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2959 commits

Author SHA1 Message Date
Mark Rutland
ed3768db58 arm64: entry: convert el1_sync to C
This patch converts the EL1 sync entry assembly logic to C code.

Doing this will allow us to make changes in a slightly more
readable way. A case in point is supporting kernel-first RAS.
do_sea() should be called on the CPU that took the fault.

Largely the assembly code is converted to C in a relatively
straightforward manner.

Since all sync sites share a common asm entry point, the ASM_BUG()
instances are no longer required for effective backtraces back to
assembly, and we don't need similar BUG() entries.

The ESR_ELx.EC codes for all (supported) debug exceptions are now
checked in the el1_sync_handler's switch statement, which renders the
check in el1_dbg redundant. This both simplifies the el1_dbg handler,
and makes the EL1 exception handling more robust to
currently-unallocated ESR_ELx.EC encodings.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[split out of a bigger series, added nokprobes, moved prototypes]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:47 +00:00
James Morse
b6e43c0e31 arm64: remove __exception annotations
Since commit 7326749801 ("arm64: unwind: reference pt_regs via embedded
stack frame") arm64 has not used the __exception annotation to dump
the pt_regs during stack tracing. in_exception_text() has no callers.

This annotation is only used to blacklist kprobes, it means the same as
__kprobes.

Section annotations like this require the functions to be grouped
together between the start/end markers, and placed according to
the linker script. For kprobes we also have NOKPROBE_SYMBOL() which
logs the symbol address in a section that kprobes parses and
blacklists at boot.

Using NOKPROBE_SYMBOL() instead lets kprobes publish the list of
blacklisted symbols, and saves us from having an arm64 specific
spelling of __kprobes.

do_debug_exception() already has a NOKPROBE_SYMBOL() annotation.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:38 +00:00
Catalin Marinas
27a22fbdee arm64: Silence clang warning on mismatched value/register sizes
Clang reports a warning on the __tlbi(aside1is, 0) macro expansion since
the value size does not match the register size specified in the inline
asm. Construct the ASID value using the __TLBI_VADDR() macro.

Fixes: 222fc0c850 ("arm64: compat: Workaround Neoverse-N1 #1542419 for compat user-space")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 09:13:21 +00:00
James Morse
222fc0c850 arm64: compat: Workaround Neoverse-N1 #1542419 for compat user-space
Compat user-space is unable to perform ICIMVAU instructions from
user-space. Instead it uses a compat-syscall. Add the workaround for
Neoverse-N1 #1542419 to this code path.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 17:48:44 +01:00
James Morse
ee9d90be9d arm64: Fake the IminLine size on systems affected by Neoverse-N1 #1542419
Systems affected by Neoverse-N1 #1542419 support DIC so do not need to
perform icache maintenance once new instructions are cleaned to the PoU.
For the errata workaround, the kernel hides DIC from user-space, so that
the unnecessary cache maintenance can be trapped by firmware.

To reduce the number of traps, produce a fake IminLine value based on
PAGE_SIZE.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 17:48:44 +01:00
James Morse
05460849c3 arm64: errata: Hide CTR_EL0.DIC on systems affected by Neoverse-N1 #1542419
Cores affected by Neoverse-N1 #1542419 could execute a stale instruction
when a branch is updated to point to freshly generated instructions.

To workaround this issue we need user-space to issue unnecessary
icache maintenance that we can trap. Start by hiding CTR_EL0.DIC.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 17:46:40 +01:00
Yunfeng Ye
bfcef4ab1d arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()
In cases like suspend-to-disk and suspend-to-ram, a large number of CPU
cores need to be shut down. At present, the CPU hotplug operation is
serialised, and the CPU cores can only be shut down one by one. In this
process, if PSCI affinity_info() does not return LEVEL_OFF quickly,
cpu_psci_cpu_kill() needs to wait for 10ms. If hundreds of CPU cores
need to be shut down, it will take a long time.

Normally, there is no need to wait 10ms in cpu_psci_cpu_kill(). So
change the wait interval from 10 ms to max 1 ms and use usleep_range()
instead of msleep() for more accurate timer.

