Commit Graph

2063 Commits

Author SHA1 Message Date
Lorenzo Pieralisi
c1e4659ba8 arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot
When secondary cpus are booted through the ACPI parking protocol, the
booted cpu should check that FW has correctly cleared its mailbox entry
point value to make sure the boot process was correctly executed.
The entry point check is carried in the cpu_ops->cpu_postboot method, that
is executed by secondary cpus when entering the kernel with irqs disabled.

The ACPI parking protocol cpu_ops maps/unmaps the mailboxes on the
primary CPU to trigger secondary boot in the cpu_ops->cpu_boot method
and on secondary processors to carry out FW checks on the booted CPU
to verify the boot protocol was successfully executed in the
cpu_ops->cpu_postboot method.

Therefore, the cpu_ops->cpu_postboot method is forced to ioremap/unmap the
mailboxes, which is wrong in that ioremap cannot be safely be carried out
with irqs disabled.

To fix this issue, this patch reshuffles the code so that the mailboxes
are still mapped after the boot processor executes the cpu_ops->cpu_boot
method for a given cpu, and the VA at which a mailbox is mapped for a given
cpu is stashed in the per-cpu data struct so that secondary cpus can
retrieve them in the cpu_ops->cpu_postboot and complete the required
FW checks.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reported-by: Itaru Kitayama <itaru.kitayama@riken.jp>
Tested-by: Loc Ho <lho@apm.com>
Tested-by: Itaru Kitayama <itaru.kitayama@riken.jp>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Loc Ho <lho@apm.com>
Cc: Itaru Kitayama <itaru.kitayama@riken.jp>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Al Stone <ahs3@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-26 15:39:52 +00:00
Suzuki K Poulose
bf50061844 arm64: Add support for Half precision floating point
ARMv8.2 extensions [1] include an optional feature, which supports
half precision(16bit) floating point/asimd data processing
instructions. This patch adds support for detecting and exposing
the same to the userspace via HWCAPs

[1] https://community.arm.com/groups/processors/blog/2016/01/05/armv8-a-architecture-evolution

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-26 15:37:01 +00:00
Andrew Pinski
104a0c02e8 arm64: Add workaround for Cavium erratum 27456
On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
instructions may cause the icache to become corrupted if it contains
data for a non-current ASID.

This patch implements the workaround (which invalidates the local
icache when switching the mm) by using code patching.

Signed-off-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-26 15:14:27 +00:00
Jeremy Linton
2f39b5f91e arm64: mm: Mark .rodata as RO
Currently the .rodata section is actually still executable when DEBUG_RODATA
is enabled. This changes that so the .rodata is actually read only, no execute.
It also adds the .rodata section to the mem_init banner.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
[catalin.marinas@arm.com: added vm_struct vmlinux_rodata in map_kernel()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-26 15:08:04 +00:00
Suzuki K Poulose
28c5dcb22f arm64: Rename cpuid_feature field extract routines
Now that we have a clear understanding of the sign of a feature,
rename the routines to reflect the sign, so that it is not misused.
The cpuid_feature_extract_field() now accepts a 'sign' parameter.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:08 +00:00
Suzuki K Poulose
ff96f7bc7b arm64: capabilities: Handle sign of the feature bit
Use the appropriate accessor for the feature bit by keeping
track of the sign of the feature

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:07 +00:00
Suzuki K Poulose
0710cfdb8d arm64: cpufeature: Fix the sign of feature bits
There is a confusion on whether the values of a feature are signed
or not in ARM. This is not clearly mentioned in the ARM ARM either.
We have dealt most of the bits as signed so far, and marked the
rest as unsigned explicitly. This fixed in ARM ARM and will be rolled
out soon.

Here is the criteria in a nutshell:

1) The fields, which are either signed or unsigned, use increasing
   numerical values to indicate an increase in functionality. Thus, if a value
   of 0x1 indicates the presence of some instructions, then the 0x2 value will
   indicate the presence of those instructions plus some additional instructions
   or functionality.

2) For ID field values where the value 0x0 defines that a feature is not present,
   the number is an unsigned value.

3) For some features where the feature was made optional or removed after the
   start of the definition of the architecture, the value 0x0 is used to
   indicate the presence of a feature, and 0xF indicates the absence of the
   feature. In these cases, the fields are, in effect, holding signed values.

So with these rules applied, we have only the following fields which are signed and
the rest are unsigned.

 a) ID_AA64PFR0_EL1: {FP, ASIMD}
 b) ID_AA64MMFR0_EL1: {TGran4K, TGran64K}
 c) ID_AA64DFR0_EL1: PMUVer (0xf - PMUv3 not implemented)
 d) ID_DFR0_EL1: PerfMon
 e) ID_MMFR0_EL1: {InnerShr, OuterShr}

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:07 +00:00
Suzuki K Poulose
e53435031a arm64: cpufeature: Correct feature register tables
Correct the feature bit entries for :
  ID_DFR0
  ID_MMFR0

to fix the default safe value for some of the bits.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:07 +00:00
Suzuki K Poulose
13f417f3b8 arm64: Ensure the secondary CPUs have safe ASIDBits size
Adds a hook for checking whether a secondary CPU has the
features used already by the kernel during early boot, based
on the boot CPU and plugs in the check for ASID size.

