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* x86/CPU/AMD: Save AMD NodeId as cpu_die_idYazen Ghannam2020-11-194-17/+15
| | | | | | | | | | | | | | | | | | | | | | | | | AMD systems provide a "NodeId" value that represents a global ID indicating to which "Node" a logical CPU belongs. The "Node" is a physical structure equivalent to a Die, and it should not be confused with logical structures like NUMA nodes. Logical nodes can be adjusted based on firmware or other settings whereas the physical nodes/dies are fixed based on hardware topology. The NodeId value can be used when a physical ID is needed by software. Save the AMD NodeId to struct cpuinfo_x86.cpu_die_id. Use the value from CPUID or MSR as appropriate. Default to phys_proc_id otherwise. Do so for both AMD and Hygon systems. Drop the node_id parameter from cacheinfo_*_init_llc_id() as it is no longer needed. Update the x86 topology documentation. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201109210659.754018-2-Yazen.Ghannam@amd.com
* Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2020-11-156-2/+26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm fixes from Paolo Bonzini: "Fixes for ARM and x86, the latter especially for old processors without two-dimensional paging (EPT/NPT)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: mmu: fix is_tdp_mmu_check when the TDP MMU is not in use KVM: SVM: Update cr3_lm_rsvd_bits for AMD SEV guests KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_arch KVM: x86: clflushopt should be treated as a no-op by emulation KVM: arm64: Handle SCXTNUM_ELx traps KVM: arm64: Unify trap handlers injecting an UNDEF KVM: arm64: Allow setting of ID_AA64PFR0_EL1.CSV2 from userspace
| * kvm: mmu: fix is_tdp_mmu_check when the TDP MMU is not in usePaolo Bonzini2020-11-151-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | In some cases where shadow paging is in use, the root page will be either mmu->pae_root or vcpu->arch.mmu->lm_root. Then it will not have an associated struct kvm_mmu_page, because it is allocated with alloc_page instead of kvm_mmu_alloc_page. Just return false quickly from is_tdp_mmu_root if the TDP MMU is not in use, which also includes the case where shadow paging is enabled. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: SVM: Update cr3_lm_rsvd_bits for AMD SEV guestsBabu Moger2020-11-131-0/+8
| | | | | | | | | | | | | | | | | | For AMD SEV guests, update the cr3_lm_rsvd_bits to mask the memory encryption bit in reserved bits. Signed-off-by: Babu Moger <babu.moger@amd.com> Message-Id: <160521948301.32054.5783800787423231162.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_archBabu Moger2020-11-133-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SEV guests fail to boot on a system that supports the PCID feature. While emulating the RSM instruction, KVM reads the guest CR3 and calls kvm_set_cr3(). If the vCPU is in the long mode, kvm_set_cr3() does a sanity check for the CR3 value. In this case, it validates whether the value has any reserved bits set. The reserved bit range is 63:cpuid_maxphysaddr(). When AMD memory encryption is enabled, the memory encryption bit is set in the CR3 value. The memory encryption bit may fall within the KVM reserved bit range, causing the KVM emulation failure. Introduce a new field cr3_lm_rsvd_bits in kvm_vcpu_arch which will cache the reserved bits in the CR3 value. This will be initialized to rsvd_bits(cpuid_maxphyaddr(vcpu), 63). If the architecture has any special bits(like AMD SEV encryption bit) that needs to be masked from the reserved bits, should be cleared in vendor specific kvm_x86_ops.vcpu_after_set_cpuid handler. Fixes: a780a3ea628268b2 ("KVM: X86: Fix reserved bits check for MOV to CR3") Signed-off-by: Babu Moger <babu.moger@amd.com> Message-Id: <160521947657.32054.3264016688005356563.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: x86: clflushopt should be treated as a no-op by emulationDavid Edmondson2020-11-131-1/+7
