Commit Graph

996846 Commits

Author SHA1 Message Date
Wei Yongjun
d19dea75b9 coresight: core: Make symbol 'csdev_sink' static
The sparse tool complains as follows:

drivers/hwtracing/coresight/coresight-core.c:26:1: warning:
 symbol '__pcpu_scope_csdev_sink' was not declared. Should it be static?

As csdev_sink is not used outside of coresight-core.c after the
introduction of coresight_[set|get]_percpu_sink() helpers, this
change marks it static.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20210409094900.1902783-1-weiyongjun1@huawei.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-13 09:35:55 -06:00
Suzuki K Poulose
4fb1379041 dts: bindings: Document device tree bindings for Arm TRBE
Document the device tree bindings for Trace Buffer Extension (TRBE).

Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-21-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Anshuman Khandual
4af4321861 Documentation: trace: Add documentation for TRBE
Add documentation for the  TRBE under trace/coresight.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
[ Split from the TRBE driver patch ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-20-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Anshuman Khandual
b20f34aec7 Documentation: coresight: trbe: Sysfs ABI description
Add sysfs ABI documentation for the TRBE devices.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
[ Split from the TRBE driver patch ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-19-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Anshuman Khandual
3fbf7f011f coresight: sink: Add TRBE driver
Trace Buffer Extension (TRBE) implements a trace buffer per CPU which is
accessible via the system registers. The TRBE supports different addressing
modes including CPU virtual address and buffer modes including the circular
buffer mode. The TRBE buffer is addressed by a base pointer (TRBBASER_EL1),
an write pointer (TRBPTR_EL1) and a limit pointer (TRBLIMITR_EL1). But the
access to the trace buffer could be prohibited by a higher exception level
(EL3 or EL2), indicated by TRBIDR_EL1.P. The TRBE can also generate a CPU
private interrupt (PPI) on address translation errors and when the buffer
is full. Overall implementation here is inspired from the Arm SPE driver.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
[ Mark the buffer truncated on WRAP event, error code cleanup ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-18-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Anshuman Khandual
2cd87a7b29 coresight: core: Add support for dedicated percpu sinks
Add support for dedicated sinks that are bound to individual CPUs. (e.g,
TRBE). To allow quicker access to the sink for a given CPU bound source,
keep a percpu array of the sink devices. Also, add support for building
a path to the CPU local sink from the ETM.

This adds a new percpu sink type CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM.
This new sink type is exclusively available and can only work with percpu
source type device CORESIGHT_DEV_SUBTYPE_SOURCE_PROC.

This defines a percpu structure that accommodates a single coresight_device
which can be used to store an initialized instance from a sink driver. As
these sinks are exclusively linked and dependent on corresponding percpu
sources devices, they should also be the default sink device during a perf
session.

Outwards device connections are scanned while establishing paths between a
source and a sink device. But such connections are not present for certain
percpu source and sink devices which are exclusively linked and dependent.
Build the path directly and skip connection scanning for such devices.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
[Moved the set/get percpu sink APIs from TRBE patch to here
 Fixed build break on arm32]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-17-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Suzuki K Poulose
549452b73e coresight: etm-perf: Handle stale output handles
The context associated with an ETM for a given perf event
includes :
  - handle -> the perf output handle for the AUX buffer.
  - the path for the trace components
  - the buffer config for the sink.

The path and the buffer config are part of the "aux_priv" data
(etm_event_data) setup by the setup_aux() callback, and made available
via perf_get_aux(handle).

Now with a sink supporting IRQ, the sink could "end" an output
handle when the buffer reaches the programmed limit and would try
to restart a handle. This could fail if there is not enough
space left the AUX buffer (e.g, the userspace has not consumed
the data). This leaves the "handle" disconnected from the "event"
and also the "perf_get_aux()" cleared. This all happens within
the sink driver, without the etm_perf driver being aware.
Now when the event is actually stopped, etm_event_stop()
will need to access the "event_data". But since the handle
is not valid anymore, we loose the information to stop the
"trace" path. So, we need a reliable way to access the etm_event_data
even when the handle may not be active.

This patch replaces the per_cpu handle array with a per_cpu context
for the ETM, which tracks the "handle" as well as the "etm_event_data".
The context notes the etm_event_data at etm_event_start() and clears
it at etm_event_stop(). This makes sure that we don't access a
stale "etm_event_data" as we are guaranteed that it is not
freed by free_aux() as long as the event is active and tracing,
also provides us with access to the critical information
needed to wind up a session even in the absence of an active
output_handle.

This is not an issue for the legacy sinks as none of them supports
an IRQ and is centrally handled by the etm-perf.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-16-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Suzuki K Poulose
e7cc4f2303 dts: bindings: Document device tree bindings for ETE
Document the device tree bindings for Embedded Trace Extensions.
ETE can be connected to legacy coresight components and thus
could optionally contain a connection graph as described by
the CoreSight bindings.

Cc: devicetree@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-15-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Suzuki K Poulose
35e1c9163e coresight: ete: Add support for ETE tracing
Add ETE as one of the supported device types we support
with ETM4x driver. The devices are named following the
existing convention as ete<N>.

ETE mandates that the trace resource status register is programmed
before the tracing is turned on. For the moment simply write to
it indicating TraceActive.