The ID_AA64MMFR0_EL1:ASIDBits determines the size of the mm context
id and is used in the early boot to make decisions. The value is
picked up from the Boot CPU and cannot be delayed until other CPUs
are up. If a secondary CPU has a smaller size than that of the Boot
CPU, things will break horribly and the usual SANITY check is not good
enough to prevent the system from crashing. So, crash the system with
enough information.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:06 +00:00
Suzuki K Poulose
fd9c2790cb arm64: Enable CPU capability verification unconditionally
We verify the capabilities of the secondary CPUs only when
hotplug is enabled. The boot time activated CPUs do not
go through the verification by checking whether the system
wide capabilities were initialised or not.

This patch removes the capability check dependency on CONFIG_HOTPLUG_CPU,
to make sure that all the secondary CPUs go through the check.
The boot time activated CPUs will still skip the system wide
capability check. The plan is to hook in a check for CPU features
used by the kernel at early boot up, based on the Boot CPU values.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:06 +00:00
Suzuki K Poulose
bb9052744f arm64: Handle early CPU boot failures
A secondary CPU could fail to come online due to insufficient
capabilities and could simply die or loop in the kernel.
e.g, a CPU with no support for the selected kernel PAGE_SIZE
loops in kernel with MMU turned off.
or a hotplugged CPU which doesn't have one of the advertised
system capability will die during the activation.

There is no way to synchronise the status of the failing CPU
back to the master. This patch solves the issue by adding a
field to the secondary_data which can be updated by the failing
CPU. If the secondary CPU fails even before turning the MMU on,
it updates the status in a special variable reserved in the head.txt
section to make sure that the update can be cache invalidated safely
without possible sharing of cache write back granule.

Here are the possible states :

 -1. CPU_MMU_OFF - Initial value set by the master CPU, this value
indicates that the CPU could not turn the MMU on, hence the status
could not be reliably updated in the secondary_data. Instead, the
CPU has updated the status @ __early_cpu_boot_status.

 0. CPU_BOOT_SUCCESS - CPU has booted successfully.

 1. CPU_KILL_ME - CPU has invoked cpu_ops->die, indicating the
master CPU to synchronise by issuing a cpu_ops->cpu_kill.

 2. CPU_STUCK_IN_KERNEL - CPU couldn't invoke die(), instead is
looping in the kernel. This information could be used by say,
kexec to check if it is really safe to do a kexec reboot.

 3. CPU_PANIC_KERNEL - CPU detected some serious issues which
requires kernel to crash immediately. The secondary CPU cannot
call panic() until it has initialised the GIC. This flag can
be used to instruct the master to do so.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[catalin.marinas@arm.com: conflict resolution]
[catalin.marinas@arm.com: converted "status" from int to long]
[catalin.marinas@arm.com: updated update_early_cpu_boot_status to use str_l]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:32:23 +00:00
Suzuki K Poulose
fce6361fe9 arm64: Move cpu_die_early to smp.c
This patch moves cpu_die_early to smp.c, where it fits better.
No functional changes, except for adding the necessary checks
for CONFIG_HOTPLUG_CPU.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 17:17:45 +00:00
Suzuki K Poulose
ee02a15919 arm64: Introduce cpu_die_early
Or in other words, make fail_incapable_cpu() reusable.

We use fail_incapable_cpu() to kill a secondary CPU early during the
bringup, which doesn't have the system advertised capabilities.
This patch makes the routine more generic, to kill a secondary
booting CPU, getting rid of the dependency on capability struct.
This can be used by checks which are not necessarily attached to
a capability struct (e.g, cpu ASIDBits).

In that process, renames the function to cpu_die_early() to better
match its functionality. This will be moved to arch/arm64/kernel/smp.c
later.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 17:17:44 +00:00
Suzuki K Poulose
c4bc34d202 arm64: Add a helper for parking CPUs in a loop
Adds a routine which can be used to park CPUs (spinning in kernel)
when they can't be killed.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 17:17:44 +00:00
Ard Biesheuvel
c031a4213c arm64: kaslr: randomize the linear region
When KASLR is enabled (CONFIG_RANDOMIZE_BASE=y), and entropy has been
provided by the bootloader, randomize the placement of RAM inside the
linear region if sufficient space is available. For instance, on a 4KB
granule/3 levels kernel, the linear region is 256 GB in size, and we can
choose any 1 GB aligned offset that is far enough from the top of the
address space to fit the distance between the start of the lowest memblock
and the top of the highest memblock.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:27 +00:00
Ard Biesheuvel
f80fb3a3d5 arm64: add support for kernel ASLR
This adds support for KASLR is implemented, based on entropy provided by
the bootloader in the /chosen/kaslr-seed DT property. Depending on the size
of the address space (VA_BITS) and the page size, the entropy in the
virtual displacement is up to 13 bits (16k/2 levels) and up to 25 bits (all
4 levels), with the sidenote that displacements that result in the kernel
image straddling a 1GB/32MB/512MB alignment boundary (for 4KB/16KB/64KB
granule kernels, respectively) are not allowed, and will be rounded up to
an acceptable value.