In addition, reducing the time interval will increase the messages
output, so remove the "Retry ..." message, instead, track time and
output to the the sucessful message.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 16:29:11 +01:00
Shaokun Zhang
7db3e57e6a arm64: cpufeature: Fix typos in comment
Fix up one typos: CTR_E0 -> CTR_EL0

Cc: Will Deacon <will@kernel.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 16:19:44 +01:00
Steven Price
e0685fa228 arm64: Retrieve stolen time as paravirtualized guest
Enable paravirtualization features when running under a hypervisor
supporting the PV_TIME_ST hypercall.

For each (v)CPU, we ask the hypervisor for the location of a shared
page which the hypervisor will use to report stolen time to us. We set
pv_time_ops to the stolen time function which simply reads the stolen
value from the shared page for a VCPU. We guarantee single-copy
atomicity using READ_ONCE which means we can also read the stolen
time for another VCPU than the currently running one while it is
potentially being updated by the hypervisor.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:31 +01:00
Steven Price
ce4d5ca2b9 arm/arm64: Make use of the SMCCC 1.1 wrapper
Rather than directly choosing which function to use based on
psci_ops.conduit, use the new arm_smccc_1_1 wrapper instead.

In some cases we still need to do some operations based on the
conduit, but the code duplication is removed.

No functional change.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:30 +01:00
Marc Zyngier
f75e2294a4 arm64: Add ARM64_WORKAROUND_1319367 for all A57 and A72 versions
Rework the EL2 vector hardening that is only selected for A57 and A72
so that the table can also be used for ARM64_WORKAROUND_1319367.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-18 12:36:56 +01:00
Kefeng Wang
a74ec64af2 arm64: Use pr_warn instead of pr_warning
As said in commit f2c2cbcc35 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent <prefix>_warn style. Let's do it.

Link: http://lkml.kernel.org/r/20191018031850.48498-2-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-10-18 10:28:33 +02:00
Will Deacon
777d062e5b Merge branch 'errata/tx2-219' into for-next/fixes
Workaround for Cavium/Marvell ThunderX2 erratum #219.

* errata/tx2-219:
  arm64: Allow CAVIUM_TX2_ERRATUM_219 to be selected
  arm64: Avoid Cavium TX2 erratum 219 when switching TTBR
  arm64: Enable workaround for Cavium TX2 erratum 219 when running SMT
  arm64: KVM: Trap VM ops when ARM64_WORKAROUND_CAVIUM_TX2_219_TVM is set
2019-10-17 13:42:42 -07:00
Will Deacon
597399d0cb arm64: tags: Preserve tags for addresses translated via TTBR1
Sign-extending TTBR1 addresses when converting to an untagged address
breaks the documented POSIX semantics for mlock() in some obscure error
cases where we end up returning -EINVAL instead of -ENOMEM as a direct
result of rewriting the upper address bits.

Rework the untagged_addr() macro to preserve the upper address bits for
TTBR1 addresses and only clear the tag bits for user addresses. This
matches the behaviour of the 'clear_address_tag' assembly macro, so
rename that and align the implementations at the same time so that they
use the same instruction sequences for the tag manipulation.

Link: https://lore.kernel.org/stable/20191014162651.GF19200@arrakis.emea.arm.com/
Reported-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-16 10:11:38 -07:00
Julien Thierry
19c95f261c arm64: entry.S: Do not preempt from IRQ before all cpufeatures are enabled
Preempting from IRQ-return means that the task has its PSTATE saved
on the stack, which will get restored when the task is resumed and does
the actual IRQ return.

However, enabling some CPU features requires modifying the PSTATE. This
means that, if a task was scheduled out during an IRQ-return before all
CPU features are enabled, the task might restore a PSTATE that does not
include the feature enablement changes once scheduled back in.

* Task 1:

PAN == 0 ---|                          |---------------
            |                          |<- return from IRQ, PSTATE.PAN = 0
            | <- IRQ                   |
            +--------+ <- preempt()  +--
                                     ^
                                     |
                                     reschedule Task 1, PSTATE.PAN == 1
* Init:
        --------------------+------------------------
                            ^
                            |
                            enable_cpu_features
                            set PSTATE.PAN on all CPUs

Worse than this, since PSTATE is untouched when task switching is done,
a task missing the new bits in PSTATE might affect another task, if both
do direct calls to schedule() (outside of IRQ/exception contexts).