Cc: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-14-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Suzuki K Poulose
3e666ad0f8 coresight: ete: Add support for ETE sysreg access
Add support for handling the system registers for Embedded Trace
Extensions (ETE). ETE shares most of the registers with ETMv4 except
for some and also adds some new registers. Re-arrange the ETMv4x list
to share the common definitions and add the ETE sysreg support.

Cc: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-13-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:38 -06:00
Suzuki K Poulose
bc2c689f06 coresight: etm4x: Add support for PE OS lock
ETE may not implement the OS lock and instead could rely on
the PE OS Lock for the trace unit access. This is indicated
by the TRCOLSR.OSM == 0b100. Add support for handling the
PE OS lock

Cc: Mike Leach <mike.leach@linaro.org>
Reviewed-by: mike.leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-12-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:37 -06:00
Suzuki K Poulose
2b921b671a coresight: Do not scan for graph if none is present
If a graph node is not found for a given node, of_get_next_endpoint()
will emit the following error message :

 OF: graph: no port node found in /<node_name>

If the given component doesn't have any explicit connections (e.g,
ETE) we could simply ignore the graph parsing. As for any legacy
component where this is mandatory, the device will not be usable
as before this patch. Updating the DT bindings to Yaml and enabling
the schema checks can detect such issues with the DT.

Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-11-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:37 -06:00
Suzuki K Poulose
0e6c205175 coresight: etm-perf: Allow an event to use different sinks
When a sink is not specified by the user, the etm perf driver
finds a suitable sink automatically, based on the first ETM
where this event could be scheduled. Then we allocate the
sink buffer based on the selected sink. This is fine for a
CPU bound event as the "sink" is always guaranteed to be
reachable from the ETM (as this is the only ETM where the
event is going to be scheduled). However, if we have a thread
bound event, the event could be scheduled on any of the ETMs
on the system. In this case, currently we automatically select
a sink and exclude any ETMs that cannot reach the selected
sink. This is problematic especially for 1x1 configurations.
We end up in tracing the event only on the "first" ETM,
as the default sink is local to the first ETM and unreachable
from the rest. However, we could allow the other ETMs to
trace if they all have a sink that is compatible with the
"selected" sink and can use the sink buffer. This can be
easily done by verifying that they are all driven by the
same driver and matches the same subtype. Please note
that at anytime there can be only one ETM tracing the event.

Adding support for different types of sinks for a single
event is complex and is not something that we expect
on a sane configuration.

Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Tested-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-10-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:37 -06:00
Suzuki K Poulose
8b4811965f coresight: etm4x: Move ETM to prohibited region for disable
If the CPU implements Arm v8.4 Trace filter controls (FEAT_TRF),
move the ETM to trace prohibited region using TRFCR, while disabling.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-9-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:37 -06:00
Suzuki K Poulose
a1319260bf arm64: KVM: Enable access to TRBE support for host
For a nvhe host, the EL2 must allow the EL1&0 translation
regime for TraceBuffer (MDCR_EL2.E2TB == 0b11). This must
be saved/restored over a trip to the guest. Also, before
entering the guest, we must flush any trace data if the
TRBE was enabled. And we must prohibit the generation
of trace while we are in EL1 by clearing the TRFCR_EL1.

For vhe, the EL2 must prevent the EL1 access to the Trace
Buffer.

The MDCR_EL2 bit definitions for TRBE are available here :

  https://developer.arm.com/documentation/ddi0601/2020-12/AArch64-Registers/

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210405164307.1720226-8-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:28 -06:00
Suzuki K Poulose
d2602bb4f5 KVM: arm64: Move SPE availability check to VCPU load
At the moment, we check the availability of SPE on the given
CPU (i.e, SPE is implemented and is allowed at the host) during
every guest entry. This can be optimized a bit by moving the
check to vcpu_load time and recording the availability of the
feature on the current CPU via a new flag. This will also be useful
for adding the TRBE support.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Alexandru Elisei <Alexandru.Elisei@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210405164307.1720226-7-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:20 -06:00
Suzuki K Poulose
cc427cbb15 KVM: arm64: Handle access to TRFCR_EL1
Rather than falling to an "unhandled access", inject add an explicit
"undefined access" for TRFCR_EL1 access from the guest.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210405164307.1720226-6-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-06 16:05:12 -06:00
Anshuman Khandual
3f9b72f6a1 arm64: Add TRBE definitions
This adds TRBE related registers and corresponding feature macros.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-5-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-05 11:25:38 -06:00
Suzuki K Poulose
be96826942 arm64: Add support for trace synchronization barrier
tsb csync synchronizes the trace operation of instructions.
The instruction is a nop when FEAT_TRF is not implemented.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-4-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-05 11:25:06 -06:00
Suzuki K Poulose
7dde51767c perf: aux: Add CoreSight PMU buffer formats
CoreSight PMU supports aux-buffer for the ETM tracing. The trace
generated by the ETM (associated with individual CPUs, like Intel PT)
is captured by a separate IP (CoreSight TMC-ETR/ETF until now).

The TMC-ETR applies formatting of the raw ETM trace data, as it
can collect traces from multiple ETMs, with the TraceID to indicate
the source of a given trace packet.

Arm Trace Buffer Extension is new "sink" IP, attached to individual
CPUs and thus do not provide additional formatting, like TMC-ETR.

