Commit Graph

11557 Commits

Author SHA1 Message Date
Heyi Guo
de858040ee arm64: entry: refine comment of stack overflow check
Stack overflow checking can be done by testing sp & (1 << THREAD_SHIFT)
only for the stacks are aligned to (2 << THREAD_SHIFT) with size of
(1 << THREAD_SIZE), and this is the case when CONFIG_VMAP_STACK is set.

Fix the code comment to avoid confusion.

Cc: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Heyi Guo <guoheyi@huawei.com>
[catalin.marinas@arm.com: Updated comment following Mark's suggestion]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-06 14:11:31 +00:00
Mark Rutland
70927d02d4 arm64: ftrace: fix ifdeffery
When I tweaked the ftrace entry assembly in commit:

  3b23e4991f ("arm64: implement ftrace with regs")

... my ifdeffery tweaks left ftrace_graph_caller undefined for
CONFIG_DYNAMIC_FTRACE && CONFIG_FUNCTION_GRAPH_TRACER when ftrace is
based on mcount.

The kbuild test robot reported that this issue is detected at link time:

| arch/arm64/kernel/entry-ftrace.o: In function `skip_ftrace_call':
| arch/arm64/kernel/entry-ftrace.S:238: undefined reference to `ftrace_graph_caller'
| arch/arm64/kernel/entry-ftrace.S:238:(.text+0x3c): relocation truncated to fit: R_AARCH64_CONDBR19 against undefined symbol
| `ftrace_graph_caller'
| arch/arm64/kernel/entry-ftrace.S:243: undefined reference to `ftrace_graph_caller'
| arch/arm64/kernel/entry-ftrace.S:243:(.text+0x54): relocation truncated to fit: R_AARCH64_CONDBR19 against undefined symbol
| `ftrace_graph_caller'

This patch fixes the ifdeffery so that the mcount version of
ftrace_graph_caller doesn't depend on CONFIG_DYNAMIC_FTRACE. At the same
time, a redundant #else is removed from the ifdeffery for the
patchable-function-entry version of ftrace_graph_caller.

Fixes: 3b23e4991f ("arm64: implement ftrace with regs")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Torsten Duwe <duwe@lst.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-06 13:25:14 +00:00
Sebastian Andrzej Siewior
0492747c72 arm64: KVM: Invoke compute_layout() before alternatives are applied
compute_layout() is invoked as part of an alternative fixup under
stop_machine(). This function invokes get_random_long() which acquires a
sleeping lock on -RT which can not be acquired in this context.

Rename compute_layout() to kvm_compute_layout() and invoke it before
stop_machine() applies the alternatives. Add a __init prefix to
kvm_compute_layout() because the caller has it, too (and so the code can be
discarded after boot).

Reviewed-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-06 12:14:45 +00:00
Catalin Marinas
df325e05a6 arm64: Validate tagged addresses in access_ok() called from kernel threads
__range_ok(), invoked from access_ok(), clears the tag of the user
address only if CONFIG_ARM64_TAGGED_ADDR_ABI is enabled and the thread
opted in to the relaxed ABI. The latter sets the TIF_TAGGED_ADDR thread
flag. In the case of asynchronous I/O (e.g. io_submit()), the
access_ok() may be called from a kernel thread. Since kernel threads
don't have TIF_TAGGED_ADDR set, access_ok() will fail for valid tagged
user addresses. Example from the ffs_user_copy_worker() thread:

	use_mm(io_data->mm);
	ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
	unuse_mm(io_data->mm);

Relax the __range_ok() check to always untag the user address if called
in the context of a kernel thread. The user pointers would have already
been checked via aio_setup_rw() -> import_{single_range,iovec}() at the
time of the asynchronous I/O request.

Fixes: 63f0c60379 ("arm64: Introduce prctl() options to control the tagged user addresses ABI")
Cc: <stable@vger.kernel.org> # 5.4.x-
Cc: Will Deacon <will@kernel.org>
Reported-by: Evgenii Stepanov <eugenis@google.com>
Tested-by: Evgenii Stepanov <eugenis@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-06 12:02:56 +00:00
Mark Brown
cba779d80a arm64: mm: Fix column alignment for UXN in kernel_page_tables
UXN is the only individual PTE bit other than the PTE_ATTRINDX_MASK ones
which doesn't have both a set and a clear value provided, meaning that the
columns in the table won't all be aligned. The PTE_ATTRINDX_MASK values
are all both mutually exclusive and longer so are listed last to make a
single final column for those values. Ensure everything is aligned by
providing a clear value for UXN.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-04 11:44:29 +00:00
Mark Rutland
ca2ef4ffab arm64: insn: consistently handle exit text
A kernel built with KASAN && FTRACE_WITH_REGS && !MODULES, produces a
boot-time splat in the bowels of ftrace:

| [    0.000000] ftrace: allocating 32281 entries in 127 pages
| [    0.000000] ------------[ cut here ]------------
| [    0.000000] WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2019 ftrace_bug+0x27c/0x328
| [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.0-rc3-00008-g7f08ae53a7e3 #13
| [    0.000000] Hardware name: linux,dummy-virt (DT)
| [    0.000000] pstate: 60000085 (nZCv daIf -PAN -UAO)
| [    0.000000] pc : ftrace_bug+0x27c/0x328
| [    0.000000] lr : ftrace_init+0x640/0x6cc
| [    0.000000] sp : ffffa000120e7e00
| [    0.000000] x29: ffffa000120e7e00 x28: ffff00006ac01b10
| [    0.000000] x27: ffff00006ac898c0 x26: dfffa00000000000
| [    0.000000] x25: ffffa000120ef290 x24: ffffa0001216df40
| [    0.000000] x23: 000000000000018d x22: ffffa0001244c700
| [    0.000000] x21: ffffa00011bf393c x20: ffff00006ac898c0
| [    0.000000] x19: 00000000ffffffff x18: 0000000000001584
| [    0.000000] x17: 0000000000001540 x16: 0000000000000007
| [    0.000000] x15: 0000000000000000 x14: ffffa00010432770
| [    0.000000] x13: ffff940002483519 x12: 1ffff40002483518
| [    0.000000] x11: 1ffff40002483518 x10: ffff940002483518
| [    0.000000] x9 : dfffa00000000000 x8 : 0000000000000001
| [    0.000000] x7 : ffff940002483519 x6 : ffffa0001241a8c0
| [    0.000000] x5 : ffff940002483519 x4 : ffff940002483519
| [    0.000000] x3 : ffffa00011780870 x2 : 0000000000000001
| [    0.000000] x1 : 1fffe0000d591318 x0 : 0000000000000000
| [    0.000000] Call trace:
| [    0.000000]  ftrace_bug+0x27c/0x328
| [    0.000000]  ftrace_init+0x640/0x6cc
| [    0.000000]  start_kernel+0x27c/0x654
| [    0.000000] random: get_random_bytes called from print_oops_end_marker+0x30/0x60 with crng_init=0
| [    0.000000] ---[ end trace 0000000000000000 ]---
| [    0.000000] ftrace faulted on writing
| [    0.000000] [<ffffa00011bf393c>] _GLOBAL__sub_D_65535_0___tracepoint_initcall_level+0x4/0x28
| [    0.000000] Initializing ftrace call sites
| [    0.000000] ftrace record flags: 0
| [    0.000000]  (0)
| [    0.000000]  expected tramp: ffffa000100b3344

This is due to an unfortunate combination of several factors.

Building with KASAN results in the compiler generating anonymous
functions to register/unregister global variables against the shadow
memory. These functions are placed in .text.startup/.text.exit, and
given mangled names like _GLOBAL__sub_{I,D}_65535_0_$OTHER_SYMBOL. The
kernel linker script places these in .init.text and .exit.text
respectively, which are both discarded at runtime as part of initmem.

Building with FTRACE_WITH_REGS uses -fpatchable-function-entry=2, which
also instruments KASAN's anonymous functions. When these are discarded
with the rest of initmem, ftrace removes dangling references to these
call sites.

Building without MODULES implicitly disables STRICT_MODULE_RWX, and
causes arm64's patch_map() function to treat any !core_kernel_text()
symbol as something that can be modified in-place. As core_kernel_text()
is only true for .text and .init.text, with the latter depending on
system_state < SYSTEM_RUNNING, we'll treat .exit.text as something that
can be patched in-place. However, .exit.text is mapped read-only.

Hence in this configuration the ftrace init code blows up while trying
to patch one of the functions generated by KASAN.

We could try to filter out the call sites in .exit.text rather than
initializing them, but this would be inconsistent with how we handle
.init.text, and requires hooking into core bits of ftrace. The behaviour
of patch_map() is also inconsistent today, so instead let's clean that
up and have it consistently handle .exit.text.

This patch teaches patch_map() to handle .exit.text at init time,
preventing the boot-time splat above. The flow of patch_map() is
reworked to make the logic clearer and minimize redundant
conditionality.

