Commit Graph

1935 Commits

Author SHA1 Message Date
Linus Torvalds
23221d997b arm64 updates for 4.17
Nothing particularly stands out here, probably because people were tied
 up with spectre/meltdown stuff last time around. Still, the main pieces
 are:
 
 - Rework of our CPU features framework so that we can whitelist CPUs that
   don't require kpti even in a heterogeneous system
 
 - Support for the IDC/DIC architecture extensions, which allow us to elide
   instruction and data cache maintenance when writing out instructions
 
 - Removal of the large memory model which resulted in suboptimal codegen
   by the compiler and increased the use of literal pools, which could
   potentially be used as ROP gadgets since they are mapped as executable
 
 - Rework of forced signal delivery so that the siginfo_t is well-formed
   and handling of show_unhandled_signals is consolidated and made
   consistent between different fault types
 
 - More siginfo cleanup based on the initial patches from Eric Biederman
 
 - Workaround for Cortex-A55 erratum #1024718
 
 - Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi
 
 - Misc cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Nothing particularly stands out here, probably because people were
  tied up with spectre/meltdown stuff last time around. Still, the main
  pieces are:

   - Rework of our CPU features framework so that we can whitelist CPUs
     that don't require kpti even in a heterogeneous system

   - Support for the IDC/DIC architecture extensions, which allow us to
     elide instruction and data cache maintenance when writing out
     instructions

   - Removal of the large memory model which resulted in suboptimal
     codegen by the compiler and increased the use of literal pools,
     which could potentially be used as ROP gadgets since they are
     mapped as executable

   - Rework of forced signal delivery so that the siginfo_t is
     well-formed and handling of show_unhandled_signals is consolidated
     and made consistent between different fault types

   - More siginfo cleanup based on the initial patches from Eric
     Biederman

   - Workaround for Cortex-A55 erratum #1024718

   - Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi

   - Misc cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits)
  arm64: uaccess: Fix omissions from usercopy whitelist
  arm64: fpsimd: Split cpu field out from struct fpsimd_state
  arm64: tlbflush: avoid writing RES0 bits
  arm64: cmpxchg: Include linux/compiler.h in asm/cmpxchg.h
  arm64: move percpu cmpxchg implementation from cmpxchg.h to percpu.h
  arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG
  arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC
  arm64: fpsimd: include <linux/init.h> in fpsimd.h
  drivers/perf: arm_pmu_platform: do not warn about affinity on uniprocessor
  perf: arm_spe: include linux/vmalloc.h for vmap()
  Revert "arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)"
  arm64: cpufeature: Avoid warnings due to unused symbols
  arm64: Add work around for Arm Cortex-A55 Erratum 1024718
  arm64: Delay enabling hardware DBM feature
  arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35
  arm64: capabilities: Handle shared entries
  arm64: capabilities: Add support for checks based on a list of MIDRs
  arm64: Add helpers for checking CPU MIDR against a range
  arm64: capabilities: Clean up midr range helpers
  arm64: capabilities: Change scope of VHE to Boot CPU feature
  ...
2018-04-04 16:01:43 -07:00
Linus Torvalds
5b1f3dc927 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "The usual pile of boring changes:

   - Consolidate tasklet functions to share code instead of duplicating
     it

   - The first step for making the low level entry handler management on
     multi-platform kernels generic

   - A new sysfs file which allows to retrieve the wakeup state of
     interrupts.

   - Ensure that the interrupt thread follows the effective affinity and
     not the programmed affinity to avoid cross core wakeups.

   - Two new interrupt controller drivers (Microsemi Ocelot and Qualcomm
     PDC)

   - Fix the wakeup path clock handling for Reneasas interrupt chips.

   - Rework the boot time register reset for ARM GIC-V2/3

   - Better suspend/resume support for ARM GIV-V3/ITS

   - Add missing locking to the ARM GIC set_type() callback

   - Small fixes for the irq simulator code

   - SPDX identifiers for the irq core code and removal of boiler plate

   - Small cleanups all over the place"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  openrisc: Set CONFIG_MULTI_IRQ_HANDLER
  arm64: Set CONFIG_MULTI_IRQ_HANDLER
  genirq: Make GENERIC_IRQ_MULTI_HANDLER depend on !MULTI_IRQ_HANDLER
  irqchip/gic: Take lock when updating irq type
  irqchip/gic: Update supports_deactivate static key to modern api
  irqchip/gic-v3: Ensure GICR_CTLR.EnableLPI=0 is observed before enabling
  irqchip: Add a driver for the Microsemi Ocelot controller
  dt-bindings: interrupt-controller: Add binding for the Microsemi Ocelot interrupt controller
  irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn
  irqchip/gic-v3: Don't try to reset AP0Rn
  irqchip/gic-v3: Do not check trigger configuration of partitionned LPIs
  genirq: Remove license boilerplate/references
  genirq: Add missing SPDX identifiers
  genirq/matrix: Cleanup SPDX identifier
  genirq: Cleanup top of file comments
  genirq: Pass desc to __irq_free instead of irq number
  irqchip/gic-v3: Loudly complain about the use of IRQ_TYPE_NONE
  irqchip/gic: Loudly complain about the use of IRQ_TYPE_NONE
  RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler
  genirq: Add CONFIG_GENERIC_IRQ_MULTI_HANDLER
  ...
2018-04-04 15:19:26 -07:00
Dave Martin
65896545b6 arm64: uaccess: Fix omissions from usercopy whitelist
When the hardend usercopy support was added for arm64, it was
concluded that all cases of usercopy into and out of thread_struct
were statically sized and so didn't require explicit whitelisting
of the appropriate fields in thread_struct.

Testing with usercopy hardening enabled has revealed that this is
not the case for certain ptrace regset manipulation calls on arm64.
This occurs because the sizes of usercopies associated with the
regset API are dynamic by construction, and because arm64 does not
always stage such copies via the stack: indeed the regset API is
designed to avoid the need for that by adding some bounds checking.

This is currently believed to affect only the fpsimd and TLS
registers.

