   13.199707] ff40: 0000000000000000 0000007f917553e0 0000000000000000 0000000000000004
[   13.207651] ff60: 0000000021670570 0000007f91835480 0000000000000004 0000007f91831638
[   13.215595] ff80: 0000000000000004 00000000004b0de0 00000000004b0000 0000000000000000
[   13.223539] ffa0: 0000000000000000 0000007fc92ac8c0 0000007f9175d178 0000007fc92ac8c0
[   13.231483] ffc0: 0000007f917ad9b8 0000000020000000 0000000000000001 0000000000000040
[   13.239427] ffe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[   13.247360] Call trace:
[   13.249866] Exception stack(0xffffffc1366cf7a0 to 0xffffffc1366cf8d0)
[   13.256386] f7a0: 0000000000001000 0000007fffffffff ffffffc1366cf990 ffffff80083c0df8
[   13.264331] f7c0: 0000000060000145 ffffff80089b5001 ffffffc13ab08130 0000000000000001
[   13.272275] f7e0: 0000000000000008 ffffffc13a8568c8 0000000000000000 0000000000000000
[   13.280220] f800: ffffffc1366cf960 ffffffc1366cf960 ffffffc1366cf930 00000000ffffffd8
[   13.288165] f820: ffffff8009931ac0 4554535953425553 4544006273753d4d 3831633d45434956
[   13.296110] f840: ffff003832313a39 ffffff800845926c ffffffc1366cf880 0000000000040987
[   13.304054] f860: 0000000000000000 ffffff8009c57000 0000000000000fff 000000013a5ff000
[   13.311999] f880: 0000000000000000 ffffff800809797c ffffff80098febb1 6c2062756820746f
[   13.319944] f8a0: 65776f702074736f 0000000005f5e0ff ffffff80098feb7f 00000000fffffffe
[   13.327884] f8c0: 0000000000000030 ffffffffffffffff
[   13.332835] [<ffffff80083c0df8>] addr_in_gen_pool+0x4/0x48
[   13.338398] [<ffffff80086004d0>] xhci_mem_cleanup+0xc8/0x51c
[   13.344137] [<ffffff80085f9250>] xhci_resume+0x308/0x65c
[   13.349524] [<ffffff80085e3de8>] xhci_brcm_resume+0x84/0x8c
[   13.355174] [<ffffff80084ad040>] platform_pm_resume+0x3c/0x64
[   13.360997] [<ffffff80084b91b4>] dpm_run_callback+0x5c/0x15c
[   13.366732] [<ffffff80084b96bc>] device_resume+0xc0/0x190
[   13.372205] [<ffffff80084baa70>] dpm_resume+0x144/0x2cc
[   13.377504] [<ffffff80084bafbc>] dpm_resume_end+0x20/0x34
[   13.382980] [<ffffff80080e0d88>] suspend_devices_and_enter+0x104/0x704
[   13.389585] [<ffffff80080e16a8>] pm_suspend+0x320/0x53c
[   13.394881] [<ffffff80080dfd08>] state_store+0xbc/0xe0
[   13.400094] [<ffffff80083a89d4>] kobj_attr_store+0x14/0x24
[   13.405655] [<ffffff800822a614>] sysfs_kf_write+0x60/0x70
[   13.411128] [<ffffff80082295d4>] kernfs_fop_write+0x130/0x194
[   13.416954] [<ffffff80081b5d10>] __vfs_write+0x60/0x150
[   13.422254] [<ffffff80081b6b20>] vfs_write+0xc8/0x164
[   13.427376] [<ffffff80081b7dd8>] SyS_write+0x70/0xc8
[   13.432412] [<ffffff8008083180>] el0_svc_naked+0x34/0x38
[   13.437800] Code: 92800173 97f6fb9e 17fffff5 d1000442 (f8408c03)
[   13.444033] ---[ end trace 2effe12f909ce205 ]---

The call path leading to this problem is xhci_mem_cleanup() ->
dma_free_coherent() -> dma_free_from_pool() -> addr_in_gen_pool. If the
atomic_pool is NULL, we can't possibly have the address in the atomic
pool anyway, so guard against that.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
pull bot pushed a commit that referenced this pull request Feb 4, 2020
The introduction of a split between the reference count on rxrpc_local
objects and the usage count didn't quite go far enough.  A number of kernel
work items need to make use of the socket to perform transmission.  These
also need to get an active count on the local object to prevent the socket
from being closed.