Additionally, a system could have both TRBE *and* TMC-ETR for
the trace collection. e.g, TMC-ETR could be used as a single
trace buffer to collect data from multiple ETMs to correlate
the traces from different CPUs. It is possible to have a
perf session where some events end up collecting the trace
in TMC-ETR while the others in TRBE. Thus we need a way
to identify the type of the trace for each AUX record.

Define the trace formats exported by the CoreSight PMU.
We don't define the flags following the "ETM" as this
information is available to the user when issuing
the session. What is missing is the additional
formatting applied by the "sink" which is decided
at the runtime and the user may not have a control on.

So we define :
 - CORESIGHT format (indicates the Frame format)
 - RAW format (indicates the format of the source)

The default value is CORESIGHT format for all the records
(i,e == 0). Add the RAW format for others that use
raw format.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-3-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-05 11:23:20 -06:00
Suzuki K Poulose
547b60988e perf: aux: Add flags for the buffer format
Allocate a byte for advertising the PMU specific format type
of the given AUX record. A PMU could end up providing hardware
trace data in multiple format in a single session.

e.g, The format of hardware buffer produced by CoreSight ETM
PMU depends on the type of the "sink" device used for collection
for an event (Traditional TMC-ETR/Bs with formatting or
TRBEs without any formatting).

 # Boring story of why this is needed. Goto The_End_of_Story for skipping.

CoreSight ETM trace allows instruction level tracing of Arm CPUs.
The ETM generates the CPU excecution trace and pumps it into CoreSight
AMBA Trace Bus and is collected by a different CoreSight component
(traditionally CoreSight TMC-ETR /ETB/ETF), called "sink".
Important to note that there is no guarantee that every CPU has
a dedicated sink.  Thus multiple ETMs could pump the trace data
into the same "sink" and thus they apply additional formatting
of the trace data for the user to decode it properly and attribute
the trace data to the corresponding ETM.

However, with the introduction of Arm Trace buffer Extensions (TRBE),
we now have a dedicated per-CPU architected sink for collecting the
trace. Since the TRBE is always per-CPU, it doesn't apply any formatting
of the trace. The support for this driver is under review [1].

Now a system could have a per-cpu TRBE and one or more shared
TMC-ETRs on the system. A user could choose a "specific" sink
for a perf session (e.g, a TMC-ETR) or the driver could automatically
select the nearest sink for a given ETM. It is possible that
some ETMs could end up using TMC-ETR (e.g, if the TRBE is not
usable on the CPU) while the others using TRBE in a single
perf session. Thus we now have "formatted" trace collected
from TMC-ETR and "unformatted" trace collected from TRBE.
However, we don't get into a situation where a single event
could end up using TMC-ETR & TRBE. i.e, any AUX buffer is
guaranteed to be either RAW or FORMATTED, but not a mix
of both.

As for perf decoding, we need to know the type of the data
in the individual AUX buffers, so that it can set up the
"OpenCSD" (library for decoding CoreSight trace) decoder
instance appropriately. Thus the perf.data file must conatin
the hints for the tool to decode the data correctly.

Since this is a runtime variable, and perf tool doesn't have
a control on what sink gets used (in case of automatic sink
selection), we need this information made available from
the PMU driver for each AUX record.

 # The_End_of_Story

Cc: Peter Ziljstra <peterz@infradead.org>
Cc: alexander.shishkin@linux.intel.com
Cc: mingo@redhat.com
Cc: will@kernel.org
Cc: mark.rutland@arm.com
Cc: mike.leach@linaro.org
Cc: acme@kernel.org
Cc: jolsa@redhat.com
Cc: Mathieu Poirier <mathieu.poirer@linaro.org>
Reviewed by: Mike Leach <mike.leach@linaro.org>
Acked-by: Peter Ziljstra <peterz@infradead.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-2-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-04-05 11:20:56 -06:00
Suzuki K Poulose
a354a64d91 KVM: arm64: Disable guest access to trace filter controls
Disable guest access to the Trace Filter control registers.
We do not advertise the Trace filter feature to the guest
(ID_AA64DFR0_EL1: TRACE_FILT is cleared) already, but the guest
can still access the TRFCR_EL1 unless we trap it.

This will also make sure that the guest cannot fiddle with
the filtering controls set by a nvhe host.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210323120647.454211-3-suzuki.poulose@arm.com
2021-03-24 17:26:38 +00:00
Suzuki K Poulose
1d676673d6 KVM: arm64: Hide system instruction access to Trace registers
Currently we advertise the ID_AA6DFR0_EL1.TRACEVER for the guest,
when the trace register accesses are trapped (CPTR_EL2.TTA == 1).
So, the guest will get an undefined instruction, if trusts the
ID registers and access one of the trace registers.
Lets be nice to the guest and hide the feature to avoid
unexpected behavior.

Even though this can be done at KVM sysreg emulation layer,
we do this by removing the TRACEVER from the sanitised feature
register field. This is fine as long as the ETM drivers
can handle the individual trace units separately, even
when there are differences among the CPUs.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210323120647.454211-2-suzuki.poulose@arm.com
2021-03-24 17:26:38 +00:00
Linus Torvalds
1e28eed176 Linux 5.12-rc3 v5.12-rc3 2021-03-14 14:41:02 -07:00
Alexey Dobriyan
c995f12ad8 prctl: fix PR_SET_MM_AUXV kernel stack leak
Doing a

	prctl(PR_SET_MM, PR_SET_MM_AUXV, addr, 1);

will copy 1 byte from userspace to (quite big) on-stack array
and then stash everything to mm->saved_auxv.
AT_NULL terminator will be inserted at the very end.