Because the whitelisted fields in thread_struct must be contiguous,
this patch groups them together in a nested struct.  It is also
necessary to be able to determine the location and size of that
struct, so rather than making the struct anonymous (which would
save on edits elsewhere) or adding an anonymous union containing
named and unnamed instances of the same struct (gross), this patch
gives the struct a name and makes the necessary edits to code that
references it (noisy but simple).

Care is needed to ensure that the new struct does not contain
padding (which the usercopy hardening would fail to protect).

For this reason, the presence of tp2_value is made unconditional,
since a padding field would be needed there in any case.  This pads
up to the 16-byte alignment required by struct user_fpsimd_state.

Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 9e8084d3f7 ("arm64: Implement thread_struct whitelist for hardened usercopy")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-28 15:25:44 +01:00
Dave Martin
20b8547277 arm64: fpsimd: Split cpu field out from struct fpsimd_state
In preparation for using a common representation of the FPSIMD
state for tasks and KVM vcpus, this patch separates out the "cpu"
field that is used to track the cpu on which the state was most
recently loaded.

This will allow common code to operate on task and vcpu contexts
without requiring the cpu field to be stored at the same offset
from the FPSIMD register data in both cases.  This should avoid the
need for messing with the definition of those parts of struct
vcpu_arch that are exposed in the KVM user ABI.

The resulting change is also convenient for grouping and defining
the set of thread_struct fields that are supposed to be accessible
to copy_{to,from}_user(), which includes user_fpsimd_state but
should exclude the cpu field.  This patch does not amend the
usercopy whitelist to match: that will be addressed in a subsequent
patch.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
[will: inline fpsimd_flush_state for now]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-28 15:20:17 +01:00
Philip Elcan
7f170499f7 arm64: tlbflush: avoid writing RES0 bits
Several of the bits of the TLBI register operand are RES0 per the ARM
ARM, so TLBI operations should avoid writing non-zero values to these
bits.

This patch adds a macro __TLBI_VADDR(addr, asid) that creates the
operand register in the correct format and honors the RES0 bits.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Philip Elcan <pelcan@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-28 15:20:17 +01:00
Will Deacon
2a58fca9a7 arm64: cmpxchg: Include linux/compiler.h in asm/cmpxchg.h
We need linux/compiler.h for unreachable(), so #include it here.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:15:49 +01:00
Will Deacon
c9406e514b arm64: move percpu cmpxchg implementation from cmpxchg.h to percpu.h
We want to avoid pulling linux/preempt.h into cmpxchg.h, since that can
introduce a circular dependency on linux/bitops.h. linux/preempt.h is
only needed by the per-cpu cmpxchg implementation, which is better off
alongside the per-cpu xchg implementation in percpu.h, so move it there
and add the missing #include.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:15:29 +01:00
Will Deacon
e8a2d040fe arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG
Having asm/cmpxchg.h pull in linux/bug.h is problematic because this
ends up pulling in the atomic bitops which themselves may be built on
top of atomic.h and cmpxchg.h.

Instead, just include build_bug.h for the definition of BUILD_BUG.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:14:54 +01:00
Will Deacon
8a624f145c arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC
When the LL/SC atomics are moved out-of-line, they are annotated as
notrace and exported to modules. Ensure we pull in the relevant include
files so that these macros are defined when we need them.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:14:49 +01:00
Will Deacon
b4f9b39074 arm64: fpsimd: include <linux/init.h> in fpsimd.h
fpsimd.h uses the __init annotation, so pull in linux/init.h

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:14:43 +01:00
Will Deacon
3f251cf0ab Revert "arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)"
This reverts commit 1f85b42a69.

The internal dma-direct.h API has changed in -next, which collides with
us trying to use it to manage non-coherent DMA devices on systems with
unreasonably large cache writeback granules.

This isn't at all trivial to resolve, so revert our changes for now and
we can revisit this after the merge window. Effectively, this just
restores our behaviour back to that of 4.16.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 12:04:51 +01:00
Suzuki K Poulose
05abb595bb arm64: Delay enabling hardware DBM feature
We enable hardware DBM bit in a capable CPU, very early in the
boot via __cpu_setup. This doesn't give us a flexibility of
optionally disable the feature, as the clearing the bit
is a bit costly as the TLB can cache the settings. Instead,
we delay enabling the feature until the CPU is brought up
into the kernel. We use the feature capability mechanism
to handle it.

The hardware DBM is a non-conflicting feature. i.e, the kernel
can safely run with a mix of CPUs with some using the feature
and the others don't. So, it is safe for a late CPU to have
this capability and enable it, even if the active CPUs don't.

To get this handled properly by the infrastructure, we
unconditionally set the capability and only enable it
on CPUs which really have the feature. Also, we print the
feature detection from the "matches" call back to make sure
we don't mislead the user when none of the CPUs could use the
feature.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:44 +01:00
Suzuki K Poulose
6e616864f2 arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35
Update the MIDR encodings for the Cortex-A55 and Cortex-A35

Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:43 +01:00
Suzuki K Poulose
ba7d9233c2 arm64: capabilities: Handle shared entries
Some capabilities have different criteria for detection and associated
actions based on the matching criteria, even though they all share the
same capability bit. So far we have used multiple entries with the same
capability bit to handle this. This is prone to errors, as the
cpu_enable is invoked for each entry, irrespective of whether the
detection rule applies to the CPU or not. And also this complicates
other helpers, e.g, __this_cpu_has_cap.

This patch adds a wrapper entry to cover all the possible variations
of a capability by maintaining list of matches + cpu_enable callbacks.
To avoid complicating the prototypes for the "matches()", we use
arm64_cpu_capabilities maintain the list and we ignore all the other
fields except the matches & cpu_enable.

This ensures :

 1) The capabilitiy is set when at least one of the entry detects
 2) Action is only taken for the entries that "matches".

This avoids explicit checks in the cpu_enable() take some action.
The only constraint here is that, all the entries should have the
same "type" (i.e, scope and conflict rules).

If a cpu_enable() method is associated with multiple matches for a
single capability, care should be taken that either the match criteria
are mutually exclusive, or that the method is robust against being
called multiple times.

This also reverts the changes introduced by commit 67948af41f
("arm64: capabilities: Handle duplicate entries for a capability").

