linux-stable.git/drivers/base, branch v4.19.86

component: fix loop condition to call unbind() if bind() fails

2019-11-20T17:46:47+00:00

[ Upstream commit bdae566d5d9733b6e32b378668b84eadf28a94d4 ]

During component_bind_all(), if bind() fails for any
particular component associated with a master, unbind()
should be called for all previous components in that
master's match array, whose bind() might have completed
successfully. As per the current logic, if bind() fails
for the component at position 'n' in the master's match
array, it would start calling unbind() from component in
'n'th position itself and work backwards, and will always
skip calling unbind() for component in 0th position in the
master's match array.
Fix this by updating the loop condition, and the logic to
refer to the components in master's match array, so that
unbind() is called for all components starting from 'n-1'st
position in the array, until (and including) component in
0th position.

Signed-off-by: Banajit Goswami 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

x86/bugs: Add ITLB_MULTIHIT bug infrastructure

2019-11-12T18:21:36+00:00

commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream.

Some processors may incur a machine check error possibly resulting in an
unrecoverable CPU lockup when an instruction fetch encounters a TLB
multi-hit in the instruction TLB. This can occur when the page size is
changed along with either the physical address or cache type. The relevant
erratum can be found here:

   https://bugzilla.kernel.org/show_bug.cgi?id=205195

There are other processors affected for which the erratum does not fully
disclose the impact.

This issue affects both bare-metal x86 page tables and EPT.

It can be mitigated by either eliminating the use of large pages or by
using careful TLB invalidations when changing the page size in the page
tables.

Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in
MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which
are mitigated against this issue.

Signed-off-by: Vineela Tummalapalli 
Co-developed-by: Pawan Gupta 
Signed-off-by: Pawan Gupta 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/speculation/taa: Add sysfs reporting for TSX Async Abort

2019-11-12T18:21:32+00:00

commit 6608b45ac5ecb56f9e171252229c39580cc85f0f upstream.

Add the sysfs reporting file for TSX Async Abort. It exposes the
vulnerability and the mitigation state similar to the existing files for
the other hardware vulnerabilities.

Sysfs file path is:
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort

Signed-off-by: Pawan Gupta 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Tested-by: Neelima Krishnan 
Reviewed-by: Mark Gross 
Reviewed-by: Tony Luck 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Josh Poimboeuf 
Signed-off-by: Greg Kroah-Hartman

cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown

2019-10-29T08:20:08+00:00

commit 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 upstream.

It is incorrect to set the cpufreq syscore shutdown callback pointer
to cpufreq_suspend(), because that function cannot be run in the
syscore stage of system shutdown for two reasons: (a) it may attempt
to carry out actions depending on devices that have already been shut
down at that point and (b) the RCU synchronization carried out by it
may not be able to make progress then.

The latter issue has been present since commit 45975c7d21a1 ("rcu:
Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds"),
but the former one has been there since commit 90de2a4aa9f3 ("cpufreq:
suspend cpufreq governors on shutdown") regardless.

Fix that by dropping cpufreq_syscore_ops altogether and making
device_shutdown() call cpufreq_suspend() directly before shutting
down devices, which is along the lines of what system-wide power
management does.

Fixes: 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds")
Fixes: 90de2a4aa9f3 ("cpufreq: suspend cpufreq governors on shutdown")
Reported-by: Ville Syrjälä 
Tested-by: Ville Syrjälä 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar 
Cc: 4.0+  # 4.0+
Signed-off-by: Greg Kroah-Hartman

drivers/base/memory.c: don't access uninitialized memmaps in soft_offline_page_store()

2019-10-29T08:19:55+00:00

commit 641fe2e9387a36f9ee01d7c69382d1fe147a5e98 upstream.

Uninitialized memmaps contain garbage and in the worst case trigger kernel
BUGs, especially with CONFIG_PAGE_POISONING.  They should not get touched.

Right now, when trying to soft-offline a PFN that resides on a memory
block that was never onlined, one gets a misleading error with
CONFIG_PAGE_POISONING:

  :/# echo 5637144576 > /sys/devices/system/memory/soft_offline_page
  [   23.097167] soft offline: 0x150000 page already poisoned

But the actual result depends on the garbage in the memmap.

soft_offline_page() can only work with online pages, it returns -EIO in
case of ZONE_DEVICE.  Make sure to only forward pages that are online
(iow, managed by the buddy) and, therefore, have an initialized memmap.

