With KASAN enabled the kernel has two different memset() functions, one
with KASAN checks (memset) and one without (__memset). KASAN uses some
macro tricks to use the proper version where required. For example
memset() calls in mm/slub.c are without KASAN checks, since they operate
on poisoned slab object metadata.
The issue is that clang emits memset() calls even when there is no
memset() in the source code. They get linked with improper memset()
implementation and the kernel fails to boot due to a huge amount of KASAN
reports during early boot stages.
The solution is to add -fno-builtin flag for files with KASAN_SANITIZE :=
n marker.
Link: http://lkml.kernel.org/r/8ffecfffe04088c52c42b92739c2bd8a0bcb3f5e.1516384594.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@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>
Currently, GCC disables -Wunused-const-variable, but not
-Wunused-variable, so warns unused variables if they are
non-constant.
While, Clang does not warn unused variables at all regardless of
the const qualifier because -Wno-unused-const-variable is implied
by the stronger option -Wno-unused-variable.
Disable -Wunused-const-variable instead of -Wunused-variable so that
GCC and Clang work in the same way.
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Every flow_offload entry is added into the table twice. Because of this,
rhashtable_free_and_destroy can't be used, since it would call kfree for
each flow_offload object twice.
This patch cleans up the flowtable via nf_flow_table_iterate() to
schedule removal of entries by setting on the dying bit, then there is
an explicitly invocation of the garbage collector to release resources.
Based on patch from Felix Fietkau.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Move the flowtable cleanup routines to nf_flow_table and expose the
nf_flow_table_cleanup() helper function.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
rateest_hash is supposed to be protected by xt_rateest_mutex,
and, as suggested by Eric, lookup and insert should be atomic,
so we should acquire the xt_rateest_mutex once for both.
So introduce a non-locking helper for internal use and keep the
locking one for external.
Reported-by: <syzbot+5cb189720978275e4c75@syzkaller.appspotmail.com>
Fixes: 5859034d7e ("[NETFILTER]: x_tables: add RATEEST target")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Based on the feedback provided:
- Uniformly use lowercase k in "Linux kernel"
- Give a one-sentence explanation of what subkeys are
- Explain what signed commits might be useful for even if upstream
developers do not use them for much of anything
- Admonish to set up gpg-agent if signed commits are turned on in
git config
- Fix a typo reported by Luc Van Oostenryck
Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
New model support added for Dell, Ideapad, Acer, Asus, Thinkpad, and GPD
laptops. Improvements to the common intel-vbtn driver, including tablet
mode, rotate, and front button support. Intel CPU support added for
Cannonlake and platform support for Dollar Cove power button.
Overhaul of the mellanox platform driver, creating a new
platform/mellanox directory for the newly multi-architecture regmap
interface.
Significant Intel PMC update with CannonLake support, Coffeelake update,
CPUID enumeration, module support, new read64 API, refactoring and
cleanups.
Revert the apple-gmux iGP IO lock, addressing reported issues with
non-binary drivers, leaving Nvidia binary driver users to comment out
conflicting code.
Miscellaneous fixes and cleanups.
