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2018-01-08arm64: Add skeleton to harden the branch predictor against aliasing attacksWill Deacon
Aliasing attacks against CPU branch predictors can allow an attacker to redirect speculative control flow on some CPUs and potentially divulge information from one context to another. This patch adds initial skeleton code behind a new Kconfig option to enable implementation-specific mitigations against these attacks for CPUs that are affected. Co-developed-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>
2018-01-08arm64: Move post_ttbr_update_workaround to C codeMarc Zyngier
We will soon need to invoke a CPU-specific function pointer after changing page tables, so move post_ttbr_update_workaround out into C code to make this possible. Signed-off-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>
2018-01-08drivers/firmware: Expose psci_get_version through psci_ops structureWill Deacon
Entry into recent versions of ARM Trusted Firmware will invalidate the CPU branch predictor state in order to protect against aliasing attacks. This patch exposes the PSCI "VERSION" function via psci_ops, so that it can be invoked outside of the PSCI driver where necessary. Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08arm64: cpufeature: Pass capability structure to ->enable callbackWill Deacon
In order to invoke the CPU capability ->matches callback from the ->enable callback for applying local-CPU workarounds, we need a handle on the capability structure. This patch passes a pointer to the capability structure to the ->enable callback. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08arm64: Take into account ID_AA64PFR0_EL1.CSV3Will Deacon
For non-KASLR kernels where the KPTI behaviour has not been overridden on the command line we can use ID_AA64PFR0_EL1.CSV3 to determine whether or not we should unmap the kernel whilst running at EL0. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entryWill Deacon
Although CONFIG_UNMAP_KERNEL_AT_EL0 does make KASLR more robust, it's actually more useful as a mitigation against speculation attacks that can leak arbitrary kernel data to userspace through speculation. Reword the Kconfig help message to reflect this, and make the option depend on EXPERT so that it is on by default for the majority of users. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08arm64: use RET instruction for exiting the trampolineWill Deacon
Speculation attacks against the entry trampoline can potentially resteer the speculative instruction stream through the indirect branch and into arbitrary gadgets within the kernel. This patch defends against these attacks by forcing a misprediction through the return stack: a dummy BL instruction loads an entry into the stack, so that the predicted program flow of the subsequent RET instruction is to a branch-to-self instruction which is finally resolved as a branch to the kernel vectors with speculation suppressed. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-05arm64: v8.4: Support for new floating point multiplication instructionsDongjiu Geng
ARM v8.4 extensions add new neon instructions for performing a multiplication of each FP16 element of one vector with the corresponding FP16 element of a second vector, and to add or subtract this without an intermediate rounding to the corresponding FP32 element in a third vector. This patch detects this feature and let the userspace know about it via a HWCAP bit and MRS emulation. Cc: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-05arm64: asid: Do not replace active_asids if already 0Catalin Marinas
Under some uncommon timing conditions, a generation check and xchg(active_asids, A1) in check_and_switch_context() on P1 can race with an ASID roll-over on P2. If P2 has not seen the update to active_asids[P1], it can re-allocate A1 to a new task T2 on P2. P1 ends up waiting on the spinlock since the xchg() returned 0 while P2 can go through a second ASID roll-over with (T2,A1,G2) active on P2. This roll-over copies active_asids[P1] == A1,G1 into reserved_asids[P1] and active_asids[P2] == A1,G2 into reserved_asids[P2]. A subsequent scheduling of T1 on P1 and T2 on P2 would match reserved_asids and get their generation bumped to G3: P1 P2 -- -- TTBR0.BADDR = T0 TTBR0.ASID = A0 asid_generation = G1 check_and_switch_context(T1,A1,G1) generation match check_and_switch_context(T2,A0,G0) new_context() ASID roll-over asid_generation = G2 flush_context() active_asids[P1] = 0 asid_map[A1] = 0 reserved_asids[P1] = A0,G0 xchg(active_asids, A1) active_asids[P1] = A1,G1 xchg returns 0 spin_lock_irqsave() allocated ASID (T2,A1,G2) asid_map[A1] = 1 active_asids[P2] = A1,G2 ... check_and_switch_context(T3,A0,G0) new_context() ASID roll-over asid_generation = G3 flush_context() active_asids[P1] = 0 asid_map[A1] = 1 reserved_asids[P1] = A1,G1 reserved_asids[P2] = A1,G2 allocated ASID (T3,A2,G3) asid_map[A2] = 1 active_asids[P2] = A2,G3 new_context() check_update_reserved_asid(A1,G1) matches reserved_asid[P1] reserved_asid[P1] = A1,G3 updated T1 ASID to (T1,A1,G3) check_and_switch_context(T2,A1,G2) new_context() check_and_switch_context(A1,G2) matches reserved_asids[P2] reserved_asids[P2] = A1,G3 updated T2 ASID to (T2,A1,G3) At this point, we have two tasks, T1 and T2 both using ASID A1 with the latest generation G3. Any of them is allowed to be scheduled on the other CPU leading to two different tasks with the same ASID on the same CPU. This patch changes the xchg to cmpxchg so that the active_asids is only updated if non-zero to avoid a race with an ASID roll-over on a different CPU. The ASID allocation algorithm has been formally verified using the TLA+ model checker (see https://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/kernel-tla.git/tree/asidalloc.tla for the spec). Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-02arm64: make label allocation style consistent in tishiftJason A. Donenfeld
