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2020-08-31Merge branch 'master-next'Bruce Ashfield
2020-08-30Merge tag 'x86-urgent-2020-08-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Three interrupt related fixes for X86: - Move disabling of the local APIC after invoking fixup_irqs() to ensure that interrupts which are incoming are noted in the IRR and not ignored. - Unbreak affinity setting. The rework of the entry code reused the regular exception entry code for device interrupts. The vector number is pushed into the errorcode slot on the stack which is then lifted into an argument and set to -1 because that's regs->orig_ax which is used in quite some places to check whether the entry came from a syscall. But it was overlooked that orig_ax is used in the affinity cleanup code to validate whether the interrupt has arrived on the new target. It turned out that this vector check is pointless because interrupts are never moved from one vector to another on the same CPU. That check is a historical leftover from the time where x86 supported multi-CPU affinities, but not longer needed with the now strict single CPU affinity. Famous last words ... - Add a missing check for an empty cpumask into the matrix allocator. The affinity change added a warning to catch the case where an interrupt is moved on the same CPU to a different vector. This triggers because a condition with an empty cpumask returns an assignment from the allocator as the allocator uses for_each_cpu() without checking the cpumask for being empty. The historical inconsistent for_each_cpu() behaviour of ignoring the cpumask and unconditionally claiming that CPU0 is in the mask struck again. Sigh. plus a new entry into the MAINTAINER file for the HPE/UV platform" * tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/matrix: Deal with the sillyness of for_each_cpu() on UP x86/irq: Unbreak interrupt affinity setting x86/hotplug: Silence APIC only after all interrupts are migrated MAINTAINERS: Add entry for HPE Superdome Flex (UV) maintainers
2020-08-30Merge tag 'irq-urgent-2020-08-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A set of fixes for interrupt chip drivers: - Revert the platform driver conversion of interrupt chip drivers as it turned out to create more problems than it solves. - Fix a trivial typo in the new module helpers which made probing reliably fail. - Small fixes in the STM32 and MIPS Ingenic drivers - The TI firmware rework which had badly managed dependencies and had to wait post rc1" * tag 'irq-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/ingenic: Leave parent IRQ unmasked on suspend irqchip/stm32-exti: Avoid losing interrupts due to clearing pending bits by mistake irqchip: Revert modular support for drivers using IRQCHIP_PLATFORM_DRIVER helperse irqchip: Fix probing deferal when using IRQCHIP_PLATFORM_DRIVER helpers arm64: dts: k3-am65: Update the RM resource types arm64: dts: k3-am65: ti-sci-inta/intr: Update to latest bindings arm64: dts: k3-j721e: ti-sci-inta/intr: Update to latest bindings irqchip/ti-sci-inta: Add support for INTA directly connecting to GIC irqchip/ti-sci-inta: Do not store TISCI device id in platform device id field dt-bindings: irqchip: Convert ti, sci-inta bindings to yaml dt-bindings: irqchip: ti, sci-inta: Update docs to support different parent. irqchip/ti-sci-intr: Add support for INTR being a parent to INTR dt-bindings: irqchip: Convert ti, sci-intr bindings to yaml dt-bindings: irqchip: ti, sci-intr: Update bindings to drop the usage of gic as parent firmware: ti_sci: Add support for getting resource with subtype firmware: ti_sci: Drop unused structure ti_sci_rm_type_map firmware: ti_sci: Drop the device id to resource type translation
2020-08-30Merge tag 'locking-urgent-2020-08-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A set of fixes for lockdep, tracing and RCU: - Prevent recursion by using raw_cpu_* operations - Fixup the interrupt state in the cpu idle code to be consistent - Push rcu_idle_enter/exit() invocations deeper into the idle path so that the lock operations are inside the RCU watching sections - Move trace_cpu_idle() into generic code so it's called before RCU goes idle. - Handle raw_local_irq* vs. local_irq* operations correctly - Move the tracepoints out from under the lockdep recursion handling which turned out to be fragile and inconsistent" * tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep,trace: Expose tracepoints lockdep: Only trace IRQ edges mips: Implement arch_irqs_disabled() arm64: Implement arch_irqs_disabled() nds32: Implement arch_irqs_disabled() locking/lockdep: Cleanup x86/entry: Remove unused THUNKs cpuidle: Move trace_cpu_idle() into generic code cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic sched,idle,rcu: Push rcu_idle deeper into the idle path cpuidle: Fixup IRQ state lockdep: Use raw_cpu_*() for per-cpu variables