Fix this by preventing preemption on IRQ-return until features are
enabled on all CPUs.

This way the only PSTATE values that are saved on the stack are from
synchronous exceptions. These are expected to be fatal this early, the
exception is BRK for WARN_ON(), but as this uses do_debug_exception()
which keeps IRQs masked, it shouldn't call schedule().

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
[james: Replaced a really cool hack, with an even simpler static key in C.
 expanded commit message with Julien's cover-letter ascii art]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-16 09:51:43 -07:00
Marc Zyngier
f226650494 arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear
The GICv3 architecture specification is incredibly misleading when it
comes to PMR and the requirement for a DSB. It turns out that this DSB
is only required if the CPU interface sends an Upstream Control
message to the redistributor in order to update the RD's view of PMR.

This message is only sent when ICC_CTLR_EL1.PMHE is set, which isn't
the case in Linux. It can still be set from EL3, so some special care
is required. But the upshot is that in the (hopefuly large) majority
of the cases, we can drop the DSB altogether.

This relies on a new static key being set if the boot CPU has PMHE
set. The drawback is that this static key has to be exported to
modules.

Cc: Will Deacon <will@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-15 12:26:09 +01:00
Pavel Tatashin
8c551f919a arm64: hibernate: check pgd table allocation
There is a bug in create_safe_exec_page(), when page table is allocated
it is not checked that table is allocated successfully:

But it is dereferenced in: pgd_none(READ_ONCE(*pgdp)).  Check that
allocation was successful.

Fixes: 82869ac57b ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-14 17:57:29 -07:00
Julien Grall
ec52c7134b arm64: cpufeature: Treat ID_AA64ZFR0_EL1 as RAZ when SVE is not enabled
If CONFIG_ARM64_SVE=n then we fail to report ID_AA64ZFR0_EL1 as 0 when
read by userspace, despite being required by the architecture. Although
this is theoretically a change in ABI, userspace will first check for
the presence of SVE via the HWCAP or the ID_AA64PFR0_EL1.SVE field
before probing the ID_AA64ZFR0_EL1 register. Given that these are
reported correctly for this configuration, we can safely tighten up the
current behaviour.

Ensure ID_AA64ZFR0_EL1 is treated as RAZ when CONFIG_ARM64_SVE=n.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Fixes: 06a916feca ("arm64: Expose SVE2 features for userspace")
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-14 17:56:57 -07:00
Mark Rutland
e6ea46511b firmware: arm_sdei: use common SMCCC_CONDUIT_*
Now that we have common definitions for SMCCC conduits, move the SDEI
code over to them, and remove the SDEI-specific definitions.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:55:14 +01:00
Mark Rutland
c98bd29917 arm64: errata: use arm_smccc_1_1_get_conduit()
Now that we have arm_smccc_1_1_get_conduit(), we can hide the PSCI
implementation details from the arm64 cpu errata code, so let's do so.

As arm_smccc_1_1_get_conduit() implicitly checks that the SMCCC version
is at least SMCCC_VERSION_1_1, we no longer need to check this
explicitly where switch statements have a default case, e.g. in
has_ssbd_mitigation().

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:55:13 +01:00
Christian Brauner
fefad9ef58 seccomp: simplify secure_computing()
Afaict, the struct seccomp_data argument to secure_computing() is unused
by all current callers. So let's remove it.
The argument was added in [1]. It was added because having the arch
supply the syscall arguments used to be faster than having it done by
secure_computing() (cf. Andy's comment in [2]). This is not true anymore
though.