Fix this by getting the active count in those places.

Also split out the raw active count get/put functions as these places tend
to hold refs on the rxrpc_local object already, so getting and putting an
extra object ref is just a waste of time.

The problem can lead to symptoms like:

    BUG: kernel NULL pointer dereference, address: 0000000000000018
    ..
    CPU: 2 PID: 818 Comm: kworker/u9:0 Not tainted 5.5.0-fscache+ #51
    ...
    RIP: 0010:selinux_socket_sendmsg+0x5/0x13
    ...
    Call Trace:
     security_socket_sendmsg+0x2c/0x3e
     sock_sendmsg+0x1a/0x46
     rxrpc_send_keepalive+0x131/0x1ae
     rxrpc_peer_keepalive_worker+0x219/0x34b
     process_one_work+0x18e/0x271
     worker_thread+0x1a3/0x247
     kthread+0xe6/0xeb
     ret_from_fork+0x1f/0x30

Fixes: 730c5fd ("rxrpc: Fix local endpoint refcounting")
Signed-off-by: David Howells <dhowells@redhat.com>
pull bot pushed a commit that referenced this pull request Jun 6, 2020
This erratum was for IBM 403GCX, 405EP and STB03xxx which are
now gone.

Remove this erratum.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1b6c9916514ef3e084bba57925ad9eb444627566.1590079969.git.christophe.leroy@csgroup.eu
pull bot pushed a commit that referenced this pull request Oct 19, 2020
The defer ops code has been finishing items in the wrong order -- if a
top level defer op creates items A and B, and finishing item A creates
more defer ops A1 and A2, we'll put the new items on the end of the
chain and process them in the order A B A1 A2.  This is kind of weird,
since it's convenient for programmers to be able to think of A and B as
an ordered sequence where all the sub-tasks for A must finish before we
move on to B, e.g. A A1 A2 D.

Right now, our log intent items are not so complex that this matters,
but this will become important for the atomic extent swapping patchset.
In order to maintain correct reference counting of extents, we have to
unmap and remap extents in that order, and we want to complete that work
before moving on to the next range that the user wants to swap.  This
patch fixes defer ops to satsify that requirement.

The primary symptom of the incorrect order was noticed in an early
performance analysis of the atomic extent swap code.  An astonishingly
large number of deferred work items accumulated when userspace requested
an atomic update of two very fragmented files.  The cause of this was
traced to the same ordering bug in the inner loop of
xfs_defer_finish_noroll.

If the ->finish_item method of a deferred operation queues new deferred
operations, those new deferred ops are appended to the tail of the
pending work list.  To illustrate, say that a caller creates a
transaction t0 with four deferred operations D0-D3.  The first thing
defer ops does is roll the transaction to t1, leaving us with:

t1: D0(t0), D1(t0), D2(t0), D3(t0)

Let's say that finishing each of D0-D3 will create two new deferred ops.
After finish D0 and roll, we'll have the following chain:

t2: D1(t0), D2(t0), D3(t0), d4(t1), d5(t1)

d4 and d5 were logged to t1.  Notice that while we're about to start
work on D1, we haven't actually completed all the work implied by D0
being finished.  So far we've been careful (or lucky) to structure the
dfops callers such that D1 doesn't depend on d4 or d5 being finished,
but this is a potential logic bomb.