Cc: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:43 +01:00
Suzuki K Poulose
be5b299830 arm64: capabilities: Add support for checks based on a list of MIDRs
Add helpers for detecting an errata on list of midr ranges
of affected CPUs, with the same work around.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:42 +01:00
Suzuki K Poulose
1df310505d arm64: Add helpers for checking CPU MIDR against a range
Add helpers for checking if the given CPU midr falls in a range
of variants/revisions for a given model.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:42 +01:00
Suzuki K Poulose
830dcc9f9a arm64: capabilities: Change scope of VHE to Boot CPU feature
We expect all CPUs to be running at the same EL inside the kernel
with or without VHE enabled and we have strict checks to ensure
that any mismatch triggers a kernel panic. If VHE is enabled,
we use the feature based on the boot CPU and all other CPUs
should follow. This makes it a perfect candidate for a capability
based on the boot CPU,  which should be matched by all the CPUs
(both when is ON and OFF). This saves us some not-so-pretty
hooks and special code, just for verifying the conflict.

The patch also makes the VHE capability entry depend on
CONFIG_ARM64_VHE.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:41 +01:00
Suzuki K Poulose
fd9d63da17 arm64: capabilities: Add support for features enabled early
The kernel detects and uses some of the features based on the boot
CPU and expects that all the following CPUs conform to it. e.g,
with VHE and the boot CPU running at EL2, the kernel decides to
keep the kernel running at EL2. If another CPU is brought up without
this capability, we use custom hooks (via check_early_cpu_features())
to handle it. To handle such capabilities add support for detecting
and enabling capabilities based on the boot CPU.

A bit is added to indicate if the capability should be detected
early on the boot CPU. The infrastructure then ensures that such
capabilities are probed and "enabled" early on in the boot CPU
and, enabled on the subsequent CPUs.

Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:41 +01:00
Suzuki K Poulose
d3aec8a28b arm64: capabilities: Restrict KPTI detection to boot-time CPUs
KPTI is treated as a system wide feature and is only detected if all
the CPUs in the sysetm needs the defense, unless it is forced via kernel
command line. This leaves a system with a mix of CPUs with and without
the defense vulnerable. Also, if a late CPU needs KPTI but KPTI was not
activated at boot time, the CPU is currently allowed to boot, which is a
potential security vulnerability.
This patch ensures that the KPTI is turned on if at least one CPU detects
the capability (i.e, change scope to SCOPE_LOCAL_CPU). Also rejetcs a late
CPU, if it requires the defense, when the system hasn't enabled it,

Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:40 +01:00
Suzuki K Poulose
5c137714dd arm64: capabilities: Introduce weak features based on local CPU
Now that we have the flexibility of defining system features based
on individual CPUs, introduce CPU feature type that can be detected
on a local SCOPE and ignores the conflict on late CPUs. This is
applicable for ARM64_HAS_NO_HW_PREFETCH, where it is fine for
the system to have CPUs without hardware prefetch turning up
later. We only suffer a performance penalty, nothing fatal.

Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:40 +01:00
Suzuki K Poulose
cce360b54c arm64: capabilities: Filter the entries based on a given mask
While processing the list of capabilities, it is useful to
filter out some of the entries based on the given mask for the
scope of the capabilities to allow better control. This can be
used later for handling LOCAL vs SYSTEM wide capabilities and more.
All capabilities should have their scope set to either LOCAL_CPU or
SYSTEM. No functional/flow change.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:38 +01:00
Suzuki K Poulose
5b4747c5dc arm64: capabilities: Add flags to handle the conflicts on late CPU
When a CPU is brought up, it is checked against the caps that are
known to be enabled on the system (via verify_local_cpu_capabilities()).
Based on the state of the capability on the CPU vs. that of System we
could have the following combinations of conflict.

	x-----------------------------x
	| Type  | System   | Late CPU |
	|-----------------------------|
	|  a    |   y      |    n     |
	|-----------------------------|
	|  b    |   n      |    y     |
	x-----------------------------x

Case (a) is not permitted for caps which are system features, which the
system expects all the CPUs to have (e.g VHE). While (a) is ignored for
all errata work arounds. However, there could be exceptions to the plain
filtering approach. e.g, KPTI is an optional feature for a late CPU as
long as the system already enables it.

Case (b) is not permitted for errata work arounds that cannot be activated
after the kernel has finished booting.And we ignore (b) for features. Here,
yet again, KPTI is an exception, where if a late CPU needs KPTI we are too
late to enable it (because we change the allocation of ASIDs etc).

Add two different flags to indicate how the conflict should be handled.

 ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU - CPUs may have the capability
 ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU - CPUs may not have the cappability.

Now that we have the flags to describe the behavior of the errata and
the features, as we treat them, define types for ERRATUM and FEATURE.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:37 +01:00
Suzuki K Poulose
143ba05d86 arm64: capabilities: Prepare for fine grained capabilities
We use arm64_cpu_capabilities to represent CPU ELF HWCAPs exposed
to the userspace and the CPU hwcaps used by the kernel, which
include cpu features and CPU errata work arounds. Capabilities
have some properties that decide how they should be treated :

 1) Detection, i.e scope : A cap could be "detected" either :
    - if it is present on at least one CPU (SCOPE_LOCAL_CPU)
	Or
    - if it is present on all the CPUs (SCOPE_SYSTEM)

 2) When is it enabled ? - A cap is treated as "enabled" when the
  system takes some action based on whether the capability is detected or
  not. e.g, setting some control register, patching the kernel code.
  Right now, we treat all caps are enabled at boot-time, after all
  the CPUs are brought up by the kernel. But there are certain caps,
  which are enabled early during the boot (e.g, VHE, GIC_CPUIF for NMI)
  and kernel starts using them, even before the secondary CPUs are brought
  up. We would need a way to describe this for each capability.

 3) Conflict on a late CPU - When a CPU is brought up, it is checked
  against the caps that are known to be enabled on the system (via
  verify_local_cpu_capabilities()). Based on the state of the capability
  on the CPU vs. that of System we could have the following combinations
  of conflict.

	x-----------------------------x
	| Type	| System   | Late CPU |
	------------------------------|
	|  a    |   y      |    n     |
	------------------------------|
	|  b    |   n      |    y     |
	x-----------------------------x

  Case (a) is not permitted for caps which are system features, which the
  system expects all the CPUs to have (e.g VHE). While (a) is ignored for
  all errata work arounds. However, there could be exceptions to the plain
  filtering approach. e.g, KPTI is an optional feature for a late CPU as
  long as the system already enables it.