| | | | | | | | | | | | | | | | | | | | | | The instruction emulator ignores clflush instructions, yet fails to support clflushopt. Treat both similarly. Fixes: 13e457e0eebf ("KVM: x86: Emulator does not decode clflush well") Signed-off-by: David Edmondson <david.edmondson@oracle.com> Message-Id: <20201103120400.240882-1-david.edmondson@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | Merge tag 'x86-urgent-2020-11-15' of ↵Linus Torvalds2020-11-152-13/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A small set of fixes for x86: - Cure the fallout from the MSI irqdomain overhaul which missed that the Intel IOMMU does not register virtual function devices and therefore never reaches the point where the MSI interrupt domain is assigned. This made the VF devices use the non-remapped MSI domain which is trapped by the IOMMU/remap unit - Remove an extra space in the SGI_UV architecture type procfs output for UV5 - Remove a unused function which was missed when removing the UV BAU TLB shootdown handler" * tag 'x86-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: iommu/vt-d: Cure VF irqdomain hickup x86/platform/uv: Fix copied UV5 output archtype x86/platform/uv: Drop last traces of uv_flush_tlb_others
| * | x86/platform/uv: Fix copied UV5 output archtypeMike Travis2020-11-131-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A test shows that the output contains a space: # cat /proc/sgi_uv/archtype NSGI4 U/UVX Remove that embedded space by copying the "trimmed" buffer instead of the untrimmed input character list. Use sizeof to remove size dependency on copy out length. Increase output buffer size by one character just in case BIOS sends an 8 character string for archtype. Fixes: 1e61f5a95f19 ("Add and decode Arch Type in UVsystab") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steve Wahl <steve.wahl@hpe.com> Link: https://lore.kernel.org/r/20201111010418.82133-1-mike.travis@hpe.com
| * | x86/platform/uv: Drop last traces of uv_flush_tlb_othersJiri Slaby2020-11-111-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 39297dde7390 ("x86/platform/uv: Remove UV BAU TLB Shootdown Handler") removed uv_flush_tlb_others. Its declaration was removed also from asm/uv/uv.h. But only for the CONFIG_X86_UV=y case. The inline definition (!X86_UV case) is still in place. So remove this implementation with everything what was added to support uv_flush_tlb_others: * include of asm/tlbflush.h * forward declarations of struct cpumask, mm_struct, and flush_tlb_info Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Mike Travis <mike.travis@hpe.com> Acked-by: Steve Wahl <steve.wahl@hpe.com> Link: https://lore.kernel.org/r/20201109093653.2042-1-jslaby@suse.cz
* | | Merge tag 'perf-urgent-2020-11-15' of ↵Linus Torvalds2020-11-157-34/+59
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A set of fixes for perf: - A set of commits which reduce the stack usage of various perf event handling functions which allocated large data structs on stack causing stack overflows in the worst case - Use the proper mechanism for detecting soft interrupts in the recursion protection - Make the resursion protection simpler and more robust - Simplify the scheduling of event groups to make the code more robust and prepare for fixing the issues vs. scheduling of exclusive event groups - Prevent event multiplexing and rotation for exclusive event groups - Correct the perf event attribute exclusive semantics to take pinned events, e.g. the PMU watchdog, into account - Make the anythread filtering conditional for Intel's generic PMU counters as it is not longer guaranteed to be supported on newer CPUs. Check the corresponding CPUID leaf to make sure - Fixup a duplicate initialization in an array which was probably caused by the usual 'copy & paste - forgot to edit' mishap" * tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Fix Add BW copypasta perf/x86/intel: Make anythread filter support conditional perf: Tweak perf_event_attr::exclusive semantics perf: Fix event multiplexing for exclusive groups perf: Simplify group_sched_in() perf: Simplify group_sched_out() perf/x86: Make dummy_iregs static perf/arch: Remove perf_sample_data::regs_user_copy perf: Optimize get_recursion_context() perf: Fix get_recursion_context() perf/x86: Reduce stack usage for x86_pmu::drain_pebs() perf: Reduce stack usage of perf_output_begin()
| * | perf/x86/intel/uncore: Fix Add BW copypastaArnd Bergmann2020-11-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc -Wextra points out a duplicate initialization of one array member: arch/x86/events/intel/uncore_snb.c:478:37: warning: initialized field overwritten [-Woverride-init] 478 | [SNB_PCI_UNCORE_IMC_DATA_READS] = { SNB_UNCORE_PCI_IMC_DATA_WRITES_BASE, The only sensible explanation is that a duplicate 'READS' was used instead of the correct 'WRITES', so change it back. Fixes: 24633d901ea4 ("perf/x86/intel/uncore: Add BW counters for GT, IA and IO breakdown") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201026215203.3893972-1-arnd@kernel.org