Fixes: 3b23e4991f ("arm64: implement ftrace with regs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Torsten Duwe <duwe@suse.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-04 11:32:20 +00:00
Will Deacon
93b90414c3 arm64: mm: Fix initialisation of DMA zones on non-NUMA systems
John reports that the recently merged commit 1a8e1cef76 ("arm64: use
both ZONE_DMA and ZONE_DMA32") breaks the boot on his DB845C board:

  | Booting Linux on physical CPU 0x0000000000 [0x517f803c]
  | Linux version 5.4.0-mainline-10675-g957a03b9e38f
  | Machine model: Thundercomm Dragonboard 845c
  | [...]
  | Built 1 zonelists, mobility grouping on.  Total pages: -188245
  | Kernel command line: earlycon
  | firmware_class.path=/vendor/firmware/ androidboot.hardware=db845c
  | init=/init androidboot.boot_devices=soc/1d84000.ufshc
  | printk.devkmsg=on buildvariant=userdebug root=/dev/sda2
  | androidboot.bootdevice=1d84000.ufshc androidboot.serialno=c4e1189c
  | androidboot.baseband=sda
  | msm_drm.dsi_display0=dsi_lt9611_1080_video_display:
  | androidboot.slot_suffix=_a skip_initramfs rootwait ro init=/init
  |
  | <hangs indefinitely here>

This is because, when CONFIG_NUMA=n, zone_sizes_init() fails to handle
memblocks that fall entirely within the ZONE_DMA region and erroneously ends up
trying to add a negatively-sized region into the following ZONE_DMA32, which is
later interpreted as a large unsigned region by the core MM code.

Rework the non-NUMA implementation of zone_sizes_init() so that the start
address of the memblock being processed is adjusted according to the end of the
previous zone, which is then range-checked before updating the hole information
of subsequent zones.

Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/lkml/CALAqxLVVcsmFrDKLRGRq7GewcW405yTOxG=KR3csVzQ6bXutkA@mail.gmail.com
Fixes: 1a8e1cef76 ("arm64: use both ZONE_DMA and ZONE_DMA32")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-12-04 11:25:20 +00:00
Anders Roxell
d8e85e144b arm64: Kconfig: add a choice for endianness
When building allmodconfig KCONFIG_ALLCONFIG=$(pwd)/arch/arm64/configs/defconfig
CONFIG_CPU_BIG_ENDIAN gets enabled. Which tends not to be what most
people want. Another concern that has come up is that ACPI isn't built
for an allmodconfig kernel today since that also depends on !CPU_BIG_ENDIAN.

Rework so that we introduce a 'choice' and default the choice to
CPU_LITTLE_ENDIAN. That means that when we build an allmodconfig kernel
it will default to CPU_LITTLE_ENDIAN that most people tends to want.

Reviewed-by: John Garry <john.garry@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-14 14:39:03 +00:00
Anders Roxell
f70c08e46d arm64: Kconfig: make CMDLINE_FORCE depend on CMDLINE
When building allmodconfig KCONFIG_ALLCONFIG=$(pwd)/arch/arm64/configs/defconfig
CONFIG_CMDLINE_FORCE gets enabled. Which forces the user to pass the
full cmdline to CONFIG_CMDLINE="...".

Rework so that CONFIG_CMDLINE_FORCE gets set only if CONFIG_CMDLINE is
set to something except an empty string.

Suggested-by: John Garry <john.garry@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-11 18:22:57 +00:00
Catalin Marinas
6be22809e5 Merge branches 'for-next/elf-hwcap-docs', 'for-next/smccc-conduit-cleanup', 'for-next/zone-dma', 'for-next/relax-icc_pmr_el1-sync', 'for-next/double-page-fault', 'for-next/misc', 'for-next/kselftest-arm64-signal' and 'for-next/kaslr-diagnostics' into for-next/core
* for-next/elf-hwcap-docs:
  : Update the arm64 ELF HWCAP documentation
  docs/arm64: cpu-feature-registers: Rewrite bitfields that don't follow [e, s]
  docs/arm64: cpu-feature-registers: Documents missing visible fields
  docs/arm64: elf_hwcaps: Document HWCAP_SB
  docs/arm64: elf_hwcaps: sort the HWCAP{, 2} documentation by ascending value

* for-next/smccc-conduit-cleanup:
  : SMC calling convention conduit clean-up
  firmware: arm_sdei: use common SMCCC_CONDUIT_*
  firmware/psci: use common SMCCC_CONDUIT_*
  arm: spectre-v2: use arm_smccc_1_1_get_conduit()
  arm64: errata: use arm_smccc_1_1_get_conduit()
  arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()

* for-next/zone-dma:
  : Reintroduction of ZONE_DMA for Raspberry Pi 4 support
  arm64: mm: reserve CMA and crashkernel in ZONE_DMA32
  dma/direct: turn ARCH_ZONE_DMA_BITS into a variable
  arm64: Make arm64_dma32_phys_limit static
  arm64: mm: Fix unused variable warning in zone_sizes_init
  mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum zone_type'
  arm64: use both ZONE_DMA and ZONE_DMA32
  arm64: rename variables used to calculate ZONE_DMA32's size
  arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys()