This is entirely cosmetic, but somehow it was missed when sending differing versions of this patch. This just makes the file a bit more uniform. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-02ARM64 / cpuidle: Use new cpuidle macro for entering retention statePrashanth Prakash
CPU_PM_CPU_IDLE_ENTER_RETENTION skips calling cpu_pm_enter() and cpu_pm_exit(). By not calling cpu_pm functions in idle entry/exit paths we can reduce the latency involved in entering and exiting the low power idle state. On ARM64 based Qualcomm server platform we measured below overhead for calling cpu_pm_enter and cpu_pm_exit for retention states. workload: stress --hdd #CPUs --hdd-bytes 32M -t 30 Average overhead of cpu_pm_enter - 1.2us Average overhead of cpu_pm_exit - 3.1us Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-02cpuidle: Add new macro to enter a retention idle statePrashanth Prakash
If a CPU is entering a low power idle state where it doesn't lose any context, then there is no need to call cpu_pm_enter()/cpu_pm_exit(). Add a new macro(CPU_PM_CPU_IDLE_ENTER_RETENTION) to be used by cpuidle drivers when they are entering retention state. By not calling cpu_pm_enter and cpu_pm_exit we reduce the latency involved in entering and exiting the retention idle states. CPU_PM_CPU_IDLE_ENTER_RETENTION assumes that no state is lost and hence CPU PM notifiers will not be called. We may need a broader change if we need to support partial retention states effeciently. On ARM64 based Qualcomm Server Platform we measured below overhead for for calling cpu_pm_enter and cpu_pm_exit for retention states. workload: stress --hdd #CPUs --hdd-bytes 32M -t 30 Average overhead of cpu_pm_enter - 1.2us Average overhead of cpu_pm_exit - 3.1us Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22Merge branch 'for-next/52-bit-pa' into for-next/coreCatalin Marinas
* for-next/52-bit-pa: arm64: enable 52-bit physical address support arm64: allow ID map to be extended to 52 bits arm64: handle 52-bit physical addresses in page table entries arm64: don't open code page table entry creation arm64: head.S: handle 52-bit PAs in PTEs in early page table setup arm64: handle 52-bit addresses in TTBR arm64: limit PA size to supported range arm64: add kconfig symbol to configure physical address size
2017-12-22arm64: enable 52-bit physical address supportKristina Martsenko
Now that 52-bit physical address support is in place, add the kconfig symbol to enable it. As described in ARMv8.2, the larger addresses are only supported with the 64k granule. Also ensure that PAN is configured (or TTBR0 PAN is not), as explained in an earlier patch in this series. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: allow ID map to be extended to 52 bitsKristina Martsenko
Currently, when using VA_BITS < 48, if the ID map text happens to be placed in physical memory above VA_BITS, we increase the VA size (up to 48) and create a new table level, in order to map in the ID map text. This is okay because the system always supports 48 bits of VA. This patch extends the code such that if the system supports 52 bits of VA, and the ID map text is placed that high up, then we increase the VA size accordingly, up to 52. One difference from the current implementation is that so far the condition of VA_BITS < 48 has meant that the top level table is always "full", with the maximum number of entries, and an extra table level is always needed. Now, when VA_BITS = 48 (and using 64k pages), the top level table is not full, and we simply need to increase the number of entries in it, instead of creating a new table level. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: reduce arguments to __create_hyp_mappings()] [catalin.marinas@arm.com: reworked/renamed __cpu_uses_extended_idmap_level()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: handle 52-bit physical addresses in page table entriesKristina Martsenko
The top 4 bits of a 52-bit physical address are positioned at bits 12..15 of a page table entry. Introduce macros to convert between a physical address and its placement in a table entry, and change all macros/functions that access PTEs to use them. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: some long lines wrapped] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: don't open code page table entry creationKristina Martsenko
Instead of open coding the generation of page table entries, use the macros/functions that exist for this - pfn_p*d and p*d_populate. Most code in the kernel already uses these macros, this patch tries to fix up the few places that don't. This is useful for the next patch in this series, which needs to change the page table entry logic, and it's better to have that logic in one place. The KVM extended ID map is special, since we're creating a level above CONFIG_PGTABLE_LEVELS and the required function isn't available. Leave it as is and add a comment to explain it. (The normal kernel ID map code doesn't need this change because its page tables are created in assembly (__create_page_tables)). Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: head.S: handle 52-bit PAs in PTEs in early page table setupKristina Martsenko