| * | perf/x86/intel: Make anythread filter support conditionalStephane Eranian2020-11-094-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Starting with Arch Perfmon v5, the anythread filter on generic counters may be deprecated. The current kernel was exporting the any filter without checking. On Icelake, it means you could do cpu/event=0x3c,any/ even though the filter does not exist. This patch corrects the problem by relying on the CPUID 0xa leaf function to determine if anythread is supported or not as described in the Intel SDM Vol3b 18.2.5.1 AnyThread Deprecation section. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201028194247.3160610-1-eranian@google.com
| * | perf/x86: Make dummy_iregs staticPeter Zijlstra2020-11-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Having pt_regs on-stack is unfortunate, it's 168 bytes. Since it isn't actually used, make it a static variable. This both gets if off the stack and ensures it gets 0 initialized, just in case someone does look at it. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201030151955.324273677@infradead.org
| * | perf/arch: Remove perf_sample_data::regs_user_copyPeter Zijlstra2020-11-091-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct perf_sample_data lives on-stack, we should be careful about it's size. Furthermore, the pt_regs copy in there is only because x86_64 is a trainwreck, solve it differently. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Steven Rostedt <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
| * | perf/x86: Reduce stack usage for x86_pmu::drain_pebs()Peter Zijlstra2020-11-093-24/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | intel_pmu_drain_pebs_*() is typically called from handle_pmi_common(), both have an on-stack struct perf_sample_data, which is *big*. Rewire things so that drain_pebs() can use the one handle_pmi_common() has. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201030151955.054099690@infradead.org
| * | perf: Reduce stack usage of perf_output_begin()Peter Zijlstra2020-11-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __perf_output_begin() has an on-stack struct perf_sample_data in the unlikely case it needs to generate a LOST record. However, every call to perf_output_begin() must already have a perf_sample_data on-stack. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
* | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2020-11-095-30/+86
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm fixes from Paolo Bonzini: "ARM: - fix compilation error when PMD and PUD are folded - fix regression in reads-as-zero behaviour of ID_AA64ZFR0_EL1 - add aarch64 get-reg-list test x86: - fix semantic conflict between two series merged for 5.10 - fix (and test) enforcement of paravirtual cpuid features selftests: - various cleanups to memory management selftests - new selftests testcase for performance of dirty logging" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (30 commits) KVM: selftests: allow two iterations of dirty_log_perf_test KVM: selftests: Introduce the dirty log perf test KVM: selftests: Make the number of vcpus global KVM: selftests: Make the per vcpu memory size global KVM: selftests: Drop pointless vm_create wrapper KVM: selftests: Add wrfract to common guest code KVM: selftests: Simplify demand_paging_test with timespec_diff_now KVM: selftests: Remove address rounding in guest code KVM: selftests: Factor code out of demand_paging_test KVM: selftests: Use a single binary for dirty/clear log test KVM: selftests: Always clear dirty bitmap after iteration KVM: selftests: Add blessed SVE registers to get-reg-list KVM: selftests: Add aarch64 get-reg-list test selftests: kvm: test enforcement of paravirtual cpuid features selftests: kvm: Add exception handling to selftests selftests: kvm: Clear uc so UCALL_NONE is being properly reported selftests: kvm: Fix the segment descriptor layout to match the actual layout KVM: x86: handle MSR_IA32_DEBUGCTLMSR with report_ignored_msrs kvm: x86: request masterclock update any time guest uses different msr kvm: x86: ensure pv_cpuid.features is initialized when enabling cap ...
