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2017-06-30Merge tag 'kvmarm-for-4.13' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM updates for 4.13 - vcpu request overhaul - allow timer and PMU to have their interrupt number selected from userspace - workaround for Cavium erratum 30115 - handling of memory poisonning - the usual crop of fixes and cleanups Conflicts: arch/s390/include/asm/kvm_host.h
2017-06-30objtool, x86: Add several functions and files to the objtool whitelistJosh Poimboeuf
In preparation for an objtool rewrite which will have broader checks, whitelist functions and files which cause problems because they do unusual things with the stack. These whitelists serve as a TODO list for which functions and files don't yet have undwarf unwinder coverage. Eventually most of the whitelists can be removed in favor of manual CFI hint annotations or objtool improvements. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/7f934a5d707a574bda33ea282e9478e627fb1829.1498659915.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-29KVM: LAPIC: Fix lapic timer injection delayWanpeng Li
If the TSC deadline timer is programmed really close to the deadline or even in the past, the computation in vmx_set_hv_timer will program the absolute target tsc value to vmcs preemption timer field w/ delta == 0, then plays a vmentry and an upcoming vmx preemption timer fire vmexit dance, the lapic timer injection is delayed due to this duration. Actually the lapic timer which is emulated by hrtimer can handle this correctly. This patch fixes it by firing the lapic timer and injecting a timer interrupt immediately during the next vmentry if the TSC deadline timer is programmed really close to the deadline or even in the past. This saves ~300 cycles on the tsc_deadline_timer test of apic.flat. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-29KVM: lapic: reorganize restart_apic_timerPaolo Bonzini
Move the code to cancel the hv timer into the caller, just before it starts the hrtimer. Check availability of the hv timer in start_hv_timer. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-29KVM: lapic: reorganize start_hv_timerPaolo Bonzini
There are many cases in which the hv timer must be canceled. Split out a new function to avoid duplication. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-28kvm: nVMX: Check memory operand to INVVPIDJim Mattson
The memory operand fetched for INVVPID is 128 bits. Bits 63:16 are reserved and must be zero. Otherwise, the instruction fails with VMfail(Invalid operand to INVEPT/INVVPID). If the INVVPID_TYPE is 0 (individual address invalidation), then bits 127:64 must be in canonical form, or the instruction fails with VMfail(Invalid operand to INVEPT/INVVPID). Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-27KVM: SVM: suppress unnecessary NMI singlestep on GIF=0 and nested exitLadi Prosek
enable_nmi_window is supposed to be a no-op if we know that we'll see a VM exit by the time the NMI window opens. This commit adds two more cases: * We intercept stgi so we don't need to singlestep on GIF=0. * We emulate nested vmexit so we don't need to singlestep when nested VM exit is required. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-27KVM: SVM: don't NMI singlestep over event injectionLadi Prosek
Singlestepping is enabled by setting the TF flag and care must be taken to not let the guest see (and reuse at an inconvenient time) the modified rflag value. One such case is event injection, as part of which flags are pushed on the stack and restored later on iret. This commit disables singlestepping when we're about to inject an event and forces an immediate exit for us to re-evaluate the NMI related state. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-27KVM: SVM: hide TF/RF flags used by NMI singlestepLadi Prosek
These flags are used internally by SVM so it's cleaner to not leak them to callers of svm_get_rflags. This is similar to how the TF flag is handled on KVM_GUESTDBG_SINGLESTEP by kvm_get_rflags and kvm_set_rflags. Without this change, the flags may propagate from host VMCB to nested VMCB or vice versa while singlestepping over a nested VM enter/exit, and then get stuck in inappropriate places. Example: NMI singlestepping is enabled while running L1 guest. The instruction to step over is VMRUN and nested vmrun emulation stashes rflags to hsave->save.rflags. Then if singlestepping is disabled while still in L2, TF/RF will be cleared from the nested VMCB but the next nested VM exit will restore them from hsave->save.rflags and cause an unexpected DB exception. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-27KVM: nSVM: do not forward NMI window singlestep VM exits to L1Ladi Prosek