2020-08-30Merge tag 'powerpc-5.9-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - Revert our removal of PROT_SAO, at least one user expressed an interest in using it on Power9. Instead don't allow it to be used in guests unless enabled explicitly at compile time. - A fix for a crash introduced by a recent change to FP handling. - Revert a change to our idle code that left Power10 with no idle support. - One minor fix for the new scv system call path to set PPR. - Fix a crash in our "generic" PMU if branch stack events were enabled. - A fix for the IMC PMU, to correctly identify host kernel samples. - The ADB_PMU powermac code was found to be incompatible with VMAP_STACK, so make them incompatible in Kconfig until the code can be fixed. - A build fix in drivers/video/fbdev/controlfb.c, and a documentation fix. Thanks to Alexey Kardashevskiy, Athira Rajeev, Christophe Leroy, Giuseppe Sacco, Madhavan Srinivasan, Milton Miller, Nicholas Piggin, Pratik Rajesh Sampat, Randy Dunlap, Shawn Anastasio, Vaidyanathan Srinivasan. * tag 'powerpc-5.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/32s: Disable VMAP stack which CONFIG_ADB_PMU Revert "powerpc/powernv/idle: Replace CPU feature check with PVR check" powerpc/perf: Fix reading of MSR[HV/PR] bits in trace-imc powerpc/perf: Fix crashes with generic_compat_pmu & BHRB powerpc/64s: Fix crash in load_fp_state() due to fpexc_mode powerpc/64s: scv entry should set PPR Documentation/powerpc: fix malformed table in syscall64-abi video: fbdev: controlfb: Fix build for COMPILE_TEST=y && PPC_PMAC=n selftests/powerpc: Update PROT_SAO test to skip ISA 3.1 powerpc/64s: Disallow PROT_SAO in LPARs by default Revert "powerpc/64s: Remove PROT_SAO support"
2020-08-29Merge tag 'fallthrough-fixes-5.9-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux Pull fallthrough fixes from Gustavo A. R. Silva: "Fix some minor issues introduced by the recent treewide fallthrough conversions: - Fix identation issue - Fix erroneous fallthrough annotation - Remove unnecessary fallthrough annotation - Fix code comment changed by fallthrough conversion" * tag 'fallthrough-fixes-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: arm64/cpuinfo: Remove unnecessary fallthrough annotation media: dib0700: Fix identation issue in dib8096_set_param_override() afs: Remove erroneous fallthough annotation iio: dpot-dac: fix code comment in dpot_dac_read_raw()
2020-08-29Merge tag 's390-5.9-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Vasily Gorbik: - Disable preemption trace in percpu macros since the lockdep code itself uses percpu variables now and it causes recursions. - Fix kernel space 4-level paging broken by recent vmem rework. * tag 's390-5.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/vmem: fix vmem_add_range for 4-level paging s390: don't trace preemption in percpu macros
2020-08-28Merge tag 'arm64-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - Fix kernel build with the integrated LLVM assembler which doesn't see the -Wa,-march option. - Fix "make vdso_install" when COMPAT_VDSO is disabled. - Make KVM more robust if the AT S1E1R instruction triggers an exception (architecture corner cases). * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: KVM: arm64: Set HCR_EL2.PTW to prevent AT taking synchronous exception KVM: arm64: Survive synchronous exceptions caused by AT instructions KVM: arm64: Add kvm_extable for vaxorcism code arm64: vdso32: make vdso32 install conditional arm64: use a common .arch preamble for inline assembly
2020-08-28KVM: arm64: Set HCR_EL2.PTW to prevent AT taking synchronous exceptionJames Morse
AT instructions do a translation table walk and return the result, or the fault in PAR_EL1. KVM uses these to find the IPA when the value is not provided by the CPU in HPFAR_EL1. If a translation table walk causes an external abort it is taken as an exception, even if it was due to an AT instruction. (DDI0487F.a's D5.2.11 "Synchronous faults generated by address translation instructions") While we previously made KVM resilient to exceptions taken due to AT instructions, the device access causes mismatched attributes, and may occur speculatively. Prevent this, by forbidding a walk through memory described as device at stage2. Now such AT instructions will report a stage2 fault. Such a fault will cause KVM to restart the guest. If the AT instructions always walk the page tables, but guest execution uses the translation cached in the TLB, the guest can't make forward progress until the TLB entry is evicted. This isn't a problem, as since commit 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending"), KVM will return to the host to process IRQs allowing the rest of the system to keep running. Cc: stable@vger.kernel.org # <v5.3: 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending") Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28KVM: arm64: Survive synchronous exceptions caused by AT instructionsJames Morse
KVM doesn't expect any synchronous exceptions when executing, any such exception leads to a panic(). AT instructions access the guest page tables, and can cause a synchronous external abort to be taken. The arm-arm is unclear on what should happen if the guest has configured the hardware update of the access-flag, and a memory type in TCR_EL1 that does not support atomic operations. B2.2.6 "Possible implementation restrictions on using atomic instructions" from DDI0487F.a lists synchronous external abort as a possible behaviour of atomic instructions that target memory that isn't writeback cacheable, but the page table walker may behave differently. Make KVM robust to synchronous exceptions caused by AT instructions. Add a get_user() style helper for AT instructions that returns -EFAULT if an exception was generated. While KVM's version of the exception table mixes synchronous and asynchronous exceptions, only one of these can occur at each location. Re-enter the guest when the AT instructions take an exception on the assumption the guest will take the same exception. This isn't guaranteed to make forward progress, as the AT instructions may always walk the page tables, but guest execution may use the translation cached in the TLB. This isn't a problem, as since commit 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending"), KVM will return to the host to process IRQs allowing the rest of the system to keep running. Cc: stable@vger.kernel.org # <v5.3: 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending") Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28KVM: arm64: Add kvm_extable for vaxorcism codeJames Morse
