In the mmap_close() path we need to stop all the AUX events that are
writing data to the AUX area that we are unmapping, before we can
safely free the pages. To determine if an event needs to be stopped,
we're comparing its ->rb against the one that's getting unmapped.
However, a SET_OUTPUT ioctl may turn up inside an AUX transaction
and swizzle event::rb to some other ring buffer, but the transaction
will keep writing data to the old ring buffer until the event gets
scheduled out. At this point, mmap_close() will skip over such an
event and will proceed to free the AUX area, while it's still being
used by this event, which will set off a warning in the mmap_close()
path and cause a memory corruption.
To avoid this, always stop an AUX event before its ->rb is updated;
this will release the (potentially) last reference on the AUX area
of the buffer. If the event gets restarted, its new ring buffer will
be used. If another SET_OUTPUT comes and switches it back to the
old ring buffer that's getting unmapped, it's also fine: this
ring buffer's aux_mmap_count will be zero and AUX transactions won't
start any more.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160906132353.19887-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The resent conversion of the cpu hotplug support in the uncore driver
introduced a regression due to the way the callbacks are invoked at
initialization time.
The old code called the prepare/starting/online function on each online cpu
as a block. The new code registers the hotplug callbacks in the core for
each state. The core invokes the callbacks at each registration on all
online cpus.
The code implicitely relied on the prepare/starting/online callbacks being
called as combo on a particular cpu, which was not obvious and completely
undocumented.
The resulting subtle wreckage happens due to the way how the uncore code
manages shared data structures for cpus which share an uncore resource in
hardware. The sharing is determined in the cpu starting callback, but the
prepare callback allocates per cpu data for the upcoming cpu because
potential sharing is unknown at this point. If the starting callback finds
a online cpu which shares the hardware resource it takes a refcount on the
percpu data of that cpu and puts the own data structure into a
'free_at_online' pointer of that shared data structure. The online callback
frees that.
With the old model this worked because in a starting callback only one non
unused structure (the one of the starting cpu) was available. The new code
allocates the data structures for all cpus when the prepare callback is
registered.
Now the starting function iterates through all online cpus and looks for a
data structure (skipping its own) which has a matching hardware id. The id
member of the data structure is initialized to 0, but the hardware id can
be 0 as well. The resulting wreckage is:
CPU0 finds a matching id on CPU1, takes a refcount on CPU1 data and puts
its own data structure into CPU1s data structure to be freed.
CPU1 skips CPU0 because the data structure is its allegedly unsued own.
It finds a matching id on CPU2, takes a refcount on CPU1 data and puts
its own data structure into CPU2s data structure to be freed.
....
Now the online callbacks are invoked.
CPU0 has a pointer to CPU1s data and frees the original CPU0 data. So
far so good.
CPU1 has a pointer to CPU2s data and frees the original CPU1 data, which
is still referenced by CPU0 ---> Booom
So there are two issues to be solved here:
1) The id field must be initialized at allocation time to a value which
cannot be a valid hardware id, i.e. -1
This prevents the above scenario, but now CPU1 and CPU2 both stick their
own data structure into the free_at_online pointer of CPU0. So we leak
CPU1s data structure.
2) Fix the memory leak described in #1
Instead of having a single pointer, use a hlist to enqueue the
superflous data structures which are then freed by the first cpu
invoking the online callback.
Ideally we should know the sharing _before_ invoking the prepare callback,
but that's way beyond the scope of this bug fix.
[ tglx: Rewrote changelog ]
Fixes: 96b2bd3866 ("perf/x86/amd/uncore: Convert to hotplug state machine")
Reported-and-tested-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20160909160822.lowgmkdwms2dheyv@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Yanqiu Zhang reported kernel panic when using mbm event
on system where CQM is detected but without mbm event
support, like with perf:
# perf stat -e 'intel_cqm/event=3/' -a
BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
IP: [<ffffffff8100d64c>] update_sample+0xbc/0xe0
...
<IRQ>
[<ffffffff8100d688>] __intel_mbm_event_init+0x18/0x20
[<ffffffff81113d6b>] flush_smp_call_function_queue+0x7b/0x160
[<ffffffff81114853>] generic_smp_call_function_single_interrupt+0x13/0x60
[<ffffffff81052017>] smp_call_function_interrupt+0x27/0x40
[<ffffffff816fb06c>] call_function_interrupt+0x8c/0xa0
...
