- Kexec support for arm64
- Kprobes support
- Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs
- Trapping of user space cache maintenance operations and emulation in
the kernel (CPU errata workaround)
- Clean-up of the early page tables creation (kernel linear mapping, EFI
run-time maps) to avoid splitting larger blocks (e.g. pmds) into
smaller ones (e.g. ptes)
- VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime()
- ARCH_HAS_KCOV enabled for arm64
- Optimise IP checksum helpers
- SWIOTLB optimisation to only allocate/initialise the buffer if the
available RAM is beyond the 32-bit mask
- Properly handle the "nosmp" command line argument
- Fix for the initialisation of the CPU debug state during early boot
- vdso-offsets.h build dependency workaround
- Build fix when RANDOMIZE_BASE is enabled with MODULES off
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- Kexec support for arm64
- Kprobes support
- Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs
- Trapping of user space cache maintenance operations and emulation in
the kernel (CPU errata workaround)
- Clean-up of the early page tables creation (kernel linear mapping,
EFI run-time maps) to avoid splitting larger blocks (e.g. pmds) into
smaller ones (e.g. ptes)
- VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime()
- ARCH_HAS_KCOV enabled for arm64
- Optimise IP checksum helpers
- SWIOTLB optimisation to only allocate/initialise the buffer if the
available RAM is beyond the 32-bit mask
- Properly handle the "nosmp" command line argument
- Fix for the initialisation of the CPU debug state during early boot
- vdso-offsets.h build dependency workaround
- Build fix when RANDOMIZE_BASE is enabled with MODULES off
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits)
arm64: arm: Fix-up the removal of the arm64 regs_query_register_name() prototype
arm64: Only select ARM64_MODULE_PLTS if MODULES=y
arm64: mm: run pgtable_page_ctor() on non-swapper translation table pages
arm64: mm: make create_mapping_late() non-allocating
arm64: Honor nosmp kernel command line option
arm64: Fix incorrect per-cpu usage for boot CPU
arm64: kprobes: Add KASAN instrumentation around stack accesses
arm64: kprobes: Cleanup jprobe_return
arm64: kprobes: Fix overflow when saving stack
arm64: kprobes: WARN if attempting to step with PSTATE.D=1
arm64: debug: remove unused local_dbg_{enable, disable} macros
arm64: debug: remove redundant spsr manipulation
arm64: debug: unmask PSTATE.D earlier
arm64: localise Image objcopy flags
arm64: ptrace: remove extra define for CPSR's E bit
kprobes: Add arm64 case in kprobe example module
arm64: Add kernel return probes support (kretprobes)
arm64: Add trampoline code for kretprobes
arm64: kprobes instruction simulation support
arm64: Treat all entry code as non-kprobe-able
...
* acpi-processor:
ACPI: enable ACPI_PROCESSOR_IDLE on ARM64
arm64: add support for ACPI Low Power Idle(LPI)
drivers: firmware: psci: initialise idle states using ACPI LPI
cpuidle: introduce CPU_PM_CPU_IDLE_ENTER macro for ARM{32, 64}
arm64: cpuidle: drop __init section marker to arm_cpuidle_init
ACPI / processor_idle: Add support for Low Power Idle(LPI) states
ACPI / processor_idle: introduce ACPI_PROCESSOR_CSTATE
* acpi-cppc:
mailbox: pcc: Add PCC request and free channel declarations
ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid data
ACPI: CPPC: Return error if _CPC is invalid on a CPU
* acpi-apei:
ACPI / APEI: Add Boot Error Record Table (BERT) support
ACPI / einj: Make error paths more talkative
ACPI / einj: Convert EINJ_PFX to proper pr_fmt
* acpi-sleep:
ACPI: Execute _PTS before system reboot
* acpi-tables:
ACPI: Rename configfs.c to acpi_configfs.c to prevent link error
ACPI: add support for loading SSDTs via configfs
ACPI: add support for configfs
efi / ACPI: load SSTDs from EFI variables
spi / ACPI: add support for ACPI reconfigure notifications
i2c / ACPI: add support for ACPI reconfigure notifications
ACPI: add support for ACPI reconfiguration notifiers
ACPI / scan: fix enumeration (visited) flags for bus rescans
ACPI / documentation: add SSDT overlays documentation
ACPI: ARM64: support for ACPI_TABLE_UPGRADE
ACPI / tables: introduce ARCH_HAS_ACPI_TABLE_UPGRADE
ACPI / tables: move arch-specific symbol to asm/acpi.h
ACPI / tables: table upgrade: refactor function definitions
ACPI / tables: table upgrade: use cacheable map for tables
Conflicts:
arch/arm64/include/asm/acpi.h
This patch adds appropriate callbacks to support ACPI Low Power Idle
(LPI) on ARM64.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit ea389daa7f (arm64: cpuidle: add __init section marker to
arm_cpuidle_init) added the __init annotation to arm_cpuidle_init
as it was not needed after booting which was correct at that time.
However with the introduction of ACPI LPI support, this will be used
from cpuhotplug path in ACPI processor driver.
This patch drops the __init annotation from arm_cpuidle_init to avoid
the following warning:
WARNING: vmlinux.o(.text+0x113c8): Section mismatch in reference from the
function acpi_processor_ffh_lpi_probe() to the function
.init.text:arm_cpuidle_init()
The function acpi_processor_ffh_lpi_probe() references
the function __init arm_cpuidle_init().
This is often because acpi_processor_ffh_lpi_probe() lacks a __init
annotation or the annotation of arm_cpuidle_init is wrong.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* kprobes:
arm64: kprobes: Add KASAN instrumentation around stack accesses
arm64: kprobes: Cleanup jprobe_return
arm64: kprobes: Fix overflow when saving stack
arm64: kprobes: WARN if attempting to step with PSTATE.D=1
kprobes: Add arm64 case in kprobe example module
arm64: Add kernel return probes support (kretprobes)
arm64: Add trampoline code for kretprobes
arm64: kprobes instruction simulation support
arm64: Treat all entry code as non-kprobe-able
arm64: Blacklist non-kprobe-able symbol
arm64: Kprobes with single stepping support
arm64: add conditional instruction simulation support
arm64: Add more test functions to insn.c
arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature
Passing "nosmp" should boot the kernel with a single processor, without
provision to enable secondary CPUs even if they are present. "nosmp" is
implemented by setting maxcpus=0. At the moment we still mark the secondary
CPUs present even with nosmp, which allows the userspace to bring them
up. This patch corrects the smp_prepare_cpus() to honor the maxcpus == 0.
Commit 44dbcc93ab ("arm64: Fix behavior of maxcpus=N") fixed the
behavior for maxcpus >= 1, but broke maxcpus = 0.
Fixes: 44dbcc93ab ("arm64: Fix behavior of maxcpus=N")
Cc: <stable@vger.kernel.org> # 4.7+
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
[catalin.marinas@arm.com: updated code comment]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In smp_prepare_boot_cpu(), we invoke cpuinfo_store_boot_cpu to store
the cpuinfo in a per-cpu ptr, before initialising the per-cpu offset for
the boot CPU. This patch reorders the sequence to make sure we initialise
the per-cpu offset before accessing the per-cpu area.
Commit 4b998ff188 ("arm64: Delay cpuinfo_store_boot_cpu") fixed the
issue where we modified the per-cpu area even before the kernel initialises
the per-cpu areas, but failed to wait until the boot cpu updated it's
offset.
Fixes: 4b998ff188 ("arm64: Delay cpuinfo_store_boot_cpu")
Cc: <stable@vger.kernel.org> # 4.4+
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
jprobe_return seems to have aged badly. Comments referring to
non-existent behaviours, and a dangerous habit of messing
with registers without telling the compiler.
This patches applies the following remedies:
- Fix the comments to describe the actual behaviour
- Tidy up the asm sequence to directly assign the
stack pointer without clobbering extra registers
- Mark the rest of the function as unreachable() so
that the compiler knows that there is no need for
an epilogue
- Stop making jprobe_return_break a global function
(you really don't want to call that guy, and it isn't
even a function).
Tested with tcp_probe.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The MIN_STACK_SIZE macro tries evaluate how much stack space needs
to be saved in the jprobes_stack array, sized at 128 bytes.
When using the IRQ stack, said macro can happily return up to
IRQ_STACK_SIZE, which is 16kB. Mayhem follows.
This patch fixes things by getting rid of the crazy macro and
limiting the copy to be at most the size of the jprobes_stack
array, no matter which stack we're on.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Stepping with PSTATE.D=1 is bad news. The step won't generate a debug
exception and we'll likely walk off into random data structures. This
should never happen, but when it does, it's a PITA to debug. Add a
WARN_ON to shout if we realise this is about to take place.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
There is no need to explicitly clear the SS bit immediately before
setting it unconditionally.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Clearing PSTATE.D is one of the requirements for generating a debug
exception. The arm64 booting protocol requires that PSTATE.D is set,
since many of the debug registers (for example, the hw_breakpoint
registers) are UNKNOWN out of reset and could potentially generate
spurious, fatal debug exceptions in early boot code if PSTATE.D was
clear. Once the debug registers have been safely initialised, PSTATE.D
is cleared, however this is currently broken for two reasons:
(1) The boot CPU clears PSTATE.D in a postcore_initcall and secondary
CPUs clear PSTATE.D in secondary_start_kernel. Since the initcall
runs after SMP (and the scheduler) have been initialised, there is
no guarantee that it is actually running on the boot CPU. In this
case, the boot CPU is left with PSTATE.D set and is not capable of
generating debug exceptions.
(2) In a preemptible kernel, we may explicitly schedule on the IRQ
return path to EL1. If an IRQ occurs with PSTATE.D set in the idle
thread, then we may schedule the kthread_init thread, run the
postcore_initcall to clear PSTATE.D and then context switch back
to the idle thread before returning from the IRQ. The exception
return path will then restore PSTATE.D from the stack, and set it
again.
This patch fixes the problem by moving the clearing of PSTATE.D earlier
to proc.S. This has the desirable effect of clearing it in one place for
all CPUs, long before we have to worry about the scheduler or any
exception handling. We ensure that the previous reset of MDSCR_EL1 has
completed before unmasking the exception, so that any spurious
exceptions resulting from UNKNOWN debug registers are not generated.
Without this patch applied, the kprobes selftests have been seen to fail
under KVM, where we end up attempting to step the OOL instruction buffer
with PSTATE.D set and therefore fail to complete the step.
Cc: <stable@vger.kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The pre-handler of this special 'trampoline' kprobe executes the return
probe handler functions and restores original return address in ELR_EL1.
This way the saved pt_regs still hold the original register context to be
carried back to the probed kernel function.
Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The trampoline code is used by kretprobes to capture a return from a probed
function. This is done by saving the registers, calling the handler, and
restoring the registers. The code then returns to the original saved caller
return address. It is necessary to do this directly instead of using a
software breakpoint because the code used in processing that breakpoint
could itself be kprobe'd and cause a problematic reentry into the debug
exception handler.
Signed-off-by: William Cohen <wcohen@redhat.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
[catalin.marinas@arm.com: removed unnecessary masking of the PSTATE bits]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Kprobes needs simulation of instructions that cannot be stepped
from a different memory location, e.g.: those instructions
that uses PC-relative addressing. In simulation, the behaviour
of the instruction is implemented using a copy of pt_regs.
The following instruction categories are simulated:
- All branching instructions(conditional, register, and immediate)
- Literal access instructions(load-literal, adr/adrp)
Conditional execution is limited to branching instructions in
ARM v8. If conditions at PSTATE do not match the condition fields
of opcode, the instruction is effectively NOP.
Thanks to Will Cohen for assorted suggested changes.
Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com>
Signed-off-by: William Cohen <wcohen@redhat.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
[catalin.marinas@arm.com: removed linux/module.h include]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Entry symbols are not kprobe safe. So blacklist them for kprobing.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
[catalin.marinas@arm.com: Do not include syscall wrappers in .entry.text]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add all function symbols which are called from do_debug_exception under
NOKPROBE_SYMBOL, as they can not kprobed.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add support for basic kernel probes(kprobes) and jump probes
(jprobes) for ARM64.
Kprobes utilizes software breakpoint and single step debug
exceptions supported on ARM v8.
A software breakpoint is placed at the probe address to trap the
kernel execution into the kprobe handler.
ARM v8 supports enabling single stepping before the break exception
return (ERET), with next PC in exception return address (ELR_EL1). The
kprobe handler prepares an executable memory slot for out-of-line
execution with a copy of the original instruction being probed, and
enables single stepping. The PC is set to the out-of-line slot address
before the ERET. With this scheme, the instruction is executed with the
exact same register context except for the PC (and DAIF) registers.
Debug mask (PSTATE.D) is enabled only when single stepping a recursive
kprobe, e.g.: during kprobes reenter so that probed instruction can be
single stepped within the kprobe handler -exception- context.
The recursion depth of kprobe is always 2, i.e. upon probe re-entry,
any further re-entry is prevented by not calling handlers and the case
counted as a missed kprobe).
Single stepping from the x-o-l slot has a drawback for PC-relative accesses
like branching and symbolic literals access as the offset from the new PC
(slot address) may not be ensured to fit in the immediate value of
the opcode. Such instructions need simulation, so reject
probing them.
Instructions generating exceptions or cpu mode change are rejected
for probing.
Exclusive load/store instructions are rejected too. Additionally, the
code is checked to see if it is inside an exclusive load/store sequence
(code from Pratyush).
System instructions are mostly enabled for stepping, except MSR/MRS
accesses to "DAIF" flags in PSTATE, which are not safe for
probing.
This also changes arch/arm64/include/asm/ptrace.h to use
include/asm-generic/ptrace.h.
Thanks to Steve Capper and Pratyush Anand for several suggested
Changes.
Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cease using the arm32 arm_check_condition() function and replace it with
a local version for use in deprecated instruction support on arm64. Also
make the function table used by this available for future use by kprobes
and/or uprobes.
This function is derived from code written by Sandeepa Prabhu.
Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Certain instructions are hard to execute correctly out-of-line (as in
kprobes). Test functions are added to insn.[hc] to identify these. The
instructions include any that use PC-relative addressing, change the PC,
or change interrupt masking. For efficiency and simplicity test
functions are also added for small collections of related instructions.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add HAVE_REGS_AND_STACK_ACCESS_API feature for arm64, including supporting
functions and defines.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
[catalin.marinas@arm.com: Remove unused functions]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
It can be useful for JIT software to be aware of MIDR_EL1 and
REVIDR_EL1 to ascertain the presence of any core errata that could
affect code generation.
This patch exposes these registers through sysfs:
/sys/devices/system/cpu/cpu$ID/regs/identification/midr_el1
/sys/devices/system/cpu/cpu$ID/regs/identification/revidr_el1
where $ID is the cpu number. For big.LITTLE systems, one can have a
mixture of cores (e.g. Cortex A53 and Cortex A57), thus all CPUs need
to be enumerated.
If the kernel does not have valid information to populate these entries
with, an empty string is returned to userspace.
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Steve Capper <steve.capper@linaro.org>
[suzuki.poulose@arm.com: ABI documentation updates, hotplug notifiers, kobject changes]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
So far the arm64 clock_gettime() vDSO implementation only supported
the following clocks, falling back to the syscall for the others:
- CLOCK_REALTIME{,_COARSE}
- CLOCK_MONOTONIC{,_COARSE}
This patch adds support for the CLOCK_MONOTONIC_RAW clock, taking
advantage of the recent refactoring of the vDSO time functions. Like
the non-_COARSE clocks, this only works when the "arch_sys_counter"
clocksource is in use (allowing us to read the current time from the
virtual counter register), otherwise we also have to fall back to the
syscall.
Most of the data is shared with CLOCK_MONOTONIC, and the algorithm is
similar. The reference implementation in kernel/time/timekeeping.c
shows that:
- CLOCK_MONOTONIC = tk->wall_to_monotonic + tk->xtime_sec +
timekeeping_get_ns(&tk->tkr_mono)
- CLOCK_MONOTONIC_RAW = tk->raw_time + timekeeping_get_ns(&tk->tkr_raw)
- tkr_mono and tkr_raw are identical (in particular, same
clocksource), except these members:
* mult (only mono's multiplier is NTP-adjusted)
* xtime_nsec (always 0 for raw)
Therefore, tk->raw_time and tkr_raw->mult are now also stored in the
vDSO data page.
Cc: Ali Saidi <ali.saidi@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Time functions are directly implemented in assembly in arm64, and it
is desirable to keep it this way for performance reasons (everything
fits in registers, so that the stack is not used at all). However, the
current implementation is quite difficult to read and understand (even
considering it's assembly). Additionally, due to the structure of
__kernel_clock_gettime, which heavily uses conditional branches to
share code between the different clocks, it is difficult to support a
new clock without making the branches even harder to follow.
This commit completely refactors the structure of clock_gettime (and
gettimeofday along the way) while keeping exactly the same algorithms.
We no longer try to share code; instead, macros provide common
operations. This new approach comes with a number of advantages:
- In clock_gettime, clock implementations are no longer interspersed,
making them much more readable. Additionally, macros only use
registers passed as arguments or reserved with .req, this way it is
easy to make sure that registers are properly allocated. To avoid a
large number of branches in a given execution path, a jump table is
used; a normal execution uses 3 unconditional branches.
- __do_get_tspec has been replaced with 2 macros (get_ts_clock_mono,
get_clock_shifted_nsec) and explicit loading of data from the vDSO
page. Consequently, clock_gettime and gettimeofday are now leaf
functions, and saving x30 (lr) is no longer necessary.
- Variables protected by tb_seq_count are now loaded all at once,
allowing to merge the seqcnt_read macro into seqcnt_check.
- For CLOCK_REALTIME_COARSE, removed an unused load of the wall to
monotonic timespec.
- For CLOCK_MONOTONIC_COARSE, removed a few shift instructions.
Obviously, the downside of sharing less code is an increase in code
size. However since the vDSO has its own code page, this does not
really matter, as long as the size of the DSO remains below 4 kB. For
now this should be all right:
Before After
vdso.so size (B) 2776 3000
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64/kernel/{vdso,signal}.c include vdso-offsets.h, as well as any
file that includes asm/vdso.h. Therefore, vdso-offsets.h must be
generated before these files are compiled.
The current rules in arm64/kernel/Makefile do not actually enforce
this, because even though $(obj)/vdso is listed as a prerequisite for
vdso-offsets.h, this does not result in the intended effect of
building the vdso subdirectory (before all the other objects). As a
consequence, depending on the order in which the rules are followed,
vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o
are built. The current rules also impose an unnecessary dependency on
vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary
rebuilds. This is made obvious when using make -j:
touch arch/arm64/kernel/vdso/gettimeofday.S && make -j$NCPUS arch/arm64/kernel
will sometimes result in none of arm64/kernel/*.o being
rebuilt, sometimes all of them, or even just some of them.
It is quite difficult to ensure that a header is generated before it
is used with recursive Makefiles by using normal rules. Instead,
arch-specific generated headers are normally built in the archprepare
recipe in the arch Makefile (see for instance arch/ia64/Makefile).
Unfortunately, asm-offsets.h is included in gettimeofday.S, and must
therefore be generated before vdso-offsets.h, which is not the case if
archprepare is used. For this reason, a rule run after archprepare has
to be used.
This commit adds rules in arm64/Makefile to build vdso-offsets.h
during the prepare step, ensuring that vdso-offsets.h is generated
before building anything. It also removes the now-unnecessary
dependencies on vdso-offsets.h in arm64/kernel/Makefile. Finally, it
removes the duplication of asm-offsets.h between arm64/kernel/vdso/
and include/generated/ and makes include/generated/vdso-offsets.h a
target in arm64/kernel/vdso/Makefile.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michal Marek <mmarek@suse.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This reverts commit 90f777beb7.
While this commit was aimed at fixing the dependencies, with a large
make -j the vdso-offsets.h file is not generated, leading to build
failures.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/{vdso,signal}.c include generated/vdso-offsets.h, and
therefore the symbol offsets must be generated before these files are
compiled.
The current rules in arm64/kernel/Makefile do not actually enforce
this, because even though $(obj)/vdso is listed as a prerequisite for
vdso-offsets.h, this does not result in the intended effect of
building the vdso subdirectory (before all the other objects). As a
consequence, depending on the order in which the rules are followed,
vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o
are built. The current rules also impose an unnecessary dependency on
vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary
rebuilds.
This patch removes the arch/arm64/kernel/vdso/vdso-offsets.h file
generation, leaving only the include/generated/vdso-offsets.h one. It
adds a forced dependency check of the vdso-offsets.h file in
arch/arm64/kernel/Makefile which, if not up to date according to the
arch/arm64/kernel/vdso/Makefile rules (depending on vdso.so.dbg), will
trigger the vdso/ subdirectory build and vdso-offsets.h re-generation.
Automatic kbuild dependency rules between kernel/{vdso,signal}.c rules
and vdso-offsets.h will guarantee that the vDSO object is built first,
followed by the generated symbol offsets header file.
Reported-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cavium erratum 27456 commit 104a0c02e8
("arm64: Add workaround for Cavium erratum 27456")
is applicable for thunderx-81xx pass1.0 SoC as well.
Adding code to enable to 81xx.
Signed-off-by: Ganapatrao Kulkarni <gkulkarni@cavium.com>
Reviewed-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
If we take an exception while at EL1, the exception handler inherits
the original context's addr_limit and PSTATE.UAO values. To be consistent
always reset addr_limit and PSTATE.UAO on (re-)entry to EL1. This
prevents accidental re-use of the original context's addr_limit.
Based on a similar patch for arm from Russell King.
Cc: <stable@vger.kernel.org> # 4.6-
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
When running the OS with a page size > 4 KB, we need to round up mappings
for regions that are not aligned to the OS's page size. We already avoid
block mappings for EfiRuntimeServicesCode/Data regions for other reasons,
but in the unlikely event that other unaliged regions exists that have the
EFI_MEMORY_RUNTIME attribute set, ensure that unaligned regions are always
mapped down to pages. This way, the overlapping page is guaranteed not to
be covered by a block mapping that needs to be split.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
To avoid triggering diagnostics in the MMU code that are finicky about
splitting block mappings into more granular mappings, ensure that regions
that are likely to appear in the Memory Attributes table as well as the
UEFI memory map are always mapped down to pages. This way, we can use
apply_to_page_range() instead of create_pgd_mapping() for the second pass,
which cannot split or merge block entries, and operates strictly on PTEs.
Note that this aligns the arm64 Memory Attributes table handling code with
the ARM code, which already uses apply_to_page_range() to set the strict
permissions.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add a bool parameter 'allow_block_mappings' to create_pgd_mapping() and
the various helper functions that it descends into, to give the caller
control over whether block entries may be used to create the mapping.
The UEFI runtime mapping routines will use this to avoid creating block
entries that would need to split up into page entries when applying the
permissions listed in the Memory Attributes firmware table.
This also replaces the block_mappings_allowed() helper function that was
added for DEBUG_PAGEALLOC functionality, but the resulting code is
functionally equivalent (given that debug_page_alloc does not operate on
EFI page table entries anyway)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The ARM errata 819472, 826319, 827319 and 824069 for affected
Cortex-A53 cores demand to promote "dc cvau" instructions to
"dc civac". Since we allow userspace to also emit those instructions,
we should make sure that "dc cvau" gets promoted there too.
So lets grasp the nettle here and actually trap every userland cache
maintenance instruction once we detect at least one affected core in
the system.
We then emulate the instruction by executing it on behalf of userland,
promoting "dc cvau" to "dc civac" on the way and injecting access
fault back into userspace.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[catalin.marinas@arm.com: s/set_segfault/arm64_notify_segfault/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The code for injecting a signal into userland if a trapped instruction
fails emulation due to a _userland_ error (like an illegal address)
will be used more often with the next patch.
Factor out the core functionality into a separate function and use
that both for the existing trap handler and for the deprecated
instructions emulation.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[catalin.marinas@arm.com: s/set_segfault/arm64_notify_segfault/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently we call the (optional) enable function for CPU _features_
only. As CPU _errata_ descriptions share the same data structure and
having an enable function is useful for errata as well (for instance
to set bits in SCTLR), lets call it when enumerating erratas too.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
As Kees Cook notes in the ARM counterpart of this patch [0]:
The _etext position is defined to be the end of the kernel text code,
and should not include any part of the data segments. This interferes
with things that might check memory ranges and expect executable code
up to _etext.
In particular, Kees is referring to the HARDENED_USERCOPY patch set [1],
which rejects attempts to call copy_to_user() on kernel ranges containing
executable code, but does allow access to the .rodata segment. Regardless
of whether one may or may not agree with the distinction, it makes sense
for _etext to have the same meaning across architectures.
So let's put _etext where it belongs, between .text and .rodata, and fix
up existing references to use __init_begin instead, which unlike _end_rodata
includes the exception and notes sections as well.
The _etext references in kaslr.c are left untouched, since its references
to [_stext, _etext) are meant to capture potential jump instruction targets,
and so disregarding .rodata is actually an improvement here.
[0] http://article.gmane.org/gmane.linux.kernel/2245084
[1] http://thread.gmane.org/gmane.linux.kernel.hardened.devel/2502
Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
To aid in debugging kexec problems or when adding new functionality to
kexec add a new routine kexec_image_info() and several inline pr_debug
statements.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add three new files, kexec.h, machine_kexec.c and relocate_kernel.S to the
arm64 architecture that add support for the kexec re-boot mechanism
(CONFIG_KEXEC) on arm64 platforms.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Reviewed-by: James Morse <james.morse@arm.com>
[catalin.marinas@arm.com: removed dead code following James Morse's comments]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Commit 68234df4ea ("arm64: kill flush_cache_all()") removed the global
arm64 routines cpu_reset() and cpu_soft_restart() needed by the arm64
kexec and kdump support. Add back a simplified version of
cpu_soft_restart() with some changes needed for kexec in the new files
cpu_reset.S, and cpu_reset.h.
When a CPU is reset it needs to be put into the exception level it had when
it entered the kernel. Update cpu_soft_restart() to accept an argument
which signals if the reset address should be entered at EL1 or EL2, and
add a new hypercall HVC_SOFT_RESTART which is used for the EL2 switch.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
kernel/smp.c has a fancy counter that keeps track of the number of CPUs
it marked as not-present and left in cpu_park_loop(). If there are any
CPUs spinning in here, features like kexec or hibernate may release them
by overwriting this memory.
This problem also occurs on machines using spin-tables to release
secondary cores.
After commit 44dbcc93ab ("arm64: Fix behavior of maxcpus=N")
we bring all known cpus into the secondary holding pen, meaning this
memory can't be re-used by kexec or hibernate.
Add a function cpus_are_stuck_in_kernel() to determine if either of these
cases have occurred.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[catalin.marinas@arm.com: cherry-picked from mainline for kexec dependency]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Hibernate relies on cpu hotplug to prevent secondary cores executing
the kernel text while it is being restored.
Add a call to cpus_are_stuck_in_kernel() to determine if there are
CPUs not counted by 'num_online_cpus()', and prevent hibernate in this
case.
Fixes: 82869ac57b ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
kernel/smp.c has a fancy counter that keeps track of the number of CPUs
it marked as not-present and left in cpu_park_loop(). If there are any
CPUs spinning in here, features like kexec or hibernate may release them
by overwriting this memory.
This problem also occurs on machines using spin-tables to release
secondary cores.
After commit 44dbcc93ab ("arm64: Fix behavior of maxcpus=N")
we bring all known cpus into the secondary holding pen, meaning this
memory can't be re-used by kexec or hibernate.
Add a function cpus_are_stuck_in_kernel() to determine if either of these
cases have occurred.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch adds support for ACPI_TABLE_UPGRADE for ARM64
To access initrd image we need to move initialization
of linear mapping a bit earlier.
The implementation of the feature acpi_table_upgrade()
(drivers/acpi/tables.c) works with initrd data represented as an array
in virtual memory. It uses some library utility to find the redefined
tables in that array and iterates over it to copy the data to new
allocated memory. So to access the initrd data via fixmap
we need to rewrite it considerably.
In x86 arch, kernel memory is already mapped by the time when
acpi_table_upgrade() and acpi_boot_table_init() are called so I
think that we can just move this mapping one function earlier too.
Signed-off-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently we treat ESR_EL1 bit 24 as software-defined for distinguishing
instruction aborts from data aborts, but this bit is architecturally
RES0 for instruction aborts, and could be allocated for an arbitrary
purpose in future. Additionally, we hard-code the value in entry.S
without the mnemonic, making the code difficult to understand.
Instead, remove ESR_LNX_EXEC, and distinguish aborts based on the esr,
which we already pass to the sole use of ESR_LNX_EXEC. A new helper,
is_el0_instruction_abort() is added to make the logic clear. Any
instruction aborts taken from EL1 will already have been handled by
bad_mode, so we need not handle that case in the helper.
For consistency, the existing permission_fault helper is renamed to
is_permission_fault, and the return type is changed to bool. There
should be no functional changes as the return value was a boolean
expression, and the result is only used in another boolean expression.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Dave P Martin <dave.martin@arm.com>
Cc: Huang Shijie <shijie.huang@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Several places open-code extraction of the EC field from an ESR_ELx
value, in subtly different ways. This is unfortunate duplication and
variation, and the precise logic used to extract the field is a
distraction.
This patch adds a new macro, ESR_ELx_EC(), to extract the EC field from
an ESR_ELx value in a consistent fashion.
Existing open-coded extractions in core arm64 code are moved over to the
new helper. KVM code is left as-is for the moment.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Huang Shijie <shijie.huang@arm.com>
Cc: Dave P Martin <dave.martin@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently dump_mem attempts to dump memory in 64-bit chunks when
reporting a failure in 64-bit code, or 32-bit chunks when reporting a
failure in 32-bit code. We added code to handle these two cases
separately in commit e147ae6d7f ("arm64: modify the dump mem for
64 bit addresses").
However, in all cases dump_mem is called, the failing context is a
kernel rather than user context. Additionally dump_mem is assumed to
only be used for kernel contexts, as internally it switches to
KERNEL_DS, and its callers pass kernel stack bounds.
This patch removes the redundant 32-bit chunk logic and associated
compat parameter, largely reverting the aforementioned commit. For the
call in __die(), the check of in_interrupt() is removed also, as __die()
is only called in response to faults from the kernel's exception level,
and thus the !user_mode(regs) check is sufficient. Were this not the
case, the used of task_stack_page(tsk) to generate the stack bounds
would be erroneous.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The upstream commit 1771c6e1a5
("x86/kasan: instrument user memory access API") added KASAN instrument to
x86 user memory access API, so added such instrument to ARM64 too.
Define __copy_to/from_user in C in order to add kasan_check_read/write call,
rename assembly implementation to __arch_copy_to/from_user.
Tested by test_kasan module.
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