| * | KVM: x86: handle MSR_IA32_DEBUGCTLMSR with report_ignored_msrsPankaj Gupta2020-11-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Windows2016 guest tries to enable LBR by setting the corresponding bits in MSR_IA32_DEBUGCTLMSR. KVM does not emulate MSR_IA32_DEBUGCTLMSR and spams the host kernel logs with error messages like: kvm [...]: vcpu1, guest rIP: 0xfffff800a8b687d3 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop" This patch fixes this by enabling error logging only with 'report_ignored_msrs=1'. Signed-off-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Message-Id: <20201105153932.24316-1-pankaj.gupta.linux@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm: x86: request masterclock update any time guest uses different msrOliver Upton2020-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5b9bb0ebbcdc ("kvm: x86: encapsulate wrmsr(MSR_KVM_SYSTEM_TIME) emulation in helper fn", 2020-10-21) subtly changed the behavior of guest writes to MSR_KVM_SYSTEM_TIME(_NEW). Restore the previous behavior; update the masterclock any time the guest uses a different msr than before. Fixes: 5b9bb0ebbcdc ("kvm: x86: encapsulate wrmsr(MSR_KVM_SYSTEM_TIME) emulation in helper fn", 2020-10-21) Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Message-Id: <20201027231044.655110-6-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm: x86: ensure pv_cpuid.features is initialized when enabling capOliver Upton2020-11-083-7/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the paravirtual cpuid enforcement mechanism idempotent to ioctl() ordering by updating pv_cpuid.features whenever userspace requests the capability. Extract this update out of kvm_update_cpuid_runtime() into a new helper function and move its other call site into kvm_vcpu_after_set_cpuid() where it more likely belongs. Fixes: 66570e966dd9 ("kvm: x86: only provide PV features if enabled in guest's CPUID") Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Message-Id: <20201027231044.655110-5-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | kvm: x86: reads of restricted pv msrs should also result in #GPOliver Upton2020-11-081-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 66570e966dd9 ("kvm: x86: only provide PV features if enabled in guest's CPUID") only protects against disallowed guest writes to KVM paravirtual msrs, leaving msr reads unchecked. Fix this by enforcing KVM_CPUID_FEATURES for msr reads as well. Fixes: 66570e966dd9 ("kvm: x86: only provide PV features if enabled in guest's CPUID") Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Message-Id: <20201027231044.655110-4-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: x86: use positive error values for msr emulation that causes #GPMaxim Levitsky2020-11-082-14/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent introduction of the userspace msr filtering added code that uses negative error codes for cases that result in either #GP delivery to the guest, or handled by the userspace msr filtering. This breaks an assumption that a negative error code returned from the msr emulation code is a semi-fatal error which should be returned to userspace via KVM_RUN ioctl and usually kill the guest. Fix this by reusing the already existing KVM_MSR_RET_INVALID error code, and by adding a new KVM_MSR_RET_FILTERED error code for the userspace filtered msrs. Fixes: 291f35fb2c1d1 ("KVM: x86: report negative values from wrmsr emulation to userspace") Reported-by: Qian Cai <cai@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20201101115523.115780-1-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | KVM: x86/mmu: fix counting of rmap entries in pte_list_addLi RongQing2020-11-081-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix an off-by-one style bug in pte_list_add() where it failed to account the last full set of SPTEs, i.e. when desc->sptes is full and desc->more is NULL. Merge the two "PTE_LIST_EXT-1" checks as part of the fix to avoid an extra comparison. Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <1601196297-24104-1-git-send-email-lirongqing@baidu.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | Merge tag 'x86-urgent-2020-11-08' of ↵Linus Torvalds2020-11-085-32/+54
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of x86 fixes: - Use SYM_FUNC_START_WEAK in the mem* ASM functions instead of a combination of .weak and SYM_FUNC_START_LOCAL which makes LLVMs integrated assembler upset - Correct the mitigation selection logic which prevented the related prctl to work correctly - Make the UV5 hubless system work correctly by fixing up the malformed table entries and adding the missing ones" * tag 'x86-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Recognize UV5 hubless system identifier x86/platform/uv: Remove spaces from OEM IDs x86/platform/uv: Fix missing OEM_TABLE_ID x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