The reason is that we currently allow to init mbm event
even if mbm support is not detected. Adding checks for
both cqm and mbm events and support into cqm's event_init.
Fixes: 33c3cc7acf ("perf/x86/mbm: Add Intel Memory B/W Monitoring enumeration and init")
Reported-by: Yanqiu Zhang <yanqzhan@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1473089407-21857-1-git-send-email-jolsa@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull x86 fix from Thomas Gleixner:
"A single fix for an AMD erratum so machines without a BIOS fix work"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/AMD: Apply erratum 665 on machines without a BIOS fix
Pull timer fixes from Thomas Gleixner:
"Two fixlet from the timers departement:
- A fix for scheduler stalls in the tick idle code affecting
NOHZ_FULL kernels
- A trivial compile fix"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/nohz: Fix softlockup on scheduler stalls in kvm guest
clocksource/drivers/atmel-pit: Fix compilation error
Pull device mapper fixes from Mike Snitzer:
- a stable fix in both DM crypt and DM log-writes for too large bios
(as generated by bcache)
- two other stable fixes for DM log-writes
- a stable fix for a DM crypt bug that could result in freeing pointers
from uninitialized memory in the tfm allocation error path
- a DM bufio cleanup to discontinue using create_singlethread_workqueue()
* tag 'dm-4.8-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm bufio: remove use of deprecated create_singlethread_workqueue()
dm crypt: fix free of bad values after tfm allocation failure
dm crypt: fix error with too large bios
dm log writes: fix check of kthread_run() return value
dm log writes: fix bug with too large bios
dm log writes: move IO accounting earlier to fix error path
Pull btrfs fixes from Chris Mason:
"I'm still prepping a set of fixes for btrfs fsync, just nailing down a
hard to trigger memory corruption. For now, these are tested and ready."
* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix one bug that process may endlessly wait for ticket in wait_reserve_ticket()
Btrfs: fix endless loop in balancing block groups
Btrfs: kill invalid ASSERT() in process_all_refs()
Pull arm64 fixes from Catalin Marinas:
"arm64 and arm/perf fixes:
- arm64 fix: debug exception unmasking on the CPU resume path
- ARM PMU fixes: memory leak on error path and NULL pointer
dereference"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: kernel: Fix unmasked debug exceptions when restoring mdscr_el1
drivers/perf: arm_pmu: Fix NULL pointer dereference during probe
drivers/perf: arm_pmu: Fix leak in error path
Pull char/misc driver fixes from Greg KH:
"Here are a number of small driver fixes for 4.8-rc5.
The largest thing here is deleting an obsolete driver,
drivers/misc/bh1780gli.c, as the functionality of it was replaced by
an iio driver a while ago.
The other fixes are things that have been reported, or reverts of
broken stuff (the binder change). All of these changes have been in
linux-next for a while with no reported issues"
* tag 'char-misc-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
thunderbolt: Don't declare Falcon Ridge unsupported
thunderbolt: Add support for INTEL_FALCON_RIDGE_2C controller.
thunderbolt: Fix resume quirk for Falcon Ridge 4C.
lkdtm: Mark lkdtm_rodata_do_nothing() notrace
mei: me: disable driver on SPT SPS firmware
Revert "android: binder: fix dangling pointer comparison"
drivers/iio/light/Kconfig: SENSORS_BH1780 cleanup
android: binder: fix dangling pointer comparison
misc: delete bh1780 driver
Pull driver core fixes from Greg KH:
"Here are three small fixes for 4.8-rc5.
One for sysfs, one for kernfs, and one documentation fix, all for
reported issues. All of these have been in linux-next for a while"
* tag 'driver-core-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
sysfs: correctly handle read offset on PREALLOC attrs
documentation: drivers/core/of: fix name of of_node symlink
kernfs: don't depend on d_find_any_alias() when generating notifications
Pull staging/IIO driver fixes from Greg KH:
"Here are a number of small fixes for staging and IIO drivers that
resolve reported problems.