KVM has a one instruction window where it will allow an SError exception to be consumed by the hypervisor without treating it as a hypervisor bug. This is used to consume asynchronous external abort that were caused by the guest. As we are about to add another location that survives unexpected exceptions, generalise this code to make it behave like the host's extable. KVM's version has to be mapped to EL2 to be accessible on nVHE systems. The SError vaxorcism code is a one instruction window, so has two entries in the extable. Because the KVM code is copied for VHE and nVHE, we end up with four entries, half of which correspond with code that isn't mapped. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28arm64: vdso32: make vdso32 install conditionalFrank van der Linden
vdso32 should only be installed if CONFIG_COMPAT_VDSO is enabled, since it's not even supposed to be compiled otherwise, and arm64 builds without a 32bit crosscompiler will fail. Fixes: 8d75785a8142 ("ARM64: vdso32: Install vdso32 from vdso_install") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Cc: stable@vger.kernel.org [5.4+] Link: https://lore.kernel.org/r/20200827234012.19757-1-fllinden@amazon.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28arm64: use a common .arch preamble for inline assemblySami Tolvanen
Commit 7c78f67e9bd9 ("arm64: enable tlbi range instructions") breaks LLVM's integrated assembler, because -Wa,-march is only passed to external assemblers and therefore, the new instructions are not enabled when IAS is used. This change adds a common architecture version preamble, which can be used in inline assembly blocks that contain instructions that require a newer architecture version, and uses it to fix __TLBI_0 and __TLBI_1 with ARM64_TLB_RANGE. Fixes: 7c78f67e9bd9 ("arm64: enable tlbi range instructions") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1106 Link: https://lore.kernel.org/r/20200827203608.1225689-1-samitolvanen@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28powerpc/32s: Disable VMAP stack which CONFIG_ADB_PMUChristophe Leroy
low_sleep_handler() can't restore the context from virtual stack because the stack can hardly be accessed with MMU OFF. For now, disable VMAP stack when CONFIG_ADB_PMU is selected. Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Cc: stable@vger.kernel.org # v5.6+ Reported-by: Giuseppe Sacco <giuseppe@sguazz.it> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ec96c15bfa1a7415ab604ee1c98cd45779c08be0.1598553015.git.christophe.leroy@csgroup.eu
2020-08-27arm64/cpuinfo: Remove unnecessary fallthrough annotationGustavo A. R. Silva
Fallthrough annotations for consecutive default and case labels are not necessary. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-27Revert "powerpc/powernv/idle: Replace CPU feature check with PVR check"Pratik Rajesh Sampat
cpuidle stop state implementation has minor optimizations for P10 where hardware preserves more SPR registers compared to P9. The current P9 driver works for P10, although does few extra save-restores. P9 driver can provide the required power management features like SMT thread folding and core level power savings on a P10 platform. Until the P10 stop driver is available, revert the commit which allows for only P9 systems to utilize cpuidle and blocks all idle stop states for P10. CPU idle states are enabled and tested on the P10 platform with this fix. This reverts commit 8747bf36f312356f8a295a0c39ff092d65ce75ae. Fixes: 8747bf36f312 ("powerpc/powernv/idle: Replace CPU feature check with PVR check") Signed-off-by: Pratik Rajesh Sampat <psampat@linux.ibm.com> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200826082918.89306-1-psampat@linux.ibm.com
2020-08-27powerpc/perf: Fix reading of MSR[HV/PR] bits in trace-imcAthira Rajeev
IMC trace-mode uses MSR[HV/PR] bits to set the cpumode for the instruction pointer captured in each sample. The bits are fetched from the third double word of the trace record. Reading third double word from IMC trace record should use be64_to_cpu() along with READ_ONCE inorder to fetch correct MSR[HV/PR] bits. Patch addresses this change. Currently we are using PERF_RECORD_MISC_HYPERVISOR as cpumode if MSR HV is 1 and PR is 0 which means the address is from host counter. But using PERF_RECORD_MISC_HYPERVISOR for host counter data will fail to resolve the address -> symbol during "perf report" because perf tools side uses PERF_RECORD_MISC_KERNEL to represent the host counter data. Therefore, fix the trace imc sample data to use PERF_RECORD_MISC_KERNEL as cpumode for host kernel information. Fixes: 77ca3951cc37 ("powerpc/perf: Add kernel support for new MSR[HV PR] bits in trace-imc") Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1598424029-1662-1-git-send-email-atrajeev@linux.vnet.ibm.com