Add a check against pfn_to_online_page() and similarly return -EIO.

Link: http://lkml.kernel.org/r/20191010141200.8985-1-david@redhat.com
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online")	[visible after d0dc12e86b319]
Signed-off-by: David Hildenbrand 
Acked-by: Naoya Horiguchi 
Acked-by: Michal Hocko 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: 	[4.13+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

soundwire: fix regmap dependencies and align with other serial links

2019-10-07T16:57:27+00:00

[ Upstream commit 8676b3ca4673517650fd509d7fa586aff87b3c28 ]

The existing code has a mixed select/depend usage which makes no sense.

config SOUNDWIRE_BUS
       tristate
       select REGMAP_SOUNDWIRE

config REGMAP_SOUNDWIRE
        tristate
        depends on SOUNDWIRE_BUS

Let's remove one layer of Kconfig definitions and align with the
solutions used by all other serial links.

Signed-off-by: Pierre-Louis Bossart 
Link: https://lore.kernel.org/r/20190718230215.18675-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

base: soc: Export soc_device_register/unregister APIs

2019-10-05T11:09:37+00:00

[ Upstream commit f7ccc7a397cf2ef64aebb2f726970b93203858d2 ]

Qcom Socinfo driver can be built as a module, so
export these two APIs.

Tested-by: Vinod Koul 
Signed-off-by: Vinod Koul 
Signed-off-by: Vaishali Thakkar 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Stephen Boyd 
Reviewed-by: Bjorn Andersson 
Signed-off-by: Bjorn Andersson 
Signed-off-by: Sasha Levin

driver core: Fix use-after-free and double free on glue directory

2019-09-19T07:09:37+00:00

commit ac43432cb1f5c2950408534987e57c2071e24d8f upstream.

There is a race condition between removing glue directory and adding a new
device under the glue dir. It can be reproduced in following test:

CPU1:                                         CPU2:

device_add()
  get_device_parent()
    class_dir_create_and_add()
      kobject_add_internal()
        create_dir()    // create glue_dir

                                              device_add()
                                                get_device_parent()
                                                  kobject_get() // get glue_dir

device_del()
  cleanup_glue_dir()
    kobject_del(glue_dir)

                                                kobject_add()
                                                  kobject_add_internal()
                                                    create_dir() // in glue_dir
                                                      sysfs_create_dir_ns()
                                                        kernfs_create_dir_ns(sd)

      sysfs_remove_dir() // glue_dir->sd=NULL
      sysfs_put()        // free glue_dir->sd

                                                          // sd is freed
                                                          kernfs_new_node(sd)
                                                            kernfs_get(glue_dir)
                                                            kernfs_add_one()
                                                            kernfs_put()

Before CPU1 remove last child device under glue dir, if CPU2 add a new
device under glue dir, the glue_dir kobject reference count will be
increase to 2 via kobject_get() in get_device_parent(). And CPU2 has
been called kernfs_create_dir_ns(), but not call kernfs_new_node().
Meanwhile, CPU1 call sysfs_remove_dir() and sysfs_put(). This result in
glue_dir->sd is freed and it's reference count will be 0. Then CPU2 call
kernfs_get(glue_dir) will trigger a warning in kernfs_get() and increase
it's reference count to 1. Because glue_dir->sd is freed by CPU1, the next
call kernfs_add_one() by CPU2 will fail(This is also use-after-free)
and call kernfs_put() to decrease reference count. Because the reference
count is decremented to 0, it will also call kmem_cache_free() to free
the glue_dir->sd again. This will result in double free.

In order to avoid this happening, we also should make sure that kernfs_node
for glue_dir is released in CPU1 only when refcount for glue_dir kobj is
1 to fix this race.