Previously merged during the 4.15-rc cycle:
- e20a8e771d platform/x86: dell-laptop: Fix keyboard max lighting for Dell Latitude E6410
- 9cd5cf3710 platform/x86: asus-wireless: send an EV_SYN/SYN_REPORT between state changes
- 91c73e8092 platform/x86: dell-wmi: check for kmalloc() errors
- 9a1a625918 platform/x86: wmi: Call acpi_wmi_init() later
The following is an automated git shortlog grouped by driver:
ACPI / LPIT:
- Export lpit_read_residency_count_address()
Input:
- add KEY_ROTATE_LOCK_TOGGLE
MAINTAINERS:
- Update tree for platform-drivers-x86
x86/cpu:
- Add Cannonlake to Intel family
acer-wireless:
- Add Acer Wireless Radio Control driver
intel_chtdc_ti_pwrbtn:
- Add support for Dollar Cove TI power button
GPD pocket fan:
- Add driver for GPD pocket custom fan controller
- Stop work on suspend
- Use a min-speed of 2 while charging
- Set speed to max on get_temp failure
apple-gmux:
- Revert: lock iGP IO to protect from vgaarb changes
alienware-wmi:
- lightbar LED support for Dell Inspiron 5675
asus-nb-wmi:
- Support ALS on the Zenbook UX430UQ
dell-laptop:
- Allocate buffer on heap rather than globally
- Add 2-in-1 devices to the DMI whitelist
- Filter out spurious keyboard backlight change events
- make some local functions static
- Use bool in struct quirk_entry for true/false fields
dell-smbios:
- Correct notation for filtering
dell-wmi:
- Add an event created by Dell Latitude 5495
Kconfig
- have ACPI_CMPC use depends instead of select for INPUT
ideapad-laptop:
- Add Y720-15IKB to no_hw_rfkill
- add lenovo RESCUER R720-15IKBN to no_hw_rfkill_list
- Use __func__ instead of write_ec_cmd in pr_err
- Remove unnecessary else
intel-hid:
- add a DMI quirk to support Wacom MobileStudio Pro
intel-vbtn:
- Replace License by SDPX identifier
- Remove redundant inclusions
- Support tablet mode switch
- Simplify autorelease logic
- support panel front button
- support KEY_ROTATE_LOCK_TOGGLE
- Support separate press/release events
- support SW_TABLET_MODE
intel_int0002_vgpio:
- Remove IRQF_NO_THREAD irq flag
intel_pmc_core:
- Special case for Coffeelake
- Add CannonLake PCH support
- Read base address from LPIT
- Remove unused header file
- Convert to ICPU macro
- Substitute PCI with CPUID enumeration
- Refactor debugfs entries
- Update Kconfig
- Fix file permission warnings
- Change driver to a module
- Fix kernel doc for pmc_dev
- Remove unused variable
- Remove unused EXPORTED API
intel_pmc_ipc:
- Add read64 API
intel_telemetry:
- Remove redundancies
- Improve S0ix logs
- Fix suspend stats
mlx-platform:
- Fix an ERR_PTR vs NULL issue
- Add hotplug device unregister to error path
- fix module aliases
- Add IO access verification callbacks
- Document pdev_hotplug field
- Allow compilation for 32 bit arch
platform/mellanox:
- mlxreg-hotplug: Add check for negative adapter number
- mlxreg-hotplug: Enable building for ARM
- mlxreg-hotplug: Modify to use a regmap interface
- Group create/destroy with attribute functions
- Rename i2c bus to nr
- mlxreg-hotplug: Remove unused wait.h include
- Move Mellanox platform hotplug driver to platform/mellanox
pmc_atom:
- introduce DEFINE_SHOW_ATTRIBUTE() macro
samsung-laptop:
- Grammar s/are can/can/
silead_dmi:
- Add Teclast X3 Plus tablet support
- Add entry for newer BIOS for Trekstor Surftab 7.0
- Add entry for the Teclast X98 Plus II
- Add entry for the Trekstor Primebook C13
- Add entry for the Chuwi Vi8 tablet
- add entry for Chuwi Hi8 tablet
- Add support for the Onda oBook 20 Plus tablet
- Add touchscreen info for SurfTab twin 10.1
thinkpad_acpi:
- suppress warning about palm detection
- Accept flat mode for type 4 multi mode status
-----BEGIN PGP SIGNATURE-----
iQEcBAABAgAGBQJaegMmAAoJEKbMaAwKp364TvUH/3D9qNtsbXpZuc3ZMNHjIysU
hdW6hOVfBN0Rk049mjw7nWv/udhWZ/6ChJDlXHX0ZugtNGnRnzbdtWGg4y38pDF1
LRuKjWfDeyMeJ11itD2xcxEaE6YsseWCKGZJ5D3T+sN4+1jgS4RLAa9cUJMl8QAo
xZsT1MKpmGuj5eTLf5GgOVL2yfMZhZHabt3kGRY0eQqNqZBgpJw/GQNI1l6v4nAH
MHPA7Gtj4HXHK8jGviZXpD9tg/iwahiUjGugG4HcxbMcpJ96a8CGyeaXmq2FlfNC
/PpmVvhVVqzLuXKWAI+DZFLAiwIvPpxzVfOKF2Lty5Rejxf7pdmHq7aCNcALys0=
=cKm9
-----END PGP SIGNATURE-----
Merge tag 'platform-drivers-x86-v4.16-1' of git://git.infradead.org/linux-platform-drivers-x86
Pull x86 platform-driver updates from Darren Hart:
"New model support added for Dell, Ideapad, Acer, Asus, Thinkpad, and
GPD laptops. Improvements to the common intel-vbtn driver, including
tablet mode, rotate, and front button support. Intel CPU support added
for Cannonlake and platform support for Dollar Cove power button.