The top 4 bits of a 52-bit physical address are positioned at bits 12..15 in page table entries. Introduce a macro to move the bits there, and change the early ID map and swapper table setup code to use it. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: additional comments for clarification] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: handle 52-bit addresses in TTBRKristina Martsenko
The top 4 bits of a 52-bit physical address are positioned at bits 2..5 in the TTBR registers. Introduce a couple of macros to move the bits there, and change all TTBR writers to use them. Leave TTBR0 PAN code unchanged, to avoid complicating it. A system with 52-bit PA will have PAN anyway (because it's ARMv8.1 or later), and a system without 52-bit PA can only use up to 48-bit PAs. A later patch in this series will add a kconfig dependency to ensure PAN is configured. In addition, when using 52-bit PA there is a special alignment requirement on the top-level table. We don't currently have any VA_BITS configuration that would violate the requirement, but one could be added in the future, so add a compile-time BUG_ON to check for it. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: added TTBR_BADD_MASK_52 comment] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: limit PA size to supported rangeKristina Martsenko
We currently copy the physical address size from ID_AA64MMFR0_EL1.PARange directly into TCR.(I)PS. This will not work for 4k and 16k granule kernels on systems that support 52-bit physical addresses, since 52-bit addresses are only permitted with the 64k granule. To fix this, fall back to 48 bits when configuring the PA size when the kernel does not support 52-bit PAs. When it does, fall back to 52, to avoid similar problems in the future if the PA size is ever increased above 52. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: tcr_set_pa_size macro renamed to tcr_compute_pa_size] [catalin.marinas@arm.com: comments added to tcr_compute_pa_size] [catalin.marinas@arm.com: definitions added for TCR_*PS_SHIFT] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: add kconfig symbol to configure physical address sizeKristina Martsenko
ARMv8.2 introduces support for 52-bit physical addresses. To prepare for supporting this, add a new kconfig symbol to configure the physical address space size. The symbols will be used in subsequent patches. Currently the only choice is 48, a later patch will add the option of 52 once the required code is in place. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: folded minor patches into this one] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-11Merge branch 'kpti' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxCatalin Marinas
Support for unmapping the kernel when running in userspace (aka "KAISER"). * 'kpti' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kaslr: Put kernel vectors address in separate data page arm64: mm: Introduce TTBR_ASID_MASK for getting at the ASID in the TTBR perf: arm_spe: Fail device probe when arm64_kernel_unmapped_at_el0() arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0 arm64: entry: Add fake CPU feature for unmapping the kernel at EL0 arm64: tls: Avoid unconditional zeroing of tpidrro_el0 for native tasks arm64: erratum: Work around Falkor erratum #E1003 in trampoline code arm64: entry: Hook up entry trampoline to exception vectors arm64: entry: Explicitly pass exception level to kernel_ventry macro arm64: mm: Map entry trampoline into trampoline and kernel page tables arm64: entry: Add exception trampoline page for exceptions from EL0 arm64: mm: Invalidate both kernel and user ASIDs when performing TLBI arm64: mm: Add arm64_kernel_unmapped_at_el0 helper arm64: mm: Allocate ASIDs in pairs arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN arm64: mm: Rename post_ttbr0_update_workaround arm64: mm: Remove pre_ttbr0_update_workaround for Falkor erratum #E1003 arm64: mm: Move ASID from TTBR0 to TTBR1 arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN arm64: mm: Use non-global mappings for kernel space
2017-12-11arm64: kaslr: Put kernel vectors address in separate data pageWill Deacon
The literal pool entry for identifying the vectors base is the only piece of information in the trampoline page that identifies the true location of the kernel. This patch moves it into a page-aligned region of the .rodata section and maps this adjacent to the trampoline text via an additional fixmap entry, which protects against any accidental leakage of the trampoline contents. Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Introduce TTBR_ASID_MASK for getting at the ASID in the TTBRWill Deacon
There are now a handful of open-coded masks to extract the ASID from a TTBR value, so introduce a TTBR_ASID_MASK and use that instead. Suggested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11perf: arm_spe: Fail device probe when arm64_kernel_unmapped_at_el0()Will Deacon
