Patch series "exec: Pin stack limit during exec".
Attempts to solve problems with the stack limit changing during exec
continue to be frustrated[1][2]. In addition to the specific issues
around the Stack Clash family of flaws, Andy Lutomirski pointed out[3]
other places during exec where the stack limit is used and is assumed to
be unchanging. Given the many places it gets used and the fact that it
can be manipulated/raced via setrlimit() and prlimit(), I think the only
way to handle this is to move away from the "current" view of the stack
limit and instead attach it to the bprm, and plumb this down into the
functions that need to know the stack limits. This series implements
the approach.
[1] 04e35f4495 ("exec: avoid RLIMIT_STACK races with prlimit()")
[2] 779f4e1c6c ("Revert "exec: avoid RLIMIT_STACK races with prlimit()"")
[3] to security@kernel.org, "Subject: existing rlimit races?"
This patch (of 3):
Since it is possible that the stack rlimit can change externally during
exec (either via another thread calling setrlimit() or another process
calling prlimit()), provide a way to pass the rlimit down into the
per-architecture mm layout functions so that the rlimit can stay in the
bprm structure instead of sitting in the signal structure until exec is
finalized.
Link: http://lkml.kernel.org/r/1518638796-20819-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nothing particularly stands out here, probably because people were tied
up with spectre/meltdown stuff last time around. Still, the main pieces
are:
- Rework of our CPU features framework so that we can whitelist CPUs that
don't require kpti even in a heterogeneous system
- Support for the IDC/DIC architecture extensions, which allow us to elide
instruction and data cache maintenance when writing out instructions
- Removal of the large memory model which resulted in suboptimal codegen
by the compiler and increased the use of literal pools, which could
potentially be used as ROP gadgets since they are mapped as executable
- Rework of forced signal delivery so that the siginfo_t is well-formed
and handling of show_unhandled_signals is consolidated and made
consistent between different fault types
- More siginfo cleanup based on the initial patches from Eric Biederman
- Workaround for Cortex-A55 erratum #1024718
- Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi
- Misc cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
"Nothing particularly stands out here, probably because people were
tied up with spectre/meltdown stuff last time around. Still, the main
pieces are:
- Rework of our CPU features framework so that we can whitelist CPUs
that don't require kpti even in a heterogeneous system
- Support for the IDC/DIC architecture extensions, which allow us to
elide instruction and data cache maintenance when writing out
instructions
- Removal of the large memory model which resulted in suboptimal
codegen by the compiler and increased the use of literal pools,
which could potentially be used as ROP gadgets since they are
mapped as executable
- Rework of forced signal delivery so that the siginfo_t is
well-formed and handling of show_unhandled_signals is consolidated
and made consistent between different fault types
- More siginfo cleanup based on the initial patches from Eric
Biederman
- Workaround for Cortex-A55 erratum #1024718
- Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi
- Misc cleanups and non-critical fixes"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits)
arm64: uaccess: Fix omissions from usercopy whitelist
arm64: fpsimd: Split cpu field out from struct fpsimd_state
arm64: tlbflush: avoid writing RES0 bits
arm64: cmpxchg: Include linux/compiler.h in asm/cmpxchg.h
arm64: move percpu cmpxchg implementation from cmpxchg.h to percpu.h
arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG
arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC
arm64: fpsimd: include <linux/init.h> in fpsimd.h
drivers/perf: arm_pmu_platform: do not warn about affinity on uniprocessor
perf: arm_spe: include linux/vmalloc.h for vmap()
Revert "arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)"
arm64: cpufeature: Avoid warnings due to unused symbols
arm64: Add work around for Arm Cortex-A55 Erratum 1024718
arm64: Delay enabling hardware DBM feature
arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35
arm64: capabilities: Handle shared entries
arm64: capabilities: Add support for checks based on a list of MIDRs
arm64: Add helpers for checking CPU MIDR against a range
arm64: capabilities: Clean up midr range helpers
arm64: capabilities: Change scope of VHE to Boot CPU feature
...
This reverts commit 1f85b42a69.
The internal dma-direct.h API has changed in -next, which collides with
us trying to use it to manage non-coherent DMA devices on systems with
unreasonably large cache writeback granules.
This isn't at all trivial to resolve, so revert our changes for now and
we can revisit this after the merge window. Effectively, this just
restores our behaviour back to that of 4.16.
Signed-off-by: Will Deacon <will.deacon@arm.com>
We enable hardware DBM bit in a capable CPU, very early in the
boot via __cpu_setup. This doesn't give us a flexibility of
optionally disable the feature, as the clearing the bit
is a bit costly as the TLB can cache the settings. Instead,
we delay enabling the feature until the CPU is brought up
into the kernel. We use the feature capability mechanism
to handle it.
The hardware DBM is a non-conflicting feature. i.e, the kernel
can safely run with a mix of CPUs with some using the feature
and the others don't. So, it is safe for a late CPU to have
this capability and enable it, even if the active CPUs don't.
To get this handled properly by the infrastructure, we
unconditionally set the capability and only enable it
on CPUs which really have the feature. Also, we print the
feature detection from the "matches" call back to make sure
we don't mislead the user when none of the CPUs could use the
feature.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
We issue the enable() call back for all CPU hwcaps capabilities
available on the system, on all the CPUs. So far we have ignored
the argument passed to the call back, which had a prototype to
accept a "void *" for use with on_each_cpu() and later with
stop_machine(). However, with commit 0a0d111d40
("arm64: cpufeature: Pass capability structure to ->enable callback"),
there are some users of the argument who wants the matching capability
struct pointer where there are multiple matching criteria for a single
capability. Clean up the declaration of the call back to make it clear.