Nested hypervisor should not see singlestep VM exits if singlestepping was enabled internally by KVM. Windows is particularly sensitive to this and known to bluescreen on unexpected VM exits. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-27KVM: SVM: introduce disable_nmi_singlestep helperLadi Prosek
Just moving the code to a new helper in preparation for following commits. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-22KVM: x86: fix singlestepping over syscallPaolo Bonzini
TF is handled a bit differently for syscall and sysret, compared to the other instructions: TF is checked after the instruction completes, so that the OS can disable #DB at a syscall by adding TF to FMASK. When the sysret is executed the #DB is taken "as if" the syscall insn just completed. KVM emulates syscall so that it can trap 32-bit syscall on Intel processors. Fix the behavior, otherwise you could get #DB on a user stack which is not nice. This does not affect Linux guests, as they use an IST or task gate for #DB. This fixes CVE-2017-7518. Cc: stable@vger.kernel.org Reported-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-22Merge branch 'linus' into x86/mm, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3()Andy Lutomirski
The kernel has several code paths that read CR3. Most of them assume that CR3 contains the PGD's physical address, whereas some of them awkwardly use PHYSICAL_PAGE_MASK to mask off low bits. Add explicit mask macros for CR3 and convert all of the CR3 readers. This will keep them from breaking when PCID is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-11KVM: async_pf: avoid async pf injection when in guest modeWanpeng Li
INFO: task gnome-terminal-:1734 blocked for more than 120 seconds. Not tainted 4.12.0-rc4+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. gnome-terminal- D 0 1734 1015 0x00000000 Call Trace: __schedule+0x3cd/0xb30 schedule+0x40/0x90 kvm_async_pf_task_wait+0x1cc/0x270 ? __vfs_read+0x37/0x150 ? prepare_to_swait+0x22/0x70 do_async_page_fault+0x77/0xb0 ? do_async_page_fault+0x77/0xb0 async_page_fault+0x28/0x30 This is triggered by running both win7 and win2016 on L1 KVM simultaneously, and then gives stress to memory on L1, I can observed this hang on L1 when at least ~70% swap area is occupied on L0. This is due to async pf was injected to L2 which should be injected to L1, L2 guest starts receiving pagefault w/ bogus %cr2(apf token from the host actually), and L1 guest starts accumulating tasks stuck in D state in kvm_async_pf_task_wait() since missing PAGE_READY async_pfs. This patch fixes the hang by doing async pf when executing L1 guest. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-08KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulationWanpeng Li
If "i" is the last element in the vcpu->arch.cpuid_entries[] array, it potentially can be exploited the vulnerability. this will out-of-bounds read and write. Luckily, the effect is small: /* when no next entry is found, the current entry[i] is reselected */ for (j = i + 1; ; j = (j + 1) % nent) { struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; if (ej->function == e->function) { It reads ej->maxphyaddr, which is user controlled. However... ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; After cpuid_entries there is int maxphyaddr; struct x86_emulate_ctxt emulate_ctxt; /* 16-byte aligned */ So we have: - cpuid_entries at offset 1B50 (6992) - maxphyaddr at offset 27D0 (6992 + 3200 = 10192) - padding at 27D4...27DF - emulate_ctxt at 27E0 And it writes in the padding. Pfew, writing the ops field of emulate_ctxt would have been much worse. This patch fixes it by modding the index to avoid the out-of-bounds access. Worst case, i == j and ej->function == e->function, the loop can bail out. Reported-by: Moguofang <moguofang@huawei.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Guofang Mo <moguofang@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-07KVM: nVMX: Update vmcs12->guest_linear_address on nested VM-exitJim Mattson