When running with the kernel unmapped whilst at EL0, the virtually-addressed SPE buffer is also unmapped, which can lead to buffer faults if userspace profiling is enabled and potentially also when writing back kernel samples unless an expensive drain operation is performed on exception return. For now, fail the SPE driver probe when arm64_kernel_unmapped_at_el0(). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0Will Deacon
Add a Kconfig entry to control use of the entry trampoline, which allows us to unmap the kernel whilst running in userspace and improve the robustness of KASLR. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: entry: Add fake CPU feature for unmapping the kernel at EL0Will Deacon
Allow explicit disabling of the entry trampoline on the kernel command line (kpti=off) by adding a fake CPU feature (ARM64_UNMAP_KERNEL_AT_EL0) that can be used to toggle the alternative sequences in our entry code and avoid use of the trampoline altogether if desired. This also allows us to make use of a static key in arm64_kernel_unmapped_at_el0(). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: tls: Avoid unconditional zeroing of tpidrro_el0 for native tasksWill Deacon
When unmapping the kernel at EL0, we use tpidrro_el0 as a scratch register during exception entry from native tasks and subsequently zero it in the kernel_ventry macro. We can therefore avoid zeroing tpidrro_el0 in the context-switch path for native tasks using the entry trampoline. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: erratum: Work around Falkor erratum #E1003 in trampoline codeWill Deacon
We rely on an atomic swizzling of TTBR1 when transitioning from the entry trampoline to the kernel proper on an exception. We can't rely on this atomicity in the face of Falkor erratum #E1003, so on affected cores we can issue a TLB invalidation to invalidate the walk cache prior to jumping into the kernel. There is still the possibility of a TLB conflict here due to conflicting walk cache entries prior to the invalidation, but this doesn't appear to be the case on these CPUs in practice. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: entry: Hook up entry trampoline to exception vectorsWill Deacon
Hook up the entry trampoline to our exception vectors so that all exceptions from and returns to EL0 go via the trampoline, which swizzles the vector base register accordingly. Transitioning to and from the kernel clobbers x30, so we use tpidrro_el0 and far_el1 as scratch registers for native tasks. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: entry: Explicitly pass exception level to kernel_ventry macroWill Deacon
We will need to treat exceptions from EL0 differently in kernel_ventry, so rework the macro to take the exception level as an argument and construct the branch target using that. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Map entry trampoline into trampoline and kernel page tablesWill Deacon
The exception entry trampoline needs to be mapped at the same virtual address in both the trampoline page table (which maps nothing else) and also the kernel page table, so that we can swizzle TTBR1_EL1 on exceptions from and return to EL0. This patch maps the trampoline at a fixed virtual address in the fixmap area of the kernel virtual address space, which allows the kernel proper to be randomized with respect to the trampoline when KASLR is enabled. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: entry: Add exception trampoline page for exceptions from EL0Will Deacon
To allow unmapping of the kernel whilst running at EL0, we need to point the exception vectors at an entry trampoline that can map/unmap the kernel on entry/exit respectively. This patch adds the trampoline page, although it is not yet plugged into the vector table and is therefore unused. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Invalidate both kernel and user ASIDs when performing TLBIWill Deacon
Since an mm has both a kernel and a user ASID, we need to ensure that broadcast TLB maintenance targets both address spaces so that things like CoW continue to work with the uaccess primitives in the kernel. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Add arm64_kernel_unmapped_at_el0 helperWill Deacon
In order for code such as TLB invalidation to operate efficiently when the decision to map the kernel at EL0 is determined at runtime, this patch introduces a helper function, arm64_kernel_unmapped_at_el0, to determine whether or not the kernel is mapped whilst running in userspace. Currently, this just reports the value of CONFIG_UNMAP_KERNEL_AT_EL0, but will later be hooked up to a fake CPU capability using a static key. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Allocate ASIDs in pairsWill Deacon
In preparation for separate kernel/user ASIDs, allocate them in pairs for each mm_struct. The bottom bit distinguishes the two: if it is set, then the ASID will map only userspace. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PANWill Deacon
With the ASID now installed in TTBR1, we can re-enable ARM64_SW_TTBR0_PAN by ensuring that we switch to a reserved ASID of zero when disabling user access and restore the active user ASID on the uaccess enable path. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Rename post_ttbr0_update_workaroundWill Deacon