Full details are in the shortlog. All of these have been in
linux-next with no reported issues"
* tag 'staging-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (35 commits)
arm: dts: rockchip: add reset node for the exist saradc SoCs
arm64: dts: rockchip: add reset saradc node for rk3368 SoCs
iio: adc: rockchip_saradc: reset saradc controller before programming it
iio: accel: kxsd9: Fix raw read return
iio: adc: ti_am335x_adc: Increase timeout value waiting for ADC sample
iio: adc: ti_am335x_adc: Protect FIFO1 from concurrent access
include/linux: fix excess fence.h kernel-doc notation
staging: wilc1000: correctly check if associatedsta has not been found
staging: wilc1000: NULL dereference on error
staging: wilc1000: txq_event: Fix coding error
MAINTAINERS: Add file patterns for ion device tree bindings
MAINTAINERS: Update maintainer entry for wilc1000
iio: chemical: atlas-ph-sensor: fix typo in val assignment
iio: fix sched WARNING "do not call blocking ops when !TASK_RUNNING"
staging: comedi: ni_mio_common: fix AO inttrig backwards compatibility
staging: comedi: dt2811: fix a precedence bug
staging: comedi: adv_pci1760: Do not return EINVAL for CMDF_ROUND_DOWN.
staging: comedi: ni_mio_common: fix wrong insn_write handler
staging: comedi: comedi_test: fix timer race conditions
staging: comedi: daqboard2000: bug fix board type matching code
...
Pull serial driver fixes from Greg KH:
"Here are some small serial driver fixes for 4.8-rc5. One fixes an
oft-reported build issue with the fintek driver, another reverts a
patch that was causing problems, one fixes a crash, and some new
device ids were added.
All of these have been in linux-next for a while"
* tag 'tty-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: 8250: added acces i/o products quad and octal serial cards
serial: 8250_mid: fix divide error bug if baud rate is 0
Revert "tty/serial/8250: use mctrl_gpio helpers"
8250/fintek: rename IRQ_MODE macro
Pull USB/PHY fixes from Greg KH:
"Here are some USB and PHY driver fixes for 4.8-rc5
Nothing major, lots of little fixes for reported bugs, and a build fix
for a missing .h file that the phy drivers needed. All of these have
been in linux-next for a while with no reported issues"
* tag 'usb-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (24 commits)
usb: musb: Fix locking errors for host only mode
usb: dwc3: gadget: always decrement by 1
usb: dwc3: debug: fix ep name on trace output
usb: gadget: udc: core: don't starve DMA resources
USB: serial: option: add WeTelecom 0x6802 and 0x6803 products
USB: avoid left shift by -1
USB: fix typo in wMaxPacketSize validation
usb: gadget: Add the gserial port checking in gs_start_tx()
usb: dwc3: gadget: don't rely on jiffies while holding spinlock
usb: gadget: fsl_qe_udc: signedness bug in qe_get_frame()
usb: gadget: function: f_rndis: socket buffer may be NULL
usb: gadget: function: f_eem: socket buffer may be NULL
usb: renesas_usbhs: gadget: fix return value check in usbhs_mod_gadget_probe()
usb: dwc2: Add reset control to dwc2
usb: dwc3: core: allow device to runtime_suspend several times
usb: dwc3: pci: runtime_resume child device
USB: serial: option: add WeTelecom WM-D200
usb: chipidea: udc: don't touch DP when controller is in host mode
USB: serial: mos7840: fix non-atomic allocation in write path
USB: serial: mos7720: fix non-atomic allocation in write path
...
In commit 8ead9dd547 ("devpts: more pty driver interface cleanups") I
made devpts_get_priv() just return the dentry->fs_data directly. And
because I thought it wouldn't happen, I added a warning if you ever saw
a pts node that wasn't on devpts.
And no, that warning never triggered under any actual real use, but you
can trigger it by creating nonsensical pts nodes by hand.
