Commit graph

203 commits

Author SHA1 Message Date
Mark Rutland
8d6acfe80d arm64: consistently use reserved_pg_dir
[ Upstream commit 833be850f1 ]

Depending on configuration options and specific code paths, we either
use the empty_zero_page or the configuration-dependent reserved_ttbr0
as a reserved value for TTBR{0,1}_EL1.

To simplify this code, let's always allocate and use the same
reserved_pg_dir, replacing reserved_ttbr0. Note that this is allocated
(and hence pre-zeroed), and is also marked as read-only in the kernel
Image mapping.

Keeping this separate from the empty_zero_page potentially helps with
robustness as the empty_zero_page is used in a number of cases where a
failure to map it read-only could allow it to become corrupted.

The (presently unused) swapper_pg_end symbol is also removed, and
comments are added wherever we rely on the offsets between the
pre-allocated pg_dirs to keep these cases easily identifiable.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201103102229.8542-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:06 +02:00
Mark Rutland
51524fa8b5 arm64: entry: always set GIC_PRIO_PSR_I_SET during entry
[ Upstream commit 4d6a38da8e ]

Zenghui reports that booting a kernel with "irqchip.gicv3_pseudo_nmi=1"
on the command line hits a warning during kernel entry, due to the way
we manipulate the PMR.

Early in the entry sequence, we call lockdep_hardirqs_off() to inform
lockdep that interrupts have been masked (as the HW sets DAIF wqhen
entering an exception). Architecturally PMR_EL1 is not affected by
exception entry, and we don't set GIC_PRIO_PSR_I_SET in the PMR early in
the exception entry sequence, so early in exception entry the PMR can
indicate that interrupts are unmasked even though they are masked by
DAIF.

If DEBUG_LOCKDEP is selected, lockdep_hardirqs_off() will check that
interrupts are masked, before we set GIC_PRIO_PSR_I_SET in any of the
exception entry paths, and hence lockdep_hardirqs_off() will WARN() that
something is amiss.

We can avoid this by consistently setting GIC_PRIO_PSR_I_SET during
exception entry so that kernel code sees a consistent environment. We
must also update local_daif_inherit() to undo this, as currently only
touches DAIF. For other paths, local_daif_restore() will update both
DAIF and the PMR. With this done, we can remove the existing special
cases which set this later in the entry code.

We always use (GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET) for consistency with
local_daif_save(), as this will warn if it ever encounters
(GIC_PRIO_IRQOFF | GIC_PRIO_PSR_I_SET), and never sets this itself. This
matches the gic_prio_kentry_setup that we have to retain for
ret_to_user.

The original splat from Zenghui's report was:

| DEBUG_LOCKS_WARN_ON(!irqs_disabled())
| WARNING: CPU: 3 PID: 125 at kernel/locking/lockdep.c:4258 lockdep_hardirqs_off+0xd4/0xe8
| Modules linked in:
| CPU: 3 PID: 125 Comm: modprobe Tainted: G        W         5.12.0-rc8+ #463
| Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
| pstate: 604003c5 (nZCv DAIF +PAN -UAO -TCO BTYPE=--)
| pc : lockdep_hardirqs_off+0xd4/0xe8
| lr : lockdep_hardirqs_off+0xd4/0xe8
| sp : ffff80002a39bad0
| pmr_save: 000000e0
| x29: ffff80002a39bad0 x28: ffff0000de214bc0
| x27: ffff0000de1c0400 x26: 000000000049b328
| x25: 0000000000406f30 x24: ffff0000de1c00a0
| x23: 0000000020400005 x22: ffff8000105f747c
| x21: 0000000096000044 x20: 0000000000498ef9
| x19: ffff80002a39bc88 x18: ffffffffffffffff
| x17: 0000000000000000 x16: ffff800011c61eb0
| x15: ffff800011700a88 x14: 0720072007200720
| x13: 0720072007200720 x12: 0720072007200720
| x11: 0720072007200720 x10: 0720072007200720
| x9 : ffff80002a39bad0 x8 : ffff80002a39bad0
| x7 : ffff8000119f0800 x6 : c0000000ffff7fff
| x5 : ffff8000119f07a8 x4 : 0000000000000001
| x3 : 9bcdab23f2432800 x2 : ffff800011730538
| x1 : 9bcdab23f2432800 x0 : 0000000000000000
| Call trace:
|  lockdep_hardirqs_off+0xd4/0xe8
|  enter_from_kernel_mode.isra.5+0x7c/0xa8
|  el1_abort+0x24/0x100
|  el1_sync_handler+0x80/0xd0
|  el1_sync+0x6c/0x100
|  __arch_clear_user+0xc/0x90
|  load_elf_binary+0x9fc/0x1450
|  bprm_execve+0x404/0x880
|  kernel_execve+0x180/0x188
|  call_usermodehelper_exec_async+0xdc/0x158
|  ret_from_fork+0x10/0x18

Fixes: 23529049c6 ("arm64: entry: fix non-NMI user<->kernel transitions")
Fixes: 7cd1ea1010 ("arm64: entry: fix non-NMI kernel<->kernel transitions")
Fixes: f0cd5ac1e4 ("arm64: entry: fix NMI {user, kernel}->kernel transitions")
Fixes: 2a9b3e6ac6 ("arm64: entry: fix EL1 debug transitions")
Link: https://lore.kernel.org/r/f4012761-026f-4e51-3a0c-7524e434e8b3@huawei.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210428111555.50880-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:13:07 +02:00
Marc Zyngier
c9f43423c4 arm64: entry: factor irq triage logic into macros
[ Upstream commit 9eb563cdab ]

In subsequent patches we'll allow an FIQ handler to be registered, and
FIQ exceptions will need to be triaged very similarly to IRQ exceptions.
So that we can reuse the existing logic, this patch factors the IRQ
triage logic out into macros that can be reused for FIQ.

The macros are named to follow the elX_foo_handler scheme used by the C
exception handlers. For consistency with other top-level exception
handlers, the kernel_entry/kernel_exit logic is not moved into the
macros. As FIQ will use a different C handler, this handler name is
provided as an argument to the macros.

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

Signed-off-by: Marc Zyngier <maz@kernel.org>
[Mark: rework macros, commit message, rebase before DAIF rework]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Hector Martin <marcan@marcan.st>
Cc: James Morse <james.morse@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210315115629.57191-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:13:07 +02:00
Catalin Marinas
496e2fabbb arm64: mte: Ensure TIF_MTE_ASYNC_FAULT is set atomically
commit 2decad92f4 upstream.

The entry from EL0 code checks the TFSRE0_EL1 register for any
asynchronous tag check faults in user space and sets the
TIF_MTE_ASYNC_FAULT flag. This is not done atomically, potentially
racing with another CPU calling set_tsk_thread_flag().

Replace the non-atomic ORR+STR with an STSET instruction. While STSET
requires ARMv8.1 and an assembler that understands LSE atomics, the MTE
feature is part of ARMv8.5 and already requires an updated assembler.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 637ec831ea ("arm64: mte: Handle synchronous and asynchronous tag check faults")
Cc: <stable@vger.kernel.org> # 5.10.x
Reported-by: Will Deacon <will@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210409173710.18582-1-catalin.marinas@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21 13:01:00 +02:00
Mark Rutland
23529049c6 arm64: entry: fix non-NMI user<->kernel transitions
When built with PROVE_LOCKING, NO_HZ_FULL, and CONTEXT_TRACKING_FORCE
will WARN() at boot time that interrupts are enabled when we call
context_tracking_user_enter(), despite the DAIF flags indicating that
IRQs are masked.

The problem is that we're not tracking IRQ flag changes accurately, and
so lockdep believes interrupts are enabled when they are not (and
vice-versa). We can shuffle things so to make this more accurate. For
kernel->user transitions there are a number of constraints we need to
consider:

1) When we call __context_tracking_user_enter() HW IRQs must be disabled
   and lockdep must be up-to-date with this.

2) Userspace should be treated as having IRQs enabled from the PoV of
   both lockdep and tracing.

3) As context_tracking_user_enter() stops RCU from watching, we cannot
   use RCU after calling it.

4) IRQ flag tracing and lockdep have state that must be manipulated
   before RCU is disabled.

... with similar constraints applying for user->kernel transitions, with
the ordering reversed.

The generic entry code has enter_from_user_mode() and
exit_to_user_mode() helpers to handle this. We can't use those directly,
so we add arm64 copies for now (without the instrumentation markers
which aren't used on arm64). These replace the existing user_exit() and
user_exit_irqoff() calls spread throughout handlers, and the exception
unmasking is left as-is.

Note that:

* The accounting for debug exceptions from userspace now happens in
  el0_dbg() and ret_to_user(), so this is removed from
  debug_exception_enter() and debug_exception_exit(). As
  user_exit_irqoff() wakes RCU, the userspace-specific check is removed.

* The accounting for syscalls now happens in el0_svc(),
  el0_svc_compat(), and ret_to_user(), so this is removed from
  el0_svc_common(). This does not adversely affect the workaround for
  erratum 1463225, as this does not depend on any of the state tracking.

* In ret_to_user() we mask interrupts with local_daif_mask(), and so we
  need to inform lockdep and tracing. Here a trace_hardirqs_off() is
  sufficient and safe as we have not yet exited kernel context and RCU
  is usable.

* As PROVE_LOCKING selects TRACE_IRQFLAGS, the ifdeferry in entry.S only
  needs to check for the latter.

* EL0 SError handling will be dealt with in a subsequent patch, as this
  needs to be treated as an NMI.

Prior to this patch, booting an appropriately-configured kernel would
result in spats as below:

| DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())
| WARNING: CPU: 2 PID: 1 at kernel/locking/lockdep.c:5280 check_flags.part.54+0x1dc/0x1f0
| Modules linked in:
| CPU: 2 PID: 1 Comm: init Not tainted 5.10.0-rc3 #3
| Hardware name: linux,dummy-virt (DT)
| pstate: 804003c5 (Nzcv DAIF +PAN -UAO -TCO BTYPE=--)
| pc : check_flags.part.54+0x1dc/0x1f0
| lr : check_flags.part.54+0x1dc/0x1f0
| sp : ffff80001003bd80
| x29: ffff80001003bd80 x28: ffff66ce801e0000
| x27: 00000000ffffffff x26: 00000000000003c0
| x25: 0000000000000000 x24: ffffc31842527258
| x23: ffffc31842491368 x22: ffffc3184282d000
| x21: 0000000000000000 x20: 0000000000000001
| x19: ffffc318432ce000 x18: 0080000000000000
| x17: 0000000000000000 x16: ffffc31840f18a78
| x15: 0000000000000001 x14: ffffc3184285c810
| x13: 0000000000000001 x12: 0000000000000000
| x11: ffffc318415857a0 x10: ffffc318406614c0
| x9 : ffffc318415857a0 x8 : ffffc31841f1d000
| x7 : 647261685f706564 x6 : ffffc3183ff7c66c
| x5 : ffff66ce801e0000 x4 : 0000000000000000
| x3 : ffffc3183fe00000 x2 : ffffc31841500000
| x1 : e956dc24146b3500 x0 : 0000000000000000
| Call trace:
|  check_flags.part.54+0x1dc/0x1f0
|  lock_is_held_type+0x10c/0x188
|  rcu_read_lock_sched_held+0x70/0x98
|  __context_tracking_enter+0x310/0x350
|  context_tracking_enter.part.3+0x5c/0xc8
|  context_tracking_user_enter+0x6c/0x80
|  finish_ret_to_user+0x2c/0x13cr

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201130115950.22492-8-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-11-30 12:11:38 +00:00
Mark Rutland
105fc33520 arm64: entry: move el1 irq/nmi logic to C
In preparation for reworking the EL1 irq/nmi entry code, move the
existing logic to C. We no longer need the asm_nmi_enter() and
asm_nmi_exit() wrappers, so these are removed. The new C functions are
marked noinstr, which prevents compiler instrumentation and runtime
probing.

In subsequent patches we'll want the new C helpers to be called in all
cases, so we don't bother wrapping the calls with ifdeferry. Even when
the new C functions are stubs the trivial calls are unlikely to have a
measurable impact on the IRQ or NMI paths anyway.

Prototypes are added to <asm/exception.h> as otherwise (in some
configurations) GCC will complain about the lack of a forward
declaration. We already do this for existing function, e.g.
enter_from_user_mode().

The new helpers are marked as noinstr (which prevents all
instrumentation, tracing, and kprobes). Otherwise, there should be no
functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201130115950.22492-7-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-11-30 12:11:38 +00:00
Mark Rutland
3cb5ed4d76 arm64: entry: prepare ret_to_user for function call
In a subsequent patch ret_to_user will need to make a C function call
(in some configurations) which may clobber x0-x18 at the start of the
finish_ret_to_user block, before enable_step_tsk consumes the flags
loaded into x1.

In preparation for this, let's load the flags into x19, which is
preserved across C function calls. This avoids a redundant reload of the
flags and ensures we operate on a consistent shapshot regardless.

There should be no functional change as a result of this patch. At this
point of the entry/exit paths we only need to preserve x28 (tsk) and the
sp, and x19 is free for this use.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201130115950.22492-6-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-11-30 12:11:37 +00:00
Rob Herring
96d389ca10 arm64: Add workaround for Arm Cortex-A77 erratum 1508412
On Cortex-A77 r0p0 and r1p0, a sequence of a non-cacheable or device load
and a store exclusive or PAR_EL1 read can cause a deadlock.

The workaround requires a DMB SY before and after a PAR_EL1 register
read. In addition, it's possible an interrupt (doing a device read) or
KVM guest exit could be taken between the DMB and PAR read, so we
also need a DMB before returning from interrupt and before returning to
a guest.

A deadlock is still possible with the workaround as KVM guests must also
have the workaround. IOW, a malicious guest can deadlock an affected
systems.

This workaround also depends on a firmware counterpart to enable the h/w
to insert DMB SY after load and store exclusive instructions. See the
errata document SDEN-1152370 v10 [1] for more information.

[1] https://static.docs.arm.com/101992/0010/Arm_Cortex_A77_MP074_Software_Developer_Errata_Notice_v10.pdf

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: kvmarm@lists.cs.columbia.edu
Link: https://lore.kernel.org/r/20201028182839.166037-2-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-10-29 12:56:01 +00:00
Will Deacon
baab853229 Merge branch 'for-next/mte' into for-next/core
Add userspace support for the Memory Tagging Extension introduced by
Armv8.5.

(Catalin Marinas and others)
* for-next/mte: (30 commits)
  arm64: mte: Fix typo in memory tagging ABI documentation
  arm64: mte: Add Memory Tagging Extension documentation
  arm64: mte: Kconfig entry
  arm64: mte: Save tags when hibernating
  arm64: mte: Enable swap of tagged pages
  mm: Add arch hooks for saving/restoring tags
  fs: Handle intra-page faults in copy_mount_options()
  arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset
  arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support
  arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks
  arm64: mte: Restore the GCR_EL1 register after a suspend
  arm64: mte: Allow user control of the generated random tags via prctl()
  arm64: mte: Allow user control of the tag check mode via prctl()
  mm: Allow arm64 mmap(PROT_MTE) on RAM-based files
  arm64: mte: Validate the PROT_MTE request via arch_validate_flags()
  mm: Introduce arch_validate_flags()
  arm64: mte: Add PROT_MTE support to mmap() and mprotect()
  mm: Introduce arch_calc_vm_flag_bits()
  arm64: mte: Tags-aware aware memcmp_pages() implementation
  arm64: Avoid unnecessary clear_user_page() indirection
  ...
2020-10-02 12:16:11 +01:00
Will Deacon
c28762070c arm64: Rewrite Spectre-v4 mitigation code
Rewrite the Spectre-v4 mitigation handling code to follow the same
approach as that taken by Spectre-v2.

For now, report to KVM that the system is vulnerable (by forcing
'ssbd_state' to ARM64_SSBD_UNKNOWN), as this will be cleared up in
subsequent steps.

Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:16 +01:00
Will Deacon
6e5f092784 arm64: Remove Spectre-related CONFIG_* options
The spectre mitigations are too configurable for their own good, leading
to confusing logic trying to figure out when we should mitigate and when
we shouldn't. Although the plethora of command-line options need to stick
around for backwards compatibility, the default-on CONFIG options that
depend on EXPERT can be dropped, as the mitigations only do anything if
the system is vulnerable, a mitigation is available and the command-line
hasn't disabled it.

Remove CONFIG_HARDEN_BRANCH_PREDICTOR and CONFIG_ARM64_SSBD in favour of
enabling this code unconditionally.

Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:15 +01:00
Vincenzo Frascino
637ec831ea arm64: mte: Handle synchronous and asynchronous tag check faults
The Memory Tagging Extension has two modes of notifying a tag check
fault at EL0, configurable through the SCTLR_EL1.TCF0 field:

1. Synchronous raising of a Data Abort exception with DFSC 17.
2. Asynchronous setting of a cumulative bit in TFSRE0_EL1.

Add the exception handler for the synchronous exception and handling of
the asynchronous TFSRE0_EL1.TF0 bit setting via a new TIF flag in
do_notify_resume().

On a tag check failure in user-space, whether synchronous or
asynchronous, a SIGSEGV will be raised on the faulting thread.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2020-09-04 12:46:06 +01:00
Marc Zyngier
d49f7d7376 arm64: Move handling of erratum 1418040 into C code
Instead of dealing with erratum 1418040 on each entry and exit,
let's move the handling to __switch_to() instead, which has
several advantages:

- It can be applied when it matters (switching between 32 and 64
  bit tasks).
- It is written in C (yay!)
- It can rely on static keys rather than alternatives

Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200731173824.107480-2-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-21 11:39:56 +01:00
Linus Torvalds
145ff1ec09 arm64 and cross-arch updates for 5.9:
- Removal of the tremendously unpopular read_barrier_depends() barrier,
   which is a NOP on all architectures apart from Alpha, in favour of
   allowing architectures to override READ_ONCE() and do whatever dance
   they need to do to ensure address dependencies provide LOAD ->
   LOAD/STORE ordering. This work also offers a potential solution if
   compilers are shown to convert LOAD -> LOAD address dependencies into
   control dependencies (e.g. under LTO), as weakly ordered architectures
   will effectively be able to upgrade READ_ONCE() to smp_load_acquire().
   The latter case is not used yet, but will be discussed further at LPC.
 
 - Make the MSI/IOMMU input/output ID translation PCI agnostic, augment
   the MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID
   bus-specific parameter and apply the resulting changes to the device
   ID space provided by the Freescale FSL bus.
 
 - arm64 support for TLBI range operations and translation table level
   hints (part of the ARMv8.4 architecture version).
 
 - Time namespace support for arm64.
 
 - Export the virtual and physical address sizes in vmcoreinfo for
   makedumpfile and crash utilities.
 
 - CPU feature handling cleanups and checks for programmer errors
   (overlapping bit-fields).
 
 - ACPI updates for arm64: disallow AML accesses to EFI code regions and
   kernel memory.
 
 - perf updates for arm64.
 
 - Miscellaneous fixes and cleanups, most notably PLT counting
   optimisation for module loading, recordmcount fix to ignore
   relocations other than R_AARCH64_CALL26, CMA areas reserved for
   gigantic pages on 16K and 64K configurations.
 
 - Trivial typos, duplicate words.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 and cross-arch updates from Catalin Marinas:
 "Here's a slightly wider-spread set of updates for 5.9.

  Going outside the usual arch/arm64/ area is the removal of
  read_barrier_depends() series from Will and the MSI/IOMMU ID
  translation series from Lorenzo.

  The notable arm64 updates include ARMv8.4 TLBI range operations and
  translation level hint, time namespace support, and perf.

  Summary:

   - Removal of the tremendously unpopular read_barrier_depends()
     barrier, which is a NOP on all architectures apart from Alpha, in
     favour of allowing architectures to override READ_ONCE() and do
     whatever dance they need to do to ensure address dependencies
     provide LOAD -> LOAD/STORE ordering.

     This work also offers a potential solution if compilers are shown
     to convert LOAD -> LOAD address dependencies into control
     dependencies (e.g. under LTO), as weakly ordered architectures will
     effectively be able to upgrade READ_ONCE() to smp_load_acquire().
     The latter case is not used yet, but will be discussed further at
     LPC.

   - Make the MSI/IOMMU input/output ID translation PCI agnostic,
     augment the MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID
     bus-specific parameter and apply the resulting changes to the
     device ID space provided by the Freescale FSL bus.

   - arm64 support for TLBI range operations and translation table level
     hints (part of the ARMv8.4 architecture version).

   - Time namespace support for arm64.

   - Export the virtual and physical address sizes in vmcoreinfo for
     makedumpfile and crash utilities.

   - CPU feature handling cleanups and checks for programmer errors
     (overlapping bit-fields).

   - ACPI updates for arm64: disallow AML accesses to EFI code regions
     and kernel memory.

   - perf updates for arm64.

   - Miscellaneous fixes and cleanups, most notably PLT counting
     optimisation for module loading, recordmcount fix to ignore
     relocations other than R_AARCH64_CALL26, CMA areas reserved for
     gigantic pages on 16K and 64K configurations.

   - Trivial typos, duplicate words"

Link: http://lkml.kernel.org/r/20200710165203.31284-1-will@kernel.org
Link: http://lkml.kernel.org/r/20200619082013.13661-1-lorenzo.pieralisi@arm.com

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (82 commits)
  arm64: use IRQ_STACK_SIZE instead of THREAD_SIZE for irq stack
  arm64/mm: save memory access in check_and_switch_context() fast switch path
  arm64: sigcontext.h: delete duplicated word
  arm64: ptrace.h: delete duplicated word
  arm64: pgtable-hwdef.h: delete duplicated words
  bus: fsl-mc: Add ACPI support for fsl-mc
  bus/fsl-mc: Refactor the MSI domain creation in the DPRC driver
  of/irq: Make of_msi_map_rid() PCI bus agnostic
  of/irq: make of_msi_map_get_device_domain() bus agnostic
  dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus
  of/device: Add input id to of_dma_configure()
  of/iommu: Make of_map_rid() PCI agnostic
  ACPI/IORT: Add an input ID to acpi_dma_configure()
  ACPI/IORT: Remove useless PCI bus walk
  ACPI/IORT: Make iort_msi_map_rid() PCI agnostic
  ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic
  ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC
  arm64: enable time namespace support
  arm64/vdso: Restrict splitting VVAR VMA
  arm64/vdso: Handle faults on timens page
  ...
2020-08-03 14:11:08 -07:00
Catalin Marinas
0e4cd9f265 Merge branch 'for-next/read-barrier-depends' into for-next/core
* for-next/read-barrier-depends:
  : Allow architectures to override __READ_ONCE()
  arm64: Reduce the number of header files pulled into vmlinux.lds.S
  compiler.h: Move compiletime_assert() macros into compiler_types.h
  checkpatch: Remove checks relating to [smp_]read_barrier_depends()
  include/linux: Remove smp_read_barrier_depends() from comments
  tools/memory-model: Remove smp_read_barrier_depends() from informal doc
  Documentation/barriers/kokr: Remove references to [smp_]read_barrier_depends()
  Documentation/barriers: Remove references to [smp_]read_barrier_depends()
  locking/barriers: Remove definitions for [smp_]read_barrier_depends()
  alpha: Replace smp_read_barrier_depends() usage with smp_[r]mb()
  vhost: Remove redundant use of read_barrier_depends() barrier
  asm/rwonce: Don't pull <asm/barrier.h> into 'asm-generic/rwonce.h'
  asm/rwonce: Remove smp_read_barrier_depends() invocation
  alpha: Override READ_ONCE() with barriered implementation
  asm/rwonce: Allow __READ_ONCE to be overridden by the architecture
  compiler.h: Split {READ,WRITE}_ONCE definitions out into rwonce.h
  tools: bpf: Use local copy of headers including uapi/linux/filter.h
2020-07-31 18:09:57 +01:00
Ard Biesheuvel
0ae3b13aab arm64/entry: deduplicate SW PAN entry/exit routines
Factor the 12 copies of the SW PAN entry and exit code into callable
subroutines, and use alternatives patching to either emit a 'bl'
instruction to call them, or a NOP if h/w PAN is found to be available
at runtime.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200721083315.4816-1-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-23 12:38:55 +01:00
Will Deacon
5f1f7f6c20 arm64: Reduce the number of header files pulled into vmlinux.lds.S
Although vmlinux.lds.S smells like an assembly file and is compiled
with __ASSEMBLY__ defined, it's actually just fed to the preprocessor to
create our linker script. This means that any assembly macros defined
by headers that it includes will result in a helpful link error:

| aarch64-linux-gnu-ld:./arch/arm64/kernel/vmlinux.lds:1: syntax error

In preparation for an arm64-private asm/rwonce.h implementation, which
will end up pulling assembly macros into linux/compiler.h, reduce the
number of headers we include directly and transitively in vmlinux.lds.S

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-07-21 10:50:37 +01:00
Will Deacon
8c3001b925 arm64: entry: Tidy up block comments and label numbers
Continually butchering our entry code with CPU errata workarounds has
led to it looking a little scruffy. Consistently used /* */ comment
style for multi-line block comments and ensure that small numeric labels
use consecutive integers.

No functional change, but the state of things was irritating.

Signed-off-by: Will Deacon <will@kernel.org>
2020-07-08 22:13:33 +01:00
Marc Zyngier
dc802f2bc0 arm64: Rework ARM_ERRATUM_1414080 handling
The current handling of erratum 1414080 has the side effect that
cntkctl_el1 can get changed for both 32 and 64bit tasks.

This isn't a problem so far, but if we ever need to mitigate another
of these errata on the 64bit side, we'd better keep the messing with
cntkctl_el1 local to 32bit tasks.

For that, make sure that on entering the kernel from a 32bit tasks,
userspace access to cntvct gets enabled, and disabled returning to
userspace, while it never gets changed for 64bit tasks.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200706163802.1836732-5-maz@kernel.org
[will: removed branch instructions per Mark's review comments]
Signed-off-by: Will Deacon <will@kernel.org>
2020-07-08 22:07:19 +01:00
Will Deacon
082af5ec50 Merge branch 'for-next/scs' into for-next/core
Support for Clang's Shadow Call Stack in the kernel
(Sami Tolvanen and Will Deacon)
* for-next/scs:
  arm64: entry-ftrace.S: Update comment to indicate that x18 is live
  scs: Move DEFINE_SCS macro into core code
  scs: Remove references to asm/scs.h from core code
  scs: Move scs_overflow_check() out of architecture code
  arm64: scs: Use 'scs_sp' register alias for x18
  scs: Move accounting into alloc/free functions
  arm64: scs: Store absolute SCS stack pointer value in thread_info
  efi/libstub: Disable Shadow Call Stack
  arm64: scs: Add shadow stacks for SDEI
  arm64: Implement Shadow Call Stack
  arm64: Disable SCS for hypervisor code
  arm64: vdso: Disable Shadow Call Stack
  arm64: efi: Restore register x18 if it was corrupted
  arm64: Preserve register x18 when CPU is suspended
  arm64: Reserve register x18 from general allocation with SCS
  scs: Disable when function graph tracing is enabled
  scs: Add support for stack usage debugging
  scs: Add page accounting for shadow call stack allocations
  scs: Add support for Clang's Shadow Call Stack (SCS)
2020-05-28 18:03:40 +01:00
Will Deacon
d27865279f Merge branch 'for-next/bti' into for-next/core
Support for Branch Target Identification (BTI) in user and kernel
(Mark Brown and others)
* for-next/bti: (39 commits)
  arm64: vdso: Fix CFI directives in sigreturn trampoline
  arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction
  arm64: bti: Fix support for userspace only BTI
  arm64: kconfig: Update and comment GCC version check for kernel BTI
  arm64: vdso: Map the vDSO text with guarded pages when built for BTI
  arm64: vdso: Force the vDSO to be linked as BTI when built for BTI
  arm64: vdso: Annotate for BTI
  arm64: asm: Provide a mechanism for generating ELF note for BTI
  arm64: bti: Provide Kconfig for kernel mode BTI
  arm64: mm: Mark executable text as guarded pages
  arm64: bpf: Annotate JITed code for BTI
  arm64: Set GP bit in kernel page tables to enable BTI for the kernel
  arm64: asm: Override SYM_FUNC_START when building the kernel with BTI
  arm64: bti: Support building kernel C code using BTI
  arm64: Document why we enable PAC support for leaf functions
  arm64: insn: Report PAC and BTI instructions as skippable
  arm64: insn: Don't assume unrecognized HINTs are skippable
  arm64: insn: Provide a better name for aarch64_insn_is_nop()
  arm64: insn: Add constants for new HINT instruction decode
  arm64: Disable old style assembly annotations
  ...
2020-05-28 18:00:51 +01:00
Will Deacon
711e8b0de0 arm64: scs: Use 'scs_sp' register alias for x18
x18 holds the SCS stack pointer value, so introduce a register alias to
make this easier to read in assembly code.