If CONFIG_RANDOMIZE_MODULE_REGION_FULL is enabled, the module region is
randomized independently from the core kernel. This makes it less likely
that the location of core kernel data structures can be determined by an
adversary, but causes all function calls from modules into the core kernel
to be resolved via entries in the module PLTs.

If CONFIG_RANDOMIZE_MODULE_REGION_FULL is not enabled, the module region is
randomized by choosing a page aligned 128 MB region inside the interval
[_etext - 128 MB, _stext + 128 MB). This gives between 10 and 14 bits of
entropy (depending on page size), independently of the kernel randomization,
but still guarantees that modules are within the range of relative branch
and jump instructions (with the caveat that, since the module region is
shared with other uses of the vmalloc area, modules may need to be loaded
further away if the module region is exhausted)

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:27 +00:00
Ard Biesheuvel
1e48ef7fcc arm64: add support for building vmlinux as a relocatable PIE binary
This implements CONFIG_RELOCATABLE, which links the final vmlinux
image with a dynamic relocation section, allowing the early boot code
to perform a relocation to a different virtual address at runtime.

This is a prerequisite for KASLR (CONFIG_RANDOMIZE_BASE).

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:27 +00:00
Ard Biesheuvel
6c94f27ac8 arm64: switch to relative exception tables
Instead of using absolute addresses for both the exception location
and the fixup, use offsets relative to the exception table entry values.
Not only does this cut the size of the exception table in half, it is
also a prerequisite for KASLR, since absolute exception table entries
are subject to dynamic relocation, which is incompatible with the sorting
of the exception table that occurs at build time.

This patch also introduces the _ASM_EXTABLE preprocessor macro (which
exists on x86 as well) and its _asm_extable assembly counterpart, as
shorthands to emit exception table entries.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:26 +00:00
Ard Biesheuvel
2bf31a4a05 arm64: avoid dynamic relocations in early boot code
Before implementing KASLR for arm64 by building a self-relocating PIE
executable, we have to ensure that values we use before the relocation
routine is executed are not subject to dynamic relocation themselves.
This applies not only to virtual addresses, but also to values that are
supplied by the linker at build time and relocated using R_AARCH64_ABS64
relocations.

So instead, use assemble time constants, or force the use of static
relocations by folding the constants into the instructions.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:25 +00:00
Ard Biesheuvel
6ad1fe5d90 arm64: avoid R_AARCH64_ABS64 relocations for Image header fields
Unfortunately, the current way of using the linker to emit build time
constants into the Image header will no longer work once we switch to
the use of PIE executables. The reason is that such constants are emitted
into the binary using R_AARCH64_ABS64 relocations, which are resolved at
runtime, not at build time, and the places targeted by those relocations
will contain zeroes before that.

So refactor the endian swapping linker script constant generation code so
that it emits the upper and lower 32-bit words separately.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:25 +00:00
Ard Biesheuvel
fd045f6cd9 arm64: add support for module PLTs
This adds support for emitting PLTs at module load time for relative
branches that are out of range. This is a prerequisite for KASLR, which
may place the kernel and the modules anywhere in the vmalloc area,
making it more likely that branch target offsets exceed the maximum
range of +/- 128 MB.

In this version, I removed the distinction between relocations against
.init executable sections and ordinary executable sections. The reason
is that it is hardly worth the trouble, given that .init.text usually
does not contain that many far branches, and this version now only
reserves PLT entry space for jump and call relocations against undefined
symbols (since symbols defined in the same module can be assumed to be
within +/- 128 MB)

For example, the mac80211.ko module (which is fairly sizable at ~400 KB)
built with -mcmodel=large gives the following relocation counts:

                    relocs    branches   unique     !local
  .text              3925       3347       518        219
  .init.text           11          8         7          1
  .exit.text            4          4         4          1
  .text.unlikely       81         67        36         17

('unique' means branches to unique type/symbol/addend combos, of which
!local is the subset referring to undefined symbols)

IOW, we are only emitting a single PLT entry for the .init sections, and
we are better off just adding it to the core PLT section instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:24 +00:00
Ard Biesheuvel
1ce99bf453 arm64/vmlinux.lds.S: Handle .init.rodata.xxx and .init.bss sections
The EFI stub is typically built into the decompressor (x86, ARM) so none
of its symbols are annotated as __init. However, on arm64, the stub is
linked into the kernel proper, and the code is __init annotated at the
section level by prepending all names of SHF_ALLOC sections with '.init'.