1) Renamed to cpu_enable(), to imply taking necessary actions on the
called CPU for the entry.
2) Pass const pointer to the capability, to allow the call back to
check the entry. (e.,g to check if any action is needed on the CPU)
3) We don't care about the result of the call back, turning this to
a void.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: James Morse <james.morse@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Dave Martin <dave.martin@arm.com>
[suzuki: convert more users, rename call back and drop results]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
On architectures with CONFIG_HAVE_ARCH_HUGE_VMAP set, ioremap() may
create pud/pmd mappings. A kernel panic was observed on arm64 systems
with Cortex-A75 in the following steps as described by Hanjun Guo.
1. ioremap a 4K size, valid page table will build,
2. iounmap it, pte0 will set to 0;
3. ioremap the same address with 2M size, pgd/pmd is unchanged,
then set the a new value for pmd;
4. pte0 is leaked;
5. CPU may meet exception because the old pmd is still in TLB,
which will lead to kernel panic.
This panic is not reproducible on x86. INVLPG, called from iounmap,
purges all levels of entries associated with purged address on x86. x86
still has memory leak.
The patch changes the ioremap path to free unmapped page table(s) since
doing so in the unmap path has the following issues:
- The iounmap() path is shared with vunmap(). Since vmap() only
supports pte mappings, making vunmap() to free a pte page is an
overhead for regular vmap users as they do not need a pte page freed
up.
- Checking if all entries in a pte page are cleared in the unmap path
is racy, and serializing this check is expensive.
- The unmap path calls free_vmap_area_noflush() to do lazy TLB purges.
Clearing a pud/pmd entry before the lazy TLB purges needs extra TLB
purge.
Add two interfaces, pud_free_pmd_page() and pmd_free_pte_page(), which
clear a given pud/pmd entry and free up a page for the lower level
entries.
This patch implements their stub functions on x86 and arm64, which work
as workaround.
[akpm@linux-foundation.org: fix typo in pmd_free_pte_page() stub]
Link: http://lkml.kernel.org/r/20180314180155.19492-2-toshi.kani@hpe.com
Fixes: e61ce6ade4 ("mm: change ioremap to set up huge I/O mappings")
Reported-by: Lei Li <lious.lilei@hisilicon.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Wang Xuefeng <wxf.wang@hisilicon.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, as reported by Eric, an invalid si_code value 0 is
passed in many signals delivered to userspace in response to faults
and other kernel errors. Typically 0 is passed when the fault is
insufficiently diagnosable or when there does not appear to be any
sensible alternative value to choose.
This appears to violate POSIX, and is intuitively wrong for at
least two reasons arising from the fact that 0 == SI_USER:
1) si_code is a union selector, and SI_USER (and si_code <= 0 in
general) implies the existence of a different set of fields
(siginfo._kill) from that which exists for a fault signal
(siginfo._sigfault). However, the code raising the signal
typically writes only the _sigfault fields, and the _kill
fields make no sense in this case.
Thus when userspace sees si_code == 0 (SI_USER) it may
legitimately inspect fields in the inactive union member _kill
and obtain garbage as a result.
There appears to be software in the wild relying on this,
albeit generally only for printing diagnostic messages.
2) Software that wants to be robust against spurious signals may
discard signals where si_code == SI_USER (or <= 0), or may
filter such signals based on the si_uid and si_pid fields of
siginfo._sigkill. In the case of fault signals, this means
that important (and usually fatal) error conditions may be
silently ignored.
In practice, many of the faults for which arm64 passes si_code == 0
are undiagnosable conditions such as exceptions with syndrome
values in ESR_ELx to which the architecture does not yet assign any
meaning, or conditions indicative of a bug or error in the kernel
or system and thus that are unrecoverable and should never occur in
normal operation.
The approach taken in this patch is to translate all such
undiagnosable or "impossible" synchronous fault conditions to
SIGKILL, since these are at least probably localisable to a single
process. Some of these conditions should really result in a kernel
panic, but due to the lack of diagnostic information it is
difficult to be certain: this patch does not add any calls to
panic(), but this could change later if justified.
Although si_code will not reach userspace in the case of SIGKILL,
it is still desirable to pass a nonzero value so that the common
siginfo handling code can detect incorrect use of si_code == 0
without false positives. In this case the si_code dependent
siginfo fields will not be correctly initialised, but since they
are not passed to userspace I deem this not to matter.
A few faults can reasonably occur in realistic userspace scenarios,
and _should_ raise a regular, handleable (but perhaps not
ignorable/blockable) signal: for these, this patch attempts to
choose a suitable standard si_code value for the raised signal in
each case instead of 0.
arm64 was the only arch to define a BUS_FIXME code, so after this
patch nobody defines it. This patch therefore also removes the
relevant code from siginfo_layout().
Cc: James Morse <james.morse@arm.com>
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The DCache clean & ICache invalidation requirements for instructions
to be data coherence are discoverable through new fields in CTR_EL0.
The following two control bits DIC and IDC were defined for this
purpose. No need to perform point of unification cache maintenance
operations from software on systems where CPU caches are transparent.