The guest-linear address field is set for VM exits due to attempts to execute LMSW with a memory operand and VM exits due to attempts to execute INS or OUTS for which the relevant segment is usable, regardless of whether or not EPT is in use. Fixes: 119a9c01a5922 ("KVM: nVMX: pass valid guest linear-address to the L1") Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-07KVM: nVMX: Don't update vmcs12->xss_exit_bitmap on nested VM-exitJim Mattson
The XSS-exiting bitmap is a VMCS control field that does not change while the CPU is in non-root mode. Transferring the unchanged value from vmcs02 to vmcs12 is unnecessary. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-07kvm: vmx: Check value written to IA32_BNDCFGSJim Mattson
Bits 11:2 must be zero and the linear addess in bits 63:12 must be canonical. Otherwise, WRMSR(BNDCFGS) should raise #GP. Fixes: 0dd376e709975779 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save") Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-07kvm: x86: Guest BNDCFGS requires guest MPX supportJim Mattson
The BNDCFGS MSR should only be exposed to the guest if the guest supports MPX. (cf. the TSC_AUX MSR and RDTSCP.) Fixes: 0dd376e709975779 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save") Change-Id: I3ad7c01bda616715137ceac878f3fa7e66b6b387 Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-07kvm: vmx: Do not disable intercepts for BNDCFGSJim Mattson
The MSR permission bitmaps are shared by all VMs. However, some VMs may not be configured to support MPX, even when the host does. If the host supports VMX and the guest does not, we should intercept accesses to the BNDCFGS MSR, so that we can synthesize a #GP fault. Furthermore, if the host does not support MPX and the "ignore_msrs" kvm kernel parameter is set, then we should intercept accesses to the BNDCFGS MSR, so that we can skip over the rdmsr/wrmsr without raising a #GP fault. Fixes: da8999d31818fdc8 ("KVM: x86: Intel MPX vmx and msr handle") Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-06KVM: nVMX: Fix exception injectionWanpeng Li
WARNING: CPU: 3 PID: 2840 at arch/x86/kvm/vmx.c:10966 nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel] CPU: 3 PID: 2840 Comm: qemu-system-x86 Tainted: G OE 4.12.0-rc3+ #23 RIP: 0010:nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel] Call Trace: ? kvm_check_async_pf_completion+0xef/0x120 [kvm] ? rcu_read_lock_sched_held+0x79/0x80 vmx_queue_exception+0x104/0x160 [kvm_intel] ? vmx_queue_exception+0x104/0x160 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x1171/0x1ce0 [kvm] ? kvm_arch_vcpu_load+0x47/0x240 [kvm] ? kvm_arch_vcpu_load+0x62/0x240 [kvm] kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? __fget+0xf3/0x210 do_vfs_ioctl+0xa4/0x700 ? __fget+0x114/0x210 SyS_ioctl+0x79/0x90 do_syscall_64+0x81/0x220 entry_SYSCALL64_slow_path+0x25/0x25 This is triggered occasionally by running both win7 and win2016 in L2, in addition, EPT is disabled on both L1 and L2. It can't be reproduced easily. Commit 0b6ac343fc (KVM: nVMX: Correct handling of exception injection) mentioned that "KVM wants to inject page-faults which it got to the guest. This function assumes it is called with the exit reason in vmcs02 being a #PF exception". Commit e011c663 (KVM: nVMX: Check all exceptions for intercept during delivery to L2) allows to check all exceptions for intercept during delivery to L2. However, there is no guarantee the exit reason is exception currently, when there is an external interrupt occurred on host, maybe a time interrupt for host which should not be injected to guest, and somewhere queues an exception, then the function nested_vmx_check_exception() will be called and the vmexit emulation codes will try to emulate the "Acknowledge interrupt on exit" behavior, the warning is triggered. Reusing the exit reason from the L2->L0 vmexit is wrong in this case, the reason must always be EXCEPTION_NMI when injecting an exception into L1 as a nested vmexit. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Fixes: e011c663b9c7 ("KVM: nVMX: Check all exceptions for intercept during delivery to L2") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-05x86/mm, KVM: Teach KVM's VMX code that CR3 isn't a constantAndy Lutomirski