| * | x86/platform/uv: Recognize UV5 hubless system identifierMike Travis2020-11-071-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Testing shows a problem in that UV5 hubless systems were not being recognized. Add them to the list of OEM IDs checked. Fixes: 6c7794423a998 ("Add UV5 direct references") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201105222741.157029-4-mike.travis@hpe.com
| * | x86/platform/uv: Remove spaces from OEM IDsMike Travis2020-11-071-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Testing shows that trailing spaces caused problems with the OEM_ID and the OEM_TABLE_ID. One being that the OEM_ID would not string compare correctly. Another the OEM_ID and OEM_TABLE_ID would be concatenated in the printout. Remove any trailing spaces. Fixes: 1e61f5a95f191 ("Add and decode Arch Type in UVsystab") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201105222741.157029-3-mike.travis@hpe.com
| * | x86/platform/uv: Fix missing OEM_TABLE_IDMike Travis2020-11-071-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Testing shows a problem in that the OEM_TABLE_ID was missing for hubless systems. This is used to determine the APIC type (legacy or extended). Add the OEM_TABLE_ID to the early hubless processing. Fixes: 1e61f5a95f191 ("Add and decode Arch Type in UVsystab") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201105222741.157029-2-mike.travis@hpe.com
| * | x86/speculation: Allow IBPB to be conditionally enabled on CPUs with ↵Anand K Mistry2020-11-051-18/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | always-on STIBP On AMD CPUs which have the feature X86_FEATURE_AMD_STIBP_ALWAYS_ON, STIBP is set to on and spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED At the same time, IBPB can be set to conditional. However, this leads to the case where it's impossible to turn on IBPB for a process because in the PR_SPEC_DISABLE case in ib_prctl_set() the spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED condition leads to a return before the task flag is set. Similarly, ib_prctl_get() will return PR_SPEC_DISABLE even though IBPB is set to conditional. More generally, the following cases are possible: 1. STIBP = conditional && IBPB = on for spectre_v2_user=seccomp,ibpb 2. STIBP = on && IBPB = conditional for AMD CPUs with X86_FEATURE_AMD_STIBP_ALWAYS_ON The first case functions correctly today, but only because spectre_v2_user_ibpb isn't updated to reflect the IBPB mode. At a high level, this change does one thing. If either STIBP or IBPB is set to conditional, allow the prctl to change the task flag. Also, reflect that capability when querying the state. This isn't perfect since it doesn't take into account if only STIBP or IBPB is unconditionally on. But it allows the conditional feature to work as expected, without affecting the unconditional one. [ bp: Massage commit message and comment; space out statements for better readability. ] Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.") Signed-off-by: Anand K Mistry <amistry@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201105163246.v2.1.Ifd7243cd3e2c2206a893ad0a5b9a4f19549e22c6@changeid
| * | x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.SFangrui Song2020-11-043-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") added .weak directives to arch/x86/lib/mem*_64.S instead of changing the existing ENTRY macros to WEAK. This can lead to the assembly snippet .weak memcpy ... .globl memcpy which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL memcpy with LLVM's integrated assembler before LLVM 12. LLVM 12 (since https://reviews.llvm.org/D90108) will error on such an overridden symbol binding. Commit ef1e03152cb0 ("x86/asm: Make some functions local") changed ENTRY in arch/x86/lib/memcpy_64.S to SYM_FUNC_START_LOCAL, which was ineffective due to the preceding .weak directive. Use the appropriate SYM_FUNC_START_WEAK instead. Fixes: 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") Fixes: ef1e03152cb0 ("x86/asm: Make some functions local") Reported-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201103012358.168682-1-maskray@google.com
* | | Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds2020-11-051-5/+9
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - clarify a comment (Michael Kelley) - change a pr_warn() to pr_info() (Olaf Hering) * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Clarify comment on x2apic mode hv_balloon: disable warning when floor reached