* for-next/relax-icc_pmr_el1-sync:
  : Relax ICC_PMR_EL1 (GICv3) accesses when ICC_CTLR_EL1.PMHE is clear
  arm64: Document ICC_CTLR_EL3.PMHE setting requirements
  arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear

* for-next/double-page-fault:
  : Avoid a double page fault in __copy_from_user_inatomic() if hw does not support auto Access Flag
  mm: fix double page fault on arm64 if PTE_AF is cleared
  x86/mm: implement arch_faults_on_old_pte() stub on x86
  arm64: mm: implement arch_faults_on_old_pte() on arm64
  arm64: cpufeature: introduce helper cpu_has_hw_af()

* for-next/misc:
  : Various fixes and clean-ups
  arm64: kpti: Add NVIDIA's Carmel core to the KPTI whitelist
  arm64: mm: Remove MAX_USER_VA_BITS definition
  arm64: mm: simplify the page end calculation in __create_pgd_mapping()
  arm64: print additional fault message when executing non-exec memory
  arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()
  arm64: pgtable: Correct typo in comment
  arm64: docs: cpu-feature-registers: Document ID_AA64PFR1_EL1
  arm64: cpufeature: Fix typos in comment
  arm64/mm: Poison initmem while freeing with free_reserved_area()
  arm64: use generic free_initrd_mem()
  arm64: simplify syscall wrapper ifdeffery

* for-next/kselftest-arm64-signal:
  : arm64-specific kselftest support with signal-related test-cases
  kselftest: arm64: fake_sigreturn_misaligned_sp
  kselftest: arm64: fake_sigreturn_bad_size
  kselftest: arm64: fake_sigreturn_duplicated_fpsimd
  kselftest: arm64: fake_sigreturn_missing_fpsimd
  kselftest: arm64: fake_sigreturn_bad_size_for_magic0
  kselftest: arm64: fake_sigreturn_bad_magic
  kselftest: arm64: add helper get_current_context
  kselftest: arm64: extend test_init functionalities
  kselftest: arm64: mangle_pstate_invalid_mode_el[123][ht]
  kselftest: arm64: mangle_pstate_invalid_daif_bits
  kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils
  kselftest: arm64: extend toplevel skeleton Makefile

* for-next/kaslr-diagnostics:
  : Provide diagnostics on boot for KASLR
  arm64: kaslr: Check command line before looking for a seed
  arm64: kaslr: Announce KASLR status on boot
2019-11-08 17:46:11 +00:00
Mark Brown
2203e1adb9 arm64: kaslr: Check command line before looking for a seed
Now that we print diagnostics at boot the reason why we do not initialise
KASLR matters. Currently we check for a seed before we check if the user
has explicitly disabled KASLR on the command line which will result in
misleading diagnostics so reverse the order of those checks. We still
parse the seed from the DT early so that if the user has both provided a
seed and disabled KASLR on the command line we still mask the seed on
the command line.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-08 17:36:51 +00:00
Mark Brown
294a9ddde6 arm64: kaslr: Announce KASLR status on boot
Currently the KASLR code is silent at boot unless it forces on KPTI in
which case a message will be printed for that. This can lead to users
incorrectly believing their system has the feature enabled when it in
fact does not, and if they notice the problem the lack of any
diagnostics makes it harder to understand the problem. Add an initcall
which prints a message showing the status of KASLR during boot to make
the status clear.

This is particularly useful in cases where we don't have a seed. It
seems to be a relatively common error for system integrators and
administrators to enable KASLR in their configuration but not provide
the seed at runtime, often due to seed provisioning breaking at some
later point after it is initially enabled and verified.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-08 17:36:48 +00:00
Catalin Marinas
51effa6d11 Merge branch 'for-next/perf' into for-next/core
- Support for additional PMU topologies on HiSilicon platforms
- Support for CCN-512 interconnect PMU
- Support for AXI ID filtering in the IMX8 DDR PMU
- Support for the CCPI2 uncore PMU in ThunderX2
- Driver cleanup to use devm_platform_ioremap_resource()