This patch optimize the three functions __flush_cache_user_range(),
clean_dcache_area_pou() and invalidate_icache_range() if the hardware
reports CTR_EL0.IDC and/or CTR_EL0.IDC. Basically it skips the two
instructions 'DC CVAU' and 'IC IVAU', and the associated loop logic
in order to avoid the unnecessary overhead.
CTR_EL0.DIC: Instruction cache invalidation requirements for
instruction to data coherence. The meaning of this bit[29].
0: Instruction cache invalidation to the point of unification
is required for instruction to data coherence.
1: Instruction cache cleaning to the point of unification is
not required for instruction to data coherence.
CTR_EL0.IDC: Data cache clean requirements for instruction to data
coherence. The meaning of this bit[28].
0: Data cache clean to the point of unification is required for
instruction to data coherence, unless CLIDR_EL1.LoC == 0b000
or (CLIDR_EL1.LoUIS == 0b000 && CLIDR_EL1.LoUU == 0b000).
1: Data cache clean to the point of unification is not required
for instruction to data coherence.
Co-authored-by: Philip Elcan <pelcan@codeaurora.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
TCR_EL1.NFD1 was allocated by SVE and ensures that fault-surpressing SVE
memory accesses (e.g. speculative accesses from a first-fault gather load)
which translate via TTBR1_EL1 result in a translation fault if they
miss in the TLB when executed from EL0. This mitigates some timing attacks
against KASLR, where the kernel address space could otherwise be probed
efficiently using the FFR in conjunction with suppressed faults on SVE
loads.
Cc: Dave Martin <Dave.Martin@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit 9730348075 ("arm64: Increase the max granular size") increased
the cache line size to 128 to match Cavium ThunderX, apparently for some
performance benefit which could not be confirmed. This change, however,
has an impact on the network packets allocation in certain
circumstances, requiring slightly over a 4K page with a significant
performance degradation.
This patch reverts L1_CACHE_SHIFT back to 6 (64-byte cache line) while
keeping ARCH_DMA_MINALIGN at 128. The cache_line_size() function was
changed to default to ARCH_DMA_MINALIGN in the absence of a meaningful
CTR_EL0.CWG bit field.
In addition, if a system with ARCH_DMA_MINALIGN < CTR_EL0.CWG is
detected, the kernel will force swiotlb bounce buffering for all
non-coherent devices since DMA cache maintenance on sub-CWG ranges is
not safe, leading to data corruption.
Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Cc: Timur Tabi <timur@codeaurora.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Reporting unhandled user pagefaults via arm64_force_sig_info means
that __do_user_fault can be drastically simplified, since it no longer
has to worry about printing the fault information and can consequently
just take the siginfo as a parameter.
Signed-off-by: Will Deacon <will.deacon@arm.com>
There's no need for callers of arm64_notify_die to print information
about user faults. Instead, they can pass a string to arm64_notify_die
which will be printed subject to show_unhandled_signals.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The routine pgattr_change_is_safe() was extended in commit 4e60205655
("arm64: mm: Permit transitioning from Global to Non-Global without BBM")
to permit changing the nG attribute from not set to set, but did so in a
way that inadvertently disallows such changes if other permitted attribute
changes take place at the same time. So update the code to take this into
account.
Fixes: 4e60205655 ("arm64: mm: Permit transitioning from Global to ...")
Cc: <stable@vger.kernel.org> # 4.14.x-
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
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>
ioremap_page_range doesn't honour break-before-make and attempts to put
down huge mappings (using p*d_set_huge) over the top of pre-existing
table entries. This leads to us leaking page table memory and also gives
rise to TLB conflicts and spurious aborts, which have been seen in
practice on Cortex-A75.
Until this has been resolved, refuse to put block mappings when the
existing entry is found to be present.
Fixes: 324420bf91 ("arm64: add support for ioremap() block mappings")
Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
Reported-by: Lei Li <lious.lilei@hisilicon.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In many cases, page tables can be accessed concurrently by either another
CPU (due to things like fast gup) or by the hardware page table walker
itself, which may set access/dirty bits. In such cases, it is important
to use READ_ONCE/WRITE_ONCE when accessing page table entries so that
entries cannot be torn, merged or subject to apparent loss of coherence
due to compiler transformations.
Whilst there are some scenarios where this cannot happen (e.g. pinned
kernel mappings for the linear region), the overhead of using READ_ONCE
/WRITE_ONCE everywhere is minimal and makes the code an awful lot easier
to reason about. This patch consistently uses these macros in the arch
code, as well as explicitly namespacing pointers to page table entries
from the entries themselves by using adopting a 'p' suffix for the former
(as is sometimes used elsewhere in the kernel source).
Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Tested-by: Richard Ruigrok <rruigrok@codeaurora.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When KASAN is enabled, the swapper page table contains many identical
mappings of the zero page, which can lead to a stall during boot whilst
the G -> nG code continually walks the same page table entries looking
for global mappings.