The post_ttbr0_update_workaround hook applies to any change to TTBRx_EL1. Since we're using TTBR1 for the ASID, rename the hook to make it clearer as to what it's doing. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Remove pre_ttbr0_update_workaround for Falkor erratum #E1003Will Deacon
The pre_ttbr0_update_workaround hook is called prior to context-switching TTBR0 because Falkor erratum E1003 can cause TLB allocation with the wrong ASID if both the ASID and the base address of the TTBR are updated at the same time. With the ASID sitting safely in TTBR1, we no longer update things atomically, so we can remove the pre_ttbr0_update_workaround macro as it's no longer required. The erratum infrastructure and documentation is left around for #E1003, as it will be required by the entry trampoline code in a future patch. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Move ASID from TTBR0 to TTBR1Will Deacon
In preparation for mapping kernelspace and userspace with different ASIDs, move the ASID to TTBR1 and update switch_mm to context-switch TTBR0 via an invalid mapping (the zero page). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Temporarily disable ARM64_SW_TTBR0_PANWill Deacon
We're about to rework the way ASIDs are allocated, switch_mm is implemented and low-level kernel entry/exit is handled, so keep the ARM64_SW_TTBR0_PAN code out of the way whilst we do the heavy lifting. It will be re-enabled in a subsequent patch. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11arm64: mm: Use non-global mappings for kernel spaceWill Deacon
In preparation for unmapping the kernel whilst running in userspace, make the kernel mappings non-global so we can avoid expensive TLB invalidation on kernel exit to userspace. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-10Linux 4.15-rc3Linus Torvalds
2017-12-10hpfs: don't bother with the i_version counter or f_versionJeff Layton
HPFS does not set SB_I_VERSION and does not use the i_version counter internally. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Mikulas Patocka <mikulas@twibright.com> Reviewed-by: Mikulas Patocka <mikulas@twibright.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-10futex: futex_wake_op, fix sign_extend32 sign bitsJiri Slaby
sign_extend32 counts the sign bit parameter from 0, not from 1. So we have to use "11" for 12th bit, not "12". This mistake means we have not allowed negative op and cmp args since commit 30d6e0a4190d ("futex: Remove duplicated code and fix undefined behaviour") till now. Fixes: 30d6e0a4190d ("futex: Remove duplicated code and fix undefined behaviour") Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <dvhart@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-10Merge tag 'for-4.15-rc3-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "This contains a few fixes (error handling, quota leak, FUA vs nobarrier mount option). There's one one worth mentioning separately - an off-by-one fix that leads to overwriting first byte of an adjacent page with 0, out of bounds of the memory allocated by an ioctl. This is under a privileged part of the ioctl, can be triggerd in some subvolume layouts" * tag 'for-4.15-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Fix possible off-by-one in btrfs_search_path_in_tree Btrfs: disable FUA if mounted with nobarrier btrfs: fix missing error return in btrfs_drop_snapshot btrfs: handle errors while updating refcounts in update_ref_for_cow btrfs: Fix quota reservation leak on preallocated files
2017-12-10Merge tag 'armsoc-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC fixes from Olof Johansson: - A revert of all SCPI changes from the 4.15 merge window. They had regressions on the Amlogic platforms, and the submaintainer isn't around to fix these bugs due to vacation, etc. So we agreed to revert and revisit in next release cycle. - A series fixing a number of bugs for ARM CCN interconnect, around module unload, smp_processor_id() in preemptable context, and fixing some memory allocation failure checks. - A handful of devicetree fixes for different platforms, fixing warnings and errors that were previously ignored by the compiler. - The usual set of mostly minor fixes for different platforms. * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (42 commits) ARM64: dts: meson-gx: fix UART pclk clock name ARM: omap2: hide omap3_save_secure_ram on non-OMAP3 builds arm: dts: nspire: Add missing #phy-cells to usb-nop-xceiv ARM: dts: Fix dm814x missing phy-cells property ARM: dts: Fix elm interrupt compiler warning bus: arm-ccn: fix module unloading Error: Removing state 147 which has instances left. bus: arm-cci: Fix use of smp_processor_id() in preemptible context bus: arm-ccn: Fix use of smp_processor_id() in preemptible context bus: arm-ccn: Simplify code bus: arm-ccn: Check memory allocation failure bus: arm-ccn: constify attribute_group structures. firmware: arm_scpi: Revert updates made during v4.15 merge window arm: dts: marvell: Add missing #phy-cells to usb-nop-xceiv arm64: dts: sort vendor subdirectories in Makefile alphabetically meson-gx-socinfo: Fix package id parsing ARM: meson: fix spelling mistake: "Couln't" -> "Couldn't" ARM: dts: meson: fix the memory region of the GPIO interrupt controller ARM: dts: meson: correct the sort order for the the gpio_intc node MAINTAINERS: exclude other Socionext SoC DT files from ARM/UNIPHIER entry arm64: dts: uniphier: remove unnecessary interrupt-parent ...