When PCID is enabled, CR3's PCID bits can change during context switches, so KVM won't be able to treat CR3 as a per-mm constant any more. I structured this like the existing CR4 handling. Under ordinary circumstances (PCID disabled or if the current PCID and the value that's already in the VMCS match), then we won't do an extra VMCS write, and we'll never do an extra direct CR3 read. The overhead should be minimal. I disallowed using the new helper in non-atomic context because PCID support will cause CR3 to stop being constant in non-atomic process context. (Frankly, it also scares me a bit that KVM ever treated CR3 as constant, but it looks like it was okay before.) Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-04KVM: add kvm_request_pendingRadim Krčmář
A first step in vcpu->requests encapsulation. Additionally, we now use READ_ONCE() when accessing vcpu->requests, which ensures we always load vcpu->requests when it's accessed. This is important as other threads can change it any time. Also, READ_ONCE() documents that vcpu->requests is used with other threads, likely requiring memory barriers, which it does. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [ Documented the new use of READ_ONCE() and converted another check in arch/mips/kvm/vz.c ] Signed-off-by: Andrew Jones <drjones@redhat.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-01KVM: x86: avoid large stack allocations in em_fxrstorNick Desaulniers
em_fxstor previously called fxstor_fixup. Both created instances of struct fxregs_state on the stack, which triggered the warning: arch/x86/kvm/emulate.c:4018:12: warning: stack frame size of 1080 bytes in function 'em_fxrstor' [-Wframe-larger-than=] static int em_fxrstor(struct x86_emulate_ctxt *ctxt) ^ with CONFIG_FRAME_WARN set to 1024. This patch does the fixup in em_fxstor now, avoiding one additional struct fxregs_state, and now fxstor_fixup can be removed as it has no other call sites. Further, the calculation for offsets into xmm_space can be shared between em_fxstor and em_fxsave. Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com> [Clean up calculation of offsets and fix it for 64-bit mode. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-01KVM: white space cleanup in nested_vmx_setup_ctls_msrs()Dan Carpenter
This should have been indented one more character over and it should use tabs. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-01KVM: Tidy the whitespace in nested_svm_check_permissions()Dan Carpenter
I moved the || to the line before. Also I replaced some spaces with a tab on the "return 0;" line. It looks OK in the diff but originally that line was only indented 7 spaces. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-06-01KVM: x86: Fix nmi injection failure when vcpu got blockedZhuangYanying
When spin_lock_irqsave() deadlock occurs inside the guest, vcpu threads, other than the lock-holding one, would enter into S state because of pvspinlock. Then inject NMI via libvirt API "inject-nmi", the NMI could not be injected into vm. The reason is: 1 It sets nmi_queued to 1 when calling ioctl KVM_NMI in qemu, and sets cpu->kvm_vcpu_dirty to true in do_inject_external_nmi() meanwhile. 2 It sets nmi_queued to 0 in process_nmi(), before entering guest, because cpu->kvm_vcpu_dirty is true. It's not enough just to check nmi_queued to decide whether to stay in vcpu_block() or not. NMI should be injected immediately at any situation. Add checking nmi_pending, and testing KVM_REQ_NMI replaces nmi_queued in vm_vcpu_has_events(). Do the same change for SMIs. Signed-off-by: Zhuang Yanying <ann.zhuangyanying@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-01KVM: SVM: do not zero out segment attributes if segment is unusable or not ↵Roman Pen
present This is a fix for the problem [1], where VMCB.CPL was set to 0 and interrupt was taken on userspace stack. The root cause lies in the specific AMD CPU behaviour which manifests itself as unusable segment attributes on SYSRET. The corresponding work around for the kernel is the following: 61f01dd941ba ("x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue") In other turn virtualization side treated unusable segment incorrectly and restored CPL from SS attributes, which were zeroed out few lines above. In current patch it is assured only that P bit is cleared in VMCB.save state and segment attributes are not zeroed out if segment is not presented or is unusable, therefore CPL can be safely restored from DPL field. This is only one part of the fix, since QEMU side should be fixed accordingly not to zero out attributes on its side. Corresponding patch will follow. [1] Message id: CAJrWOzD6Xq==b-zYCDdFLgSRMPM-NkNuTSDFEtX=7MreT45i7Q@mail.gmail.com Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com> Signed-off-by: Mikhail Sennikovskii <mikhail.sennikovskii@profitbricks.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-30KVM: SVM: ignore type when setting segment registersGioh Kim