* for-next/perf:
  drivers/perf: hisi: update the sccl_id/ccl_id for certain HiSilicon platform
  perf/imx_ddr: Dump AXI ID filter info to userspace
  docs/perf: Add AXI ID filter capabilities information
  perf/imx_ddr: Add driver for DDR PMU in i.MX8MPlus
  perf/imx_ddr: Add enhanced AXI ID filter support
  bindings: perf: imx-ddr: Add new compatible string
  docs/perf: Add explanation for DDR_CAP_AXI_ID_FILTER_ENHANCED quirk
  arm64: perf: Simplify the ARMv8 PMUv3 event attributes
  drivers/perf: Add CCPI2 PMU support in ThunderX2 UNCORE driver.
  Documentation: perf: Update documentation for ThunderX2 PMU uncore driver
  Documentation: Add documentation for CCN-512 DTS binding
  perf: arm-ccn: Enable stats for CCN-512 interconnect
  perf/smmuv3: use devm_platform_ioremap_resource() to simplify code
  perf/arm-cci: use devm_platform_ioremap_resource() to simplify code
  perf/arm-ccn: use devm_platform_ioremap_resource() to simplify code
  perf: xgene: use devm_platform_ioremap_resource() to simplify code
  perf: hisi: use devm_platform_ioremap_resource() to simplify code
2019-11-08 10:57:14 +00:00
Catalin Marinas
c1c9ea6371 Merge branch 'arm64/ftrace-with-regs' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux into for-next/core
FTRACE_WITH_REGS support for arm64.

* 'arm64/ftrace-with-regs' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux:
  arm64: ftrace: minimize ifdeffery
  arm64: implement ftrace with regs
  arm64: asm-offsets: add S_FP
  arm64: insn: add encoder for MOV (register)
  arm64: module/ftrace: intialize PLT at load time
  arm64: module: rework special section handling
  module/ftrace: handle patchable-function-entry
  ftrace: add ftrace_init_nop()
2019-11-07 11:26:54 +00:00
Nicolas Saenz Julienne
bff3b04460 arm64: mm: reserve CMA and crashkernel in ZONE_DMA32
With the introduction of ZONE_DMA in arm64 we moved the default CMA and
crashkernel reservation into that area. This caused a regression on big
machines that need big CMA and crashkernel reservations. Note that
ZONE_DMA is only 1GB big.

Restore the previous behavior as the wide majority of devices are OK
with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA
will configure it explicitly.

Fixes: 1a8e1cef76 ("arm64: use both ZONE_DMA and ZONE_DMA32")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-07 11:22:20 +00:00
Mark Rutland
7f08ae53a7 arm64: ftrace: minimize ifdeffery
Now that we no longer refer to mod->arch.ftrace_trampolines in the body
of ftrace_make_call(), we can use IS_ENABLED() rather than ifdeffery,
and make the code easier to follow. Likewise in ftrace_make_nop().

Let's do so.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:36 +00:00
Torsten Duwe
3b23e4991f arm64: implement ftrace with regs
This patch implements FTRACE_WITH_REGS for arm64, which allows a traced
function's arguments (and some other registers) to be captured into a
struct pt_regs, allowing these to be inspected and/or modified. This is
a building block for live-patching, where a function's arguments may be
forwarded to another function. This is also necessary to enable ftrace
and in-kernel pointer authentication at the same time, as it allows the
LR value to be captured and adjusted prior to signing.

Using GCC's -fpatchable-function-entry=N option, we can have the
compiler insert a configurable number of NOPs between the function entry
point and the usual prologue. This also ensures functions are AAPCS
compliant (e.g. disabling inter-procedural register allocation).

For example, with -fpatchable-function-entry=2, GCC 8.1.0 compiles the
following:

| unsigned long bar(void);
|
| unsigned long foo(void)
| {
|         return bar() + 1;
| }

... to:

| <foo>:
|         nop
|         nop
|         stp     x29, x30, [sp, #-16]!
|         mov     x29, sp
|         bl      0 <bar>
|         add     x0, x0, #0x1
|         ldp     x29, x30, [sp], #16
|         ret

This patch builds the kernel with -fpatchable-function-entry=2,
prefixing each function with two NOPs. To trace a function, we replace
these NOPs with a sequence that saves the LR into a GPR, then calls an
ftrace entry assembly function which saves this and other relevant
registers:

| mov	x9, x30
| bl	<ftrace-entry>

Since patchable functions are AAPCS compliant (and the kernel does not
use x18 as a platform register), x9-x18 can be safely clobbered in the
patched sequence and the ftrace entry code.

There are now two ftrace entry functions, ftrace_regs_entry (which saves
all GPRs), and ftrace_entry (which saves the bare minimum). A PLT is
allocated for each within modules.

Signed-off-by: Torsten Duwe <duwe@suse.de>
[Mark: rework asm, comments, PLTs, initialization, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Julien Thierry <jthierry@redhat.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:35 +00:00
Mark Rutland
1f377e043b arm64: asm-offsets: add S_FP
So that assembly code can more easily manipulate the FP (x29) within a
pt_regs, add an S_FP asm-offsets definition.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:34 +00:00
Mark Rutland
e3bf8a67f7 arm64: insn: add encoder for MOV (register)
For FTRACE_WITH_REGS, we're going to want to generate a MOV (register)
instruction as part of the callsite intialization. As MOV (register) is
an alias for ORR (shifted register), we can generate this with
aarch64_insn_gen_logical_shifted_reg(), but it's somewhat verbose and
difficult to read in-context.

Add a aarch64_insn_gen_move_reg() wrapper for this case so that we can
write callers in a more straightforward way.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:33 +00:00
Mark Rutland
f1a54ae9af arm64: module/ftrace: intialize PLT at load time
Currently we lazily-initialize a module's ftrace PLT at runtime when we
install the first ftrace call. To do so we have to apply a number of
sanity checks, transiently mark the module text as RW, and perform an
IPI as part of handling Neoverse-N1 erratum #1542419.

We only expect the ftrace trampoline to point at ftrace_caller() (AKA
FTRACE_ADDR), so let's simplify all of this by intializing the PLT at
module load time, before the module loader marks the module RO and
performs the intial I-cache maintenance for the module.

Thus we can rely on the module having been correctly intialized, and can
simplify the runtime work necessary to install an ftrace call in a
module. This will also allow for the removal of module_disable_ro().

Tested by forcing ftrace_make_call() to use the module PLT, and then
loading up a module after setting up ftrace with:

| echo ":mod:<module-name>" > set_ftrace_filter;
| echo function > current_tracer;
| modprobe <module-name>

Since FTRACE_ADDR is only defined when CONFIG_DYNAMIC_FTRACE is
selected, we wrap its use along with most of module_init_ftrace_plt()
with ifdeffery rather than using IS_ENABLED().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:32 +00:00
Mark Rutland
bd8b21d3dd arm64: module: rework special section handling
When we load a module, we have to perform some special work for a couple
of named sections. To do this, we iterate over all of the module's
sections, and perform work for each section we recognize.

To make it easier to handle the unexpected absence of a section, and to
make the section-specific logic easer to read, let's factor the section
search into a helper. Similar is already done in the core module loader,
and other architectures (and ideally we'd unify these in future).

If we expect a module to have an ftrace trampoline section, but it
doesn't have one, we'll now reject loading the module. When
ARM64_MODULE_PLTS is selected, any correctly built module should have
one (and this is assumed by arm64's ftrace PLT code) and the absence of
such a section implies something has gone wrong at build time.

Subsequent patches will make use of the new helper.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:31 +00:00
Rich Wiley
918e1946c8 arm64: kpti: Add NVIDIA's Carmel core to the KPTI whitelist
NVIDIA Carmel CPUs don't implement ID_AA64PFR0_EL1.CSV3 but
aren't susceptible to Meltdown, so add Carmel to kpti_safe_list[].

Signed-off-by: Rich Wiley <rwiley@nvidia.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-06 11:31:03 +00:00
Bhupesh Sharma
218564b164 arm64: mm: Remove MAX_USER_VA_BITS definition
commit 9b31cf493f ("arm64: mm: Introduce MAX_USER_VA_BITS definition")
introduced the MAX_USER_VA_BITS definition, which was used to support
the arm64 mm use-cases where the user-space could use 52-bit virtual
addresses whereas the kernel-space would still could a maximum of 48-bit
virtual addressing.

But, now with commit b6d00d47e8 ("arm64: mm: Introduce 52-bit Kernel
VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence
there is no longer any scenario where user VA != kernel VA size
(even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true).

Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to
VA_BITS (maximum VA space size) in all possible use-cases. Note that
even though the 'vabits_actual' value would be 48 for arm64 hardware
which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52
is enabled), VA_BITS would still be set to a value 52. Hence this change
would be safe in all possible VA address space combinations.

Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-kernel@vger.kernel.org
Cc: kexec@lists.infradead.org
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-06 11:19:25 +00:00
Masahiro Yamada
32d1870877 arm64: mm: simplify the page end calculation in __create_pgd_mapping()
Calculate the page-aligned end address more simply.

The local variable, "length" is unneeded.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-06 11:17:09 +00:00
Shaokun Zhang
9ef8567ccf arm64: perf: Simplify the ARMv8 PMUv3 event attributes
For each PMU event, there is a ARMV8_EVENT_ATTR(xx, XX) and
&armv8_event_attr_xx.attr.attr. Let's redefine the ARMV8_EVENT_ATTR
to simplify the armv8_pmuv3_event_attrs.