  Case (b) is not permitted for errata work arounds which requires some
  work around, which cannot be delayed. And we ignore (b) for features.
  Here, yet again, KPTI is an exception, where if a late CPU needs KPTI we
  are too late to enable it (because we change the allocation of ASIDs
  etc).

So this calls for a lot more fine grained behavior for each capability.
And if we define all the attributes to control their behavior properly,
we may be able to use a single table for the CPU hwcaps (which cover
errata and features, not the ELF HWCAPs). This is a prepartory step
to get there. More bits would be added for the properties listed above.

We are going to use a bit-mask to encode all the properties of a
capabilities. This patch encodes the "SCOPE" of the capability.

As such there is no change in how the capabilities are treated.

Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:37 +01:00
Suzuki K Poulose
1e89baed5d arm64: capabilities: Move errata processing code
We have errata work around processing code in cpu_errata.c,
which calls back into helpers defined in cpufeature.c. Now
that we are going to make the handling of capabilities
generic, by adding the information to each capability,
move the errata work around specific processing code.
No functional changes.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:36 +01:00
Dave Martin
c0cda3b8ee arm64: capabilities: Update prototype for enable call back
We issue the enable() call back for all CPU hwcaps capabilities
available on the system, on all the CPUs. So far we have ignored
the argument passed to the call back, which had a prototype to
accept a "void *" for use with on_each_cpu() and later with
stop_machine(). However, with commit 0a0d111d40
("arm64: cpufeature: Pass capability structure to ->enable callback"),
there are some users of the argument who wants the matching capability
struct pointer where there are multiple matching criteria for a single
capability. Clean up the declaration of the call back to make it clear.

 1) Renamed to cpu_enable(), to imply taking necessary actions on the
    called CPU for the entry.
 2) Pass const pointer to the capability, to allow the call back to
    check the entry. (e.,g to check if any action is needed on the CPU)
 3) We don't care about the result of the call back, turning this to
    a void.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: James Morse <james.morse@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Dave Martin <dave.martin@arm.com>
[suzuki: convert more users, rename call back and drop results]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:00:37 +01:00
Marc Zyngier
33625282ad irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn
We would like to reset the Group-0 Active Priority Registers
at boot time if they are available to us. They would be available
if SCR_EL3.FIQ was not set, but we cannot directly probe this bit,
and short of checking, we may end-up trapping to EL3, and the
firmware may not be please to get such an exception. Yes, this
is dumb.

Instead, let's use PMR to find out if its value gets affected by
SCR_EL3.FIQ being set. We use the fact that when SCR_EL3.FIQ is
set, the LSB of the priority is lost due to the shifting back and
forth of the actual priority. If we read back a 0, we know that
Group0 is unavailable. In case we read a non-zero value, we can
safely reset the AP0Rn register.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-22 13:46:18 +00:00
Dave Martin
af4a81b9cd arm64: fpsimd: Fix bad si_code for undiagnosed SIGFPE
Currently a SIGFPE delivered in response to a floating-point
exception trap may have si_code set to 0 on arm64.  As reported by
Eric, this is a bad idea since this is the value of SI_USER -- yet
this signal is definitely not the result of kill(2), tgkill(2) etc.
and si_uid and si_pid make limited sense whereas we do want to
yield a value for si_addr (which doesn't exist for SI_USER).

It's not entirely clear whether the architecure permits a
"spurious" fp exception trap where none of the exception flag bits
in ESR_ELx is set.  (IMHO the architectural intent is to forbid
this.)  However, it does permit those bits to contain garbage if
the TFV bit in ESR_ELx is 0.  That case isn't currently handled at
all and may result in si_code == 0 or si_code containing a FPE_FLT*
constant corresponding to an exception that did not in fact happen.

There is nothing sensible we can return for si_code in such cases,
but SI_USER is certainly not appropriate and will lead to violation
of legitimate userspace assumptions.

This patch allocates a new si_code value FPE_UNKNOWN that at least
does not conflict with any existing SI_* or FPE_* code, and yields
this in si_code for undiagnosable cases.  This is probably the best
simplicity/incorrectness tradeoff achieveable without relying on
implementation-dependent features or adding a lot of code.  In any
case, there appears to be no perfect solution possible that would
justify a lot of effort here.

Yielding FPE_UNKNOWN when some well-defined fp exception caused the
trap is a violation of POSIX, but this is forced by the
architecture.  We have no realistic prospect of yielding the
correct code in such cases.  At present I am not aware of any ARMv8
implementation that supports trapped floating-point exceptions in
any case.

The new code may be applicable to other architectures for similar
reasons.

No attempt is made to provide ESR_ELx to userspace in the signal
frame, since architectural limitations mean that it is unlikely to
provide much diagnostic value, doesn't benefit existing software
and would create ABI with no proven purpose.  The existing
mechanism for passing it also has problems of its own which may
result in the wrong value being passed to userspace due to
interaction with mm faults.  The implied rework does not appear
justified.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-20 10:03:11 +00:00
Suzuki K Poulose
7206dc93a5 arm64: Expose Arm v8.4 features
Expose the new features introduced by Arm v8.4 extensions to
Arm v8-A profile.

These include :

 1) Data indpendent timing of instructions. (DIT, exposed as HWCAP_DIT)
 2) Unaligned atomic instructions and Single-copy atomicity of loads
    and stores. (AT, expose as HWCAP_USCAT)
 3) LDAPR and STLR instructions with immediate offsets (extension to
    LRCPC, exposed as HWCAP_ILRCPC)
 4) Flag manipulation instructions (TS, exposed as HWCAP_FLAGM).