Overhaul of the mellanox platform driver, creating a new
platform/mellanox directory for the newly multi-architecture regmap
interface.
Significant Intel PMC update with CannonLake support, Coffeelake
update, CPUID enumeration, module support, new read64 API, refactoring
and cleanups.
Revert the apple-gmux iGP IO lock, addressing reported issues with
non-binary drivers, leaving Nvidia binary driver users to comment out
conflicting code.
Miscellaneous fixes and cleanups"
* tag 'platform-drivers-x86-v4.16-1' of git://git.infradead.org/linux-platform-drivers-x86: (81 commits)
platform/x86: mlx-platform: Fix an ERR_PTR vs NULL issue
platform/x86: intel_pmc_core: Special case for Coffeelake
platform/x86: intel_pmc_core: Add CannonLake PCH support
x86/cpu: Add Cannonlake to Intel family
platform/x86: intel_pmc_core: Read base address from LPIT
ACPI / LPIT: Export lpit_read_residency_count_address()
platform/x86: intel-vbtn: Replace License by SDPX identifier
platform/x86: intel-vbtn: Remove redundant inclusions
platform/x86: intel-vbtn: Support tablet mode switch
platform/x86: dell-laptop: Allocate buffer on heap rather than globally
platform/x86: intel_pmc_core: Remove unused header file
platform/x86: mlx-platform: Add hotplug device unregister to error path
platform/x86: mlx-platform: fix module aliases
platform/mellanox: mlxreg-hotplug: Add check for negative adapter number
platform/x86: mlx-platform: Add IO access verification callbacks
platform/x86: mlx-platform: Document pdev_hotplug field
platform/x86: mlx-platform: Allow compilation for 32 bit arch
platform/mellanox: mlxreg-hotplug: Enable building for ARM
platform/mellanox: mlxreg-hotplug: Modify to use a regmap interface
platform/mellanox: Group create/destroy with attribute functions
...
Pull thermal management updates from Zhang Rui:
- fix a race condition issue in power allocator governor (Yi Zeng).
- add support for AP806 and CP110 in armada thermal driver, together
with several improvements (Baruch Siach, Miquel Raynal)
- add support for r8z7743 in rcar thermal driver (Biju Das)
- convert thermal core to use new hwmon API to avoid warning (Fabio
Estevam)
- small fixes and cleanups in thermal core and x86_pkg_thermal,
int3400_thermal, hisi_thermal, mtk_thermal and imx_thermal drivers
(Pravin Shedge, Geert Uytterhoeven, Alexey Khoroshilov, Brian Bian,
Matthias Brugger, Nicolin Chen, Uwe Kleine-König)
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (25 commits)
thermal: thermal_hwmon: Convert to hwmon_device_register_with_info()
thermal/x86 pkg temp: Remove debugfs_create_u32() casts
thermal: int3400_thermal: fix error handling in int3400_thermal_probe()
thermal/drivers/hisi: Remove bogus const from function return type
thermal: armada: Give meaningful names to the thermal zones
thermal: armada: Wait sensors validity before exiting the init callback
thermal: armada: Change sensors trim default value
thermal: armada: Update Kconfig and module description
thermal: armada: Add support for Armada CP110
thermal: armada: Add support for Armada AP806
thermal: armada: Use real status register name
thermal: armada: Clarify control registers accesses
thermal: armada: Simplify the check of the validity bit
thermal: armada: Use msleep for long delays
dt-bindings: thermal: Describe Armada AP806 and CP110
dt-bindings: thermal: rcar: Add device tree support for r8a7743
thermal: mtk: Cleanup unused defines
thermal: imx: update to new formula according to NXP AN5215
thermal: imx: use consistent style to write temperatures
thermal: imx: improve comments describing algorithm for temp calculation
...