Commit 19bca6ab75d8 ("KVM: SVM: Fix cross vendor migration issue with unusable bit") added checking type when setting unusable. So unusable can be set if present is 0 OR type is 0. According to the AMD processor manual, long mode ignores the type value in segment descriptor. And type can be 0 if it is read-only data segment. Therefore type value is not related to unusable flag. This patch is based on linux-next v4.12.0-rc3. Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-30KVM: nVMX: fix nested_vmx_check_vmptr failure paths under debuggingRadim Krčmář
kvm_skip_emulated_instruction() will return 0 if userspace is single-stepping the guest. kvm_skip_emulated_instruction() uses return status convention of exit handler: 0 means "exit to userspace" and 1 means "continue vm entries". The problem is that nested_vmx_check_vmptr() return status means something else: 0 is ok, 1 is error. This means we would continue executing after a failure. Static checker noticed it because vmptr was not initialized. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 6affcbedcac7 ("KVM: x86: Add kvm_skip_emulated_instruction and use it.") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-26KVM: x86: Fix virtual wire modeJan H. Schönherr
Intel SDM says, that at most one LAPIC should be configured with ExtINT delivery. KVM configures all LAPICs this way. This causes pic_unlock() to kick the first available vCPU from the internal KVM data structures. If this vCPU is not the BSP, but some not-yet-booted AP, the BSP may never realize that there is an interrupt. Fix that by enabling ExtINT delivery only for the BSP. This allows booting a Linux guest without a TSC in the above situation. Otherwise the BSP gets stuck in calibrate_delay_converge(). Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-26KVM: nVMX: Fix handling of lmsw instructionJan H. Schönherr
The decision whether or not to exit from L2 to L1 on an lmsw instruction is based on bogus values: instead of using the information encoded within the exit qualification, it uses the data also used for the mov-to-cr instruction, which boils down to using whatever is in %eax at that point. Use the correct values instead. Without this fix, an L1 may not get notified when a 32-bit Linux L2 switches its secondary CPUs to protected mode; the L1 is only notified on the next modification of CR0. This short time window poses a problem, when there is some other reason to exit to L1 in between. Then, L2 will be resumed in real mode and chaos ensues. Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-26KVM: X86: Fix preempt the preemption timer cancelWanpeng Li
Preemption can occur during cancel preemption timer, and there will be inconsistent status in lapic, vmx and vmcs field. CPU0 CPU1 preemption timer vmexit handle_preemption_timer(vCPU0) kvm_lapic_expired_hv_timer vmx_cancel_hv_timer vmx->hv_deadline_tsc = -1 vmcs_clear_bits /* hv_timer_in_use still true */ sched_out sched_in kvm_arch_vcpu_load vmx_set_hv_timer write vmx->hv_deadline_tsc vmcs_set_bits /* back in kvm_lapic_expired_hv_timer */ hv_timer_in_use = false ... vmx_vcpu_run vmx_arm_hv_run write preemption timer deadline spurious preemption timer vmexit handle_preemption_timer(vCPU0) kvm_lapic_expired_hv_timer WARN_ON(!apic->lapic_timer.hv_timer_in_use); This can be reproduced sporadically during boot of L2 on a preemptible L1, causing a splat on L1. WARNING: CPU: 3 PID: 1952 at arch/x86/kvm/lapic.c:1529 kvm_lapic_expired_hv_timer+0xb5/0xd0 [kvm] CPU: 3 PID: 1952 Comm: qemu-system-x86 Not tainted 4.12.0-rc1+ #24 RIP: 0010:kvm_lapic_expired_hv_timer+0xb5/0xd0 [kvm] Call Trace: handle_preemption_timer+0xe/0x20 [kvm_intel] vmx_handle_exit+0xc9/0x15f0 [kvm_intel] ? lock_acquire+0xdb/0x250 ? lock_acquire+0xdb/0x250 ? kvm_arch_vcpu_ioctl_run+0xdf3/0x1ce0 [kvm] kvm_arch_vcpu_ioctl_run+0xe55/0x1ce0 [kvm] kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? __fget+0xf3/0x210 do_vfs_ioctl+0xa4/0x700 ? __fget+0x114/0x210 SyS_ioctl+0x79/0x90 do_syscall_64+0x8f/0x750 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL64_slow_path+0x25/0x25 This patch fixes it by disabling preemption while cancelling preemption timer. This way cancel_hv_timer is atomic with respect to kvm_arch_vcpu_load. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-19KVM: x86: prevent uninitialized variable warning in check_svme()Radim Krčmář