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19 18:14:27 +00:00
Ard Biesheuvel
350e1dad0d arm64: asm: drop special versions of adr_l/ldr_l/str_l for modules
Now that we started keeping modules within 4 GB of the core kernel
in all cases, we no longer need to special case the adr_l/ldr_l/str_l
macros for modules to deal with them being loaded farther away.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19 18:14:26 +00:00
Dave Martin
af40ff687b arm64: signal: Ensure si_code is valid for all fault signals
Currently, as reported by Eric, an invalid si_code value 0 is
passed in many signals delivered to userspace in response to faults
and other kernel errors.  Typically 0 is passed when the fault is
insufficiently diagnosable or when there does not appear to be any
sensible alternative value to choose.

This appears to violate POSIX, and is intuitively wrong for at
least two reasons arising from the fact that 0 == SI_USER:

 1) si_code is a union selector, and SI_USER (and si_code <= 0 in
    general) implies the existence of a different set of fields
    (siginfo._kill) from that which exists for a fault signal
    (siginfo._sigfault).  However, the code raising the signal
    typically writes only the _sigfault fields, and the _kill
    fields make no sense in this case.

    Thus when userspace sees si_code == 0 (SI_USER) it may
    legitimately inspect fields in the inactive union member _kill
    and obtain garbage as a result.

    There appears to be software in the wild relying on this,
    albeit generally only for printing diagnostic messages.

 2) Software that wants to be robust against spurious signals may
    discard signals where si_code == SI_USER (or <= 0), or may
    filter such signals based on the si_uid and si_pid fields of
    siginfo._sigkill.  In the case of fault signals, this means
    that important (and usually fatal) error conditions may be
    silently ignored.

In practice, many of the faults for which arm64 passes si_code == 0
are undiagnosable conditions such as exceptions with syndrome
values in ESR_ELx to which the architecture does not yet assign any
meaning, or conditions indicative of a bug or error in the kernel
or system and thus that are unrecoverable and should never occur in
normal operation.

The approach taken in this patch is to translate all such
undiagnosable or "impossible" synchronous fault conditions to
SIGKILL, since these are at least probably localisable to a single
process.  Some of these conditions should really result in a kernel
panic, but due to the lack of diagnostic information it is
difficult to be certain: this patch does not add any calls to
panic(), but this could change later if justified.

Although si_code will not reach userspace in the case of SIGKILL,
it is still desirable to pass a nonzero value so that the common
siginfo handling code can detect incorrect use of si_code == 0
without false positives.  In this case the si_code dependent
siginfo fields will not be correctly initialised, but since they
are not passed to userspace I deem this not to matter.

A few faults can reasonably occur in realistic userspace scenarios,
and _should_ raise a regular, handleable (but perhaps not
ignorable/blockable) signal: for these, this patch attempts to
choose a suitable standard si_code value for the raised signal in
each case instead of 0.

arm64 was the only arch to define a BUS_FIXME code, so after this
patch nobody defines it.  This patch therefore also removes the
relevant code from siginfo_layout().

Cc: James Morse <james.morse@arm.com>
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:58:36 +00:00
Shanker Donthineni
6ae4b6e057 arm64: Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC
The DCache clean & ICache invalidation requirements for instructions
to be data coherence are discoverable through new fields in CTR_EL0.
The following two control bits DIC and IDC were defined for this
purpose. No need to perform point of unification cache maintenance
operations from software on systems where CPU caches are transparent.

This patch optimize the three functions __flush_cache_user_range(),
clean_dcache_area_pou() and invalidate_icache_range() if the hardware
reports CTR_EL0.IDC and/or CTR_EL0.IDC. Basically it skips the two
instructions 'DC CVAU' and 'IC IVAU', and the associated loop logic
in order to avoid the unnecessary overhead.

CTR_EL0.DIC: Instruction cache invalidation requirements for
 instruction to data coherence. The meaning of this bit[29].
  0: Instruction cache invalidation to the point of unification
     is required for instruction to data coherence.
  1: Instruction cache cleaning to the point of unification is
      not required for instruction to data coherence.

CTR_EL0.IDC: Data cache clean requirements for instruction to data
 coherence. The meaning of this bit[28].
  0: Data cache clean to the point of unification is required for
     instruction to data coherence, unless CLIDR_EL1.LoC == 0b000
     or (CLIDR_EL1.LoUIS == 0b000 && CLIDR_EL1.LoUU == 0b000).
  1: Data cache clean to the point of unification is not required
     for instruction to data coherence.

Co-authored-by: Philip Elcan <pelcan@codeaurora.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:57:57 +00:00
Ard Biesheuvel
ca79acca27 arm64/kernel: enable A53 erratum #8434319 handling at runtime
Omit patching of ADRP instruction at module load time if the current
CPUs are not susceptible to the erratum.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: Drop duplicate initialisation of .def_scope field]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:23:09 +00:00
Ard Biesheuvel
e8002e02ab arm64/errata: add REVIDR handling to framework
In some cases, core variants that are affected by a certain erratum
also exist in versions that have the erratum fixed, and this fact is
recorded in a dedicated bit in system register REVIDR_EL1.

Since the architecture does not require that a certain bit retains
its meaning across different variants of the same model, each such
REVIDR bit is tightly coupled to a certain revision/variant value,
and so we need a list of revidr_mask/midr pairs to carry this
information.

So add the struct member and the associated macros and handling to
allow REVIDR fixes to be taken into account.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:23:08 +00:00
Ard Biesheuvel
a257e02579 arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419
Working around Cortex-A53 erratum #843419 involves special handling of
ADRP instructions that end up in the last two instruction slots of a
4k page, or whose output register gets overwritten without having been
read. (Note that the latter instruction sequence is never emitted by
a properly functioning compiler, which is why it is disregarded by the
handling of the same erratum in the bfd.ld linker which we rely on for
the core kernel)

Normally, this gets taken care of by the linker, which can spot such
sequences at final link time, and insert a veneer if the ADRP ends up
at a vulnerable offset. However, linux kernel modules are partially
linked ELF objects, and so there is no 'final link time' other than the
runtime loading of the module, at which time all the static relocations
are resolved.

For this reason, we have implemented the #843419 workaround for modules
by avoiding ADRP instructions altogether, by using the large C model,
and by passing -mpc-relative-literal-loads to recent versions of GCC
that may emit adrp/ldr pairs to perform literal loads. However, this
workaround forces us to keep literal data mixed with the instructions
in the executable .text segment, and literal data may inadvertently
turn into an exploitable speculative gadget depending on the relative
offsets of arbitrary symbols.