/* References */
[1]: 2f275de5d1 ("seccomp: Add a seccomp_data parameter secure_computing()")
[2]: https://lore.kernel.org/r/CALCETrU_fs_At-hTpr231kpaAd0z7xJN4ku-DvzhRU6cvcJA_w@mail.gmail.com

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: x86@kernel.org
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20190924064420.6353-1-christian.brauner@ubuntu.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-10-10 14:55:24 -07:00
Yunfeng Ye
3e7c93bd04 arm64: armv8_deprecated: Checking return value for memory allocation
There are no return value checking when using kzalloc() and kcalloc() for
memory allocation. so add it.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-08 13:34:04 +01:00
Marc Zyngier
9405447ef7 arm64: Avoid Cavium TX2 erratum 219 when switching TTBR
As a PRFM instruction racing against a TTBR update can have undesirable
effects on TX2, NOP-out such PRFM on cores that are affected by
the TX2-219 erratum.

Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-08 12:25:25 +01:00
Marc Zyngier
93916beb70 arm64: Enable workaround for Cavium TX2 erratum 219 when running SMT
It appears that the only case where we need to apply the TX2_219_TVM
mitigation is when the core is in SMT mode. So let's condition the
enabling on detecting a CPU whose MPIDR_EL1.Aff0 is non-zero.

Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-08 12:25:25 +01:00
Will Deacon
eff9cb67be arm64: vdso32: Rename COMPATCC to CC_COMPAT
For consistency with CROSS_COMPILE_COMPAT, mechanically rename COMPATCC
to CC_COMPAT so that specifying aspects of the compat vDSO toolchain in
the environment isn't needlessly confusing.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:13 +01:00
Will Deacon
7424ee2b16 arm64: vdso32: Pass '--target' option to clang via VDSO_CAFLAGS
Directly passing the '--target' option to clang by appending to
COMPATCC does not work if COMPATCC has been specified explicitly as
an argument to Make unless the 'override' directive is used, which is
ugly and different to what is done in the top-level Makefile.

Move the '--target' option for clang out of COMPATCC and into
VDSO_CAFLAGS, where it will be picked up when compiling and assembling
the 32-bit vDSO under clang.

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:09 +01:00
Will Deacon
c71e88c437 arm64: vdso32: Don't use KBUILD_CPPFLAGS unconditionally
KBUILD_CPPFLAGS is defined differently depending on whether the main
compiler is clang or not. This means that it is not possible to build
the compat vDSO with GCC if the rest of the kernel is built with clang.

Define VDSO_CPPFLAGS directly to break this dependency and allow a clang
kernel to build a compat vDSO with GCC:

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
    CROSS_COMPILE_COMPAT=arm-linux-gnueabihf- CC=clang \
    COMPATCC=arm-linux-gnueabihf-gcc

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:05 +01:00
Will Deacon
bcaf9b57e4 arm64: vdso32: Move definition of COMPATCC into vdso32/Makefile
There's no need to export COMPATCC, so just define it locally in the
vdso32/Makefile, which is the only place where it is used.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:02 +01:00
Vincenzo Frascino
a7f93103f8 arm64: vdso32: Remove jump label config option in Makefile
The jump labels are not used in vdso32 since it is not possible to run
runtime patching on them.

Remove the configuration option from the Makefile.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 11:07:17 +01:00
Vincenzo Frascino
0df2c90eba arm64: vdso32: Detect binutils support for dmb ishld
Older versions of binutils (prior to 2.24) do not support the "ISHLD"
option for memory barrier instructions, which leads to a build failure
when assembling the vdso32 library.

Add a compilation time mechanism that detects if binutils supports those
instructions and configure the kernel accordingly.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 11:07:16 +01:00
Vincenzo Frascino
37a5076098 arm64: vdso: Remove stale files from old assembly implementation
Moving over to the generic C implementation of the vDSO inadvertently
left some stale files behind which are no longer used. Remove them.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 11:07:16 +01:00
Vincenzo Frascino
e0de01aafc arm64: vdso32: Fix broken compat vDSO build warnings
The .config file and the generated include/config/auto.conf can
end up out of sync after a set of commands since
CONFIG_CROSS_COMPILE_COMPAT_VDSO is not updated correctly.