get_msr() of MSR_EFER is currently always going to succeed, but static checker doesn't see that far. Don't complicate stuff and just use 0 for the fallback -- it means that the feature is not present. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-19KVM: x86/vPMU: fix undefined shift in intel_pmu_refresh()Radim Krčmář
Static analysis noticed that pmu->nr_arch_gp_counters can be 32 (INTEL_PMC_MAX_GENERIC) and therefore cannot be used to shift 'int'. I didn't add BUILD_BUG_ON for it as we have a better checker. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 25462f7f5295 ("KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch") Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-19KVM: x86: zero base3 of unusable segmentsRadim Krčmář
Static checker noticed that base3 could be used uninitialized if the segment was not present (useable). Random stack values probably would not pass VMCS entry checks. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 1aa366163b8b ("KVM: x86 emulator: consolidate segment accessors") Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-19KVM: X86: Fix read out-of-bounds vulnerability in kvm pio emulationWanpeng Li
Huawei folks reported a read out-of-bounds vulnerability in kvm pio emulation. - "inb" instruction to access PIT Mod/Command register (ioport 0x43, write only, a read should be ignored) in guest can get a random number. - "rep insb" instruction to access PIT register port 0x43 can control memcpy() in emulator_pio_in_emulated() to copy max 0x400 bytes but only read 1 bytes, which will disclose the unimportant kernel memory in host but no crash. The similar test program below can reproduce the read out-of-bounds vulnerability: void hexdump(void *mem, unsigned int len) { unsigned int i, j; for(i = 0; i < len + ((len % HEXDUMP_COLS) ? (HEXDUMP_COLS - len % HEXDUMP_COLS) : 0); i++) { /* print offset */ if(i % HEXDUMP_COLS == 0) { printf("0x%06x: ", i); } /* print hex data */ if(i < len) { printf("%02x ", 0xFF & ((char*)mem)[i]); } else /* end of block, just aligning for ASCII dump */ { printf(" "); } /* print ASCII dump */ if(i % HEXDUMP_COLS == (HEXDUMP_COLS - 1)) { for(j = i - (HEXDUMP_COLS - 1); j <= i; j++) { if(j >= len) /* end of block, not really printing */ { putchar(' '); } else if(isprint(((char*)mem)[j])) /* printable char */ { putchar(0xFF & ((char*)mem)[j]); } else /* other char */ { putchar('.'); } } putchar('\n'); } } } int main(void) { int i; if (iopl(3)) { err(1, "set iopl unsuccessfully\n"); return -1; } static char buf[0x40]; /* test ioport 0x40,0x41,0x42,0x43,0x44,0x45 */ memset(buf, 0xab, sizeof(buf)); asm volatile("push %rdi;"); asm volatile("mov %0, %%rdi;"::"q"(buf)); asm volatile ("mov $0x40, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x41, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x42, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x43, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x44, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x45, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("pop %rdi;"); hexdump(buf, 0x40); printf("\n"); /* ins port 0x40 */ memset(buf, 0xab, sizeof(buf)); asm volatile("push %rdi;"); asm volatile("mov %0, %%rdi;"::"q"(buf)); asm volatile ("mov $0x20, %rcx;"); asm volatile ("mov $0x40, %rdx;"); asm volatile ("rep insb;"); asm volatile ("pop %rdi;"); hexdump(buf, 0x40); printf("\n"); /* ins port 0x43 */ memset(buf, 0xab, sizeof(buf)); asm volatile("push %rdi;"); asm volatile("mov %0, %%rdi;"::"q"(buf)); asm volatile ("mov $0x20, %rcx;"); asm volatile ("mov $0x43, %rdx;"); asm volatile ("rep insb;"); asm volatile ("pop %rdi;"); hexdump(buf, 0x40); printf("\n"); return 0; } The vcpu->arch.pio_data buffer is used by both in/out instrutions emulation w/o clear after using which results in some random datas are left over in the buffer. Guest reads port 0x43 will be ignored since it is write only, however, the function kernel_pio() can't distigush this ignore from successfully reads data from device's ioport. There is no new data fill the buffer from port 0x43, however, emulator_pio_in_emulated() will copy the stale data in the buffer to the guest unconditionally. This patch fixes it by clearing the buffer before in instruction emulation to avoid to grant guest the stale data in the buffer. In addition, string I/O is not supported for in kernel device. So there is no iteration to read ioport %RCX times for string I/O. The function kernel_pio() just reads one round, and then copy the io size * %RCX to the guest unconditionally, actually it copies the one round ioport data w/ other random datas which are left over in the vcpu->arch.pio_data buffer to the guest. This patch fixes it by introducing the string I/O support for in kernel device in order to grant the right ioport datas to the guest. Before the patch: 0x000000: fe 38 93 93 ff ff ab ab .8...... 