Now that we've standardised on SMCCC v1.1 to perform the branch
prediction invalidation, let's drop the previous band-aid.
If vendors haven't updated their firmware to do SMCCC 1.1, they
haven't updated PSCI either, so we don't loose anything.
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>
Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1.
It is lovely. Really.
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>
One of the major improvement of SMCCC v1.1 is that it only clobbers
the first 4 registers, both on 32 and 64bit. This means that it
becomes very easy to provide an inline version of the SMC call
primitive, and avoid performing a function call to stash the
registers that would otherwise be clobbered by SMCCC v1.0.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
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>
Function identifiers are a 32bit, unsigned quantity. But we never
tell so to the compiler, resulting in the following:
4ac: b26187e0 mov x0, #0xffffffff80000001
We thus rely on the firmware narrowing it for us, which is not
always a reasonable expectation.
Cc: stable@vger.kernel.org
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
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>
Since PSCI 1.0 allows the SMCCC version to be (indirectly) probed,
let's do that at boot time, and expose the version of the calling
convention as part of the psci_ops structure.
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
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>
In order to call into the firmware to apply workarounds, it is
useful to find out whether we're using HVC or SMC. Let's expose
this through the psci_ops.
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
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>
We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible.
So let's intercept it as early as we can by testing for the
function call number as soon as we've identified a HVC call
coming from the guest.
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>
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>
We're about to need kvm_psci_version in HYP too. So let's turn it
into a static inline, and pass the kvm structure as a second
parameter (so that HYP can do a kern_hyp_va on it).
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>
The new SMC Calling Convention (v1.1) allows for a reduced overhead
when calling into the firmware, and provides a new feature discovery
mechanism.
Make it visible to KVM guests.
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>
PSCI 1.0 can be trivially implemented by providing the FEATURES
call on top of PSCI 0.2 and returning 1.0 as the PSCI version.
We happily ignore everything else, as they are either optional or
are clarifications that do not require any additional change.
PSCI 1.0 is now the default until we decide to add a userspace
selection API.
Reviewed-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>
Instead of open coding the accesses to the various registers,
let's add explicit SMCCC accessors.
Reviewed-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>
As we're about to trigger a PSCI version explosion, it doesn't
hurt to introduce a PSCI_VERSION helper that is going to be
used everywhere.
Reviewed-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>
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>
When handling an SMC trap, the "preferred return address" is set
to that of the SMC, and not the next PC (which is a departure from
the behaviour of an SMC that isn't trapped).
Increment PC in the handler, as the guest is otherwise forever
stuck...
Cc: stable@vger.kernel.org
Fixes: acfb3b883f ("arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls")
Reviewed-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>
KVM doesn't follow the SMCCC when it comes to unimplemented calls,
and inject an UNDEF instead of returning an error. Since firmware
calls are now used for security mitigation, they are becoming more
common, and the undef is counter productive.
Instead, let's follow the SMCCC which states that -1 must be returned
to the caller when getting an unknown function number.
Cc: <stable@vger.kernel.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>
KVM doesn't follow the SMCCC when it comes to unimplemented calls,
and inject an UNDEF instead of returning an error. Since firmware
calls are now used for security mitigation, they are becoming more
common, and the undef is counter productive.
Instead, let's follow the SMCCC which states that -1 must be returned
to the caller when getting an unknown function number.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
It is possible to take an IRQ from EL0 following a branch to a kernel
address in such a way that the IRQ is prioritised over the instruction
abort. Whilst an attacker would need to get the stars to align here,
it might be sufficient with enough calibration so perform BP hardening
in the rare case that we see a kernel address in the ELR when handling
an IRQ from EL0.