There's a second problem lurking.  Let's see what happens as we finish
D1-D3:

t3: D2(t0), D3(t0), d4(t1), d5(t1), d6(t2), d7(t2)
t4: D3(t0), d4(t1), d5(t1), d6(t2), d7(t2), d8(t3), d9(t3)
t5: d4(t1), d5(t1), d6(t2), d7(t2), d8(t3), d9(t3), d10(t4), d11(t4)

Let's say that d4-d11 are simple work items that don't queue any other
operations, which means that we can complete each d4 and roll to t6:

t6: d5(t1), d6(t2), d7(t2), d8(t3), d9(t3), d10(t4), d11(t4)
t7: d6(t2), d7(t2), d8(t3), d9(t3), d10(t4), d11(t4)
...
t11: d10(t4), d11(t4)
t12: d11(t4)
<done>

When we try to roll to transaction #12, we're holding defer op d11,
which we logged way back in t4.  This means that the tail of the log is
pinned at t4.  If the log is very small or there are a lot of other
threads updating metadata, this means that we might have wrapped the log
and cannot get roll to t11 because there isn't enough space left before
we'd run into t4.

Let's shift back to the original failure.  I mentioned before that I
discovered this flaw while developing the atomic file update code.  In
that scenario, we have a defer op (D0) that finds a range of file blocks
to remap, creates a handful of new defer ops to do that, and then asks
to be continued with however much work remains.

So, D0 is the original swapext deferred op.  The first thing defer ops
does is rolls to t1:

t1: D0(t0)

We try to finish D0, logging d1 and d2 in the process, but can't get all
the work done.  We log a done item and a new intent item for the work
that D0 still has to do, and roll to t2:

t2: D0'(t1), d1(t1), d2(t1)

We roll and try to finish D0', but still can't get all the work done, so
we log a done item and a new intent item for it, requeue D0 a second
time, and roll to t3:

t3: D0''(t2), d1(t1), d2(t1), d3(t2), d4(t2)

If it takes 48 more rolls to complete D0, then we'll finally dispense
with D0 in t50:

t50: D<fifty primes>(t49), d1(t1), ..., d102(t50)

We then try to roll again to get a chain like this:

t51: d1(t1), d2(t1), ..., d101(t50), d102(t50)
...
t152: d102(t50)
<done>

Notice that in rolling to transaction #51, we're holding on to a log
intent item for d1 that was logged in transaction #1.  This means that
the tail of the log is pinned at t1.  If the log is very small or there
are a lot of other threads updating metadata, this means that we might
have wrapped the log and cannot roll to t51 because there isn't enough
space left before we'd run into t1.  This is of course problem #2 again.

But notice the third problem with this scenario: we have 102 defer ops
tied to this transaction!  Each of these items are backed by pinned
kernel memory, which means that we risk OOM if the chains get too long.

Yikes.  Problem #1 is a subtle logic bomb that could hit someone in the
future; problem #2 applies (rarely) to the current upstream, and problem
#3 applies to work under development.

This is not how incremental deferred operations were supposed to work.
The dfops design of logging in the same transaction an intent-done item
and a new intent item for the work remaining was to make it so that we
only have to juggle enough deferred work items to finish that one small
piece of work.  Deferred log item recovery will find that first
unfinished work item and restart it, no matter how many other intent
items might follow it in the log.  Therefore, it's ok to put the new
intents at the start of the dfops chain.

For the first example, the chains look like this:

t2: d4(t1), d5(t1), D1(t0), D2(t0), D3(t0)
t3: d5(t1), D1(t0), D2(t0), D3(t0)
...
t9: d9(t7), D3(t0)
t10: D3(t0)
t11: d10(t10), d11(t10)
t12: d11(t10)

For the second example, the chains look like this:

t1: D0(t0)
t2: d1(t1), d2(t1), D0'(t1)
t3: d2(t1), D0'(t1)
t4: D0'(t1)
t5: d1(t4), d2(t4), D0''(t4)
...
t148: D0<50 primes>(t147)
t149: d101(t148), d102(t148)
t150: d102(t148)
<done>

This actually sucks more for pinning the log tail (we try to roll to t10
while holding an intent item that was logged in t1) but we've solved
problem #1.  We've also reduced the maximum chain length from:

    sum(all the new items) + nr_original_items

to:

    max(new items that each original item creates) + nr_original_items

This solves problem #3 by sharply reducing the number of defer ops that
can be attached to a transaction at any given time.  The change makes
the problem of log tail pinning worse, but is improvement we need to
solve problem #2.  Actually solving #2, however, is left to the next
patch.