This patch sets the nG bit (bit 11, which is IGNORED) in table entries
after processing the subtree so we can easily skip them if we see them
a second time.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
ARM:
- Include icache invalidation optimizations, improving VM startup time
- Support for forwarded level-triggered interrupts, improving
performance for timers and passthrough platform devices
- A small fix for power-management notifiers, and some cosmetic changes
PPC:
- Add MMIO emulation for vector loads and stores
- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
requiring the complex thread synchronization of older CPU versions
- Improve the handling of escalation interrupts with the XIVE interrupt
controller
- Support decrement register migration
- Various cleanups and bugfixes.
s390:
- Cornelia Huck passed maintainership to Janosch Frank
- Exitless interrupts for emulated devices
- Cleanup of cpuflag handling
- kvm_stat counter improvements
- VSIE improvements
- mm cleanup
x86:
- Hypervisor part of SEV
- UMIP, RDPID, and MSR_SMI_COUNT emulation
- Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
- Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
features
- Show vcpu id in its anonymous inode name
- Many fixes and cleanups
- Per-VCPU MSR bitmaps (already merged through x86/pti branch)
- Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
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Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Radim Krčmář:
"ARM:
- icache invalidation optimizations, improving VM startup time
- support for forwarded level-triggered interrupts, improving
performance for timers and passthrough platform devices
- a small fix for power-management notifiers, and some cosmetic
changes
PPC:
- add MMIO emulation for vector loads and stores
- allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
requiring the complex thread synchronization of older CPU versions
- improve the handling of escalation interrupts with the XIVE
interrupt controller
- support decrement register migration
- various cleanups and bugfixes.
s390:
- Cornelia Huck passed maintainership to Janosch Frank
- exitless interrupts for emulated devices
- cleanup of cpuflag handling
- kvm_stat counter improvements
- VSIE improvements
- mm cleanup
x86:
- hypervisor part of SEV
- UMIP, RDPID, and MSR_SMI_COUNT emulation
- paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
- allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
AVX512 features
- show vcpu id in its anonymous inode name
- many fixes and cleanups
- per-VCPU MSR bitmaps (already merged through x86/pti branch)
- stable KVM clock when nesting on Hyper-V (merged through
x86/hyperv)"
* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
KVM: PPC: Book3S HV: Branch inside feature section
KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
KVM: PPC: Book3S PR: Fix broken select due to misspelling
KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
KVM: PPC: Book3S HV: Drop locks before reading guest memory
kvm: x86: remove efer_reload entry in kvm_vcpu_stat
KVM: x86: AMD Processor Topology Information
x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
kvm: embed vcpu id to dentry of vcpu anon inode
kvm: Map PFN-type memory regions as writable (if possible)
x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
KVM: arm/arm64: Fixup userspace irqchip static key optimization
KVM: arm/arm64: Fix userspace_irqchip_in_use counting
KVM: arm/arm64: Fix incorrect timer_is_pending logic
MAINTAINERS: update KVM/s390 maintainers
MAINTAINERS: add Halil as additional vfio-ccw maintainer
MAINTAINERS: add David as a reviewer for KVM/s390
...
Spectre v1 mitigation:
- back-end version of array_index_mask_nospec()
- masking of the syscall number to restrict speculation through the
syscall table
- masking of __user pointers prior to deference in uaccess routines
Spectre v2 mitigation update:
- using the new firmware SMC calling convention specification update
- removing the current PSCI GET_VERSION firmware call mitigation as
vendors are deploying new SMCCC-capable firmware
- additional branch predictor hardening for synchronous exceptions and
interrupts while in user mode
Meltdown v3 mitigation update for Cavium Thunder X: unaffected but
hardware erratum gets in the way. The kernel now starts with the page
tables mapped as global and switches to non-global if kpti needs to be
enabled.
Other:
- Theoretical trylock bug fixed
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull more arm64 updates from Catalin Marinas:
"As I mentioned in the last pull request, there's a second batch of
security updates for arm64 with mitigations for Spectre/v1 and an
improved one for Spectre/v2 (via a newly defined firmware interface
API).
Spectre v1 mitigation:
- back-end version of array_index_mask_nospec()
- masking of the syscall number to restrict speculation through the
syscall table
- masking of __user pointers prior to deference in uaccess routines
Spectre v2 mitigation update:
- using the new firmware SMC calling convention specification update
- removing the current PSCI GET_VERSION firmware call mitigation as
vendors are deploying new SMCCC-capable firmware
- additional branch predictor hardening for synchronous exceptions
and interrupts while in user mode
Meltdown v3 mitigation update:
- Cavium Thunder X is unaffected but a hardware erratum gets in the
way. The kernel now starts with the page tables mapped as global
and switches to non-global if kpti needs to be enabled.
Other:
- Theoretical trylock bug fixed"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (38 commits)
arm64: Kill PSCI_GET_VERSION as a variant-2 workaround
arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support
arm/arm64: smccc: Implement SMCCC v1.1 inline primitive
arm/arm64: smccc: Make function identifiers an unsigned quantity
firmware/psci: Expose SMCCC version through psci_ops
firmware/psci: Expose PSCI conduit
arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support
arm/arm64: KVM: Turn kvm_psci_version into a static inline
arm/arm64: KVM: Advertise SMCCC v1.1
arm/arm64: KVM: Implement PSCI 1.0 support
arm/arm64: KVM: Add smccc accessors to PSCI code
arm/arm64: KVM: Add PSCI_VERSION helper
arm/arm64: KVM: Consolidate the PSCI include files
arm64: KVM: Increment PC after handling an SMC trap
arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
arm64: entry: Apply BP hardening for suspicious interrupts from EL0
arm64: entry: Apply BP hardening for high-priority synchronous exceptions
arm64: futex: Mask __user pointers prior to dereference
...
Right now the fact that KASAN uses a single shadow byte for 8 bytes of
memory is scattered all over the code.