So let's reimplement this workaround in a way that allows us to switch
back to the small C model, and to drop the -mpc-relative-literal-loads
GCC switch, by patching affected ADRP instructions at runtime:
- ADRP instructions that do not appear at 4k relative offset 0xff8 or
  0xffc are ignored
- ADRP instructions that are within 1 MB of their target symbol are
  converted into ADR instructions
- remaining ADRP instructions are redirected via a veneer that performs
  the load using an unaffected movn/movk sequence.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: tidied up ADRP -> ADR instruction patching.]
[will: use ULL suffix for 64-bit immediate]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:21:53 +00:00
Ard Biesheuvel
7e611e7dbb efi/arm64: Check whether x18 is preserved by runtime services calls
Whether or not we will ever decide to start using x18 as a platform
register in Linux is uncertain, but by that time, we will need to
ensure that UEFI runtime services calls don't corrupt it.

So let's start issuing warnings now for this, and increase the
likelihood that these firmware images have all been replaced by that time.

This has been fixed on the EDK2 side in commit:

  6d73863b5464 ("BaseTools/tools_def AARCH64: mark register x18 as reserved")

dated July 13, 2017.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180308080020.22828-6-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 08:58:22 +01:00
Will Deacon
e03e61c317 arm64: kaslr: Set TCR_EL1.NFD1 when CONFIG_RANDOMIZE_BASE=y
TCR_EL1.NFD1 was allocated by SVE and ensures that fault-surpressing SVE
memory accesses (e.g. speculative accesses from a first-fault gather load)
which translate via TTBR1_EL1 result in a translation fault if they
miss in the TLB when executed from EL0. This mitigates some timing attacks
against KASLR, where the kernel address space could otherwise be probed
efficiently using the FFR in conjunction with suppressed faults on SVE
loads.

Cc: Dave Martin <Dave.Martin@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:34 +00:00
Catalin Marinas
1f85b42a69 arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)
Commit 9730348075 ("arm64: Increase the max granular size") increased
the cache line size to 128 to match Cavium ThunderX, apparently for some
performance benefit which could not be confirmed. This change, however,
has an impact on the network packets allocation in certain
circumstances, requiring slightly over a 4K page with a significant
performance degradation.

This patch reverts L1_CACHE_SHIFT back to 6 (64-byte cache line) while
keeping ARCH_DMA_MINALIGN at 128. The cache_line_size() function was
changed to default to ARCH_DMA_MINALIGN in the absence of a meaningful
CTR_EL0.CWG bit field.

In addition, if a system with ARCH_DMA_MINALIGN < CTR_EL0.CWG is
detected, the kernel will force swiotlb bounce buffering for all
non-coherent devices since DMA cache maintenance on sub-CWG ranges is
not safe, leading to data corruption.

Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Cc: Timur Tabi <timur@codeaurora.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:32 +00:00
Will Deacon
a26731d9d1 arm64: Move show_unhandled_signals_ratelimited into traps.c
show_unhandled_signals_ratelimited is only called in traps.c, so move it
out of its macro in the dreaded system_misc.h and into a static function
in traps.c

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:31 +00:00
Will Deacon
a1ece8216c arm64: Introduce arm64_force_sig_info and hook up in arm64_notify_die
In preparation for consolidating our handling of printing unhandled
signals, introduce a wrapper around force_sig_info which can act as
the canonical place for dealing with show_unhandled_signals.

Initially, we just hook this up to arm64_notify_die.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:23 +00:00
Will Deacon
2c9120f3a8 arm64: signal: Make force_signal_inject more robust
force_signal_inject is a little flakey:

  * It only knows about SIGILL and SIGSEGV, so can potentially deliver
    other signals based on a partially initialised siginfo_t

  * It sets si_addr to point at the PC for SIGSEGV

  * It always operates on current, so doesn't need the regs argument

This patch fixes these issues by always assigning the si_addr field to
the address parameter of the function and updates the callers (including
those that indirectly call via arm64_notify_segfault) accordingly.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:22 +00:00
Pratyush Anand
9f416319f4 arm64: fix unwind_frame() for filtered out fn for function graph tracing
do_task_stat() calls get_wchan(), which further does unwind_frame().
unwind_frame() restores frame->pc to original value in case function
graph tracer has modified a return address (LR) in a stack frame to hook
a function return. However, if function graph tracer has hit a filtered
function, then we can't unwind it as ftrace_push_return_trace() has
biased the index(frame->graph) with a 'huge negative'
offset(-FTRACE_NOTRACE_DEPTH).

Moreover, arm64 stack walker defines index(frame->graph) as unsigned
int, which can not compare a -ve number.

Similar problem we can have with calling of walk_stackframe() from
save_stack_trace_tsk() or dump_backtrace().

This patch fixes unwind_frame() to test the index for -ve value and
restore index accordingly before we can restore frame->pc.

Reproducer:

cd /sys/kernel/debug/tracing/
echo schedule > set_graph_notrace
echo 1 > options/display-graph
echo wakeup > current_tracer
ps -ef | grep -i agent

Above commands result in:
Unable to handle kernel paging request at virtual address ffff801bd3d1e000
pgd = ffff8003cbe97c00
[ffff801bd3d1e000] *pgd=0000000000000000, *pud=0000000000000000
Internal error: Oops: 96000006 [#1] SMP
[...]
CPU: 5 PID: 11696 Comm: ps Not tainted 4.11.0+ #33
[...]
task: ffff8003c21ba000 task.stack: ffff8003cc6c0000
PC is at unwind_frame+0x12c/0x180
LR is at get_wchan+0xd4/0x134
pc : [<ffff00000808892c>] lr : [<ffff0000080860b8>] pstate: 60000145
sp : ffff8003cc6c3ab0
x29: ffff8003cc6c3ab0 x28: 0000000000000001
x27: 0000000000000026 x26: 0000000000000026
x25: 00000000000012d8 x24: 0000000000000000
x23: ffff8003c1c04000 x22: ffff000008c83000
x21: ffff8003c1c00000 x20: 000000000000000f
x19: ffff8003c1bc0000 x18: 0000fffffc593690
x17: 0000000000000000 x16: 0000000000000001
x15: 0000b855670e2b60 x14: 0003e97f22cf1d0f
x13: 0000000000000001 x12: 0000000000000000
x11: 00000000e8f4883e x10: 0000000154f47ec8
x9 : 0000000070f367c0 x8 : 0000000000000000
x7 : 00008003f7290000 x6 : 0000000000000018
x5 : 0000000000000000 x4 : ffff8003c1c03cb0
x3 : ffff8003c1c03ca0 x2 : 00000017ffe80000
x1 : ffff8003cc6c3af8 x0 : ffff8003d3e9e000