/proc/*/auxv handler will find that AT_NULL terminator
and copy original stack contents to userspace.

This devious scheme requires CAP_SYS_RESOURCE.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-14 14:33:27 -07:00
Linus Torvalds
70404fe303 Merge tag 'irq-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 "A set of irqchip updates:

   - Make the GENERIC_IRQ_MULTI_HANDLER configuration correct

   - Add a missing DT compatible string for the Ingenic driver

   - Remove the pointless debugfs_file pointer from struct irqdomain"

* tag 'irq-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/ingenic: Add support for the JZ4760
  dt-bindings/irq: Add compatible string for the JZ4760B
  irqchip: Do not blindly select CONFIG_GENERIC_IRQ_MULTI_HANDLER
  ARM: ep93xx: Select GENERIC_IRQ_MULTI_HANDLER directly
  irqdomain: Remove debugfs_file from struct irq_domain
2021-03-14 13:33:33 -07:00
Linus Torvalds
802b31c0dd Merge tag 'timers-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "A single fix in for hrtimers to prevent an interrupt storm caused by
  the lack of reevaluation of the timers which expire in softirq context
  under certain circumstances, e.g. when the clock was set"

* tag 'timers-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Update softirq_expires_next correctly after __hrtimer_get_next_event()
2021-03-14 13:29:38 -07:00
Linus Torvalds
c72cbc9361 Merge tag 'sched-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler updates:

   - Prevent a NULL pointer dereference in the migration_stop_cpu()
     mechanims

   - Prevent self concurrency of affine_move_task()

   - Small fixes and cleanups related to task migration/affinity setting

   - Ensure that sync_runqueues_membarrier_state() is invoked on the
     current CPU when it is in the cpu mask"

* tag 'sched-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/membarrier: fix missing local execution of ipi_sync_rq_state()
  sched: Simplify set_affinity_pending refcounts
  sched: Fix affine_move_task() self-concurrency
  sched: Optimize migration_cpu_stop()
  sched: Collate affine_move_task() stoppers
  sched: Simplify migration_cpu_stop()
  sched: Fix migration_cpu_stop() requeueing
2021-03-14 13:27:06 -07:00
Linus Torvalds
19469d2ada Merge tag 'objtool-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fix from Thomas Gleixner:
 "A single objtool fix to handle the PUSHF/POPF validation correctly for
  the paravirt changes which modified arch_local_irq_restore not to use
  popf"

* tag 'objtool-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool,x86: Fix uaccess PUSHF/POPF validation
2021-03-14 13:15:55 -07:00
Linus Torvalds
fa509ff879 Merge tag 'locking-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
 "A couple of locking fixes:

   - A fix for the static_call mechanism so it handles unaligned
     addresses correctly.

   - Make u64_stats_init() a macro so every instance gets a seperate
     lockdep key.

   - Make seqcount_latch_init() a macro as well to preserve the static
     variable which is used for the lockdep key"

* tag 'locking-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  seqlock,lockdep: Fix seqcount_latch_init()
  u64_stats,lockdep: Fix u64_stats_init() vs lockdep
  static_call: Fix the module key fixup
2021-03-14 13:03:21 -07:00
Linus Torvalds
75013c6c52 Merge tag 'perf_urgent_for_v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:

 - Make sure PMU internal buffers are flushed for per-CPU events too and
   properly handle PID/TID for large PEBS.

 - Handle the case properly when there's no PMU and therefore return an
   empty list of perf MSRs for VMX to switch instead of reading random
   garbage from the stack.

* tag 'perf_urgent_for_v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/perf: Use RET0 as default for guest_get_msrs to handle "no PMU" case
  perf/x86/intel: Set PERF_ATTACH_SCHED_CB for large PEBS and LBR
  perf/core: Flush PMU internal buffers for per-CPU events
2021-03-14 12:57:17 -07:00
Linus Torvalds
836d7f0572 Merge tag 'efi-urgent-for-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fix from Ard Biesheuvel via Borislav Petkov:
 "Fix an oversight in the handling of EFI_RT_PROPERTIES_TABLE, which was
  added v5.10, but failed to take the SetVirtualAddressMap() RT service
  into account"

* tag 'efi-urgent-for-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP table
2021-03-14 12:54:56 -07:00
Linus Torvalds
0a7c10df49 Merge tag 'x86_urgent_for_v5.12_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:

 - A couple of SEV-ES fixes and robustifications: verify usermode stack
   pointer in NMI is not coming from the syscall gap, correctly track
   IRQ states in the #VC handler and access user insn bytes atomically
   in same handler as latter cannot sleep.

 - Balance 32-bit fast syscall exit path to do the proper work on exit
   and thus not confuse audit and ptrace frameworks.

 - Two fixes for the ORC unwinder going "off the rails" into KASAN
   redzones and when ORC data is missing.