2017-12-10Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Radim Krčmář: "ARM: - A number of issues in the vgic discovered using SMATCH - A bit one-off calculation in out stage base address mask (32-bit and 64-bit) - Fixes to single-step debugging instructions that trap for other reasons such as MMMIO aborts - Printing unavailable hyp mode as error - Potential spinlock deadlock in the vgic - Avoid calling vgic vcpu free more than once - Broken bit calculation for big endian systems s390: - SPDX tags - Fence storage key accesses from problem state - Make sure that irq_state.flags is not used in the future x86: - Intercept port 0x80 accesses to prevent host instability (CVE) - Use userspace FPU context for guest FPU (mainly an optimization that fixes a double use of kernel FPU) - Do not leak one page per module load - Flush APIC page address cache from MMU invalidation notifiers" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits) KVM: x86: fix APIC page invalidation KVM: s390: Fix skey emulation permission check KVM: s390: mark irq_state.flags as non-usable KVM: s390: Remove redundant license text KVM: s390: add SPDX identifiers to the remaining files KVM: VMX: fix page leak in hardware_setup() KVM: VMX: remove I/O port 0x80 bypass on Intel hosts x86,kvm: remove KVM emulator get_fpu / put_fpu x86,kvm: move qemu/guest FPU switching out to vcpu_run KVM: arm/arm64: Fix broken GICH_ELRSR big endian conversion KVM: arm/arm64: kvm_arch_destroy_vm cleanups KVM: arm/arm64: Fix spinlock acquisition in vgic_set_owner kvm: arm: don't treat unavailable HYP mode as an error KVM: arm/arm64: Avoid attempting to load timer vgic state without a vgic kvm: arm64: handle single-step of hyp emulated mmio instructions kvm: arm64: handle single-step during SError exceptions kvm: arm64: handle single-step of userspace mmio instructions kvm: arm64: handle single-stepping trapped instructions KVM: arm/arm64: debug: Introduce helper for single-step arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one ...
2017-12-09Merge branch 'fixes' into for-nextOlof Johansson
* fixes: ARM64: dts: meson-gx: fix UART pclk clock name ARM: dts: Fix dm814x missing phy-cells property ARM: dts: Fix elm interrupt compiler warning bus: arm-ccn: fix module unloading Error: Removing state 147 which has instances left. bus: arm-cci: Fix use of smp_processor_id() in preemptible context bus: arm-ccn: Fix use of smp_processor_id() in preemptible context bus: arm-ccn: Simplify code bus: arm-ccn: Check memory allocation failure bus: arm-ccn: constify attribute_group structures. meson-gx-socinfo: Fix package id parsing ARM: meson: fix spelling mistake: "Couln't" -> "Couldn't" ARM: dts: meson: fix the memory region of the GPIO interrupt controller ARM: dts: meson: correct the sort order for the the gpio_intc node
2017-12-09Merge tag 'amlogic-fixes-1' of ↵Olof Johansson
git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-amlogic into fixes Amlogic fixes for v4.15-rc - GPIO interrupt fixes - socinfo fix for GX series - fix typo * tag 'amlogic-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-amlogic: ARM64: dts: meson-gx: fix UART pclk clock name meson-gx-socinfo: Fix package id parsing ARM: meson: fix spelling mistake: "Couln't" -> "Couldn't" ARM: dts: meson: fix the memory region of the GPIO interrupt controller ARM: dts: meson: correct the sort order for the the gpio_intc node Signed-off-by: Olof Johansson <olof@lixom.net>