Note that a subsequent analysis of some hard-to-trigger reflink and COW
livelocks on extremely fragmented filesystems (or systems running a lot
of IO threads) showed the same symptoms -- uncomfortably large numbers
of incore deferred work items and occasional stalls in the transaction
grant code while waiting for log reservations.  I think this patch and
the next one will also solve these problems.

As originally written, the code used list_splice_tail_init instead of
list_splice_init, so change that, and leave a short comment explaining
our actions.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
pull bot pushed a commit that referenced this pull request Nov 1, 2020
With LOCKDEP enabled, CTI driver triggers the following splat due
to uninitialized lock class for dynamically allocated attribute
objects.

[    5.372901] coresight etm0: CPU0: ETM v4.0 initialized
[    5.376694] coresight etm1: CPU1: ETM v4.0 initialized
[    5.380785] coresight etm2: CPU2: ETM v4.0 initialized
[    5.385851] coresight etm3: CPU3: ETM v4.0 initialized
[    5.389808] BUG: key ffff00000564a798 has not been registered!
[    5.392456] ------------[ cut here ]------------
[    5.398195] DEBUG_LOCKS_WARN_ON(1)
[    5.398233] WARNING: CPU: 1 PID: 32 at kernel/locking/lockdep.c:4623 lockdep_init_map_waits+0x14c/0x260
[    5.406149] Modules linked in:
[    5.415411] CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.9.0-12034-gbbe85027ce80 #51
[    5.418553] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[    5.426453] Workqueue: events amba_deferred_retry_func
[    5.433299] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--)
[    5.438252] pc : lockdep_init_map_waits+0x14c/0x260
[    5.444410] lr : lockdep_init_map_waits+0x14c/0x260
[    5.449007] sp : ffff800012bbb720
...

[    5.531561] Call trace:
[    5.536847]  lockdep_init_map_waits+0x14c/0x260
[    5.539027]  __kernfs_create_file+0xa8/0x1c8
[    5.543539]  sysfs_add_file_mode_ns+0xd0/0x208
[    5.548054]  internal_create_group+0x118/0x3c8
[    5.552307]  internal_create_groups+0x58/0xb8
[    5.556733]  sysfs_create_groups+0x2c/0x38
[    5.561160]  device_add+0x2d8/0x768
[    5.565148]  device_register+0x28/0x38
[    5.568537]  coresight_register+0xf8/0x320
[    5.572358]  cti_probe+0x1b0/0x3f0

...

Fix this by initializing the attributes when they are allocated.

Fixes: 3c5597e ("coresight: cti: Add connection information to sysfs")
Reported-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201029164559.1268531-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull bot pushed a commit that referenced this pull request Nov 19, 2020
If a user unbinds and re-binds a NC-SI aware driver the kernel will
attempt to register the netlink interface at runtime. The structure is
marked __ro_after_init so registration fails spectacularly at this point.