This change defines KASAN_SHADOW_SCALE_SHIFT early in asm include files
and makes use of this constant where necessary.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/34937ca3b90736eaad91b568edf5684091f662e3.1515775666.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is possible to take an IRQ from EL0 following a branch to a kernel
address in such a way that the IRQ is prioritised over the instruction
abort. Whilst an attacker would need to get the stars to align here,
it might be sufficient with enough calibration so perform BP hardening
in the rare case that we see a kernel address in the ELR when handling
an IRQ from EL0.
Reported-by: Dan Hettena <dhettena@nvidia.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Software-step and PC alignment fault exceptions have higher priority than
instruction abort exceptions, so apply the BP hardening hooks there too
if the user PC appears to reside in kernel space.
Reported-by: Dan Hettena <dhettena@nvidia.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently, USER_DS represents an exclusive limit while KERNEL_DS is
inclusive. In order to do some clever trickery for speculation-safe
masking, we need them both to behave equivalently - there aren't enough
bits to make KERNEL_DS exclusive, so we have precisely one option. This
also happens to correct a longstanding false negative for a range
ending on the very top byte of kernel memory.
Mark Rutland points out that we've actually got the semantics of
addresses vs. segments muddled up in most of the places we need to
amend, so shuffle the {USER,KERNEL}_DS definitions around such that we
can correct those properly instead of just pasting "-1"s everywhere.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The identity map is mapped as both writeable and executable by the
SWAPPER_MM_MMUFLAGS and this is relied upon by the kpti code to manage
a synchronisation flag. Update the .pushsection flags to reflect the
actual mapping attributes.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Since AArch64 assembly instructions take the destination register as
their first operand, do the same thing for the phys_to_ttbr macro.
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Defaulting to global mappings for kernel space is generally good for
performance and appears to be necessary for Cavium ThunderX. If we
subsequently decide that we need to enable kpti, then we need to rewrite
our existing page table entries to be non-global. This is fiddly, and
made worse by the possible use of contiguous mappings, which require
a strict break-before-make sequence.
Since the enable callback runs on each online CPU from stop_machine
context, we can have all CPUs enter the idmap, where secondaries can
wait for the primary CPU to rewrite swapper with its MMU off. It's all
fairly horrible, but at least it only runs once.
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Break-before-make is not needed when transitioning from Global to
Non-Global mappings, provided that the contiguous hint is not being used.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* Require struct page by default for filesystem DAX to remove a number of
surprising failure cases. This includes failures with direct I/O, gdb and
fork(2).
* Add support for the new Platform Capabilities Structure added to the NFIT in
ACPI 6.2a. This new table tells us whether the platform supports flushing
of CPU and memory controller caches on unexpected power loss events.
* Revamp vmem_altmap and dev_pagemap handling to clean up code and better
support future future PCI P2P uses.
* Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has become
out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL spec, and
instead rely on the generic ND_CMD_CALL approach used by the two other IOCTL
families, NVDIMM_FAMILY_{HPE,MSFT}.
* Enhance nfit_test so we can test some of the new things added in version 1.6
of the DSM specification. This includes testing firmware download and
simulating the Last Shutdown State (LSS) status.
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Merge tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Ross Zwisler:
- Require struct page by default for filesystem DAX to remove a number
of surprising failure cases. This includes failures with direct I/O,
gdb and fork(2).
- Add support for the new Platform Capabilities Structure added to the
NFIT in ACPI 6.2a. This new table tells us whether the platform
supports flushing of CPU and memory controller caches on unexpected
power loss events.
- Revamp vmem_altmap and dev_pagemap handling to clean up code and
better support future future PCI P2P uses.
- Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has
become out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL
spec, and instead rely on the generic ND_CMD_CALL approach used by
the two other IOCTL families, NVDIMM_FAMILY_{HPE,MSFT}.
- Enhance nfit_test so we can test some of the new things added in
version 1.6 of the DSM specification. This includes testing firmware
download and simulating the Last Shutdown State (LSS) status.
* tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (37 commits)
libnvdimm, namespace: remove redundant initialization of 'nd_mapping'
acpi, nfit: fix register dimm error handling
libnvdimm, namespace: make min namespace size 4K
tools/testing/nvdimm: force nfit_test to depend on instrumented modules
libnvdimm/nfit_test: adding support for unit testing enable LSS status
libnvdimm/nfit_test: add firmware download emulation
nfit-test: Add platform cap support from ACPI 6.2a to test
libnvdimm: expose platform persistence attribute for nd_region
acpi: nfit: add persistent memory control flag for nd_region
acpi: nfit: Add support for detect platform CPU cache flush on power loss
device-dax: Fix trailing semicolon
libnvdimm, btt: fix uninitialized err_lock
dax: require 'struct page' by default for filesystem dax
ext2: auto disable dax instead of failing mount
ext4: auto disable dax instead of failing mount
mm, dax: introduce pfn_t_special()
mm: Fix devm_memremap_pages() collision handling
mm: Fix memory size alignment in devm_memremap_pages_release()
memremap: merge find_dev_pagemap into get_dev_pagemap
memremap: change devm_memremap_pages interface to use struct dev_pagemap
...
This pull requests contains a consolidation of the generic no-IOMMU code,
a well as the glue code for swiotlb. All the code is based on the x86
implementation with hooks to allow all architectures that aren't cache
coherent to use it. The x86 conversion itself has been deferred because
the x86 maintainers were a little busy in the last months.
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Merge tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping
Pull dma mapping updates from Christoph Hellwig:
"Except for a runtime warning fix from Christian this is all about
consolidation of the generic no-IOMMU code, a well as the glue code
for swiotlb.