This results in section names like .init.rodata.str1.8 (for string literals)
and .init.bss (which is tiny), both of which can be moved into the .init.data
output section.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1455712566-16727-6-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-22 08:26:26 +01:00
Ard Biesheuvel
a7f8de168a arm64: allow kernel Image to be loaded anywhere in physical memory
This relaxes the kernel Image placement requirements, so that it
may be placed at any 2 MB aligned offset in physical memory.

This is accomplished by ignoring PHYS_OFFSET when installing
memblocks, and accounting for the apparent virtual offset of
the kernel Image. As a result, virtual address references
below PAGE_OFFSET are correctly mapped onto physical references
into the kernel Image regardless of where it sits in memory.

Special care needs to be taken for dealing with memory limits passed
via mem=, since the generic implementation clips memory top down, which
may clip the kernel image itself if it is loaded high up in memory. To
deal with this case, we simply add back the memory covering the kernel
image, which may result in more memory to be retained than was passed
as a mem= parameter.

Since mem= should not be considered a production feature, a panic notifier
handler is installed that dumps the memory limit at panic time if one was
set.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 18:16:53 +00:00
Ard Biesheuvel
ab893fb9f1 arm64: introduce KIMAGE_VADDR as the virtual base of the kernel region
This introduces the preprocessor symbol KIMAGE_VADDR which will serve as
the symbolic virtual base of the kernel region, i.e., the kernel's virtual
offset will be KIMAGE_VADDR + TEXT_OFFSET. For now, we define it as being
equal to PAGE_OFFSET, but in the future, it will be moved below it once
we move the kernel virtual mapping out of the linear mapping.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 18:16:27 +00:00
Catalin Marinas
e950631e84 arm64: Remove the get_thread_info() function
This function was introduced by previous commits implementing UAO.
However, it can be replaced with task_thread_info() in
uao_thread_switch() or get_fs() in do_page_fault() (the latter being
called only on the current context, so no need for using the saved
pt_regs).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 17:27:05 +00:00
James Morse
7054419600 arm64: kernel: Don't toggle PAN on systems with UAO
If a CPU supports both Privileged Access Never (PAN) and User Access
Override (UAO), we don't need to disable/re-enable PAN round all
copy_to_user() like calls.

UAO alternatives cause these calls to use the 'unprivileged' load/store
instructions, which are overridden to be the privileged kind when
fs==KERNEL_DS.

This patch changes the copy_to_user() calls to have their PAN toggling
depend on a new composite 'feature' ARM64_ALT_PAN_NOT_UAO.

If both features are detected, PAN will be enabled, but the copy_to_user()
alternatives will not be applied. This means PAN will be enabled all the
time for these functions. If only PAN is detected, the toggling will be
enabled as normal.

This will save the time taken to disable/re-enable PAN, and allow us to
catch copy_to_user() accesses that occur with fs==KERNEL_DS.

Futex and swp-emulation code continue to hang their PAN toggling code on
ARM64_HAS_PAN.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 17:27:05 +00:00
James Morse
644c2ae198 arm64: cpufeature: Test 'matches' pointer to find the end of the list
CPU feature code uses the desc field as a test to find the end of the list,
this means every entry must have a description. This generates noise for
entries in the list that aren't really features, but combinations of them.
e.g.
> CPU features: detected feature: Privileged Access Never
> CPU features: detected feature: PAN and not UAO

These combination features are needed for corner cases with alternatives,
where cpu features interact.

Change all walkers of the arm64_features[] and arm64_hwcaps[] lists to test
'matches' not 'desc', and only print 'desc' if it is non-NULL.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 17:27:05 +00:00
James Morse
57f4959bad arm64: kernel: Add support for User Access Override
'User Access Override' is a new ARMv8.2 feature which allows the
unprivileged load and store instructions to be overridden to behave in
the normal way.

This patch converts {get,put}_user() and friends to use ldtr*/sttr*
instructions - so that they can only access EL0 memory, then enables
UAO when fs==KERNEL_DS so that these functions can access kernel memory.

This allows user space's read/write permissions to be checked against the
page tables, instead of testing addr<USER_DS, then using the kernel's
read/write permissions.

Signed-off-by: James Morse <james.morse@arm.com>
[catalin.marinas@arm.com: move uao_thread_switch() above dsb()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 17:27:04 +00:00
Jan Glauber
c210ae80e4 arm64: perf: Extend event mask for ARMv8.1
ARMv8.1 increases the PMU event number space to 16 bit so increase
the EVTYPE mask.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-18 17:23:41 +00:00
Jan Glauber
7175f0591e arm64: perf: Enable PMCR long cycle counter bit
With the long cycle counter bit (LC) disabled the cycle counter is not
working on ThunderX SOC (ThunderX only implements Aarch64).
Also, according to documentation LC == 0 is deprecated.