Tested-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-18 17:47:37 +01:00
Sami Tolvanen
439dc2a117 arm64: scs: Add shadow stacks for SDEI
This change adds per-CPU shadow call stacks for the SDEI handler.
Similarly to how the kernel stacks are handled, we add separate shadow
stacks for normal and critical events.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-15 16:35:50 +01:00
Sami Tolvanen
5287569a79 arm64: Implement Shadow Call Stack
This change implements shadow stack switching, initial SCS set-up,
and interrupt shadow stacks for arm64.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-15 16:35:50 +01:00
Mark Brown
06607c7e93 arm64: entry: Refactor and modernise annotation for ret_to_user
As part of an effort to clarify and clean up the assembler annotations
new macros have been introduced which annotate the start and end of blocks
of code in assembler files. Currently ret_to_user has an out of line slow
path work_pending placed above the main function which makes annotating the
start and end of these blocks of code awkward.

Since work_pending is only referenced from within ret_to_user try to make
things a bit clearer by moving it after the current ret_to_user and then
marking both ret_to_user and work_pending as part of a single ret_to_user
code block.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200501115430.37315-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-04 12:46:03 +01:00
Mark Rutland
d0055da526 arm64: remove ptrauth_keys_install_kernel sync arg
The 'sync' argument to ptrauth_keys_install_kernel macro is somewhat
opaque at callsites, so instead lets have regular and _nosync variants
of the macro to make this a little more obvious.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200423101606.37601-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28 11:23:21 +01:00
Catalin Marinas
44ca0e00b6 Merge branch 'for-next/kernel-ptrauth' into for-next/core
* for-next/kernel-ptrauth:
  : Return address signing - in-kernel support
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  arm64: ptrauth: Add bootup/runtime flags for __cpu_setup
  arm64: install user ptrauth keys at kernel exit time
  arm64: rename ptrauth key structures to be user-specific
  arm64: cpufeature: add pointer auth meta-capabilities
  arm64: cpufeature: Fix meta-capability cpufeature check
2020-03-25 11:11:08 +00:00
Amit Daniel Kachhap
e51f5f56dd arm64: suspend: restore the kernel ptrauth keys
This patch restores the kernel keys from current task during cpu resume
after the mmu is turned on and ptrauth is enabled.

A flag is added in macro ptrauth_keys_install_kernel to check if isb
instruction needs to be executed.

Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:21 +00:00
Kristina Martsenko
33e4523498 arm64: initialize and switch ptrauth kernel keys
Set up keys to use pointer authentication within the kernel. The kernel
will be compiled with APIAKey instructions, the other keys are currently
unused. Each task is given its own APIAKey, which is initialized during
fork. The key is changed during context switch and on kernel entry from
EL0.

The keys for idle threads need to be set before calling any C functions,
because it is not possible to enter and exit a function with different
keys.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Modified secondary cores key structure, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:20 +00:00
Kristina Martsenko
be12984256 arm64: install user ptrauth keys at kernel exit time
As we're going to enable pointer auth within the kernel and use a
different APIAKey for the kernel itself, so move the user APIAKey
switch to EL0 exception return.

The other 4 keys could remain switched during task switch, but are also
moved to keep things consistent.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: commit msg, re-positioned the patch, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:19 +00:00
Mark Brown
1242b9b303 arm64: sdei: Annotate SDEI entry points using new style annotations
In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions.

The SDEI entry points are currently annotated as normal functions but
are called from non-kernel contexts with non-standard calling convention
and should therefore be annotated as such so do so.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: James Morse <james.Morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-09 17:36:03 +00:00
Mark Brown
a5d4420b26 arm64: kernel: Convert to modern annotations for assembly data
In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These include specific
annotations for the start and end of data, update symbols for data to use
these.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-09 17:35:24 +00:00
Mark Brown
e7bf697217 arm64: entry: Additional annotation conversions for entry.S
In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC with separate annotations for standard C callable functions,
data and code with different calling conventions.  Update the
remaining annotations in the entry.S code to the new macros.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-09 17:35:10 +00:00
Mark Brown
c3357fc541 arm64: entry: Annotate ret_from_fork as code
In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions.

ret_from_fork is not a normal C function and should therefore be
annotated as code.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-09 17:35:08 +00:00
Mark Brown
0ccbd98a92 arm64: entry: Annotate vector table and handlers as code
In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions. The vector table and handlers aren't
normal C style code so should be annotated as CODE.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-09 17:35:06 +00:00
Linus Torvalds
c677124e63 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "These were the main changes in this cycle:

   - More -rt motivated separation of CONFIG_PREEMPT and
     CONFIG_PREEMPTION.

   - Add more low level scheduling topology sanity checks and warnings
     to filter out nonsensical topologies that break scheduling.