The sequence can be reproduced as follows:

$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
[...]
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig
[set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"]
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-

Which results in:

arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty,
the compat vDSO will not be built

even though the compat vDSO has been built:

$ file arch/arm64/kernel/vdso32/vdso.so
arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM,
EABI5 version 1 (SYSV), dynamically linked,
BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped

A similar case that involves changing the configuration parameter
multiple times can be reconducted to the same family of problems.

Remove the use of CONFIG_CROSS_COMPILE_COMPAT_VDSO altogether and
instead rely on the cross-compiler prefix coming from the environment
via CROSS_COMPILE_COMPAT, much like we do for the rest of the kernel.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 11:07:16 +01:00
James Morse
dd8a1f1348 arm64: ftrace: Ensure synchronisation in PLT setup for Neoverse-N1 #1542419
CPUs affected by Neoverse-N1 #1542419 may execute a stale instruction if
it was recently modified. The affected sequence requires freshly written
instructions to be executable before a branch to them is updated.

There are very few places in the kernel that modify executable text,
all but one come with sufficient synchronisation:
 * The module loader's flush_module_icache() calls flush_icache_range(),
   which does a kick_all_cpus_sync()
 * bpf_int_jit_compile() calls flush_icache_range().
 * Kprobes calls aarch64_insn_patch_text(), which does its work in
   stop_machine().
 * static keys and ftrace both patch between nops and branches to
   existing kernel code (not generated code).

The affected sequence is the interaction between ftrace and modules.
The module PLT is cleaned using __flush_icache_range() as the trampoline
shouldn't be executable until we update the branch to it.

Drop the double-underscore so that this path runs kick_all_cpus_sync()
too.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-04 11:44:05 +01:00
James Morse
f46f27a576 arm64: Fix incorrect irqflag restore for priority masking for compat
Commit bd82d4bd21 ("arm64: Fix incorrect irqflag restore for priority
masking") added a macro to the entry.S call paths that leave the
PSTATE.I bit set. This tells the pPNMI masking logic that interrupts
are masked by the CPU, not by the PMR. This value is read back by
local_daif_save().

Commit bd82d4bd21 added this call to el0_svc, as el0_svc_handler
is called with interrupts masked. el0_svc_compat was missed, but should
be covered in the same way as both of these paths end up in
el0_svc_common(), which expects to unmask interrupts.

Fixes: bd82d4bd21 ("arm64: Fix incorrect irqflag restore for priority masking")
Signed-off-by: James Morse <james.morse@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-04 11:44:03 +01:00
Julien Grall
7230f7e99f arm64: cpufeature: Effectively expose FRINT capability to userspace
The HWCAP framework will detect a new capability based on the sanitized
version of the ID registers.

Sanitization is based on a whitelist, so any field not described will end
up to be zeroed.

At the moment, ID_AA64ISAR1_EL1.FRINTTS is not described in
ftr_id_aa64isar1. This means the field will be zeroed and therefore the
userspace will not be able to see the HWCAP even if the hardware
supports the feature.

This can be fixed by describing the field in ftr_id_aa64isar1.

Fixes: ca9503fc9e ("arm64: Expose FRINT capabilities to userspace")
Signed-off-by: Julien Grall <julien.grall@arm.com>
Cc: mark.brown@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-04 11:43:43 +01:00
Masayoshi Mizuma
4585fc59c0 arm64/sve: Fix wrong free for task->thread.sve_state
The system which has SVE feature crashed because of
the memory pointed by task->thread.sve_state was destroyed
by someone.

That is because sve_state is freed while the forking the
child process. The child process has the pointer of sve_state
which is same as the parent's because the child's task_struct
is copied from the parent's one. If the copy_process()
fails as an error on somewhere, for example, copy_creds(),
then the sve_state is freed even if the parent is alive.
The flow is as follows.

copy_process
        p = dup_task_struct
            => arch_dup_task_struct
                *dst = *src;  // copy the entire region.
:
        retval = copy_creds
        if (retval < 0)
                goto bad_fork_free;
:
bad_fork_free:
...
        delayed_free_task(p);
          => free_task
             => arch_release_task_struct
                => fpsimd_release_task
                   => __sve_free
                      => kfree(task->thread.sve_state);
                         // free the parent's sve_state

Move child's sve_state = NULL and clearing TIF_SVE flag
to arch_dup_task_struct() so that the child doesn't free the
parent's one.
There is no need to wait until copy_process() to clear TIF_SVE for
dst, because the thread flags for dst are initialized already by
copying the src task_struct.
This change simplifies the code, so get rid of comments that are no
longer needed.