* tag 'x86_urgent_for_v5.12_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev-es: Use __copy_from_user_inatomic()
  x86/sev-es: Correctly track IRQ states in runtime #VC handler
  x86/sev-es: Check regs->sp is trusted before adjusting #VC IST stack
  x86/sev-es: Introduce ip_within_syscall_gap() helper
  x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls
  x86/unwind/orc: Silence warnings caused by missing ORC data
  x86/unwind/orc: Disable KASAN checking in the ORC unwinder, part 2
2021-03-14 12:48:10 -07:00
Linus Torvalds
c3c7579f5e Merge tag 'powerpc-5.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.12:

   - Fix wrong instruction encoding for lis in ppc_function_entry(),
     which could potentially lead to missed kprobes.

   - Fix SET_FULL_REGS on 32-bit and 64e, which prevented ptrace of
     non-volatile GPRs immediately after exec.

   - Clean up a missed SRR specifier in the recent interrupt rework.

   - Don't treat unrecoverable_exception() as an interrupt handler, it's
     called from other handlers so shouldn't do the interrupt entry/exit
     accounting itself.

   - Fix build errors caused by missing declarations for
     [en/dis]able_kernel_vsx().

  Thanks to Christophe Leroy, Daniel Axtens, Geert Uytterhoeven, Jiri
  Olsa, Naveen N. Rao, and Nicholas Piggin"

* tag 'powerpc-5.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/traps: unrecoverable_exception() is not an interrupt handler
  powerpc: Fix missing declaration of [en/dis]able_kernel_vsx()
  powerpc/64s/exception: Clean up a missed SRR specifier
  powerpc: Fix inverted SET_FULL_REGS bitop
  powerpc/64s: Use symbolic macros for function entry encoding
  powerpc/64s: Fix instruction encoding for lis in ppc_function_entry()
2021-03-14 12:37:43 -07:00
Linus Torvalds
9d0c8e793f Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
 "More fixes for ARM and x86"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: LAPIC: Advancing the timer expiration on guest initiated write
  KVM: x86/mmu: Skip !MMU-present SPTEs when removing SP in exclusive mode
  KVM: kvmclock: Fix vCPUs > 64 can't be online/hotpluged
  kvm: x86: annotate RCU pointers
  KVM: arm64: Fix exclusive limit for IPA size
  KVM: arm64: Reject VM creation when the default IPA size is unsupported
  KVM: arm64: Ensure I-cache isolation between vcpus of a same VM
  KVM: arm64: Don't use cbz/adr with external symbols
  KVM: arm64: Fix range alignment when walking page tables
  KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
  KVM: arm64: Rename __vgic_v3_get_ich_vtr_el2() to __vgic_v3_get_gic_config()
  KVM: arm64: Don't access PMSELR_EL0/PMUSERENR_EL0 when no PMU is available
  KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key
  KVM: arm64: Fix nVHE hyp panic host context restore
  KVM: arm64: Avoid corrupting vCPU context register in guest exit
  KVM: arm64: nvhe: Save the SPE context early
  kvm: x86: use NULL instead of using plain integer as pointer
  KVM: SVM: Connect 'npt' module param to KVM's internal 'npt_enabled'
  KVM: x86: Ensure deadline timer has truly expired before posting its IRQ
2021-03-14 12:35:02 -07:00
Linus Torvalds
50eb842fe5 Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "28 patches.

  Subsystems affected by this series: mm (memblock, pagealloc, hugetlb,
  highmem, kfence, oom-kill, madvise, kasan, userfaultfd, memcg, and
  zram), core-kernel, kconfig, fork, binfmt, MAINTAINERS, kbuild, and
  ia64"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits)
  zram: fix broken page writeback
  zram: fix return value on writeback_store
  mm/memcg: set memcg when splitting page
  mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument
  ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign
  ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls
  mm/userfaultfd: fix memory corruption due to writeprotect
  kasan: fix KASAN_STACK dependency for HW_TAGS
  kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC
  mm/madvise: replace ptrace attach requirement for process_madvise
  include/linux/sched/mm.h: use rcu_dereference in in_vfork()
  kfence: fix reports if constant function prefixes exist
  kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations
  kfence: fix printk format for ptrdiff_t
  linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP*
  MAINTAINERS: exclude uapi directories in API/ABI section
  binfmt_misc: fix possible deadlock in bm_register_write
  mm/highmem.c: fix zero_user_segments() with start > end
  hugetlb: do early cow when page pinned on src mm
  mm: use is_cow_mapping() across tree where proper
  ...
2021-03-14 12:23:34 -07:00
Thomas Gleixner
b470ebc9e0 Merge tag 'irqchip-fixes-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent
Pull irqchip fixes from Marc Zyngier:

  - More compatible strings for the Ingenic irqchip (introducing the
    JZ4760B SoC)
  - Select GENERIC_IRQ_MULTI_HANDLER on the ARM ep93xx platform
  - Drop all GENERIC_IRQ_MULTI_HANDLER selections from the irqchip
    Kconfig, now relying on the architecture to get it right
  - Drop the debugfs_file field from struct irq_domain, now that
    debugfs can track things on its own
2021-03-14 16:34:35 +01:00
Linus Torvalds
88fe49249c Merge tag 'char-misc-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
 "Here are some small misc/char driver fixes to resolve some reported
  problems:

   - habanalabs driver fixes

   - Acrn build fixes (reported many times)

   - pvpanic module table export fix

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc/pvpanic: Export module FDT device table
  misc: fastrpc: restrict user apps from sending kernel RPC messages
  virt: acrn: Correct type casting of argument of copy_from_user()
  virt: acrn: Use EPOLLIN instead of POLLIN
  virt: acrn: Use vfs_poll() instead of f_op->poll()
  virt: acrn: Make remove_cpu sysfs invisible with !CONFIG_HOTPLUG_CPU
  cpu/hotplug: Fix build error of using {add,remove}_cpu() with !CONFIG_SMP
  habanalabs: fix debugfs address translation
  habanalabs: Disable file operations after device is removed
  habanalabs: Call put_pid() when releasing control device
  drivers: habanalabs: remove unused dentry pointer for debugfs files
  habanalabs: mark hl_eq_inc_ptr() as static
2021-03-13 12:38:44 -08:00
Linus Torvalds
be61af330e Merge tag 'staging-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver fixes from Greg KH:
 "Here are some small staging driver fixes for reported problems. They
  include:

   - wfx header file cleanup patch reverted as it could cause problems

   - comedi driver endian fixes

   - buffer overflow problems for staging wifi drivers

   - build dependency issue for rtl8192e driver

  All have been in linux-next for a while with no reported problems"

* tag 'staging-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (23 commits)
  Revert "staging: wfx: remove unused included header files"
  staging: rtl8188eu: prevent ->ssid overflow in rtw_wx_set_scan()
  staging: rtl8188eu: fix potential memory corruption in rtw_check_beacon_data()
  staging: rtl8192u: fix ->ssid overflow in r8192_wx_set_scan()
  staging: comedi: pcl726: Use 16-bit 0 for interrupt data
  staging: comedi: ni_65xx: Use 16-bit 0 for interrupt data
  staging: comedi: ni_6527: Use 16-bit 0 for interrupt data
  staging: comedi: comedi_parport: Use 16-bit 0 for interrupt data
  staging: comedi: amplc_pc236_common: Use 16-bit 0 for interrupt data
  staging: comedi: pcl818: Fix endian problem for AI command data
  staging: comedi: pcl711: Fix endian problem for AI command data
  staging: comedi: me4000: Fix endian problem for AI command data
  staging: comedi: dmm32at: Fix endian problem for AI command data
  staging: comedi: das800: Fix endian problem for AI command data
  staging: comedi: das6402: Fix endian problem for AI command data
  staging: comedi: adv_pci1710: Fix endian problem for AI command data
  staging: comedi: addi_apci_1500: Fix endian problem for command sample
  staging: comedi: addi_apci_1032: Fix endian problem for COS sample
  staging: ks7010: prevent buffer overflow in ks_wlan_set_scan()
  staging: rtl8712: Fix possible buffer overflow in r8712_sitesurvey_cmd
  ...
2021-03-13 12:36:53 -08:00
Linus Torvalds
cc14086f22 Merge tag 'tty-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
 "Here are some small tty and serial driver fixes to resolve some
  reported problems:

   - led tty trigger fixes based on review and were acked by the led
     maintainer

   - revert a max310x serial driver patch as it was causing problems

   - revert a pty change as it was also causing problems

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'tty-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "drivers:tty:pty: Fix a race causing data loss on close"
  Revert "serial: max310x: rework RX interrupt handling"
  leds: trigger/tty: Use led_set_brightness_sync() from workqueue
  leds: trigger: Fix error path to not unlock the unlocked mutex
2021-03-13 12:34:29 -08:00
Linus Torvalds
5c7bdbf882 Merge tag 'usb-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
 "Here are a small number of USB fixes for 5.12-rc3 to resolve a bunch
  of reported issues:

   - usbip fixups for issues found by syzbot

   - xhci driver fixes and quirk additions

   - gadget driver fixes

   - dwc3 QCOM driver fix

   - usb-serial new ids and fixes

   - usblp fix for a long-time issue

   - cdc-acm quirk addition

   - other tiny fixes for reported problems

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'usb-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (25 commits)
  xhci: Fix repeated xhci wake after suspend due to uncleared internal wake state
  usb: xhci: Fix ASMedia ASM1042A and ASM3242 DMA addressing
  xhci: Improve detection of device initiated wake signal.
  usb: xhci: do not perform Soft Retry for some xHCI hosts
  usbip: fix vudc usbip_sockfd_store races leading to gpf
  usbip: fix vhci_hcd attach_store() races leading to gpf
  usbip: fix stub_dev usbip_sockfd_store() races leading to gpf
  usbip: fix vudc to check for stream socket
  usbip: fix vhci_hcd to check for stream socket
  usbip: fix stub_dev to check for stream socket
  usb: dwc3: qcom: Add missing DWC3 OF node refcount decrement
  USB: usblp: fix a hang in poll() if disconnected
  USB: gadget: udc: s3c2410_udc: fix return value check in s3c2410_udc_probe()
  usb: renesas_usbhs: Clear PIPECFG for re-enabling pipe with other EPNUM
  usb: dwc3: qcom: Honor wakeup enabled/disabled state
  usb: gadget: f_uac1: stop playback on function disable
  usb: gadget: f_uac2: always increase endpoint max_packet_size by one audio slot
  USB: gadget: u_ether: Fix a configfs return code
  usb: dwc3: qcom: add ACPI device id for sc8180x
  Goodix Fingerprint device is not a modem
  ...
2021-03-13 12:32:57 -08:00
Linus Torvalds
420623430a Merge tag 'erofs-for-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs fix from Gao Xiang:
 "Fix an urgent regression introduced by commit baa2c7c971 ("block:
  set .bi_max_vecs as actual allocated vector number"), which could
  cause unexpected hung since linux 5.12-rc1.