2020-08-27powerpc/perf: Fix crashes with generic_compat_pmu & BHRBAlexey Kardashevskiy
The bhrb_filter_map ("The Branch History Rolling Buffer") callback is only defined in raw CPUs' power_pmu structs. The "architected" CPUs use generic_compat_pmu, which does not have this callback, and crashes occur if a user tries to enable branch stack for an event. This add a NULL pointer check for bhrb_filter_map() which behaves as if the callback returned an error. This does not add the same check for config_bhrb() as the only caller checks for cpuhw->bhrb_users which remains zero if bhrb_filter_map==0. Fixes: be80e758d0c2 ("powerpc/perf: Add generic compat mode pmu driver") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200602025612.62707-1-aik@ozlabs.ru
2020-08-27powerpc/64s: Fix crash in load_fp_state() due to fpexc_modeMichael Ellerman
The recent commit 01eb01877f33 ("powerpc/64s: Fix restore_math unnecessarily changing MSR") changed some of the handling of floating point/vector restore. In particular it caused current->thread.fpexc_mode to be copied into the current MSR (via msr_check_and_set()), rather than just into regs->msr (which is moved into MSR on return to userspace). This can lead to a crash in the kernel if we take a floating point exception when restoring FPSCR: Oops: Exception in kernel mode, sig: 8 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 3 PID: 101213 Comm: ld64.so.2 Not tainted 5.9.0-rc1-00098-g18445bf405cb-dirty #9 NIP: c00000000000fbb4 LR: c00000000001a7ac CTR: c000000000183570 REGS: c0000016b7cfb3b0 TRAP: 0700 Not tainted (5.9.0-rc1-00098-g18445bf405cb-dirty) MSR: 900000000290b933 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 44002444 XER: 00000000 CFAR: c00000000001a7a8 IRQMASK: 1 GPR00: c00000000001ae40 c0000016b7cfb640 c0000000011b7f00 c000001542a0f740 GPR04: c000001542a0f720 c000001542a0eb00 0000000000000900 c000001542a0eb00 GPR08: 000000000000000a 0000000000002000 9000000000009033 0000000000000000 GPR12: 0000000000004000 c0000017ffffd900 0000000000000001 c000000000df5a58 GPR16: c000000000e19c18 c0000000010e1123 0000000000000001 c000000000e1a638 GPR20: 0000000000000000 c0000000044b1d00 0000000000000000 c000001542a0f2a0 GPR24: 00000016c7fe0000 c000001542a0f720 c000000001c93da0 c000000000fe5f28 GPR28: c000001542a0f720 0000000000800000 c0000016b7cfbe90 0000000002802900 NIP load_fp_state+0x4/0x214 LR restore_math+0x17c/0x1f0 Call Trace: 0xc0000016b7cfb680 (unreliable) __switch_to+0x330/0x460 __schedule+0x318/0x920 schedule+0x74/0x140 schedule_timeout+0x318/0x3f0 wait_for_completion+0xc8/0x210 call_usermodehelper_exec+0x234/0x280 do_coredump+0xedc/0x13c0 get_signal+0x1d4/0xbe0 do_notify_resume+0x1a0/0x490 interrupt_exit_user_prepare+0x1c4/0x230 interrupt_return+0x14/0x1c0 Instruction dump: ebe10168 e88101a0 7c8ff120 382101e0 e8010010 7c0803a6 4e800020 790605c4 782905c4 7c0008a8 7c0008a8 c8030200 <fffe058e> 48000088 c8030000 c8230010 Fix it by only loading the fpexc_mode value into regs->msr. Also add a comment to explain that although VSX is subject to the value of fpexc_mode, we don't have to handle that separately because we only allow VSX to be enabled if FP is also enabled. Fixes: 01eb01877f33 ("powerpc/64s: Fix restore_math unnecessarily changing MSR") Reported-by: Milton Miller <miltonm@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Link: https://lore.kernel.org/r/20200825093424.3967813-1-mpe@ellerman.id.au
2020-08-27powerpc/64s: scv entry should set PPRNicholas Piggin
Kernel entry sets PPR to HMT_MEDIUM by convention. The scv entry path missed this. Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200825075309.224184-1-npiggin@gmail.com
2020-08-27x86/irq: Unbreak interrupt affinity settingThomas Gleixner
Several people reported that 5.8 broke the interrupt affinity setting mechanism. The consolidation of the entry code reused the regular exception entry code for device interrupts and changed the way how the vector number is conveyed from ptregs->orig_ax to a function argument. The low level entry uses the hardware error code slot to push the vector number onto the stack which is retrieved from there into a function argument and the slot on stack is set to -1. The reason for setting it to -1 is that the error code slot is at the position where pt_regs::orig_ax is. A positive value in pt_regs::orig_ax indicates that the entry came via a syscall. If it's not set to a negative value then a signal delivery on return to userspace would try to restart a syscall. But there are other places which rely on pt_regs::orig_ax being a valid indicator for syscall entry. But setting pt_regs::orig_ax to -1 has a nasty side effect vs. the interrupt affinity setting mechanism, which was overlooked when this change was made. Moving interrupts on x86 happens in several steps. A new vector on a different CPU is allocated and the relevant interrupt source is reprogrammed to that. But that's racy and there might be an interrupt already in flight to the old vector. So the old vector is preserved until the first interrupt arrives on the new vector and the new target CPU. Once that happens the old vector is cleaned up, but this cleanup still depends on the vector number being stored in pt_regs::orig_ax, which is now -1. That -1 makes the check for cleanup: pt_regs::orig_ax == new_vector always false. As a consequence the interrupt is