The following calltrace is captured in kernel 4.14 with the following patch
applied:

commit 726e41097920 ("drivers: core: Remove glue dirs from sysfs earlier")

--------------------------------------------------------------------------
[    3.633703] WARNING: CPU: 4 PID: 513 at .../fs/kernfs/dir.c:494
                Here is WARN_ON(!atomic_read(&kn->count) in kernfs_get().
....
[    3.633986] Call trace:
[    3.633991]  kernfs_create_dir_ns+0xa8/0xb0
[    3.633994]  sysfs_create_dir_ns+0x54/0xe8
[    3.634001]  kobject_add_internal+0x22c/0x3f0
[    3.634005]  kobject_add+0xe4/0x118
[    3.634011]  device_add+0x200/0x870
[    3.634017]  _request_firmware+0x958/0xc38
[    3.634020]  request_firmware_into_buf+0x4c/0x70
....
[    3.634064] kernel BUG at .../mm/slub.c:294!
                Here is BUG_ON(object == fp) in set_freepointer().
....
[    3.634346] Call trace:
[    3.634351]  kmem_cache_free+0x504/0x6b8
[    3.634355]  kernfs_put+0x14c/0x1d8
[    3.634359]  kernfs_create_dir_ns+0x88/0xb0
[    3.634362]  sysfs_create_dir_ns+0x54/0xe8
[    3.634366]  kobject_add_internal+0x22c/0x3f0
[    3.634370]  kobject_add+0xe4/0x118
[    3.634374]  device_add+0x200/0x870
[    3.634378]  _request_firmware+0x958/0xc38
[    3.634381]  request_firmware_into_buf+0x4c/0x70
--------------------------------------------------------------------------

Fixes: 726e41097920 ("drivers: core: Remove glue dirs from sysfs earlier")
Signed-off-by: Muchun Song 
Reviewed-by: Mukesh Ojha 
Signed-off-by: Prateek Sood 
Link: https://lore.kernel.org/r/20190727032122.24639-1-smuchun@gmail.com
Signed-off-by: Greg Kroah-Hartman

drivers/base: Introduce kill_device()

2019-08-09T15:52:28+00:00

commit 00289cd87676e14913d2d8492d1ce05c4baafdae upstream.

The libnvdimm subsystem arranges for devices to be destroyed as a result
of a sysfs operation. Since device_unregister() cannot be called from
an actively running sysfs attribute of the same device libnvdimm
arranges for device_unregister() to be performed in an out-of-line async
context.

The driver core maintains a 'dead' state for coordinating its own racing
async registration / de-registration requests. Rather than add local
'dead' state tracking infrastructure to libnvdimm device objects, export
the existing state tracking via a new kill_device() helper.

The kill_device() helper simply marks the device as dead, i.e. that it
is on its way to device_del(), or returns that the device was already
dead. This can be used in advance of calling device_unregister() for
subsystems like libnvdimm that might need to handle multiple user
threads racing to delete a device.

This refactoring does not change any behavior, but it is a pre-requisite
for follow-on fixes and therefore marked for -stable.

Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Fixes: 4d88a97aa9e8 ("libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver...")
Cc: 
Tested-by: Jane Chu 
Reviewed-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/156341207332.292348.14959761496009347574.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams 
Signed-off-by: Sasha Levin

driver core: Establish order of operations for device_add and device_del via bitflag

2019-08-09T15:52:28+00:00

commit 3451a495ef244a88ed6317a035299d835554d579 upstream.

Add an additional bit flag to the device_private struct named "dead".

This additional flag provides a guarantee that when a device_del is
executed on a given interface an async worker will not attempt to attach
the driver following the earlier device_del call. Previously this
guarantee was not present and could result in the device_del call
attempting to remove a driver from an interface only to have the async
worker attempt to probe the driver later when it finally completes the
asynchronous probe call.

One additional change added was that I pulled the check for dev->driver
out of the __device_attach_driver call and instead placed it in the
__device_attach_async_helper call. This was motivated by the fact that the
only other caller of this, __device_attach, had already taken the
device_lock() and checked for dev->driver. Instead of testing for this
twice in this path it makes more sense to just consolidate the dev->dead
and dev->driver checks together into one set of checks.

Reviewed-by: Dan Williams 
Reviewed-by: Rafael J. Wysocki 
Signed-off-by: Alexander Duyck 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin