Commit Graph

1070 Commits

Author SHA1 Message Date
Linus Torvalds 7a1e8b80fb Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Highlights:

   - TPM core and driver updates/fixes
   - IPv6 security labeling (CALIPSO)
   - Lots of Apparmor fixes
   - Seccomp: remove 2-phase API, close hole where ptrace can change
     syscall #"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (156 commits)
  apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling
  tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family)
  tpm: Factor out common startup code
  tpm: use devm_add_action_or_reset
  tpm2_i2c_nuvoton: add irq validity check
  tpm: read burstcount from TPM_STS in one 32-bit transaction
  tpm: fix byte-order for the value read by tpm2_get_tpm_pt
  tpm_tis_core: convert max timeouts from msec to jiffies
  apparmor: fix arg_size computation for when setprocattr is null terminated
  apparmor: fix oops, validate buffer size in apparmor_setprocattr()
  apparmor: do not expose kernel stack
  apparmor: fix module parameters can be changed after policy is locked
  apparmor: fix oops in profile_unpack() when policy_db is not present
  apparmor: don't check for vmalloc_addr if kvzalloc() failed
  apparmor: add missing id bounds check on dfa verification
  apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task
  apparmor: use list_next_entry instead of list_entry_next
  apparmor: fix refcount race when finding a child profile
  apparmor: fix ref count leak when profile sha1 hash is read
  apparmor: check that xindex is in trans_table bounds
  ...
2016-07-29 17:38:46 -07:00
Linus Torvalds a6408f6cb6 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug updates from Thomas Gleixner:
 "This is the next part of the hotplug rework.

   - Convert all notifiers with a priority assigned

   - Convert all CPU_STARTING/DYING notifiers

     The final removal of the STARTING/DYING infrastructure will happen
     when the merge window closes.

  Another 700 hundred line of unpenetrable maze gone :)"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  timers/core: Correct callback order during CPU hot plug
  leds/trigger/cpu: Move from CPU_STARTING to ONLINE level
  powerpc/numa: Convert to hotplug state machine
  arm/perf: Fix hotplug state machine conversion
  irqchip/armada: Avoid unused function warnings
  ARC/time: Convert to hotplug state machine
  clocksource/atlas7: Convert to hotplug state machine
  clocksource/armada-370-xp: Convert to hotplug state machine
  clocksource/exynos_mct: Convert to hotplug state machine
  clocksource/arm_global_timer: Convert to hotplug state machine
  rcu: Convert rcutree to hotplug state machine
  KVM/arm/arm64/vgic-new: Convert to hotplug state machine
  smp/cfd: Convert core to hotplug state machine
  x86/x2apic: Convert to CPU hotplug state machine
  profile: Convert to hotplug state machine
  timers/core: Convert to hotplug state machine
  hrtimer: Convert to hotplug state machine
  x86/tboot: Convert to hotplug state machine
  arm64/armv8 deprecated: Convert to hotplug state machine
  hwtracing/coresight-etm4x: Convert to hotplug state machine
  ...
2016-07-29 13:55:30 -07:00
Linus Torvalds 08fd8c1768 Merge tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from David Vrabel:
 "Features and fixes for 4.8-rc0:

   - ACPI support for guests on ARM platforms.
   - Generic steal time support for arm and x86.
   - Support cases where kernel cpu is not Xen VCPU number (e.g., if
     in-guest kexec is used).
   - Use the system workqueue instead of a custom workqueue in various
     places"

* tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits)
  xen: add static initialization of steal_clock op to xen_time_ops
  xen/pvhvm: run xen_vcpu_setup() for the boot CPU
  xen/evtchn: use xen_vcpu_id mapping
  xen/events: fifo: use xen_vcpu_id mapping
  xen/events: use xen_vcpu_id mapping in events_base
  x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info
  x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op
  xen: introduce xen_vcpu_id mapping
  x86/acpi: store ACPI ids from MADT for future usage
  x86/xen: update cpuid.h from Xen-4.7
  xen/evtchn: add IOCTL_EVTCHN_RESTRICT
  xen-blkback: really don't leak mode property
  xen-blkback: constify instance of "struct attribute_group"
  xen-blkfront: prefer xenbus_scanf() over xenbus_gather()
  xen-blkback: prefer xenbus_scanf() over xenbus_gather()
  xen: support runqueue steal time on xen
  arm/xen: add support for vm_assist hypercall
  xen: update xen headers
  xen-pciback: drop superfluous variables
  xen-pciback: short-circuit read path used for merging write values
  ...
2016-07-27 11:35:37 -07:00
Linus Torvalds e831101a73 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
  ...
2016-07-27 11:16:05 -07:00
Rafael J. Wysocki 6149dffcb5 Merge branches 'acpi-processor', 'acpi-cppc', 'acpi-apei' and 'acpi-sleep'
* 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
2016-07-25 13:42:25 +02:00
Rafael J. Wysocki d5f017b796 Merge branch 'acpi-tables'
* 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
2016-07-25 13:41:01 +02:00
Rafael J. Wysocki d85f4eb699 Merge branch 'acpi-numa'
* acpi-numa:
  ACPI / NUMA: Enable ACPI based NUMA on ARM64
  arm64, ACPI, NUMA: NUMA support based on SRAT and SLIT
  ACPI / processor: Add acpi_map_madt_entry()
  ACPI / NUMA: Improve SRAT error detection and add messages
  ACPI / NUMA: Move acpi_numa_memory_affinity_init() to drivers/acpi/numa.c
  ACPI / NUMA: remove unneeded acpi_numa=1
  ACPI / NUMA: move bad_srat() and srat_disabled() to drivers/acpi/numa.c
  x86 / ACPI / NUMA: cleanup acpi_numa_processor_affinity_init()
  arm64, NUMA: Cleanup NUMA disabled messages
  arm64, NUMA: rework numa_add_memblk()
  ACPI / NUMA: move acpi_numa_slit_init() to drivers/acpi/numa.c
  ACPI / NUMA: Move acpi_numa_arch_fixup() to ia64 only
  ACPI / NUMA: remove duplicate NULL check
  ACPI / NUMA: Replace ACPI_DEBUG_PRINT() with pr_debug()
  ACPI / NUMA: Use pr_fmt() instead of printk
2016-07-25 13:40:39 +02:00
Sudeep Holla 5a611ed969 arm64: add support for ACPI Low Power Idle(LPI)
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>
2016-07-21 23:29:38 +02:00
Sudeep Holla ce3ad71026 arm64: cpuidle: drop __init section marker to arm_cpuidle_init
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>
2016-07-21 23:29:37 +02:00
Catalin Marinas a95b0644b3 Merge branch 'for-next/kprobes' into for-next/core
* 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
2016-07-21 18:20:41 +01:00
Suzuki K Poulose e75118a7b5 arm64: Honor nosmp kernel command line option
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>
2016-07-21 16:48:37 +01:00
Suzuki K Poulose 9113c2aa05 arm64: Fix incorrect per-cpu usage for boot CPU
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>
2016-07-21 15:59:16 +01:00
Catalin Marinas f7e35c5ba4 arm64: kprobes: Add KASAN instrumentation around stack accesses
This patch disables KASAN around the memcpy from/to the kernel or IRQ
stacks to avoid warnings like below:

BUG: KASAN: stack-out-of-bounds in setjmp_pre_handler+0xe4/0x170 at addr ffff800935cbbbc0
Read of size 128 by task swapper/0/1
page:ffff7e0024d72ec0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x1000000000000000()
page dumped because: kasan: bad access detected
CPU: 4 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc4+ #1
Hardware name: ARM Juno development board (r0) (DT)
Call trace:
[<ffff20000808ad88>] dump_backtrace+0x0/0x280
[<ffff20000808b01c>] show_stack+0x14/0x20
[<ffff200008563a64>] dump_stack+0xa4/0xc8
[<ffff20000824a1fc>] kasan_report_error+0x4fc/0x528
[<ffff20000824a5e8>] kasan_report+0x40/0x48
[<ffff20000824948c>] check_memory_region+0x144/0x1a0
[<ffff200008249814>] memcpy+0x34/0x68
[<ffff200008c3ee2c>] setjmp_pre_handler+0xe4/0x170
[<ffff200008c3ec5c>] kprobe_breakpoint_handler+0xec/0x1d8
[<ffff2000080853a4>] brk_handler+0x5c/0xa0
[<ffff2000080813f0>] do_debug_exception+0xa0/0x138

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-21 11:47:53 +01:00
Marc Zyngier 3b7d14e9f3 arm64: kprobes: Cleanup jprobe_return
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>
2016-07-21 11:47:52 +01:00
Marc Zyngier ab4c1325d4 arm64: kprobes: Fix overflow when saving stack
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>
2016-07-20 17:54:35 +01:00
Will Deacon 44bd887ce1 arm64: kprobes: WARN if attempting to step with PSTATE.D=1
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>
2016-07-19 17:00:29 +01:00
Will Deacon 6b68e14e71 arm64: debug: remove redundant spsr manipulation
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>
2016-07-19 16:58:56 +01:00
Will Deacon 2ce39ad151 arm64: debug: unmask PSTATE.D earlier
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>
2016-07-19 16:56:46 +01:00
Sandeepa Prabhu fcfd708b8c arm64: Add kernel return probes support (kretprobes)
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>
2016-07-19 15:03:22 +01:00
William Cohen da6a91252a arm64: Add trampoline code for kretprobes
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>
2016-07-19 15:03:22 +01:00
Sandeepa Prabhu 39a67d49ba arm64: kprobes instruction simulation support
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>
2016-07-19 15:03:21 +01:00
Pratyush Anand 888b3c8720 arm64: Treat all entry code as non-kprobe-able
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>
2016-07-19 15:03:21 +01:00
Pratyush Anand 44b53f67c9 arm64: Blacklist non-kprobe-able symbol
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>
2016-07-19 15:03:20 +01:00
Sandeepa Prabhu 2dd0e8d2d2 arm64: Kprobes with single stepping support
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>
2016-07-19 15:03:20 +01:00
David A. Long 2af3ec08b4 arm64: add conditional instruction simulation support
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>
2016-07-19 15:03:19 +01:00