| * | | x86/hyperv: Clarify comment on x2apic modeMichael Kelley2020-10-261-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment about Hyper-V accessors is unclear regarding their potential use in x2apic mode, as is the associated commit message in e211288b72f1. Clarify that while the architectural and synthetic MSRs are equivalent in x2apic mode, the full set of xapic accessors cannot be used because of register layout differences. Fixes: e211288b72f1 ("x86/hyperv: Make vapic support x2apic mode") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1603723972-81303-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* | | | Merge tag 'x86_seves_for_v5.10_rc3' of ↵Linus Torvalds2020-11-038-8/+167
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV-ES fixes from Borislav Petkov: "A couple of changes to the SEV-ES code to perform more stringent hypervisor checks before enabling encryption (Joerg Roedel)" * tag 'x86_seves_for_v5.10_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev-es: Do not support MMIO to/from encrypted memory x86/head/64: Check SEV encryption before switching to kernel page-table x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path x86/boot/compressed/64: Sanity-check CPUID results in the early #VC handler x86/boot/compressed/64: Introduce sev_status
| * | | x86/sev-es: Do not support MMIO to/from encrypted memoryJoerg Roedel2020-10-291-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MMIO memory is usually not mapped encrypted, so there is no reason to support emulated MMIO when it is mapped encrypted. Prevent a possible hypervisor attack where a RAM page is mapped as an MMIO page in the nested page-table, so that any guest access to it will trigger a #VC exception and leak the data on that page to the hypervisor via the GHCB (like with valid MMIO). On the read side this attack would allow the HV to inject data into the guest. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-6-joro@8bytes.org
| * | | x86/head/64: Check SEV encryption before switching to kernel page-tableJoerg Roedel2020-10-292-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When SEV is enabled, the kernel requests the C-bit position again from the hypervisor to build its own page-table. Since the hypervisor is an untrusted source, the C-bit position needs to be verified before the kernel page-table is used. Call sev_verify_cbit() before writing the CR3. [ bp: Massage. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-5-joro@8bytes.org
| * | | x86/boot/compressed/64: Check SEV encryption in 64-bit boot-pathJoerg Roedel2020-10-294-0/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check whether the hypervisor reported the correct C-bit when running as an SEV guest. Using a wrong C-bit position could be used to leak sensitive data from the guest to the hypervisor. The check function is in a separate file: arch/x86/kernel/sev_verify_cbit.S so that it can be re-used in the running kernel image. [ bp: Massage. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-4-joro@8bytes.org
| * | | x86/boot/compressed/64: Sanity-check CPUID results in the early #VC handlerJoerg Roedel2020-10-291-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The early #VC handler which doesn't have a GHCB can only handle CPUID exit codes. It is needed by the early boot code to handle #VC exceptions raised in verify_cpu() and to get the position of the C-bit. But the CPUID information comes from the hypervisor which is untrusted and might return results which trick the guest into the no-SEV boot path with no C-bit set in the page-tables. All data written to memory would then be unencrypted and could leak sensitive data to the hypervisor. Add sanity checks to the early #VC handler to make sure the hypervisor can not pretend that SEV is disabled. [ bp: Massage a bit. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-3-joro@8bytes.org
| * | | x86/boot/compressed/64: Introduce sev_statusJoerg Roedel2020-10-291-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce sev_status and initialize it together with sme_me_mask to have an indicator which SEV features are enabled. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-2-joro@8bytes.org
* | | | Merge tag 'x86-urgent-2020-11-01' of ↵Linus Torvalds2020-11-011-13/+30
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Three fixes all related to #DB: - Handle the BTF bit correctly so it doesn't get lost due to a kernel #DB - Only clear and set the virtual DR6 value used by ptrace on user space triggered #DB. A kernel #DB must leave it alone to ensure data consistency for ptrace. - Make the bitmasking of the virtual DR6 storage correct so it does not lose DR_STEP" * tag 'x86-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/debug: Fix DR_STEP vs ptrace_get_debugreg(6) x86/debug: Only clear/set ->virtual_dr6 for userspace #DB x86/debug: Fix BTF handling