All the code is based on the x86 implementation with hooks to allow
all architectures that aren't cache coherent to use it.
The x86 conversion itself has been deferred because the x86
maintainers were a little busy in the last months"
* tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping: (57 commits)
MAINTAINERS: add the iommu list for swiotlb and xen-swiotlb
arm64: use swiotlb_alloc and swiotlb_free
arm64: replace ZONE_DMA with ZONE_DMA32
mips: use swiotlb_{alloc,free}
mips/netlogic: remove swiotlb support
tile: use generic swiotlb_ops
tile: replace ZONE_DMA with ZONE_DMA32
unicore32: use generic swiotlb_ops
ia64: remove an ifdef around the content of pci-dma.c
ia64: clean up swiotlb support
ia64: use generic swiotlb_ops
ia64: replace ZONE_DMA with ZONE_DMA32
swiotlb: remove various exports
swiotlb: refactor coherent buffer allocation
swiotlb: refactor coherent buffer freeing
swiotlb: wire up ->dma_supported in swiotlb_dma_ops
swiotlb: add common swiotlb_map_ops
swiotlb: rename swiotlb_free to swiotlb_exit
x86: rename swiotlb_dma_ops
powerpc: rename swiotlb_dma_ops
...
Pull siginfo cleanups from Eric Biederman:
"Long ago when 2.4 was just a testing release copy_siginfo_to_user was
made to copy individual fields to userspace, possibly for efficiency
and to ensure initialized values were not copied to userspace.
Unfortunately the design was complex, it's assumptions unstated, and
humans are fallible and so while it worked much of the time that
design failed to ensure unitialized memory is not copied to userspace.
This set of changes is part of a new design to clean up siginfo and
simplify things, and hopefully make the siginfo handling robust enough
that a simple inspection of the code can be made to ensure we don't
copy any unitializied fields to userspace.
The design is to unify struct siginfo and struct compat_siginfo into a
single definition that is shared between all architectures so that
anyone adding to the set of information shared with struct siginfo can
see the whole picture. Hopefully ensuring all future si_code
assignments are arch independent.
The design is to unify copy_siginfo_to_user32 and
copy_siginfo_from_user32 so that those function are complete and cope
with all of the different cases documented in signinfo_layout. I don't
think there was a single implementation of either of those functions
that was complete and correct before my changes unified them.
The design is to introduce a series of helpers including
force_siginfo_fault that take the values that are needed in struct
siginfo and build the siginfo structure for their callers. Ensuring
struct siginfo is built correctly.
The remaining work for 4.17 (unless someone thinks it is post -rc1
material) is to push usage of those helpers down into the
architectures so that architecture specific code will not need to deal
with the fiddly work of intializing struct siginfo, and then when
struct siginfo is guaranteed to be fully initialized change copy
siginfo_to_user into a simple wrapper around copy_to_user.
Further there is work in progress on the issues that have been
documented requires arch specific knowledge to sort out.
The changes below fix or at least document all of the issues that have
been found with siginfo generation. Then proceed to unify struct
siginfo the 32 bit helpers that copy siginfo to and from userspace,
and generally clean up anything that is not arch specific with regards
to siginfo generation.
It is a lot but with the unification you can of siginfo you can
already see the code reduction in the kernel"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (45 commits)
signal/memory-failure: Use force_sig_mceerr and send_sig_mceerr
mm/memory_failure: Remove unused trapno from memory_failure
signal/ptrace: Add force_sig_ptrace_errno_trap and use it where needed
signal/powerpc: Remove unnecessary signal_code parameter of do_send_trap
signal: Helpers for faults with specialized siginfo layouts
signal: Add send_sig_fault and force_sig_fault
signal: Replace memset(info,...) with clear_siginfo for clarity
signal: Don't use structure initializers for struct siginfo
signal/arm64: Better isolate the COMPAT_TASK portion of ptrace_hbptriggered
ptrace: Use copy_siginfo in setsiginfo and getsiginfo
signal: Unify and correct copy_siginfo_to_user32
signal: Remove the code to clear siginfo before calling copy_siginfo_from_user32
signal: Unify and correct copy_siginfo_from_user32
signal/blackfin: Remove pointless UID16_SIGINFO_COMPAT_NEEDED
signal/blackfin: Move the blackfin specific si_codes to asm-generic/siginfo.h
signal/tile: Move the tile specific si_codes to asm-generic/siginfo.h
signal/frv: Move the frv specific si_codes to asm-generic/siginfo.h
signal/ia64: Move the ia64 specific si_codes to asm-generic/siginfo.h
signal/powerpc: Remove redefinition of NSIGTRAP on powerpc
signal: Move addr_lsb into the _sigfault union for clarity
...
- Security mitigations:
- variant 2: invalidating the branch predictor with a call to secure firmware
- variant 3: implementing KPTI for arm64
- 52-bit physical address support for arm64 (ARMv8.2)
- arm64 support for RAS (firmware first only) and SDEI (software
delegated exception interface; allows firmware to inject a RAS error
into the OS)
- Perf support for the ARM DynamIQ Shared Unit PMU
- CPUID and HWCAP bits updated for new floating point multiplication
instructions in ARMv8.4
- Removing some virtual memory layout printks during boot
- Fix initial page table creation to cope with larger than 32M kernel
images when 16K pages are enabled
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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:
"The main theme of this pull request is security covering variants 2
and 3 for arm64. I expect to send additional patches next week
covering an improved firmware interface (requires firmware changes)
for variant 2 and way for KPTI to be disabled on unaffected CPUs
(Cavium's ThunderX doesn't work properly with KPTI enabled because of
a hardware erratum).