  Resolve it by avoiding using bio->bi_max_vecs completely"

* tag 'erofs-for-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix bio->bi_max_vecs behavior change
2021-03-13 12:26:22 -08:00
Linus Torvalds
e83bad7f77 Merge tag 'kbuild-fixes-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:

 - avoid 'make image_name' invoking syncconfig

 - fix a couple of bugs in scripts/dummy-tools

 - fix LLD_VENDOR and locale issues in scripts/ld-version.sh

 - rebuild GCC plugins when the compiler is upgraded

 - allow LTO to be enabled with KASAN_HW_TAGS

 - allow LTO to be enabled without LLVM=1

* tag 'kbuild-fixes-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: fix ld-version.sh to not be affected by locale
  kbuild: remove meaningless parameter to $(call if_changed_rule,dtc)
  kbuild: remove LLVM=1 test from HAS_LTO_CLANG
  kbuild: remove unneeded -O option to dtc
  kbuild: dummy-tools: adjust to scripts/cc-version.sh
  kbuild: Allow LTO to be selected with KASAN_HW_TAGS
  kbuild: dummy-tools: support MPROFILE_KERNEL checks for ppc
  kbuild: rebuild GCC plugins when the compiler is upgraded
  kbuild: Fix ld-version.sh script if LLD was built with LLD_VENDOR
  kbuild: dummy-tools: fix inverted tests for gcc
  kbuild: add image_name to no-sync-config-targets
2021-03-13 12:18:59 -08:00
Minchan Kim
2766f18216 zram: fix broken page writeback
commit 0d8359620d ("zram: support page writeback") introduced two
problems.  It overwrites writeback_store's return value as kstrtol's
return value, which makes return value zero so user could see zero as
return value of write syscall even though it wrote data successfully.

It also breaks index value in the loop in that it doesn't increase the
index any longer.  It means it can write only first starting block index
so user couldn't write all idle pages in the zram so lose memory saving
chance.

This patch fixes those issues.

Link: https://lkml.kernel.org/r/20210312173949.2197662-2-minchan@kernel.org
Fixes: 0d8359620d9b("zram: support page writeback")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Amos Bianchi <amosbianchi@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: John Dias <joaodias@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-13 11:27:31 -08:00
Minchan Kim
57e0076e65 zram: fix return value on writeback_store
writeback_store's return value is overwritten by submit_bio_wait's return
value.  Thus, writeback_store will return zero since there was no IO
error.  In the end, write syscall from userspace will see the zero as
return value, which could make the process stall to keep trying the write
until it will succeed.

Link: https://lkml.kernel.org/r/20210312173949.2197662-1-minchan@kernel.org
Fixes: 3b82a051c101("drivers/block/zram/zram_drv.c: fix error return codes not being returned in writeback_store")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: John Dias <joaodias@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-13 11:27:31 -08:00
Zhou Guanghui
e1baddf847 mm/memcg: set memcg when splitting page
As described in the split_page() comment, for the non-compound high order
page, the sub-pages must be freed individually.  If the memcg of the first
page is valid, the tail pages cannot be uncharged when be freed.

For example, when alloc_pages_exact is used to allocate 1MB continuous
physical memory, 2MB is charged(kmemcg is enabled and __GFP_ACCOUNT is
set).  When make_alloc_exact free the unused 1MB and free_pages_exact free
the applied 1MB, actually, only 4KB(one page) is uncharged.

Therefore, the memcg of the tail page needs to be set when splitting a
page.

Michel:

There are at least two explicit users of __GFP_ACCOUNT with
alloc_exact_pages added recently.  See 7efe8ef274 ("KVM: arm64:
Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT") and c419621873
("KVM: s390: Add memcg accounting to KVM allocations"), so this is not
just a theoretical issue.

Link: https://lkml.kernel.org/r/20210304074053.65527-3-zhouguanghui1@huawei.com
Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Cc: Tianhong Ding <dingtianhong@huawei.com>
Cc: Weilong Chen <chenweilong@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-13 11:27:31 -08:00
Zhou Guanghui
be6c8982e4 mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument
Rename mem_cgroup_split_huge_fixup to split_page_memcg and explicitly pass
in page number argument.

In this way, the interface name is more common and can be used by
potential users.  In addition, the complete info(memcg and flag) of the
memcg needs to be set to the tail pages.

Link: https://lkml.kernel.org/r/20210304074053.65527-2-zhouguanghui1@huawei.com
Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Tianhong Ding <dingtianhong@huawei.com>
Cc: Weilong Chen <chenweilong@huawei.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-13 11:27:31 -08:00
Sergei Trofimovich
61bf318eac ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign
In https://bugs.gentoo.org/769614 Dmitry noticed that
`ptrace(PTRACE_GET_SYSCALL_INFO)` does not return error sign properly.