moved once, but then it cannot be moved anymore because the cleanup of the old vector never happens. There would be several ways to convey the vector information to that place in the guts of the interrupt handling, but on deeper inspection it turned out that this check is pointless and a leftover from the old affinity model of X86 which supported multi-CPU affinities. Under this model it was possible that an interrupt had an old and a new vector on the same CPU, so the vector match was required. Under the new model the effective affinity of an interrupt is always a single CPU from the requested affinity mask. If the affinity mask changes then either the interrupt stays on the CPU and on the same vector when that CPU is still in the new affinity mask or it is moved to a different CPU, but it is never moved to a different vector on the same CPU. Ergo the cleanup check for the matching vector number is not required and can be removed which makes the dependency on pt_regs:orig_ax go away. The remaining check for new_cpu == smp_processsor_id() is completely sufficient. If it matches then the interrupt was successfully migrated and the cleanup can proceed. For paranoia sake add a warning into the vector assignment code to validate that the assumption of never moving to a different vector on the same CPU holds. Fixes: 633260fa143 ("x86/irq: Convey vector as argument and not in ptregs") Reported-by: Alex bykov <alex.bykov@scylladb.com> Reported-by: Avi Kivity <avi@scylladb.com> Reported-by: Alexander Graf <graf@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Graf <graf@amazon.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87wo1ltaxz.fsf@nanos.tec.linutronix.de
2020-08-27x86/hotplug: Silence APIC only after all interrupts are migratedAshok Raj
There is a race when taking a CPU offline. Current code looks like this: native_cpu_disable() { ... apic_soft_disable(); /* * Any existing set bits for pending interrupt to * this CPU are preserved and will be sent via IPI * to another CPU by fixup_irqs(). */ cpu_disable_common(); { .... /* * Race window happens here. Once local APIC has been * disabled any new interrupts from the device to * the old CPU are lost */ fixup_irqs(); // Too late to capture anything in IRR. ... } } The fix is to disable the APIC *after* cpu_disable_common(). Testing was done with a USB NIC that provided a source of frequent interrupts. A script migrated interrupts to a specific CPU and then took that CPU offline. Fixes: 60dcaad5736f ("x86/hotplug: Silence APIC and NMI when CPU is dead") Reported-by: Evan Green <evgreen@chromium.org> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mathias Nyman <mathias.nyman@linux.intel.com> Tested-by: Evan Green <evgreen@chromium.org> Reviewed-by: Evan Green <evgreen@chromium.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/875zdarr4h.fsf@nanos.tec.linutronix.de/ Link: https://lore.kernel.org/r/1598501530-45821-1-git-send-email-ashok.raj@intel.com
2020-08-26s390/vmem: fix vmem_add_range for 4-level pagingVasily Gorbik
The kernel currently crashes if 4-level paging is used. Add missing p4d_populate for just allocated pud entry. Fixes: 3e0d3e408e63 ("s390/vmem: consolidate vmem_add_range() and vmem_remove_range()") Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-08-26s390: don't trace preemption in percpu macrosSven Schnelle
Since commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") the lockdep code itself uses percpu variables. This leads to recursions because the percpu macros are calling preempt_enable() which might call trace_preempt_on(). Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-08-26lockdep: Only trace IRQ edgesNicholas Piggin
Problem: raw_local_irq_save(); // software state on local_irq_save(); // software state off ... local_irq_restore(); // software state still off, because we don't enable IRQs raw_local_irq_restore(); // software state still off, *whoopsie* existing instances: - lock_acquire() raw_local_irq_save() __lock_acquire() arch_spin_lock(&graph_lock) pv_wait() := kvm_wait() (same or worse for Xen/HyperV) local_irq_save() - trace_clock_global() raw_local_irq_save() arch_spin_lock() pv_wait() := kvm_wait() local_irq_save() - apic_retrigger_irq() raw_local_irq_save() apic->send_IPI() := default_send_IPI_single_phys() local_irq_save() Possible solutions: A) make it work by enabling the tracing inside raw_*() B) make it work by keeping tracing disabled inside raw_*() C) call it broken and clean it up now Now, given that the only reason to use the raw_* variant is because you don't want tracing. Therefore A) seems like a weird option (although it can be done). C) is tempting, but OTOH it ends up converting a _lot_ of code to raw just because there is one raw user, this strips the validation/tracing off for all the other users. So we pick B) and declare any code that ends up doing: raw_local_irq_save() local_irq_save() lockdep_assert_irqs_disabled(); broken. AFAICT this problem has existed forever, the only reason it came up is because commit: 859d069ee1dd ("lockdep: Prepare for NMI IRQ state tracking") changed IRQ tracing vs lockdep recursion and the first instance is fairly common, the other cases hardly ever happen. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [rewrote changelog] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200723105615.1268126-1-npiggin@gmail.com
2020-08-26mips: Implement arch_irqs_disabled()Peter Zijlstra