To keep the code simple the patch does not introduce 64 bit wide counter
functions. Instead writing the cycle counter always sets the upper
32 bits so overflow interrupts are generated as before.

Original patch from Andrew Pinksi <Andrew.Pinksi@caviumnetworks.com>

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-18 17:23:41 +00:00
Jan Glauber
d0aa2bffcf arm64/perf: Add Cavium ThunderX PMU support
Support PMU events on Caviums ThunderX SOC. ThunderX supports
some additional counters compared to the default ARMv8 PMUv3:

- branch instructions counter
- stall frontend & backend counters
- L1 dcache load & store counters
- L1 icache counters
- iTLB & dTLB counters
- L1 dcache & icache prefetch counters

Signed-off-by: Jan Glauber <jglauber@cavium.com>
[will: capitalisation]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-18 17:23:39 +00:00
Jan Glauber
5f140ccef3 arm64: perf: Rename Cortex A57 events
The implemented Cortex A57 events are strictly-speaking not
A57 specific. They are ARM recommended implementation defined events
and can be found on other ARMv8 SOCs like Cavium ThunderX too.

Therefore rename these events to allow using them in other
implementations too.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
[will: capitalisation and ordering]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-18 17:22:42 +00:00
James Morse
406e308770 arm64: add ARMv8.2 id_aa64mmfr2 boiler plate
ARMv8.2 adds a new feature register id_aa64mmfr2. This patch adds the
cpu feature boiler plate used by the actual features in later patches.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 12:00:01 +00:00
James Morse
0f54b14e76 arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macro
Older assemblers may not have support for newer feature registers. To get
round this, sysreg.h provides a 'mrs_s' macro that takes a register
encoding and generates the raw instruction.

Change read_cpuid() to use mrs_s in all cases so that new registers
don't have to be a special case. Including sysreg.h means we need to move
the include and definition of read_cpuid() after the #ifndef __ASSEMBLY__
to avoid syntax errors in vmlinux.lds.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 11:59:54 +00:00
David Brown
88d8a7994e arm64: vdso: Mark vDSO code as read-only
Although the arm64 vDSO is cleanly separated by code/data with the
code being read-only in userspace mappings, the code page is still
writable from the kernel.  There have been exploits (such as
http://itszn.com/blog/?p=21) that take advantage of this on x86 to go
from a bad kernel write to full root.

Prevent this specific exploit on arm64 by putting the vDSO code page
in read-only memory as well.

Before the change:
[    3.138366] vdso: 2 pages (1 code @ ffffffc000a71000, 1 data @ ffffffc000a70000)
---[ Kernel Mapping ]---
0xffffffc000000000-0xffffffc000082000         520K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc000082000-0xffffffc000200000        1528K     ro x  SHD AF            UXN MEM/NORMAL
0xffffffc000200000-0xffffffc000800000           6M     ro x  SHD AF        BLK UXN MEM/NORMAL
0xffffffc000800000-0xffffffc0009b6000        1752K     ro x  SHD AF            UXN MEM/NORMAL
0xffffffc0009b6000-0xffffffc000c00000        2344K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc000c00000-0xffffffc008000000         116M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc00c000000-0xffffffc07f000000        1840M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc800000000-0xffffffc840000000           1G     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc840000000-0xffffffc87ae00000         942M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc87ae00000-0xffffffc87ae70000         448K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87af80000-0xffffffc87af8a000          40K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87af8b000-0xffffffc87b000000         468K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87b000000-0xffffffc87fe00000          78M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc87fe00000-0xffffffc87ff50000        1344K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87ff90000-0xffffffc87ffa0000          64K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87fff0000-0xffffffc880000000          64K     RW NX SHD AF            UXN MEM/NORMAL

After:
[    3.138368] vdso: 2 pages (1 code @ ffffffc0006de000, 1 data @ ffffffc000a74000)
---[ Kernel Mapping ]---
0xffffffc000000000-0xffffffc000082000         520K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc000082000-0xffffffc000200000        1528K     ro x  SHD AF            UXN MEM/NORMAL
0xffffffc000200000-0xffffffc000800000           6M     ro x  SHD AF        BLK UXN MEM/NORMAL
0xffffffc000800000-0xffffffc0009b8000        1760K     ro x  SHD AF            UXN MEM/NORMAL
0xffffffc0009b8000-0xffffffc000c00000        2336K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc000c00000-0xffffffc008000000         116M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc00c000000-0xffffffc07f000000        1840M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc800000000-0xffffffc840000000           1G     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc840000000-0xffffffc87ae00000         942M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc87ae00000-0xffffffc87ae70000         448K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87af80000-0xffffffc87af8a000          40K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87af8b000-0xffffffc87b000000         468K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87b000000-0xffffffc87fe00000          78M     RW NX SHD AF        BLK UXN MEM/NORMAL
0xffffffc87fe00000-0xffffffc87ff50000        1344K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87ff90000-0xffffffc87ffa0000          64K     RW NX SHD AF            UXN MEM/NORMAL
0xffffffc87fff0000-0xffffffc880000000          64K     RW NX SHD AF            UXN MEM/NORMAL

Inspired by https://lkml.org/lkml/2016/1/19/494 based on work by the
PaX Team, Brad Spengler, and Kees Cook.