Summary:
- Security mitigations:
- variant 2: invalidate the branch predictor with a call to
secure firmware
- variant 3: implement KPTI for arm64
- 52-bit physical address support for arm64 (ARMv8.2)
- arm64 support for RAS (firmware first only) and SDEI (software
delegated exception interface; allows firmware to inject a RAS
error into the OS)
- perf support for the ARM DynamIQ Shared Unit PMU
- CPUID and HWCAP bits updated for new floating point multiplication
instructions in ARMv8.4
- remove some virtual memory layout printks during boot
- fix initial page table creation to cope with larger than 32M kernel
images when 16K pages are enabled"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (104 commits)
arm64: Fix TTBR + PAN + 52-bit PA logic in cpu_do_switch_mm
arm64: Turn on KPTI only on CPUs that need it
arm64: Branch predictor hardening for Cavium ThunderX2
arm64: Run enable method for errata work arounds on late CPUs
arm64: Move BP hardening to check_and_switch_context
arm64: mm: ignore memory above supported physical address size
arm64: kpti: Fix the interaction between ASID switching and software PAN
KVM: arm64: Emulate RAS error registers and set HCR_EL2's TERR & TEA
KVM: arm64: Handle RAS SErrors from EL2 on guest exit
KVM: arm64: Handle RAS SErrors from EL1 on guest exit
KVM: arm64: Save ESR_EL2 on guest SError
KVM: arm64: Save/Restore guest DISR_EL1
KVM: arm64: Set an impdef ESR for Virtual-SError using VSESR_EL2.
KVM: arm/arm64: mask/unmask daif around VHE guests
arm64: kernel: Prepare for a DISR user
arm64: Unconditionally enable IESB on exception entry/return for firmware-first
arm64: kernel: Survive corrected RAS errors notified by SError
arm64: cpufeature: Detect CPU RAS Extentions
arm64: sysreg: Move to use definitions for all the SCTLR bits
arm64: cpufeature: __this_cpu_has_cap() shouldn't stop early
...
In cpu_do_switch_mm(.) with ARM64_SW_TTBR0_PAN=y we apply phys_to_ttbr
to a value that already has an ASID inserted into the upper bits. For
52-bit PA configurations this then can give us TTBR0_EL1 registers that
cause translation table walks to attempt to access non-zero PA[51:48]
spuriously. Ultimately leading to a Synchronous External Abort on level
1 translation.
This patch re-arranges the logic in cpu_do_switch_mm(.) such that
phys_to_ttbr is called before the ASID is inserted into the TTBR0 value.
Fixes: 6b88a32c7a ("arm64: kpti: Fix the interaction between ASID switching and software PAN")
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Kristina Martsenko <kristina.martsenko@arm.com>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We call arm64_apply_bp_hardening() from post_ttbr_update_workaround,
which has the unexpected consequence of being triggered on every
exception return to userspace when ARM64_SW_TTBR0_PAN is selected,
even if no context switch actually occured.
This is a bit suboptimal, and it would be more logical to only
invalidate the branch predictor when we actually switch to
a different mm.
In order to solve this, move the call to arm64_apply_bp_hardening()
into check_and_switch_context(), where we're guaranteed to pick
a different mm context.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When booting a kernel without 52-bit PA support (e.g. a kernel with 4k
pages) on a system with 52-bit memory, the kernel will currently try to
use the 52-bit memory and crash. Fix this by ignoring any memory higher
than what the kernel supports.
Fixes: f77d281713 ("arm64: enable 52-bit physical address support")
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add an extra temporary register parameter to uaccess_ttbr0_disable which
is about to be required for arm64 PAN support.
This patch doesn't introduce any functional change but ensures that the
kernel compiles once the KVM/ARM tree is merged with the arm64 tree by
ensuring a trivially mergable conflict with commit
6b88a32c7a
("arm64: kpti: Fix the interaction between ASID switching and software PAN").
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
With ARM64_SW_TTBR0_PAN enabled, the exception entry code checks the
active ASID to decide whether user access was enabled (non-zero ASID)
when the exception was taken. On return from exception, if user access
was previously disabled, it re-instates TTBR0_EL1 from the per-thread
saved value (updated in switch_mm() or efi_set_pgd()).
Commit 7655abb953 ("arm64: mm: Move ASID from TTBR0 to TTBR1") makes a
TTBR0_EL1 + ASID switching non-atomic. Subsequently, commit 27a921e757
("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN") changes the
__uaccess_ttbr0_disable() function and asm macro to first write the
reserved TTBR0_EL1 followed by the ASID=0 update in TTBR1_EL1. If an
exception occurs between these two, the exception return code will
re-instate a valid TTBR0_EL1. Similar scenario can happen in
cpu_switch_mm() between setting the reserved TTBR0_EL1 and the ASID
update in cpu_do_switch_mm().
This patch reverts the entry.S check for ASID == 0 to TTBR0_EL1 and
disables the interrupts around the TTBR0_EL1 and ASID switching code in
__uaccess_ttbr0_disable(). It also ensures that, when returning from the
EFI runtime services, efi_set_pgd() doesn't leave a non-zero ASID in
TTBR1_EL1 by using uaccess_ttbr0_{enable,disable}.
The accesses to current_thread_info()->ttbr0 are updated to use
READ_ONCE/WRITE_ONCE.