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Paul Burton <paulburton@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200826101653.GE1362448@hirez.programming.kicks-ass.net
2020-08-26arm64: Implement arch_irqs_disabled()Peter Zijlstra
Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lkml.kernel.org/r/20200821085348.664425120@infradead.org
2020-08-26nds32: Implement arch_irqs_disabled()Peter Zijlstra
Cc: Nick Hu <nickhu@andestech.com> Cc: Greentime Hu <green.hu@gmail.com> Cc: Vincent Chen <deanbo422@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.604899379@infradead.org
2020-08-26x86/entry: Remove unused THUNKsPeter Zijlstra
Unused remnants Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.487040689@infradead.org
2020-08-26cpuidle: Move trace_cpu_idle() into generic codePeter Zijlstra
Remove trace_cpu_idle() from the arch_cpu_idle() implementations and put it in the generic code, right before disabling RCU. Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.428433395@infradead.org
2020-08-26cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED genericPeter Zijlstra
This allows moving the leave_mm() call into generic code before rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org
2020-08-24powerpc/64s: Disallow PROT_SAO in LPARs by defaultShawn Anastasio
Since migration of guests using SAO to ISA 3.1 hosts may cause issues, disable PROT_SAO in LPARs by default and introduce a new Kconfig option PPC_PROT_SAO_LPAR to allow users to enable it if desired. Signed-off-by: Shawn Anastasio <shawn@anastas.io> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200821185558.35561-3-shawn@anastas.io
2020-08-24Revert "powerpc/64s: Remove PROT_SAO support"Shawn Anastasio
This reverts commit 5c9fa16e8abd342ce04dc830c1ebb2a03abf6c05. Since PROT_SAO can still be useful for certain classes of software, reintroduce it. Concerns about guest migration for LPARs using SAO will be addressed next. Signed-off-by: Shawn Anastasio <shawn@anastas.io> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200821185558.35561-2-shawn@anastas.io
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23Merge tag 'powerpc-5.9-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - Add perf support for emitting extended registers for power10. - A fix for CPU hotplug on pseries, where on large/loaded systems we may not wait long enough for the CPU to be offlined, leading to crashes. - Addition of a raw cputable entry for Power10, which is not required to boot, but is required to make our PMU setup work correctly in guests. - Three fixes for the recent changes on 32-bit Book3S to move modules into their own segment for strict RWX. - A fix for a recent change in our powernv PCI code that could lead to crashes. - A change to our perf interrupt accounting to avoid soft lockups when using some events, found by syzkaller. - A change in the way we handle power loss events from the hypervisor on pseries. We no longer immediately shut down if we're told we're running on a UPS. - A few other minor fixes. Thanks to Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Athira Rajeev, Christophe Leroy, Frederic Barrat, Greg Kurz, Kajol Jain, Madhavan Srinivasan, Michael Neuling, Michael Roth, Nageswara R Sastry, Oliver O'Halloran, Thiago Jung Bauermann, Vaidyanathan Srinivasan, Vasant Hegde. * tag 'powerpc-5.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/perf/hv-24x7: Move cpumask file to top folder of hv-24x7 driver powerpc/32s: Fix module loading failure when VMALLOC_END is over 0xf0000000 powerpc/pseries: Do not initiate shutdown when system is running on UPS powerpc/perf: Fix soft lockups due to missed interrupt accounting powerpc/powernv/pci: Fix possible crash when releasing DMA resources powerpc/pseries/hotplug-cpu: wait indefinitely for vCPU death powerpc/32s: Fix is_module_segment() when MODULES_VADDR is defined powerpc/kasan: Fix KASAN_SHADOW_START on BOOK3S_32 powerpc/fixmap: Fix the size of the early debug area powerpc/pkeys: Fix build error with PPC_MEM_KEYS disabled powerpc/kernel: Cleanup machine check function declarations powerpc: Add POWER10 raw mode cputable entry powerpc/perf: Add extended regs support for power10 platform powerpc/perf: Add support for outputting extended regs in perf intr_regs powerpc: Fix P10 PVR revision in /proc/cpuinfo for SMT4 cores
2020-08-23Merge tag 'x86-urgent-2020-08-23' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Thomas Gleixner: "A single fix for x86 which removes the RDPID usage from the paranoid entry path and unconditionally uses LSL to retrieve the CPU number. RDPID depends on MSR_TSX_AUX. KVM has an optmization to avoid expensive MRS read/writes on VMENTER/EXIT. It caches the MSR values and restores them either when leaving the run loop, on preemption or when going out to user space. MSR_TSX_AUX is part of that lazy MSR set, so after writing the guest value and before the lazy restore any exception using the paranoid entry will read the guest value and use it as CPU number to retrieve the GSBASE value for the current CPU when FSGSBASE is enabled. As RDPID is only used in that particular entry path, there is no reason to burden VMENTER/EXIT with two extra MSR writes. Remove the RDPID optimization, which is not even backed by numbers from the paranoid entry path instead" * tag 'x86-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry/64: Do not use RDPID in paranoid entry to accomodate KVM