Signed-off-by: David Brown <david.brown@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[catalin.marinas@arm.com: removed superfluous __PAGE_ALIGNED_DATA]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 18:20:23 +00:00
Yang Shi
cf0a25436f arm64: replace read_lock to rcu lock in call_step_hook
BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917
in_atomic(): 1, irqs_disabled(): 128, pid: 383, name: sh
Preemption disabled at:[<ffff800000124c18>] kgdb_cpu_enter+0x158/0x6b8

CPU: 3 PID: 383 Comm: sh Tainted: G        W       4.1.13-rt13 #2
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Call trace:
[<ffff8000000885e8>] dump_backtrace+0x0/0x128
[<ffff800000088734>] show_stack+0x24/0x30
[<ffff80000079a7c4>] dump_stack+0x80/0xa0
[<ffff8000000bd324>] ___might_sleep+0x18c/0x1a0
[<ffff8000007a20ac>] __rt_spin_lock+0x2c/0x40
[<ffff8000007a2268>] rt_read_lock+0x40/0x58
[<ffff800000085328>] single_step_handler+0x38/0xd8
[<ffff800000082368>] do_debug_exception+0x58/0xb8
Exception stack(0xffff80834a1e7c80 to 0xffff80834a1e7da0)
7c80: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7e40 ffff8083 001bfcc4 ffff8000
7ca0: f2000400 00000000 00000000 00000000 4a1e7d80 ffff8083 0049501c ffff8000
7cc0: 00005402 00000000 00aaa210 ffff8000 4a1e7ea0 ffff8083 000833f4 ffff8000
7ce0: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7ea0 ffff8083 001bfcc0 ffff8000
7d00: 4a0fc400 ffff8083 00005402 00000000 4a1e7d40 ffff8083 00490324 ffff8000
7d20: ffffff9c 00000000 92c23ba0 0000ffff 000a0000 00000000 00000000 00000000
7d40: 00000008 00000000 00080000 00000000 92c23b8b 0000ffff 92c23b8e 0000ffff
7d60: 00000038 00000000 00001cb2 00000000 00000005 00000000 92d7b498 0000ffff
7d80: 01010101 01010101 92be9000 0000ffff 00000000 00000000 00000030 00000000
[<ffff8000000833f4>] el1_dbg+0x18/0x6c

This issue is similar with 62c6c61("arm64: replace read_lock to rcu lock in
call_break_hook"), but comes to single_step_handler.

This also solves kgdbts boot test silent hang issue on 4.4 -rt kernel.

Signed-off-by: Yang Shi <yang.shi@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:40:45 +00:00
Will Deacon
d5370f7548 arm64: prefetch: add alternative pattern for CPUs without a prefetcher
Most CPUs have a hardware prefetcher which generally performs better
without explicit prefetch instructions issued by software, however
some CPUs (e.g. Cavium ThunderX) rely solely on explicit prefetch
instructions.

This patch adds an alternative pattern (ARM64_HAS_NO_HW_PREFETCH) to
allow our library code to make use of explicit prefetch instructions
during things like copy routines only when the CPU does not have the
capability to perform the prefetching itself.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:12:32 +00:00
Lorenzo Pieralisi
5e89c55e4e arm64: kernel: implement ACPI parking protocol
The SBBR and ACPI specifications allow ACPI based systems that do not
implement PSCI (eg systems with no EL3) to boot through the ACPI parking
protocol specification[1].

This patch implements the ACPI parking protocol CPU operations, and adds
code that eases parsing the parking protocol data structures to the
ARM64 SMP initializion carried out at the same time as cpus enumeration.

To wake-up the CPUs from the parked state, this patch implements a
wakeup IPI for ARM64 (ie arch_send_wakeup_ipi_mask()) that mirrors the
ARM one, so that a specific IPI is sent for wake-up purpose in order
to distinguish it from other IPI sources.

Given the current ACPI MADT parsing API, the patch implements a glue
layer that helps passing MADT GICC data structure from SMP initialization
code to the parking protocol implementation somewhat overriding the CPU
operations interfaces. This to avoid creating a completely trasparent
DT/ACPI CPU operations layer that would require creating opaque
structure handling for CPUs data (DT represents CPU through DT nodes, ACPI
through static MADT table entries), which seems overkill given that ACPI
on ARM64 mandates only two booting protocols (PSCI and parking protocol),
so there is no need for further protocol additions.