As a safety measure, __uaccess_ttbr0_enable() always masks out any
existing non-zero ASID TTBR1_EL1 before writing in the new ASID.
Fixes: 27a921e757 ("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN")
Acked-by: Will Deacon <will.deacon@arm.com>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Co-developed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
KVM would like to consume any pending SError (or RAS error) after guest
exit. Today it has to unmask SError and use dsb+isb to synchronise the
CPU. With the RAS extensions we can use ESB to synchronise any pending
SError.
Add the necessary macros to allow DISR to be read and converted to an
ESR.
We clear the DISR register when we enable the RAS cpufeature, and the
kernel has not executed any ESB instructions. Any value we find in DISR
must have belonged to firmware. Executing an ESB instruction is the
only way to update DISR, so we can expect firmware to have handled
any deferred SError. By the same logic we clear DISR in the idle path.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
__cpu_setup() configures SCTLR_EL1 using some hard coded hex masks,
and el2_setup() duplicates some this when setting RES1 bits.
Lets make this the same as KVM's hyp_init, which uses named bits.
First, we add definitions for all the SCTLR_EL{1,2} bits, the RES{1,0}
bits, and those we want to set or clear.
Add a build_bug checks to ensures all bits are either set or clear.
This means we don't need to preserve endian-ness configuration
generated elsewhere.
Finally, move the head.S and proc.S users of these hard-coded masks
over to the macro versions.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Printing kernel addresses should be done in limited circumstances, mostly
for debugging purposes. Printing out the virtual memory layout at every
kernel bootup doesn't really fall into this category so delete the prints.
There are other ways to get the same information.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The generic swiotlb_alloc and swiotlb_free routines already take care
of CMA allocations and adding GFP_DMA32 where needed, so use them
instead of the arm specific helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
arm64 uses ZONE_DMA for allocations below 32-bits. These days we
name the zone for that ZONE_DMA32, which will allow to use the
dma-direct and generic swiotlb code as-is, so rename it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
We'll need that name for a generic implementation soon.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Currently the early assembler page table code assumes that precisely
1xpgd, 1xpud, 1xpmd are sufficient to represent the early kernel text
mappings.
Unfortunately this is rarely the case when running with a 16KB granule,
and we also run into limits with 4KB granule when building much larger
kernels.
This patch re-writes the early page table logic to compute indices of
mappings for each level of page table, and if multiple indices are
required, the next-level page table is scaled up accordingly.
Also the required size of the swapper_pg_dir is computed at link time
to cover the mapping [KIMAGE_ADDR + VOFFSET, _end]. When KASLR is
enabled, an extra page is set aside for each level that may require extra
entries at runtime.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
SDEI needs to calculate an offset in the trampoline page too. Move
the extern char[] to sections.h.
This patch just moves code around.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Now that KVM uses tpidr_el2 in the same way as Linux's cpu_offset in
tpidr_el1, merge the two. This saves KVM from save/restoring tpidr_el1
on VHE hosts, and allows future code to blindly access per-cpu variables
without triggering world-switch.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Setting si_code to 0 results in a userspace seeing an si_code of 0.
This is the same si_code as SI_USER. Posix and common sense requires
that SI_USER not be a signal specific si_code. As such this use of 0
for the si_code is a pretty horribly broken ABI.
Further use of si_code == 0 guaranteed that copy_siginfo_to_user saw a
value of __SI_KILL and now sees a value of SIL_KILL with the result
that uid and pid fields are copied and which might copying the si_addr
field by accident but certainly not by design. Making this a very
flakey implementation.
Utilizing FPE_FIXME, BUS_FIXME, TRAP_FIXME siginfo_layout will now return
SIL_FAULT and the appropriate fields will be reliably copied.
But folks this is a new and unique kind of bad. This is massively
untested code bad. This is inventing new and unique was to get
siginfo wrong bad. This is don't even think about Posix or what
siginfo means bad. This is lots of eyeballs all missing the fact
that the code does the wrong thing bad. This is getting stuck
and keep making the same mistake bad.
I really hope we can find a non userspace breaking fix for this on a
port as new as arm64.
Possible ABI fixes include:
- Send the signal without siginfo
- Don't generate a signal
- Possibly assign and use an appropriate si_code
- Don't handle cases which can't happen
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tyler Baicar <tbaicar@codeaurora.org>
Cc: James Morse <james.morse@arm.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org
Ref: 53631b54c8 ("arm64: Floating point and SIMD")
Ref: 32015c2356 ("arm64: exception: handle Synchronous External Abort")
Ref: 1d18c47c73 ("arm64: MMU fault handling and page table management")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
phys_to_dma, dma_to_phys and dma_capable are helpers published by
architecture code for use of swiotlb and xen-swiotlb only. Drivers are
not supposed to use these directly, but use the DMA API instead.
Move these to a new asm/dma-direct.h helper, included by a
linux/dma-direct.h wrapper that provides the default linear mapping
unless the architecture wants to override it.
In the MIPS case the existing dma-coherent.h is reused for now as
untangling it will take a bit of work.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Add an extra temporary register parameter to uaccess_ttbr0_enable which
is about to be required for arm64 PAN support.
This patch doesn't introduce any functional change but ensures that the
kernel compiles once the KVM/ARM tree is merged with the arm64 tree by
ensuring a trivially mergable conflict with commit
27a921e757
("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN").
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We can just pass this on instead of having to do a radix tree lookup
without proper locking a few levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