Process ps (pid: 11696, stack limit = 0xffff8003cc6c0000)
Stack: (0xffff8003cc6c3ab0 to 0xffff8003cc6c4000)
[...]
[<ffff00000808892c>] unwind_frame+0x12c/0x180
[<ffff000008305008>] do_task_stat+0x864/0x870
[<ffff000008305c44>] proc_tgid_stat+0x3c/0x48
[<ffff0000082fde0c>] proc_single_show+0x5c/0xb8
[<ffff0000082b27e0>] seq_read+0x160/0x414
[<ffff000008289e6c>] __vfs_read+0x58/0x164
[<ffff00000828b164>] vfs_read+0x88/0x144
[<ffff00000828c2e8>] SyS_read+0x60/0xc0
[<ffff0000080834a0>] __sys_trace_return+0x0/0x4

Fixes: 20380bb390 (arm64: ftrace: fix a stack tracer's output under function graph tracer)
Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
[catalin.marinas@arm.com: replace WARN_ON with WARN_ON_ONCE]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-23 13:46:38 +00:00
Robin Murphy
9085b34d0e arm64: uaccess: Formalise types for access_ok()
In converting __range_ok() into a static inline, I inadvertently made
it more type-safe, but without considering the ordering of the relevant
conversions. This leads to quite a lot of Sparse noise about the fact
that we use __chk_user_ptr() after addr has already been converted from
a user pointer to an unsigned long.

Rather than just adding another cast for the sake of shutting Sparse up,
it seems reasonable to rework the types to make logical sense (although
the resulting codegen for __range_ok() remains identical). The only
callers this affects directly are our compat traps where the inferred
"user-pointer-ness" of a register value now warrants explicit casting.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-19 13:59:58 +00:00
Bhupesh Sharma
04c4927359 arm64: Fix compilation error while accessing MPIDR_HWID_BITMASK from .S files
Since commit e1a50de378 (arm64: cputype: Silence Sparse warnings),
compilation of arm64 architecture is broken with the following error
messages:

  AR      arch/arm64/kernel/built-in.o
  arch/arm64/kernel/head.S: Assembler messages:
  arch/arm64/kernel/head.S:677: Error: found 'L', expected: ')'
  arch/arm64/kernel/head.S:677: Error: found 'L', expected: ')'
  arch/arm64/kernel/head.S:677: Error: found 'L', expected: ')'
  arch/arm64/kernel/head.S:677: Error: junk at end of line, first
  unrecognized character is `L'
  arch/arm64/kernel/head.S:677: Error: unexpected characters following
  instruction at operand 2 -- `movz x1,:abs_g1_s:0xff00ffffffUL'
  arch/arm64/kernel/head.S:677: Error: unexpected characters following
  instruction at operand 2 -- `movk x1,:abs_g0_nc:0xff00ffffffUL'

This patch fixes the same by using the UL() macro correctly for
assigning the MPIDR_HWID_BITMASK macro value.

Fixes: e1a50de378 ("arm64: cputype: Silence Sparse warnings")
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-19 12:13:29 +00:00
Robin Murphy
e1a50de378 arm64: cputype: Silence Sparse warnings
Sparse makes a fair bit of noise about our MPIDR mask being implicitly
long - let's explicitly describe it as such rather than just relying on
the value forcing automatic promotion.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-17 08:37:05 +00:00
Will Deacon
20a004e7b0 arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables
In many cases, page tables can be accessed concurrently by either another
CPU (due to things like fast gup) or by the hardware page table walker
itself, which may set access/dirty bits. In such cases, it is important
to use READ_ONCE/WRITE_ONCE when accessing page table entries so that
entries cannot be torn, merged or subject to apparent loss of coherence
due to compiler transformations.

Whilst there are some scenarios where this cannot happen (e.g. pinned
kernel mappings for the linear region), the overhead of using READ_ONCE
/WRITE_ONCE everywhere is minimal and makes the code an awful lot easier
to reason about. This patch consistently uses these macros in the arch
code, as well as explicitly namespacing pointers to page table entries
from the entries themselves by using adopting a 'p' suffix for the former
(as is sometimes used elsewhere in the kernel source).

Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Tested-by: Richard Ruigrok <rruigrok@codeaurora.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-16 18:13:57 +00:00
Linus Torvalds
15303ba5d1 KVM changes for 4.16
ARM:
 - Include icache invalidation optimizations, improving VM startup time
 
 - Support for forwarded level-triggered interrupts, improving
   performance for timers and passthrough platform devices
 
 - A small fix for power-management notifiers, and some cosmetic changes
 
 PPC:
 - Add MMIO emulation for vector loads and stores
 
 - Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
   requiring the complex thread synchronization of older CPU versions
 
 - Improve the handling of escalation interrupts with the XIVE interrupt
   controller
 
 - Support decrement register migration
 
 - Various cleanups and bugfixes.
 
 s390:
 - Cornelia Huck passed maintainership to Janosch Frank
 
 - Exitless interrupts for emulated devices
 
 - Cleanup of cpuflag handling
 
 - kvm_stat counter improvements
 
 - VSIE improvements
 
 - mm cleanup
 
 x86:
 - Hypervisor part of SEV
 
 - UMIP, RDPID, and MSR_SMI_COUNT emulation
 
 - Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
 
 - Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
   features
 
 - Show vcpu id in its anonymous inode name
 
 - Many fixes and cleanups
 
 - Per-VCPU MSR bitmaps (already merged through x86/pti branch)
 
 - Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
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Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "ARM:

   - icache invalidation optimizations, improving VM startup time

   - support for forwarded level-triggered interrupts, improving
     performance for timers and passthrough platform devices

   - a small fix for power-management notifiers, and some cosmetic
     changes

  PPC:

   - add MMIO emulation for vector loads and stores

   - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
     requiring the complex thread synchronization of older CPU versions

   - improve the handling of escalation interrupts with the XIVE
     interrupt controller

   - support decrement register migration

   - various cleanups and bugfixes.

  s390:

   - Cornelia Huck passed maintainership to Janosch Frank

   - exitless interrupts for emulated devices

   - cleanup of cpuflag handling

   - kvm_stat counter improvements

   - VSIE improvements

   - mm cleanup

  x86:

   - hypervisor part of SEV

   - UMIP, RDPID, and MSR_SMI_COUNT emulation

   - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit

   - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
     AVX512 features

   - show vcpu id in its anonymous inode name

   - many fixes and cleanups

   - per-VCPU MSR bitmaps (already merged through x86/pti branch)

   - stable KVM clock when nesting on Hyper-V (merged through
     x86/hyperv)"

* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
  KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
  KVM: PPC: Book3S HV: Branch inside feature section
  KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
  KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
  KVM: PPC: Book3S PR: Fix broken select due to misspelling
  KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
  KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
  KVM: PPC: Book3S HV: Drop locks before reading guest memory
  kvm: x86: remove efer_reload entry in kvm_vcpu_stat
  KVM: x86: AMD Processor Topology Information
  x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
  kvm: embed vcpu id to dentry of vcpu anon inode
  kvm: Map PFN-type memory regions as writable (if possible)
  x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
  KVM: arm/arm64: Fixup userspace irqchip static key optimization
  KVM: arm/arm64: Fix userspace_irqchip_in_use counting
  KVM: arm/arm64: Fix incorrect timer_is_pending logic
  MAINTAINERS: update KVM/s390 maintainers
  MAINTAINERS: add Halil as additional vfio-ccw maintainer
  MAINTAINERS: add David as a reviewer for KVM/s390
  ...
2018-02-10 13:16:35 -08:00
Linus Torvalds
c013632192 2nd set of arm64 updates for 4.16:
Spectre v1 mitigation:
 - back-end version of array_index_mask_nospec()
 - masking of the syscall number to restrict speculation through the
   syscall table
 - masking of __user pointers prior to deference in uaccess routines
 
 Spectre v2 mitigation update:
 - using the new firmware SMC calling convention specification update
 - removing the current PSCI GET_VERSION firmware call mitigation as
   vendors are deploying new SMCCC-capable firmware
 - additional branch predictor hardening for synchronous exceptions and
   interrupts while in user mode
 
 Meltdown v3 mitigation update for Cavium Thunder X: unaffected but
 hardware erratum gets in the way. The kernel now starts with the page
 tables mapped as global and switches to non-global if kpti needs to be
 enabled.
 
 Other:
 - Theoretical trylock bug fixed
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull more arm64 updates from Catalin Marinas:
 "As I mentioned in the last pull request, there's a second batch of
  security updates for arm64 with mitigations for Spectre/v1 and an
  improved one for Spectre/v2 (via a newly defined firmware interface
  API).

  Spectre v1 mitigation:

   - back-end version of array_index_mask_nospec()

   - masking of the syscall number to restrict speculation through the
     syscall table

   - masking of __user pointers prior to deference in uaccess routines

  Spectre v2 mitigation update:

   - using the new firmware SMC calling convention specification update

   - removing the current PSCI GET_VERSION firmware call mitigation as
     vendors are deploying new SMCCC-capable firmware

   - additional branch predictor hardening for synchronous exceptions
     and interrupts while in user mode

  Meltdown v3 mitigation update:

    - Cavium Thunder X is unaffected but a hardware erratum gets in the
      way. The kernel now starts with the page tables mapped as global
      and switches to non-global if kpti needs to be enabled.

  Other:

   - Theoretical trylock bug fixed"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (38 commits)
  arm64: Kill PSCI_GET_VERSION as a variant-2 workaround
  arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support
  arm/arm64: smccc: Implement SMCCC v1.1 inline primitive
  arm/arm64: smccc: Make function identifiers an unsigned quantity
  firmware/psci: Expose SMCCC version through psci_ops
  firmware/psci: Expose PSCI conduit
  arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
  arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support
  arm/arm64: KVM: Turn kvm_psci_version into a static inline
  arm/arm64: KVM: Advertise SMCCC v1.1
  arm/arm64: KVM: Implement PSCI 1.0 support
  arm/arm64: KVM: Add smccc accessors to PSCI code
  arm/arm64: KVM: Add PSCI_VERSION helper
  arm/arm64: KVM: Consolidate the PSCI include files
  arm64: KVM: Increment PC after handling an SMC trap
  arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  arm64: entry: Apply BP hardening for suspicious interrupts from EL0
  arm64: entry: Apply BP hardening for high-priority synchronous exceptions
  arm64: futex: Mask __user pointers prior to dereference
  ...
2018-02-08 10:44:25 -08:00
Andrey Konovalov
917538e212 kasan: clean up KASAN_SHADOW_SCALE_SHIFT usage
Right now the fact that KASAN uses a single shadow byte for 8 bytes of
memory is scattered all over the code.

This change defines KASAN_SHADOW_SCALE_SHIFT early in asm include files
and makes use of this constant where necessary.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/34937ca3b90736eaad91b568edf5684091f662e3.1515775666.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Marc Zyngier
6167ec5c91 arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support
A new feature of SMCCC 1.1 is that it offers firmware-based CPU
workarounds. In particular, SMCCC_ARCH_WORKAROUND_1 provides
BP hardening for CVE-2017-5715.

If the host has some mitigation for this issue, report that
we deal with it using SMCCC_ARCH_WORKAROUND_1, as we apply the
host workaround on every guest exit.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:54:05 +00:00
Marc Zyngier
1a2fb94e6a arm/arm64: KVM: Consolidate the PSCI include files
As we're about to update the PSCI support, and because I'm lazy,
let's move the PSCI include file to include/kvm so that both
ARM architectures can find it.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:53:54 +00:00