Based on the original work by Mark Salter <msalter@redhat.com>

[1] https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.docx

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Loc Ho <lho@apm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Al Stone <ahs3@redhat.com>
[catalin.marinas@arm.com: Added WARN_ONCE(!acpi_parking_protocol_valid() on the IPI]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:12:32 +00:00
Mark Rutland
fca082bfb5 arm64: ensure _stext and _etext are page-aligned
Currently we have separate ALIGN_DEBUG_RO{,_MIN} directives to align
_etext and __init_begin. While we ensure that __init_begin is
page-aligned, we do not provide the same guarantee for _etext. This is
not problematic currently as the alignment of __init_begin is sufficient
to prevent issues when we modify permissions.

Subsequent patches will assume page alignment of segments of the kernel
we wish to map with different permissions. To ensure this, move _etext
after the ALIGN_DEBUG_RO_MIN for the init section. This renders the
prior ALIGN_DEBUG_RO irrelevant, and hence it is removed. Likewise,
upgrade to ALIGN_DEBUG_RO_MIN(PAGE_SIZE) for _stext.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:10:46 +00:00
Mark Rutland
86ccce896c arm64: unmap idmap earlier
During boot we leave the idmap in place until paging_init, as we
previously had to wait for the zero page to become allocated and
accessible.

Now that we have a statically-allocated zero page, we can uninstall the
idmap much earlier in the boot process, making it far easier to spot
accidental use of physical addresses. This also brings the cold boot
path in line with the secondary boot path.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:10:45 +00:00
Mark Rutland
9e8e865bbe arm64: unify idmap removal
We currently open-code the removal of the idmap and restoration of the
current task's MMU state in a few places.

Before introducing yet more copies of this sequence, unify these to call
a new helper, cpu_uninstall_idmap.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:10:44 +00:00
Mark Rutland
5227cfa71f arm64: mm: place empty_zero_page in bss
Currently the zero page is set up in paging_init, and thus we cannot use
the zero page earlier. We use the zero page as a reserved TTBR value
from which no TLB entries may be allocated (e.g. when uninstalling the
idmap). To enable such usage earlier (as may be required for invasive
changes to the kernel page tables), and to minimise the time that the
idmap is active, we need to be able to use the zero page before
paging_init.

This patch follows the example set by x86, by allocating the zero page
at compile time, in .bss. This means that the zero page itself is
available immediately upon entry to start_kernel (as we zero .bss before
this), and also means that the zero page takes up no space in the raw
Image binary. The associated struct page is allocated in bootmem_init,
and remains unavailable until this time.

Outside of arch code, the only users of empty_zero_page assume that the
empty_zero_page symbol refers to the zeroed memory itself, and that
ZERO_PAGE(x) must be used to acquire the associated struct page,
following the example of x86. This patch also brings arm64 inline with
these assumptions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:10:44 +00:00
Thierry Reding
7f4e346263 arm64/efi: Make strnlen() available to the EFI namespace
Changes introduced in the upstream version of libfdt pulled in by commit
91feabc2e2 ("scripts/dtc: Update to upstream commit b06e55c88b9b") use
the strnlen() function, which isn't currently available to the EFI name-
space. Add it to the EFI namespace to avoid a linker error.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Rob Herring <robh@kernel.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-16 10:32:10 +00:00
Yang Shi
a80a0eb70c arm64: make irq_stack_ptr more robust
Switching between stacks is only valid if we are tracing ourselves while on the
irq_stack, so it is only valid when in current and non-preemptible context,
otherwise is is just zeroed off.

Fixes: 132cd887b5 ("arm64: Modify stack trace and dump for use with irq_stack")
Acked-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-12 15:53:51 +00:00
Lorenzo Pieralisi
8b6f2499ac ARM: 8511/1: ARM64: kernel: PSCI: move PSCI idle management code to drivers/firmware
ARM64 PSCI kernel interfaces that initialize idle states and implement
the suspend API to enter them are generic and can be shared with the
ARM architecture.

To achieve that goal, this patch moves ARM64 PSCI idle management
code to drivers/firmware, so that the interface to initialize and
enter idle states can actually be shared by ARM and ARM64 arches
back-ends.

The ARM generic CPUidle implementation also requires the definition of
a cpuidle_ops section entry for the kernel to initialize the CPUidle
operations at boot based on the enable-method (ie ARM64 has the
statically initialized cpu_ops counterparts for that purpose); therefore
this patch also adds the required section entry on CONFIG_ARM for PSCI so
that the kernel can initialize the PSCI CPUidle back-end when PSCI is
the probed enable-method.