| * | | | x86/debug: Fix DR_STEP vs ptrace_get_debugreg(6)Peter Zijlstra2020-10-271-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") changed the semantics of the variable from random collection of bits, to exactly only those bits that ptrace() needs. Unfortunately this lost DR_STEP for PTRACE_{BLOCK,SINGLE}STEP. Furthermore, it turns out that userspace expects DR_STEP to be unconditionally available, even for manual TF usage outside of PTRACE_{BLOCK,SINGLE}_STEP. Fixes: d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") Reported-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/20201027183330.GM2628@hirez.programming.kicks-ass.net
| * | | | x86/debug: Only clear/set ->virtual_dr6 for userspace #DBPeter Zijlstra2020-10-271-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ->virtual_dr6 is the value used by ptrace_{get,set}_debugreg(6). A kernel #DB clearing it could mean spurious malfunction of ptrace() expectations. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/20201027093608.028952500@infradead.org
| * | | | x86/debug: Fix BTF handlingPeter Zijlstra2020-10-271-7/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The SDM states that #DB clears DEBUGCTLMSR_BTF, this means that when the bit is set for userspace (TIF_BLOCKSTEP) and a kernel #DB happens first, the BTF bit meant for userspace execution is lost. Have the kernel #DB handler restore the BTF bit when it was requested for userspace. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/20201027093607.956147736@infradead.org
* | | | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2020-11-018-32/+31
|\ \ \ \ \ | |/ / / / |/| | | / | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm fixes from Paolo Bonzini: "ARM: - selftest fix - force PTE mapping on device pages provided via VFIO - fix detection of cacheable mapping at S2 - fallback to PMD/PTE mappings for composite huge pages - fix accounting of Stage-2 PGD allocation - fix AArch32 handling of some of the debug registers - simplify host HYP entry - fix stray pointer conversion on nVHE TLB invalidation - fix initialization of the nVHE code - simplify handling of capabilities exposed to HYP - nuke VCPUs caught using a forbidden AArch32 EL0 x86: - new nested virtualization selftest - miscellaneous fixes - make W=1 fixes - reserve new CPUID bit in the KVM leaves" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: vmx: remove unused variable KVM: selftests: Don't require THP to run tests KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work again KVM: selftests: test behavior of unmapped L2 APIC-access address KVM: x86: Fix NULL dereference at kvm_msr_ignored_check() KVM: x86: replace static const variables with macros KVM: arm64: Handle Asymmetric AArch32 systems arm64: cpufeature: upgrade hyp caps to final arm64: cpufeature: reorder cpus_have_{const, final}_cap() KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code() KVM: arm64: Force PTE mapping on fault resulting in a device mapping KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes KVM: arm64: Fix masks in stage2_pte_cacheable() KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR KVM: arm64: Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation KVM: arm64: Don't corrupt tpidr_el2 on failed HVC call x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_ID
| * | | KVM: vmx: remove unused variablePaolo Bonzini2020-10-311-2/+0
| | | | | | | | | | | | | | | | | | | | Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work againVitaly Kuznetsov2020-10-313-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was noticed that evmcs_sanitize_exec_ctrls() is not being executed nowadays despite the code checking 'enable_evmcs' static key looking correct. Turns out, static key magic doesn't work in '__init' section (and it is unclear when things changed) but setup_vmcs_config() is called only once per CPU so we don't really need it to. Switch to checking 'enlightened_vmcs' instead, it is supposed to be in sync with 'enable_evmcs'. Opportunistically make evmcs_sanitize_exec_ctrls '__init' and drop unneeded extra newline from it. Reported-by: Yang Weijiang <weijiang.yang@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20201014143346.2430936-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: x86: Fix NULL dereference at kvm_msr_ignored_check()Takashi Iwai2020-10-301-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The newly introduced kvm_msr_ignored_check() tries