So just revert the warning, and make devpts_get_priv() return NULL for
that case like it used to.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org # 4.6+
Cc: Eric W Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull block fixes from Jens Axboe:
"A collection of fixes for the nvme over fabrics code"
* 'for-linus' of git://git.kernel.dk/linux-block:
nvme-rdma: Get rid of redundant defines
nvme-rdma: Get rid of duplicate variable
nvme: fabrics drivers don't need the nvme-pci driver
nvme-fabrics: get a reference when reusing a nvme_host structure
nvme-fabrics: change NQN UUID to big-endian format
nvme-loop: set sqsize to 0-based value, per spec
nvme-rdma: fix sqsize/hsqsize per spec
fabrics: define admin sqsize min default, per spec
nvmet-rdma: +1 to *queue_size from hsqsize/hrqsize
nvmet-rdma: Fix use after free
nvme-rdma: initialize ret to zero to avoid returning garbage
Pull TPM bugfix from James Morris.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
tpm: invalid self test error message
Pull ACPI fixes ffrom Rafael Wysocki:
"Two stable-candidate fixes for the ACPI early device probing code
added during the 4.4 cycle, one fixing a typo in a stub macro used
when CONFIG_ACPI is unset and one that prevents sleeping functions
from being called under a spinlock (Lorenzo Pieralisi)"
* tag 'acpi-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / drivers: replace acpi_probe_lock spinlock with mutex
ACPI / drivers: fix typo in ACPI_DECLARE_PROBE_ENTRY macro
Pull power management fixes from Rafael Wysocki:
"This includes a stable-candidate cpufreq-dt driver problem fix and
annotations of tracepoints in the runtime PM framework.
Specifics:
- Fix the definition of the cpufreq-dt driver's machines table
introduced during the 4.7 cycle that should be NULL-terminated, but
the termination entry is missing from it (Wei Yongjun).
- Annotate tracepoints in the runtime PM framework's core so as to
allow the functions containing them to be called from the idle code
path without causing RCU to complain about illegal usage (Paul
McKenney)"
* tag 'pm-4.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / runtime: Add _rcuidle suffix to allow rpm_idle() use from idle
PM / runtime: Add _rcuidle suffix to allow rpm_resume() to be called from idle
cpufreq: dt: Add terminate entry for of_device_id tables
* pm-cpufreq-fixes:
cpufreq: dt: Add terminate entry for of_device_id tables
* pm-core-fixes:
PM / runtime: Add _rcuidle suffix to allow rpm_idle() use from idle
PM / runtime: Add _rcuidle suffix to allow rpm_resume() to be called from idle
Commit e647b53227 ("ACPI: Add early device probing infrastructure")
introduced code that allows inserting driver specific
struct acpi_probe_entry probe entries into ACPI linker sections
(one per-subsystem, eg irqchip, clocksource) that are then walked
to retrieve the data and function hooks required to probe the
respective kernel components.
Probing for all entries in a section is triggered through
the __acpi_probe_device_table() function, that in turn, according
to the table ID a given probe entry reports parses the table
with the function retrieved from the respective section structures
(ie struct acpi_probe_entry). Owing to the current ACPI table
parsing implementation, the __acpi_probe_device_table() function
has to share global variables with the acpi_match_madt() function, so
in order to guarantee mutual exclusion locking is required
between the two functions.
Current kernel code implements the locking through the acpi_probe_lock
spinlock; this has the side effect of requiring all code called
within the lock (ie struct acpi_probe_entry.probe_{table/subtbl} hooks)
not to sleep.
However, kernel subsystems that make use of the early probing
infrastructure are relying on kernel APIs that may sleep (eg
irq_domain_alloc_fwnode(), among others) in the function calls
pointed at by struct acpi_probe_entry.{probe_table/subtbl} entries
(eg gic_v2_acpi_init()), which is a bug.
Since __acpi_probe_device_table() is called from context
that is allowed to sleep the acpi_probe_lock spinlock can be replaced
with a mutex; this fixes the issue whilst still guaranteeing
mutual exclusion.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Fixes: e647b53227 (ACPI: Add early device probing infrastructure)
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When the ACPI_DECLARE_PROBE_ENTRY macro was added in
commit e647b53227 ("ACPI: Add early device probing infrastructure"),
a stub macro adding an unused entry was added for the !CONFIG_ACPI
Kconfig option case to make sure kernel code making use of the
macro did not require to be guarded within CONFIG_ACPI in order to
be compiled.
The stub macro was never used since all kernel code that defines
ACPI_DECLARE_PROBE_ENTRY entries is currently guarded within
CONFIG_ACPI; it contains a typo that should be nonetheless fixed.
Fix the typo in the stub (ie !CONFIG_ACPI) ACPI_DECLARE_PROBE_ENTRY()
macro so that it can actually be used if needed.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Fixes: e647b53227 (ACPI: Add early device probing infrastructure)
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Alexander Shishkin
Sebastian Andrzej Siewior
Jiri Olsa
Peter Zijlstra
Linus Torvalds
Jarkko Sakkinen
Rafael J. Wysocki
Lorenzo Pieralisi
Emanuel Czirai