Reported-by: Dan Hettena <dhettena@nvidia.com>
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>
Software-step and PC alignment fault exceptions have higher priority than
instruction abort exceptions, so apply the BP hardening hooks there too
if the user PC appears to reside in kernel space.
Reported-by: Dan Hettena <dhettena@nvidia.com>
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>
The arm64 futex code has some explicit dereferencing of user pointers
where performing atomic operations in response to a futex command. This
patch uses masking to limit any speculative futex operations to within
the user address space.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Like we've done for get_user and put_user, ensure that user pointers
are masked before invoking the underlying __arch_{clear,copy_*}_user
operations.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
access_ok isn't an expensive operation once the addr_limit for the current
thread has been loaded into the cache. Given that the initial access_ok
check preceding a sequence of __{get,put}_user operations will take
the brunt of the miss, we can make the __* variants identical to the
full-fat versions, which brings with it the benefits of address masking.
The likely cost in these sequences will be from toggling PAN/UAO, which
we can address later by implementing the *_unsafe versions.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
A mispredicted conditional call to set_fs could result in the wrong
addr_limit being forwarded under speculation to a subsequent access_ok
check, potentially forming part of a spectre-v1 attack using uaccess
routines.
This patch prevents this forwarding from taking place, but putting heavy
barriers in set_fs after writing the addr_limit.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In a similar manner to array_index_mask_nospec, this patch introduces an
assembly macro (mask_nospec64) which can be used to bound a value under
speculation. This macro is then used to ensure that the indirect branch
through the syscall table is bounded under speculation, with out-of-range
addresses speculating as calls to sys_io_setup (0).
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Similarly to x86, mitigate speculation past an access_ok() check by
masking the pointer against the address limit before use.
Even if we don't expect speculative writes per se, it is plausible that
a CPU may still speculate at least as far as fetching a cache line for
writing, hence we also harden put_user() and clear_user() for peace of
mind.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently, USER_DS represents an exclusive limit while KERNEL_DS is
inclusive. In order to do some clever trickery for speculation-safe
masking, we need them both to behave equivalently - there aren't enough
bits to make KERNEL_DS exclusive, so we have precisely one option. This
also happens to correct a longstanding false negative for a range
ending on the very top byte of kernel memory.
Mark Rutland points out that we've actually got the semantics of
addresses vs. segments muddled up in most of the places we need to
amend, so shuffle the {USER,KERNEL}_DS definitions around such that we
can correct those properly instead of just pasting "-1"s everywhere.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Provide an optimised, assembly implementation of array_index_mask_nospec()
for arm64 so that the compiler is not in a position to transform the code
in ways which affect its ability to inhibit speculation (e.g. by introducing
conditional branches).
This is similar to the sequence used by x86, modulo architectural differences
in the carry/borrow flags.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
For CPUs capable of data value prediction, CSDB waits for any outstanding
predictions to architecturally resolve before allowing speculative execution
to continue. Provide macros to expose it to the arch code.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The identity map is mapped as both writeable and executable by the
SWAPPER_MM_MMUFLAGS and this is relied upon by the kpti code to manage
a synchronisation flag. Update the .pushsection flags to reflect the
actual mapping attributes.
Reported-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>
pte_to_phys lives in assembler.h and takes its destination register as
the first argument. Move phys_to_pte out of head.S to sit with its
counterpart and rejig it to follow the same calling convention.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We don't fully understand the Cavium ThunderX erratum, but it appears
that mapping the kernel as nG can lead to horrible consequences such as
attempting to execute userspace from kernel context. Since kpti isn't
enabled for these CPUs anyway, simplify the comment justifying the lack
of post_ttbr_update_workaround in the exception trampoline.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Since AArch64 assembly instructions take the destination register as
their first operand, do the same thing for the phys_to_ttbr macro.