to print error or debug messages via vcpu_*() macros, but those may cause Oops when NULL vcpu is passed for KVM_GET_MSRS ioctl. Fix it by replacing the print calls with kvm_*() macros. (Note that this will leave vcpu argument completely unused in the function, but I didn't touch it to make the fix as small as possible. A clean up may be applied later.) Fixes: 12bc2132b15e ("KVM: X86: Do the same ignore_msrs check for feature msrs") BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1178280 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Message-Id: <20201030151414.20165-1-tiwai@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: x86: replace static const variables with macrosPaolo Bonzini2020-10-303-21/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Even though the compiler is able to replace static const variables with their value, it will warn about them being unused when Linux is built with W=1. Use good old macros instead, this is not C++. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_IDDavid Woodhouse2020-10-281-0/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No functional change; just reserve the feature bit for now so that VMMs can start to implement it. This will allow the host to indicate that MSI emulation supports 15-bit destination IDs, allowing up to 32768 CPUs without interrupt remapping. cf. https://patchwork.kernel.org/patch/11816693/ for qemu Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <4cd59bed05f4b7410d3d1ffd1e997ab53683874d.camel@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | Merge tag 'x86-urgent-2020-10-27' of ↵Linus Torvalds2020-10-274-14/+17
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A couple of x86 fixes which missed rc1 due to my stupidity: - Drop lazy TLB mode before switching to the temporary address space for text patching. text_poke() switches to the temporary mm which clears the lazy mode and restores the original mm afterwards. Due to clearing lazy mode this might restore a already dead mm if exit_mmap() runs in parallel on another CPU. - Document the x32 syscall design fail vs. syscall numbers 512-547 properly. - Fix the ORC unwinder to handle the inactive task frame correctly. This was unearthed due to the slightly different code generation of gcc-10. - Use an up to date screen_info for the boot params of kexec instead of the possibly stale and invalid version which happened to be valid when the kexec kernel was loaded" * tag 'x86-urgent-2020-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternative: Don't call text_poke() in lazy TLB mode x86/syscalls: Document the fact that syscalls 512-547 are a legacy mistake x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels hyperv_fb: Update screen_info after removing old framebuffer x86/kexec: Use up-to-dated screen_info copy to fill boot params
| * | | x86/alternative: Don't call text_poke() in lazy TLB modeJuergen Gross2020-10-221-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running in lazy TLB mode the currently active page tables might be the ones of a previous process, e.g. when running a kernel thread. This can be problematic in case kernel code is being modified via text_poke() in a kernel thread, and on another processor exit_mmap() is active for the process which was running on the first cpu before the kernel thread. As text_poke() is using a temporary address space and the former address space (obtained via cpu_tlbstate.loaded_mm) is restored afterwards, there is a race possible in case the cpu on which exit_mmap() is running wants to make sure there are no stale references to that address space on any cpu active (this e.g. is required when running as a Xen PV guest, where this problem has been observed and analyzed). In order to avoid that, drop off TLB lazy mode before switching to the temporary address space. Fixes: cefa929c034eb5d ("x86/mm: Introduce temporary mm structs") Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201009144225.12019-1-jgross@suse.com
| * | | x86/syscalls: Document the fact that syscalls 512-547 are a legacy mistakeAndy Lutomirski2020-10-141-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since this commit: 6365b842aae4 ("x86/syscalls: Split the x32 syscalls into their own table") there is no need for special x32-specific syscall numbers. I forgot to update the comments in syscall_64.tbl. Add comments to make it clear to future contributors that this range is a legacy wart. Reported-by: Jessica Clarke <jrtc27@jrtc27.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/6c56fb4ddd18fc60a238eb4d867e4b3d97c6351e.1602471055.git.luto@kernel.org
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-12 22:35:12 +0000