As a note, arm64 used to have thread_info on the stack. So it
would not be possible to clear TIF_SVE until the stack is initialized.
From commit c02433dd6d ("arm64: split thread_info from task stack"),
the thread_info is part of the task, so it should be valid to modify
the flag from arch_dup_task_struct().

Cc: stable@vger.kernel.org # 4.15.x-
Fixes: bc0ee47603 ("arm64/sve: Core task context handling")
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Reported-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Suggested-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-01 13:30:52 +01:00
Thierry Reding
7a292b6c7c arm64: errata: Update stale comment
Commit 73f3816609 ("arm64: Advertise mitigation of Spectre-v2, or lack
thereof") renamed the caller of the install_bp_hardening_cb() function
but forgot to update a comment, which can be confusing when trying to
follow the code flow.

Fixes: 73f3816609 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-01 13:30:17 +01:00
Alexandre Ghiti
e7142bf5d2 arm64, mm: make randomization selected by generic topdown mmap layout
This commits selects ARCH_HAS_ELF_RANDOMIZE when an arch uses the generic
topdown mmap layout functions so that this security feature is on by
default.

Note that this commit also removes the possibility for arm64 to have elf
randomization and no MMU: without MMU, the security added by randomization
is worth nothing.

Link: http://lkml.kernel.org/r/20190730055113.23635-6-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:11 -07:00
Linus Torvalds
e77fafe9af arm64 updates for 5.4:
- 52-bit virtual addressing in the kernel
 
 - New ABI to allow tagged user pointers to be dereferenced by syscalls
 
 - Early RNG seeding by the bootloader
 
 - Improve robustness of SMP boot
 
 - Fix TLB invalidation in light of recent architectural clarifications
 
 - Support for i.MX8 DDR PMU
 
 - Remove direct LSE instruction patching in favour of static keys
 
 - Function error injection using kprobes
 
 - Support for the PPTT "thread" flag introduced by ACPI 6.3
 
 - Move PSCI idle code into proper cpuidle driver
 
 - Relaxation of implicit I/O memory barriers
 
 - Build with RELR relocations when toolchain supports them
 
 - Numerous 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:
 "Although there isn't tonnes of code in terms of line count, there are
  a fair few headline features which I've noted both in the tag and also
  in the merge commits when I pulled everything together.

  The part I'm most pleased with is that we had 35 contributors this
  time around, which feels like a big jump from the usual small group of
  core arm64 arch developers. Hopefully they all enjoyed it so much that
  they'll continue to contribute, but we'll see.

  It's probably worth highlighting that we've pulled in a branch from
  the risc-v folks which moves our CPU topology code out to where it can
  be shared with others.

  Summary:

   - 52-bit virtual addressing in the kernel

   - New ABI to allow tagged user pointers to be dereferenced by
     syscalls

   - Early RNG seeding by the bootloader

   - Improve robustness of SMP boot

   - Fix TLB invalidation in light of recent architectural
     clarifications

   - Support for i.MX8 DDR PMU

   - Remove direct LSE instruction patching in favour of static keys

   - Function error injection using kprobes

   - Support for the PPTT "thread" flag introduced by ACPI 6.3

   - Move PSCI idle code into proper cpuidle driver

   - Relaxation of implicit I/O memory barriers

   - Build with RELR relocations when toolchain supports them

   - Numerous cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (114 commits)
  arm64: remove __iounmap
  arm64: atomics: Use K constraint when toolchain appears to support it
  arm64: atomics: Undefine internal macros after use
  arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL
  arm64: asm: Kill 'asm/atomic_arch.h'
  arm64: lse: Remove unused 'alt_lse' assembly macro
  arm64: atomics: Remove atomic_ll_sc compilation unit
  arm64: avoid using hard-coded registers for LSE atomics
  arm64: atomics: avoid out-of-line ll/sc atomics
  arm64: Use correct ll/sc atomic constraints
  jump_label: Don't warn on __exit jump entries
  docs/perf: Add documentation for the i.MX8 DDR PMU
  perf/imx_ddr: Add support for AXI ID filtering
  arm64: kpti: ensure patched kernel text is fetched from PoU
  arm64: fix fixmap copy for 16K pages and 48-bit VA
  perf/smmuv3: Validate groups for global filtering
  perf/smmuv3: Validate group size
  arm64: Relax Documentation/arm64/tagged-pointers.rst
  arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F
  arm64: mm: Ignore spurious translation faults taken from the kernel
  ...
2019-09-16 14:31:40 -07:00
Will Deacon
ac12cf85d6 Merge branches 'for-next/52-bit-kva', 'for-next/cpu-topology', 'for-next/error-injection', 'for-next/perf', 'for-next/psci-cpuidle', 'for-next/rng', 'for-next/smpboot', 'for-next/tbi' and 'for-next/tlbi' into for-next/core
* for-next/52-bit-kva: (25 commits)
  Support for 52-bit virtual addressing in kernel space

* for-next/cpu-topology: (9 commits)
  Move CPU topology parsing into core code and add support for ACPI 6.3

* for-next/error-injection: (2 commits)
  Support for function error injection via kprobes

* for-next/perf: (8 commits)
  Support for i.MX8 DDR PMU and proper SMMUv3 group validation

* for-next/psci-cpuidle: (7 commits)
  Move PSCI idle code into a new CPUidle driver

* for-next/rng: (4 commits)
  Support for 'rng-seed' property being passed in the devicetree

* for-next/smpboot: (3 commits)
  Reduce fragility of secondary CPU bringup in debug configurations

* for-next/tbi: (10 commits)
  Introduce new syscall ABI with relaxed requirements for pointer tags

* for-next/tlbi: (6 commits)
  Handle spurious page faults arising from kernel space
2019-08-30 12:46:12 +01:00
Will Deacon
ebef746543 arm64: smp: Treat unknown boot failures as being 'stuck in kernel'
When we fail to bring a secondary CPU online and it fails in an unknown
state, we should assume the worst and increment 'cpus_stuck_in_kernel'
so that things like kexec() are disabled.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:37:05 +01:00
Will Deacon
5b1cfe3a0b arm64: smp: Don't enter kernel with NULL stack pointer or task struct
Although SMP bringup is inherently racy, we can significantly reduce
the window during which secondary CPUs can unexpectedly enter the
kernel by sanity checking the 'stack' and 'task' fields of the
'secondary_data' structure. If the booting CPU gave up waiting for us,
then they will have been cleared to NULL and we should spin in a WFE; WFI
loop instead.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:37:02 +01:00
Will Deacon
0e1645557d arm64: smp: Increase secondary CPU boot timeout value
When many debug options are enabled simultaneously (e.g. PROVE_LOCKING,
KMEMLEAK, DEBUG_PAGE_ALLOC, KASAN etc), it is possible for us to timeout
when attempting to boot a secondary CPU and give up. Unfortunately, the
CPU will /eventually/ appear, and sit in the background happily stuck
in a recursive exception due to a NULL stack pointer.

Increase the timeout to 5s, which will of course be enough for anybody.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:36:50 +01:00
Hsin-Yi Wang
7f591fa7a6 arm64: kexec_file: add rng-seed support
Adding "rng-seed" to dtb. It's fine to add this property if original
fdt doesn't contain it. Since original seed will be wiped after
read, so use a default size 128 bytes here.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23 16:40:14 +01:00
Hsin-Yi Wang
e112b032a7 arm64: map FDT as RW for early_init_dt_scan()
Currently in arm64, FDT is mapped to RO before it's passed to
early_init_dt_scan(). However, there might be some codes
(eg. commit "fdt: add support for rng-seed") that need to modify FDT
during init. Map FDT to RO after early fixups are done.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23 16:39:16 +01:00
James Morse
2671828c3f arm64: entry: Move ct_user_exit before any other exception
When taking an SError or Debug exception from EL0, we run the C
handler for these exceptions before updating the context tracking
code and unmasking lower priority interrupts.