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cavium ThunderX's erratum 27456 results in a corruption of icache
entries that are loaded from memory that is mapped as non-global
(i.e. ASID-tagged).
As KPTI is based on memory being mapped non-global, let's prevent
it from kicking in if this erratum is detected.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[will: Update comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Defaulting to global mappings for kernel space is generally good for
performance and appears to be necessary for Cavium ThunderX. If we
subsequently decide that we need to enable kpti, then we need to rewrite
our existing page table entries to be non-global. This is fiddly, and
made worse by the possible use of contiguous mappings, which require
a strict break-before-make sequence.
Since the enable callback runs on each online CPU from stop_machine
context, we can have all CPUs enter the idmap, where secondaries can
wait for the primary CPU to rewrite swapper with its MMU off. It's all
fairly horrible, but at least it only runs once.
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
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>
Break-before-make is not needed when transitioning from Global to
Non-Global mappings, provided that the contiguous hint is not being used.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
To allow systems which do not require kpti to continue running with
global kernel mappings (which appears to be a requirement for Cavium
ThunderX due to a CPU erratum), make the use of nG in the kernel page
tables dependent on arm64_kernel_unmapped_at_el0(), which is resolved
at runtime.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The ARM architecture defines the memory locations that are permitted
to be accessed as the result of a speculative instruction fetch from
an exception level for which all stages of translation are disabled.
Specifically, the core is permitted to speculatively fetch from the
4KB region containing the current program counter 4K and next 4K.
When translation is changed from enabled to disabled for the running
exception level (SCTLR_ELn[M] changed from a value of 1 to 0), the
Falkor core may errantly speculatively access memory locations outside
of the 4KB region permitted by the architecture. The errant memory
access may lead to one of the following unexpected behaviors.
1) A System Error Interrupt (SEI) being raised by the Falkor core due
to the errant memory access attempting to access a region of memory
that is protected by a slave-side memory protection unit.
2) Unpredictable device behavior due to a speculative read from device
memory. This behavior may only occur if the instruction cache is
disabled prior to or coincident with translation being changed from
enabled to disabled.
The conditions leading to this erratum will not occur when either of the
following occur:
1) A higher exception level disables translation of a lower exception level
(e.g. EL2 changing SCTLR_EL1[M] from a value of 1 to 0).
2) An exception level disabling its stage-1 translation if its stage-2
translation is enabled (e.g. EL1 changing SCTLR_EL1[M] from a value of 1
to 0 when HCR_EL2[VM] has a value of 1).
To avoid the errant behavior, software must execute an ISB immediately
prior to executing the MSR that will change SCTLR_ELn[M] from 1 to 0.
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
If the spinlock "next" ticket wraps around between the initial LDR
and the cmpxchg in the LSE version of spin_trylock, then we can erroneously
think that we have successfuly acquired the lock because we only check
whether the next ticket return by the cmpxchg is equal to the owner ticket
in our updated lock word.
This patch fixes the issue by performing a full 32-bit check of the lock
word when trying to determine whether or not the CASA instruction updated
memory.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The classic error injection mechanism, should_fail_request() does not
support use cases where more information is required (from the entire
struct bio, for example).
To that end, this patch introduces should_fail_bio(), which calls
should_fail_request() under the hood but provides a convenient
place for kprobes to hook into if they require the entire struct bio.
This patch also replaces some existing calls to should_fail_request()
with should_fail_bio() with no degradation in performance.
Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the idr kernel-doc to its own idr.rst file and add a few
paragraphs about how to use it. Also add some more kernel-doc.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
About 20% of the IDR users in the kernel want the allocated IDs to start
at 1. The implementation currently searches all the way down the left
hand side of the tree, finds no free ID other than ID 0, walks all the
way back up, and then all the way down again. This patch 'rebases' the
ID so we fill the entire radix tree, rather than leave a gap at 0.
Chris Wilson says: "I did the quick hack of allocating index 0 of the
idr and that eradicated idr_get_free() from being at the top of the
profiles for the many-object stress tests. This improvement will be
much appreciated."
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