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
[will: Dropped unnecessary array syntax]
Signed-off-by: Will Deacon <will@kernel.org>
2019-11-01 14:51:19 +00:00
Nicolas Saenz Julienne
8b5369ea58 dma/direct: turn ARCH_ZONE_DMA_BITS into a variable
Some architectures, notably ARM, are interested in tweaking this
depending on their runtime DMA addressing limitations.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-01 09:41:18 +00:00
Xiang Zheng
e44ec4a35d arm64: print additional fault message when executing non-exec memory
When attempting to executing non-executable memory, the fault message
shows:

  Unable to handle kernel read from unreadable memory at virtual address
  ffff802dac469000

This may confuse someone, so add a new fault message for instruction
abort.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-29 15:41:14 +00:00
Catalin Marinas
8301ae822d Merge branch 'for-next/entry-s-to-c' into for-next/core
Move the synchronous exception paths from entry.S into a C file to
improve the code readability.

* for-next/entry-s-to-c:
  arm64: entry-common: don't touch daif before bp-hardening
  arm64: Remove asmlinkage from updated functions
  arm64: entry: convert el0_sync to C
  arm64: entry: convert el1_sync to C
  arm64: add local_daif_inherit()
  arm64: Add prototypes for functions called by entry.S
  arm64: remove __exception annotations
2019-10-28 17:02:56 +00:00
Catalin Marinas
4686da5140 arm64: Make arm64_dma32_phys_limit static
This variable is only used in the arch/arm64/mm/init.c file for
ZONE_DMA32 initialisation, no need to expose it.

Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 16:46:43 +00:00
Catalin Marinas
346f6a4636 Merge branch 'kvm-arm64/erratum-1319367' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into for-next/core
Similarly to erratum 1165522 that affects Cortex-A76, A57 and A72
respectively suffer from errata 1319537 and 1319367, potentially
resulting in TLB corruption if the CPU speculates an AT instruction
while switching guests.

The fix is slightly more involved since we don't have VHE to help us
here, but the idea is the same: when switching a guest in, we must
prevent any speculated AT from being able to parse the page tables
until S2 is up and running. Only at this stage can we allow AT to take
place.

For this, we always restore the guest sysregs first, except for its
SCTLR and TCR registers, which must be set with SCTLR.M=1 and
TCR.EPD{0,1} = {1, 1}, effectively disabling the PTW and TLB
allocation. Once S2 is setup, we restore the guest's SCTLR and
TCR. Similar things must be done on TLB invalidation...

* 'kvm-arm64/erratum-1319367' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms:
  arm64: Enable and document ARM errata 1319367 and 1319537
  arm64: KVM: Prevent speculative S1 PTW when restoring vcpu context
  arm64: KVM: Disable EL1 PTW when invalidating S2 TLBs
  arm64: KVM: Reorder system register restoration and stage-2 activation
  arm64: Add ARM64_WORKAROUND_1319367 for all A57 and A72 versions
2019-10-28 16:22:49 +00:00
Catalin Marinas
6a036afb55 Merge branch 'for-next/neoverse-n1-stale-instr' into for-next/core
Neoverse-N1 cores with the 'COHERENT_ICACHE' feature may fetch stale
instructions when software depends on prefetch-speculation-protection
instead of explicit synchronization. [0]

The workaround is to trap I-Cache maintenance and issue an
inner-shareable TLBI. The affected cores have a Coherent I-Cache, so the
I-Cache maintenance isn't necessary. The core tells user-space it can
skip it with CTR_EL0.DIC. We also have to trap this register to hide the
bit forcing DIC-aware user-space to perform the maintenance.

To avoid trapping all cache-maintenance, this workaround depends on
a firmware component that only traps I-cache maintenance from EL0 and
performs the workaround.

For user-space, the kernel's work is to trap CTR_EL0 to hide DIC, and
produce a fake IminLine. EL3 traps the now-necessary I-Cache maintenance
and performs the inner-shareable-TLBI that makes everything better.

[0] https://developer.arm.com/docs/sden885747/latest/arm-neoverse-n1-mp050-software-developer-errata-notice

* for-next/neoverse-n1-stale-instr:
  arm64: Silence clang warning on mismatched value/register sizes
  arm64: compat: Workaround Neoverse-N1 #1542419 for compat user-space
  arm64: Fake the IminLine size on systems affected by Neoverse-N1 #1542419
  arm64: errata: Hide CTR_EL0.DIC on systems affected by Neoverse-N1 #1542419
2019-10-28 16:12:40 +00:00
Catalin Marinas
ba95e9bd96 Merge remote-tracking branch 'arm64/for-next/fixes' into for-next/core
This is required to solve the conflicts with subsequent merges of two
more errata workaround branches.

* arm64/for-next/fixes:
  arm64: tags: Preserve tags for addresses translated via TTBR1
  arm64: mm: fix inverted PAR_EL1.F check
  arm64: sysreg: fix incorrect definition of SYS_PAR_EL1_F
  arm64: entry.S: Do not preempt from IRQ before all cpufeatures are enabled
  arm64: hibernate: check pgd table allocation
  arm64: cpufeature: Treat ID_AA64ZFR0_EL1 as RAZ when SVE is not enabled
  arm64: Fix kcore macros after 52-bit virtual addressing fallout
  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
2019-10-28 15:30:52 +00:00
James Morse
bfe298745a arm64: entry-common: don't touch daif before bp-hardening
The previous patches mechanically transformed the assembly version of
entry.S to entry-common.c for synchronous exceptions.