2020-08-23Merge tag 'perf-urgent-2020-08-23' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 perf fix from Thomas Gleixner: "A single update for perf on x86 which has support for the broken down bandwith counters" * tag 'perf-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Add BW counters for GT, IA and IO breakdown
2020-08-23Merge tag 'efi-urgent-2020-08-23' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI fixes from Thomas Gleixner: - Enforce NX on RO data in mixed EFI mode - Destroy workqueue in an error handling path to prevent UAF - Stop argument parser at '--' which is the delimiter for init - Treat a NULL command line pointer as empty instead of dereferncing it unconditionally. - Handle an unterminated command line correctly - Cleanup the 32bit code leftovers and remove obsolete documentation * tag 'efi-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation: efi: remove description of efi=old_map efi/x86: Move 32-bit code into efi_32.c efi/libstub: Handle unterminated cmdline efi/libstub: Handle NULL cmdline efi/libstub: Stop parsing arguments at "--" efi: add missed destroy_workqueue when efisubsys_init fails efi/x86: Mark kernel rodata non-executable for mixed mode
2020-08-22Merge tag 'arm64-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - Allow booting of late secondary CPUs affected by erratum 1418040 (currently they are parked if none of the early CPUs are affected by this erratum). - Add the 32-bit vdso Makefile to the vdso_install rule so that 'make vdso_install' installs the 32-bit compat vdso when it is compiled. - Print a warning that untrusted guests without a CPU erratum workaround (Cortex-A57 832075) may deadlock the affected system. * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: ARM64: vdso32: Install vdso32 from vdso_install KVM: arm64: Print warning when cpu erratum can cause guests to deadlock arm64: Allow booting of late CPUs affected by erratum 1418040 arm64: Move handling of erratum 1418040 into C code
2020-08-22Merge tag 's390-5.9-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Vasily Gorbik: - a couple of fixes for storage key handling relevant for debugging - add cond_resched into potentially slow subchannels scanning loop - fixes for PF/VF linking and to ignore stale PCI configuration request events * tag 's390-5.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/pci: fix PF/VF linking on hot plug s390/pci: re-introduce zpci_remove_device() s390/pci: fix zpci_bus_link_virtfn() s390/ptrace: fix storage key handling s390/runtime_instrumentation: fix storage key handling s390/pci: ignore stale configuration request event s390/cio: add cond_resched() in the slow_eval_known_fn() loop
2020-08-22Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: - PAE and PKU bugfixes for x86 - selftests fix for new binutils - MMU notifier fix for arm64 * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set KVM: Pass MMU notifier range flags to kvm_unmap_hva_range() kvm: x86: Toggling CR4.PKE does not load PDPTEs in PAE mode kvm: x86: Toggling CR4.SMAP does not load PDPTEs in PAE mode KVM: x86: fix access code passed to gva_to_gpa selftests: kvm: Use a shorter encoding to clear RAX
2020-08-21KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not setWill Deacon
When an MMU notifier call results in unmapping a range that spans multiple PGDs, we end up calling into cond_resched_lock() when crossing a PGD boundary, since this avoids running into RCU stalls during VM teardown. Unfortunately, if the VM is destroyed as a result of OOM, then blocking is not permitted and the call to the scheduler triggers the following BUG(): | BUG: sleeping function called from invalid context at arch/arm64/kvm/mmu.c:394 | in_atomic(): 1, irqs_disabled(): 0, non_block: 1, pid: 36, name: oom_reaper | INFO: lockdep is turned off. | CPU: 3 PID: 36 Comm: oom_reaper Not tainted 5.8.0 #1 | Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x1c/0x28 | dump_stack+0xf0/0x1a4 | ___might_sleep+0x2bc/0x2cc | unmap_stage2_range+0x160/0x1ac | kvm_unmap_hva_range+0x1a0/0x1c8 | kvm_mmu_notifier_invalidate_range_start+0x8c/0xf8 | __mmu_notifier_invalidate_range_start+0x218/0x31c | mmu_notifier_invalidate_range_start_nonblock+0x78/0xb0 | __oom_reap_task_mm+0x128/0x268 | oom_reap_task+0xac/0x298 | oom_reaper+0x178/0x17c | kthread+0x1e4/0x1fc | ret_from_fork+0x10/0x30 Use the new 'flags' argument to kvm_unmap_hva_range() to ensure that we only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is set in the notifier flags. Cc: <stable@vger.kernel.org> Fixes: 8b3405e345b5 ("kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd") Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Message-Id: <20200811102725.7121-3-will@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()Will Deacon