 # echo 1e660000.ethernet > /sys/bus/platform/drivers/ftgmac100/unbind
 # echo 1e660000.ethernet > /sys/bus/platform/drivers/ftgmac100/bind
  ftgmac100 1e660000.ethernet: Read MAC address 52:54:00:12:34:56 from chip
  ftgmac100 1e660000.ethernet: Using NCSI interface
  8<--- cut here ---
  Unable to handle kernel paging request at virtual address 80a8f858
  pgd = 8c768dd6
  [80a8f858] *pgd=80a0841e(bad)
  Internal error: Oops: 80d [#1] SMP ARM
  CPU: 0 PID: 116 Comm: sh Not tainted 5.10.0-rc3-next-20201111-00003-gdd25b227ec1e #51
  Hardware name: Generic DT based system
  PC is at genl_register_family+0x1f8/0x6d4
  LR is at 0xff26ffff
  pc : [<8073f930>]    lr : [<ff26ffff>]    psr: 20000153
  sp : 8553bc80  ip : 81406244  fp : 8553bd04
  r10: 8085d12c  r9 : 80a8f73c  r8 : 85739000
  r7 : 00000017  r6 : 80a8f860  r5 : 80c8ab98  r4 : 80a8f858
  r3 : 00000000  r2 : 00000000  r1 : 81406130  r0 : 00000017
  Flags: nzCv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment none
  Control: 00c5387d  Table: 85524008  DAC: 00000051
  Process sh (pid: 116, stack limit = 0x1f1988d6)
 ...
  Backtrace:
  [<8073f738>] (genl_register_family) from [<80860ac0>] (ncsi_init_netlink+0x20/0x48)
   r10:8085d12c r9:80c8fb0c r8:85739000 r7:00000000 r6:81218000 r5:85739000
   r4:8121c000
  [<80860aa0>] (ncsi_init_netlink) from [<8085d740>] (ncsi_register_dev+0x1b0/0x210)
   r5:8121c400 r4:8121c000
  [<8085d590>] (ncsi_register_dev) from [<805a8060>] (ftgmac100_probe+0x6e0/0x778)
   r10:00000004 r9:80950228 r8:8115bc10 r7:8115ab00 r6:9eae2c24 r5:813b6f88
   r4:85739000
  [<805a7980>] (ftgmac100_probe) from [<805355ec>] (platform_drv_probe+0x58/0xa8)
   r9:80c76bb0 r8:00000000 r7:80cd4974 r6:80c76bb0 r5:8115bc10 r4:00000000
  [<80535594>] (platform_drv_probe) from [<80532d58>] (really_probe+0x204/0x514)
   r7:80cd4974 r6:00000000 r5:80cd4868 r4:8115bc10

Jakub pointed out that ncsi_register_dev is obviously broken, because
there is only one family so it would never work if there was more than
one ncsi netdev.

Fix the crash by registering the netlink family once on boot, and drop
the code to unregister it.

Fixes: 955dc68 ("net/ncsi: Add generic netlink family")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Link: https://lore.kernel.org/r/20201112061210.914621-1-joel@jms.id.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Dec 16, 2020
 CHECK: Alignment should match open parenthesis
 #24: FILE: drivers/mfd/tps65910.c:296:
 +	ret = regmap_clear_bits(tps65910->regmap, TPS65910_DEVCTRL,
  						DEVCTRL_CK32K_CTRL_MASK);

 CHECK: Alignment should match open parenthesis
 #33: FILE: drivers/mfd/tps65910.c:318:
 +	ret = regmap_set_bits(tps65910->regmap, TPS65910_DEVCTRL,
  				DEVCTRL_DEV_SLP_MASK);

 CHECK: Alignment should match open parenthesis
 #42: FILE: drivers/mfd/tps65910.c:326:
 +		ret = regmap_set_bits(tps65910->regmap,
  				TPS65910_SLEEP_KEEP_RES_ON,

 CHECK: Alignment should match open parenthesis
 #51: FILE: drivers/mfd/tps65910.c:336:
 +		ret = regmap_set_bits(tps65910->regmap,
  				TPS65910_SLEEP_KEEP_RES_ON,

 CHECK: Alignment should match open parenthesis
 #60: FILE: drivers/mfd/tps65910.c:346:
 +		ret = regmap_set_bits(tps65910->regmap,
  				TPS65910_SLEEP_KEEP_RES_ON,

 CHECK: Alignment should match open parenthesis
 #69: FILE: drivers/mfd/tps65910.c:358:
 +	regmap_clear_bits(tps65910->regmap, TPS65910_DEVCTRL,
  				DEVCTRL_DEV_SLP_MASK);

 CHECK: Alignment should match open parenthesis
 #78: FILE: drivers/mfd/tps65910.c:440:
 +	if (regmap_set_bits(tps65910->regmap, TPS65910_DEVCTRL,
  			DEVCTRL_PWR_OFF_MASK) < 0)

 CHECK: Alignment should match open parenthesis
 #83: FILE: drivers/mfd/tps65910.c:444:
 +	regmap_clear_bits(tps65910->regmap, TPS65910_DEVCTRL,
  			DEVCTRL_DEV_ON_MASK);

Signed-off-by: Lee Jones <lee.jones@linaro.org>
pull bot pushed a commit that referenced this pull request May 5, 2021
Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Tested-By: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
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