The C version of local_daif_restore() doesn't quite do the same thing
as the assembly versions if pseudo-NMI is in use. In particular,
| local_daif_restore(DAIF_PROCCTX_NOIRQ)
will still allow pNMI to be delivered. This is not the behaviour
do_el0_ia_bp_hardening() and do_sp_pc_abort() want as it should not
be possible for the PMU handler to run as an NMI until the bp-hardening
sequence has run.

The bp-hardening calls were placed where they are because this was the
first C code to run after the relevant exceptions. As we've now moved
that point earlier, move the checks and calls earlier too.

This makes it clearer that this stuff runs before any kind of exception,
and saves modifying PSTATE twice.

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 11:22:54 +00:00
James Morse
afa7c0e5b9 arm64: Remove asmlinkage from updated functions
Now that the callers of these functions have moved into C, they no longer
need the asmlinkage annotation. Remove it.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:51 +00:00
Mark Rutland
582f95835a arm64: entry: convert el0_sync to C
This is largely a 1-1 conversion of asm to C, with a couple of caveats.

The el0_sync{_compat} switches explicitly handle all the EL0 debug
cases, so el0_dbg doesn't have to try to bail out for unexpected EL1
debug ESR values. This also means that an unexpected vector catch from
AArch32 is routed to el0_inv.

We *could* merge the native and compat switches, which would make the
diffstat negative, but I've tried to stay as close to the existing
assembly as possible for the moment.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[split out of a bigger series, added nokprobes. removed irq trace
 calls as the C helpers do this. renamed el0_dbg's use of FAR]
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 11:22:49 +00:00
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
Mark Rutland
51077e03b8 arm64: add local_daif_inherit()
Some synchronous exceptions can be taken from a number of contexts,
e.g. where IRQs may or may not be masked. In the entry assembly for
these exceptions, we use the inherit_daif assembly macro to ensure
that we only mask those exceptions which were masked when the exception
was taken.

So that we can do the same from C code, this patch adds a new
local_daif_inherit() function, following the existing local_daif_*()
naming scheme.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[moved away from local_daif_restore()]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:43 +00:00
James Morse
e540e0a7fa arm64: Add prototypes for functions called by entry.S
Functions that are only called by assembly don't always have a
C header file prototype.

Add the prototypes before moving the assembly callers to C.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:41 +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
Marc Zyngier
c2cc62d831 arm64: Enable and document ARM errata 1319367 and 1319537
Now that everything is in place, let's get the ball rolling
by allowing the corresponding config option to be selected.
Also add the required information to silicon_errata.rst.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-26 10:44:49 +01:00
Marc Zyngier
bd227553ad arm64: KVM: Prevent speculative S1 PTW when restoring vcpu context
When handling erratum 1319367, we must ensure that the page table
walker cannot parse the S1 page tables while the guest is in an
inconsistent state. This is done as follows:

On guest entry:
- TCR_EL1.EPD{0,1} are set, ensuring that no PTW can occur
- all system registers are restored, except for TCR_EL1 and SCTLR_EL1
- stage-2 is restored
- SCTLR_EL1 and TCR_EL1 are restored

On guest exit:
- SCTLR_EL1.M and TCR_EL1.EPD{0,1} are set, ensuring that no PTW can occur
- stage-2 is disabled
- All host system registers are restored

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-26 10:44:49 +01:00
Marc Zyngier
37553941c6 arm64: KVM: Disable EL1 PTW when invalidating S2 TLBs
When erratum 1319367 is being worked around, special care must
be taken not to allow the page table walker to populate TLBs
while we have the stage-2 translation enabled (which would otherwise
result in a bizare mix of the host S1 and the guest S2).

We enforce this by setting TCR_EL1.EPD{0,1} before restoring the S2
configuration, and clear the same bits after having disabled S2.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-26 10:43:53 +01:00
Marc Zyngier
1d8cd06af5 arm64: KVM: Reorder system register restoration and stage-2 activation
In order to prepare for handling erratum 1319367, we need to make
sure that all system registers (and most importantly the registers
configuring the virtual memory) are set before we enable stage-2
translation.

This results in a minor reorganisation of the load sequence, without
any functional change.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-26 10:43:32 +01:00
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
Mark Brown
a5315819c5 arm64: pgtable: Correct typo in comment
vmmemmap -> vmemmap

Signed-off-by: Mark Brown <broonie@kernel.org>
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