The 'flags' field of 'struct mmu_notifier_range' is used to indicate whether invalidate_range_{start,end}() are permitted to block. In the case of kvm_mmu_notifier_invalidate_range_start(), this field is not forwarded on to the architecture-specific implementation of kvm_unmap_hva_range() and therefore the backend cannot sensibly decide whether or not to block. Add an extra 'flags' parameter to kvm_unmap_hva_range() so that architectures are aware as to whether or not they are permitted to block. Cc: <stable@vger.kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Message-Id: <20200811102725.7121-2-will@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21Merge tag 'riscv-for-linus-5.9-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - The CLINT driver has been split in two: one to handle the M-mode CLINT (memory mapped and used on NOMMU systems) and one to handle the S-mode CLINT (via SBI). - The addition of SiFive's drivers to rv32_defconfig * tag 'riscv-for-linus-5.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Add SiFive drivers to rv32_defconfig dt-bindings: timer: Add CLINT bindings RISC-V: Remove CLINT related code from timer and arch clocksource/drivers: Add CLINT timer driver RISC-V: Add mechanism to provide custom IPI operations
2020-08-21Merge tag 'for-linus-5.9-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: "One build fix and a minor fix for suppressing a useless warning when booting a Xen dom0 via UEFI" * tag 'for-linus-5.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: Fix build error when CONFIG_ACPI is not set/enabled: efi: avoid error message when booting under Xen
2020-08-21ARM64: vdso32: Install vdso32 from vdso_installStephen Boyd
Add the 32-bit vdso Makefile to the vdso_install rule so that 'make vdso_install' installs the 32-bit compat vdso when it is compiled. Fixes: a7f71a2c8903 ("arm64: compat: Add vDSO") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Will Deacon <will@kernel.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20200818014950.42492-1-swboyd@chromium.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-21x86/entry/64: Do not use RDPID in paranoid entry to accomodate KVMSean Christopherson
KVM has an optmization to avoid expensive MRS read/writes on VMENTER/EXIT. It caches the MSR values and restores them either when leaving the run loop, on preemption or when going out to user space. The affected MSRs are not required for kernel context operations. This changed with the recently introduced mechanism to handle FSGSBASE in the paranoid entry code which has to retrieve the kernel GSBASE value by accessing per CPU memory. The mechanism needs to retrieve the CPU number and uses either LSL or RDPID if the processor supports it. Unfortunately RDPID uses MSR_TSC_AUX which is in the list of cached and lazily restored MSRs, which means between the point where the guest value is written and the point of restore, MSR_TSC_AUX contains a random number. If an NMI or any other exception which uses the paranoid entry path happens in such a context, then RDPID returns the random guest MSR_TSC_AUX value. As a consequence this reads from the wrong memory location to retrieve the kernel GSBASE value. Kernel GS is used to for all regular this_cpu_*() operations. If the GSBASE in the exception handler points to the per CPU memory of a different CPU then this has the obvious consequences of data corruption and crashes. As the paranoid entry path is the only place which accesses MSR_TSX_AUX (via RDPID) and the fallback via LSL is not significantly slower, remove the RDPID alternative from the entry path and always use LSL. The alternative would be to write MSR_TSC_AUX on every VMENTER and VMEXIT which would be inflicting massive overhead on that code path. [ tglx: Rewrote changelog ] Fixes: eaad981291ee3 ("x86/entry/64: Introduce the FIND_PERCPU_BASE macro") Reported-by: Tom Lendacky <thomas.lendacky@amd.com> Debugged-by: Tom Lendacky <thomas.lendacky@amd.com> Suggested-by: Andy Lutomirski <luto@kernel.org> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200821105229.18938-1-pbonzini@redhat.com
2020-08-21powerpc/perf/hv-24x7: Move cpumask file to top folder of hv-24x7 driverKajol Jain
Commit 792f73f747b8 ("powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show cpumask") added cpumask file as part of hv-24x7 driver inside the interface folder. The cpumask file is supposed to be in the top folder of the PMU driver in order to make hotplug work. This patch fixes that issue and creates new group 'cpumask_attr_group' to add cpumask file and make sure it added in top folder. command:# cat /sys/devices/hv_24x7/cpumask 0 Fixes: 792f73f747b8 ("powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show cpumask") Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200821080610.123997-1-kjain@linux.ibm.com
2020-08-21powerpc/32s: Fix module loading failure when VMALLOC_END is over 0xf0000000Christophe Leroy
In is_module_segment(), when VMALLOC_END is over 0xf0000000, ALIGN(VMALLOC_END, SZ_256M) has value 0. In that case, addr >= ALIGN(VMALLOC_END, SZ_256M) is always true then is_module_segment() always returns false. Use (ALIGN(VMALLOC_END, SZ_256M) - 1) which will have value 0xffffffff and will be suitable for the comparison. Fixes: c49643319715 ("powerpc/32s: Only leave NX unset on segments used for modules") Reported-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/09fc73fe9c7423c6b4cf93f93df9bb0ed8eefab5.1597994047.git.christophe.leroy@csgroup.eu
2020-08-21KVM: arm64: Print warning when cpu erratum can cause guests to deadlockRob Herring
If guests don't have certain CPU erratum workarounds implemented, then there is a possibility a guest can deadlock the system. IOW, only trusted guests should be used on systems with the erratum. This is the case for Cortex-A57 erratum 832075. Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Cc: kvmarm@lists.cs.columbia.edu Link: https://lore.kernel.org/r/20200803193127.3012242-2-robh@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>