The bug is in mismatch between get/set errors:

static inline long syscall_get_error(struct task_struct *task,
                                     struct pt_regs *regs)
{
        return regs->r10 == -1 ? regs->r8:0;
}

static inline long syscall_get_return_value(struct task_struct *task,
                                            struct pt_regs *regs)
{
        return regs->r8;
}

static inline void syscall_set_return_value(struct task_struct *task,
                                            struct pt_regs *regs,
                                            int error, long val)
{
        if (error) {
                /* error < 0, but ia64 uses > 0 return value */
                regs->r8 = -error;
                regs->r10 = -1;
        } else {
                regs->r8 = val;
                regs->r10 = 0;
        }
}

Tested on v5.10 on rx3600 machine (ia64 9040 CPU).

Link: https://lkml.kernel.org/r/20210221002554.333076-2-slyfox@gentoo.org
Link: https://bugs.gentoo.org/769614
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-13 11:27:31 -08:00
Sergei Trofimovich
0ceb1ace4a ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls
In https://bugs.gentoo.org/769614 Dmitry noticed that
`ptrace(PTRACE_GET_SYSCALL_INFO)` does not work for syscalls called via
glibc's syscall() wrapper.

ia64 has two ways to call syscalls from userspace: via `break` and via
`eps` instructions.

The difference is in stack layout:

1. `eps` creates simple stack frame: no locals, in{0..7} == out{0..8}
2. `break` uses userspace stack frame: may be locals (glibc provides
   one), in{0..7} == out{0..8}.

Both work fine in syscall handling cde itself.

But `ptrace(PTRACE_GET_SYSCALL_INFO)` uses unwind mechanism to
re-extract syscall arguments but it does not account for locals.

The change always skips locals registers. It should not change `eps`
path as kernel's handler already enforces locals=0 and fixes `break`.

Tested on v5.10 on rx3600 machine (ia64 9040 CPU).

Link: https://lkml.kernel.org/r/20210221002554.333076-1-slyfox@gentoo.org
Link: https://bugs.gentoo.org/769614
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-13 11:27:31 -08:00
Nadav Amit
6ce64428d6 mm/userfaultfd: fix memory corruption due to writeprotect
Userfaultfd self-test fails occasionally, indicating a memory corruption.

Analyzing this problem indicates that there is a real bug since mmap_lock
is only taken for read in mwriteprotect_range() and defers flushes, and
since there is insufficient consideration of concurrent deferred TLB
flushes in wp_page_copy().  Although the PTE is flushed from the TLBs in
wp_page_copy(), this flush takes place after the copy has already been
performed, and therefore changes of the page are possible between the time
of the copy and the time in which the PTE is flushed.

To make matters worse, memory-unprotection using userfaultfd also poses a
problem.  Although memory unprotection is logically a promotion of PTE
permissions, and therefore should not require a TLB flush, the current
userrfaultfd code might actually cause a demotion of the architectural PTE
permission: when userfaultfd_writeprotect() unprotects memory region, it
unintentionally *clears* the RW-bit if it was already set.  Note that this
unprotecting a PTE that is not write-protected is a valid use-case: the
userfaultfd monitor might ask to unprotect a region that holds both
write-protected and write-unprotected PTEs.

The scenario that happens in selftests/vm/userfaultfd is as follows:

cpu0				cpu1			cpu2
----				----			----
							[ Writable PTE
							  cached in TLB ]
userfaultfd_writeprotect()
[ write-*unprotect* ]
mwriteprotect_range()
mmap_read_lock()
change_protection()

change_protection_range()
...
change_pte_range()
[ *clear* “write”-bit ]
[ defer TLB flushes ]
				[ page-fault ]
				...
				wp_page_copy()
				 cow_user_page()
				  [ copy page ]
							[ write to old
							  page ]
				...
				 set_pte_at_notify()

A similar scenario can happen:

cpu0		cpu1		cpu2		cpu3
----		----		----		----
						[ Writable PTE
				  		  cached in TLB ]
userfaultfd_writeprotect()
[ write-protect ]
[ deferred TLB flush ]
		userfaultfd_writeprotect()
		[ write-unprotect ]
		[ deferred TLB flush]
				[ page-fault ]
				wp_page_copy()
				 cow_user_page()
				 [ copy page ]
				 ...		[ write to page ]
				set_pte_at_notify()

This race exists since commit 292924b260 ("userfaultfd: wp: apply
_PAGE_UFFD_WP bit").  Yet, as Yu Zhao pointed, these races became apparent
since commit 09854ba94c ("mm: do_wp_page() simplification") which made
wp_page_copy() more likely to take place, specifically if page_count(page)
> 1.

To resolve the aforementioned races, check whether there are pending
flushes on uffd-write-protected VMAs, and if there are, perform a flush
before doing the COW.

Further optimizations will follow to avoid during uffd-write-unprotect
unnecassary PTE write-protection and TLB flushes.

Link: https://lkml.kernel.org/r/20210304095423.3825684-1-namit@vmware.com
Fixes: 09854ba94c ("mm: do_wp_page() simplification")
Signed-off-by: Nadav Amit <namit@vmware.com>
Suggested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>	[5.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-13 11:27:31 -08:00