On ARM64 this patch provides no functional change.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arch/arm64]
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Jisheng Zhang <jszhang@marvell.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-11 15:33:38 +00:00
Will Deacon
e04a28d45f arm64: debug: re-enable irqs before sending breakpoint SIGTRAP
force_sig_info can sleep under an -rt kernel, so attempting to send a
breakpoint SIGTRAP with interrupts disabled yields the following BUG:

  BUG: sleeping function called from invalid context at
  /kernel-source/kernel/locking/rtmutex.c:917
  in_atomic(): 0, irqs_disabled(): 128, pid: 551, name: test.sh
  CPU: 5 PID: 551 Comm: test.sh Not tainted 4.1.13-rt13 #7
  Hardware name: Freescale Layerscape 2085a RDB Board (DT)
  Call trace:
	 dump_backtrace+0x0/0x128
	 show_stack+0x24/0x30
	 dump_stack+0x80/0xa0
	 ___might_sleep+0x128/0x1a0
	 rt_spin_lock+0x2c/0x40
	 force_sig_info+0xcc/0x210
	 brk_handler.part.2+0x6c/0x80
	 brk_handler+0xd8/0xe8
	 do_debug_exception+0x58/0xb8

This patch fixes the problem by ensuring that interrupts are enabled
prior to sending the SIGTRAP if they were already enabled in the user
context.

Reported-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-10 16:05:28 +00:00
Yang Shi
bcaf669b4b arm64: disable kasan when accessing frame->fp in unwind_frame
When boot arm64 kernel with KASAN enabled, the below error is reported by
kasan:

BUG: KASAN: out-of-bounds in unwind_frame+0xec/0x260 at addr ffffffc064d57ba0
Read of size 8 by task pidof/499
page:ffffffbdc39355c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 2 PID: 499 Comm: pidof Not tainted 4.5.0-rc1 #119
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Call trace:
[<ffffffc00008d078>] dump_backtrace+0x0/0x290
[<ffffffc00008d32c>] show_stack+0x24/0x30
[<ffffffc0006a981c>] dump_stack+0x8c/0xd8
[<ffffffc0002e4400>] kasan_report_error+0x558/0x588
[<ffffffc0002e4958>] kasan_report+0x60/0x70
[<ffffffc0002e3188>] __asan_load8+0x60/0x78
[<ffffffc00008c92c>] unwind_frame+0xec/0x260
[<ffffffc000087e60>] get_wchan+0x110/0x160
[<ffffffc0003b647c>] do_task_stat+0xb44/0xb68
[<ffffffc0003b7730>] proc_tgid_stat+0x40/0x50
[<ffffffc0003ac840>] proc_single_show+0x88/0xd8
[<ffffffc000345be8>] seq_read+0x370/0x770
[<ffffffc00030aba0>] __vfs_read+0xc8/0x1d8
[<ffffffc00030c0ec>] vfs_read+0x94/0x168
[<ffffffc00030d458>] SyS_read+0xb8/0x128
[<ffffffc000086530>] el0_svc_naked+0x24/0x28
Memory state around the buggy address:
 ffffffc064d57a80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f4 f4
 ffffffc064d57b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffc064d57b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                  ^
 ffffffc064d57c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc064d57c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Since the shadow byte pointed by the report is 0, so it may mean it is just hit
oob in non-current task. So, disable the instrumentation to silence these
warnings.

Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-09 17:55:30 +00:00
Bjorn Helgaas
234234c2e1 ARM64: PCI: Remove generated include of asm-generic/pci-bridge.h
arm64 generates asm/pci-bridge.h, which merely includes the now-empty
asm-generic/pci-bridge.h.  Stop generating asm/pci-bridge.h, and stop
including it.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
2016-02-05 16:29:12 -06:00
Toshi Kani
35d98e93fe arch: Set IORESOURCE_SYSTEM_RAM flag for System RAM
Set IORESOURCE_SYSTEM_RAM in flags of resource ranges with
"System RAM", "Kernel code", "Kernel data", and "Kernel bss".

Note that:

 - IORESOURCE_SYSRAM (i.e. modifier bit) is set in flags when
   IORESOURCE_MEM is already set. IORESOURCE_SYSTEM_RAM is defined
   as (IORESOURCE_MEM|IORESOURCE_SYSRAM).

 - Some archs do not set 'flags' for children nodes, such as
   "Kernel code".  This patch does not change 'flags' in this
   case.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@linux-mips.org
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1453841853-11383-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 09:49:57 +01:00
Lorenzo Pieralisi
f436b2ac90 arm64: kernel: fix architected PMU registers unconditional access
The Performance Monitors extension is an optional feature of the
AArch64 architecture, therefore, in order to access Performance
Monitors registers safely, the kernel should detect the architected
PMU unit presence through the ID_AA64DFR0_EL1 register PMUVer field
before accessing them.

This patch implements a guard by reading the ID_AA64DFR0_EL1 register
PMUVer field to detect the architected PMU presence and prevent accessing
PMU system registers if the Performance Monitors extension is not
implemented in the core.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Fixes: 60792ad349 ("arm64: kernel: enforce pmuserenr_el0 initialization and restore")
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-25 11:09:06 +00:00