   - Extend uclamp constraints to influence wakeup CPU placement

   - Make the RT scheduler more aware of asymmetric topologies and CPU
     capacities, via uclamp metrics, if CONFIG_UCLAMP_TASK=y

   - Make idle CPU selection more consistent

   - Various fixes, smaller cleanups, updates and enhancements - please
     see the git log for details"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  sched/fair: Define sched_idle_cpu() only for SMP configurations
  sched/topology: Assert non-NUMA topology masks don't (partially) overlap
  idle: fix spelling mistake "iterrupts" -> "interrupts"
  sched/fair: Remove redundant call to cpufreq_update_util()
  sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled
  sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP
  sched/fair: calculate delta runnable load only when it's needed
  sched/cputime: move rq parameter in irqtime_account_process_tick
  stop_machine: Make stop_cpus() static
  sched/debug: Reset watchdog on all CPUs while processing sysrq-t
  sched/core: Fix size of rq::uclamp initialization
  sched/uclamp: Fix a bug in propagating uclamp value in new cgroups
  sched/fair: Load balance aggressively for SCHED_IDLE CPUs
  sched/fair : Improve update_sd_pick_busiest for spare capacity case
  watchdog: Remove soft_lockup_hrtimer_cnt and related code
  sched/rt: Make RT capacity-aware
  sched/fair: Make EAS wakeup placement consider uclamp restrictions
  sched/fair: Make task_fits_capacity() consider uclamp restrictions
  sched/uclamp: Rename uclamp_util_with() into uclamp_rq_util_with()
  sched/uclamp: Make uclamp util helpers use and return UL values
  ...
2020-01-28 10:07:09 -08:00
Will Deacon
aa246c056c Merge branch 'for-next/asm-annotations' into for-next/core
* for-next/asm-annotations: (6 commits)
  arm64: kernel: Correct annotation of end of el0_sync
  ...
2020-01-22 11:34:21 +00:00
Will Deacon
4f6cdf296c Merge branches 'for-next/acpi', 'for-next/cpufeatures', 'for-next/csum', 'for-next/e0pd', 'for-next/entry', 'for-next/kbuild', 'for-next/kexec/cleanup', 'for-next/kexec/file-kdump', 'for-next/misc', 'for-next/nofpsimd', 'for-next/perf' and 'for-next/scs' into for-next/core
* for-next/acpi:
  ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map()

* for-next/cpufeatures: (2 commits)
  arm64: Introduce ID_ISAR6 CPU register
  ...

* for-next/csum: (2 commits)
  arm64: csum: Fix pathological zero-length calls
  ...

* for-next/e0pd: (7 commits)
  arm64: kconfig: Fix alignment of E0PD help text
  ...

* for-next/entry: (5 commits)
  arm64: entry: cleanup sp_el0 manipulation
  ...

* for-next/kbuild: (4 commits)
  arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'
  ...

* for-next/kexec/cleanup: (11 commits)
  Revert "arm64: kexec: make dtb_mem always enabled"
  ...

* for-next/kexec/file-kdump: (2 commits)
  arm64: kexec_file: add crash dump support
  ...

* for-next/misc: (12 commits)
  arm64: entry: Avoid empty alternatives entries
  ...

* for-next/nofpsimd: (7 commits)
  arm64: nofpsmid: Handle TIF_FOREIGN_FPSTATE flag cleanly
  ...

* for-next/perf: (2 commits)
  perf/imx_ddr: Fix cpu hotplug state cleanup
  ...

* for-next/scs: (6 commits)
  arm64: kernel: avoid x18 in __cpu_soft_restart
  ...
2020-01-22 11:32:31 +00:00
Julien Thierry
108eae2d4d arm64: entry: Avoid empty alternatives entries
kernel_ventry will create alternative entries to potentially replace
0 instructions with 0 instructions for EL1 vectors. While this does not
cause an issue, it pointlessly takes up some bytes in the alternatives
section.

Do not generate such entries.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-21 09:55:18 +00:00
Mark Rutland
3e3934176a arm64: entry: cleanup sp_el0 manipulation
The kernel stashes the current task struct in sp_el0 so that this can be
acquired consistently/cheaply when required. When we take an exception
from EL0 we have to:

1) stash the original sp_el0 value
2) find the current task
3) update sp_el0 with the current task pointer

Currently steps #1 and #2 occur in one place, and step #3 a while later.
As the value of sp_el0 is immaterial between these points, let's move
them together to make the code clearer and minimize ifdeffery. This
necessitates moving the comment for MDSCR_EL1.SS.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 13:22:14 +00:00
Mark Brown
73d6890fe8 arm64: kernel: Correct annotation of end of el0_sync
Commit 582f95835a ("arm64: entry: convert el0_sync to C") caused
the ENDPROC() annotating the end of el0_sync to be placed after the code
for el0_sync_compat. This replaced the previous annotation where it was
located after all the cases that are now converted to C, including after
the currently unannotated el0_irq_compat and el0_error_compat. Move the
annotation to the end of the function and add separate annotations for
the _compat ones.

Fixes: 582f95835a (arm64: entry: convert el0_sync to C)
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-13 11:38:43 +00:00
Ingo Molnar
1e5f8a3085 Linux 5.5-rc3
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Merge tag 'v5.5-rc3' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-25 10:41:37 +01:00
Thomas Gleixner
7ef858dad9 sched/rt, arm64: Use CONFIG_PREEMPTION
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Switch the Kconfig dependency, entry code and preemption handling over
to use CONFIG_PREEMPTION. Add PREEMPT_RT output in show_stack().

[bigeasy: +traps.c, Kconfig]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20191015191821.11479-3-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-08 14:37:32 +01:00
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
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
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
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
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