When booting with nohz_full lockdep tells us we got this wrong:
| =============================
| WARNING: suspicious RCU usage
| 5.3.0-rc2-00010-gb4b5e9dcb11b-dirty #11271 Not tainted
| -----------------------------
| include/linux/rcupdate.h:643 rcu_read_unlock() used illegally wh!
|
| other info that might help us debug this:
|
|
| RCU used illegally from idle CPU!
| rcu_scheduler_active = 2, debug_locks = 1
| RCU used illegally from extended quiescent state!
| 1 lock held by a.out/432:
|  #0: 00000000c7a79515 (rcu_read_lock){....}, at: brk_handler+0x00
|
| stack backtrace:
| CPU: 1 PID: 432 Comm: a.out Not tainted 5.3.0-rc2-00010-gb4b5e9d1
| Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno De8
| Call trace:
|  dump_backtrace+0x0/0x140
|  show_stack+0x14/0x20
|  dump_stack+0xbc/0x104
|  lockdep_rcu_suspicious+0xf8/0x108
|  brk_handler+0x164/0x1b0
|  do_debug_exception+0x11c/0x278
|  el0_dbg+0x14/0x20

Moving the ct_user_exit calls to be before do_debug_exception() means
they are also before trace_hardirqs_off() has been updated. Add a new
ct_user_exit_irqoff macro to avoid the context-tracking code using
irqsave/restore before we've updated trace_hardirqs_off(). To be
consistent, do this everywhere.

The C helper is called enter_from_user_mode() to match x86 in the hope
we can merge them into kernel/context_tracking.c later.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 6c81fe7925 ("arm64: enable context tracking")
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-21 18:45:52 +01:00
Catalin Marinas
413235fced arm64: Change the tagged_addr sysctl control semantics to only prevent the opt-in
First rename the sysctl control to abi.tagged_addr_disabled and make it
default off (zero). When abi.tagged_addr_disabled == 1, only block the
enabling of the TBI ABI via prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE).
Getting the status of the ABI or disabling it is still allowed.

Acked-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 18:18:10 +01:00
Raphael Gault
d91cc2f46a arm64: perf_event: Add missing header needed for smp_processor_id()
In perf_event.c we use smp_processor_id(), but we haven't included
<linux/smp.h> where it is defined, and rely on this being pulled in
via a transitive include. Let's make this more robust by including
<linux.smp.h> explicitly.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 17:10:05 +01:00
Linus Torvalds
b7e7c85dc7 arm64 fixes:
- Don't taint the kernel if CPUs have different sets of page sizes
   supported (other than the one in use).
 
 - Issue I-cache maintenance for module ftrace trampoline.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Don't taint the kernel if CPUs have different sets of page sizes
   supported (other than the one in use).

 - Issue I-cache maintenance for module ftrace trampoline.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: ftrace: Ensure module ftrace trampoline is coherent with I-side
  arm64: cpufeature: Don't treat granule sizes as strict
2019-08-16 10:51:47 -07:00
Will Deacon
b6143d10d2 arm64: ftrace: Ensure module ftrace trampoline is coherent with I-side
The initial support for dynamic ftrace trampolines in modules made use
of an indirect branch which loaded its target from the beginning of
a special section (e71a4e1beb ("arm64: ftrace: add support for far
branches to dynamic ftrace")). Since no instructions were being patched,
no cache maintenance was needed. However, later in be0f272bfc ("arm64:
ftrace: emit ftrace-mod.o contents through code") this code was reworked
to output the trampoline instructions directly into the PLT entry but,
unfortunately, the necessary cache maintenance was overlooked.

Add a call to __flush_icache_range() after writing the new trampoline
instructions but before patching in the branch to the trampoline.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: James Morse <james.morse@arm.com>
Cc: <stable@vger.kernel.org>
Fixes: be0f272bfc ("arm64: ftrace: emit ftrace-mod.o contents through code")
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-08-16 17:40:03 +01:00