0x000008: ab ab ab ab ab ab ab ab ........ 0x000010: ab ab ab ab ab ab ab ab ........ 0x000018: ab ab ab ab ab ab ab ab ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: f6 00 00 00 00 00 00 00 ........ 0x000008: 00 00 00 00 00 00 00 00 ........ 0x000010: 00 00 00 00 4d 51 30 30 ....MQ00 0x000018: 30 30 20 33 20 20 20 20 00 3 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: f6 00 00 00 00 00 00 00 ........ 0x000008: 00 00 00 00 00 00 00 00 ........ 0x000010: 00 00 00 00 4d 51 30 30 ....MQ00 0x000018: 30 30 20 33 20 20 20 20 00 3 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ After the patch: 0x000000: 1e 02 f8 00 ff ff ab ab ........ 0x000008: ab ab ab ab ab ab ab ab ........ 0x000010: ab ab ab ab ab ab ab ab ........ 0x000018: ab ab ab ab ab ab ab ab ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: d2 e2 d2 df d2 db d2 d7 ........ 0x000008: d2 d3 d2 cf d2 cb d2 c7 ........ 0x000010: d2 c4 d2 c0 d2 bc d2 b8 ........ 0x000018: d2 b4 d2 b0 d2 ac d2 a8 ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: 00 00 00 00 00 00 00 00 ........ 0x000008: 00 00 00 00 00 00 00 00 ........ 0x000010: 00 00 00 00 00 00 00 00 ........ 0x000018: 00 00 00 00 00 00 00 00 ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ Reported-by: Moguofang <moguofang@huawei.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Moguofang <moguofang@huawei.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-19KVM: x86: Fix potential preemption when get the current kvmclock timestampWanpeng Li
BUG: using __this_cpu_read() in preemptible [00000000] code: qemu-system-x86/2809 caller is __this_cpu_preempt_check+0x13/0x20 CPU: 2 PID: 2809 Comm: qemu-system-x86 Not tainted 4.11.0+ #13 Call Trace: dump_stack+0x99/0xce check_preemption_disabled+0xf5/0x100 __this_cpu_preempt_check+0x13/0x20 get_kvmclock_ns+0x6f/0x110 [kvm] get_time_ref_counter+0x5d/0x80 [kvm] kvm_hv_process_stimers+0x2a1/0x8a0 [kvm] ? kvm_hv_process_stimers+0x2a1/0x8a0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xac9/0x1ce0 [kvm] kvm_arch_vcpu_ioctl_run+0x5bf/0x1ce0 [kvm] kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? __fget+0xf3/0x210 do_vfs_ioctl+0xa4/0x700 ? __fget+0x114/0x210 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc2 RIP: 0033:0x7f9d164ed357 ? __this_cpu_preempt_check+0x13/0x20 This can be reproduced by run kvm-unit-tests/hyperv_stimer.flat w/ CONFIG_PREEMPT and CONFIG_DEBUG_PREEMPT enabled. Safe access to per-CPU data requires a couple of constraints, though: the thread working with the data cannot be preempted and it cannot be migrated while it manipulates per-CPU variables. If the thread is preempted, the thread that replaces it could try to work with the same variables; migration to another CPU could also cause confusion. However there is no preemption disable when reads host per-CPU tsc rate to calculate the current kvmclock timestamp. This patch fixes it by utilizing get_cpu/put_cpu pair to guarantee both __this_cpu_read() and rdtsc() are not preempted. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-18KVM: Silence underflow warning in avic_get_physical_id_entry()Dan Carpenter
Smatch complains that we check cap the upper bound of "index" but don't check for negatives. It's a false positive because "index" is never negative. But it's also simple enough to make it unsigned which makes the code easier to audit. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-15KVM: nVMX: fix EPT permissions as reported in exit qualificationPaolo Bonzini
This fixes the new ept_access_test_read_only and ept_access_test_read_write testcases from vmx.flat. The problem is that gpte_access moves bits around to switch from EPT bit order (XWR) to ACC_*_MASK bit order (RWX). This results in an incorrect exit qualification. To fix this, make pt_access and pte_access operate on raw PTE values (only with NX flipped to mean "can execute") and call gpte_access at the end of the walk. This lets us use pte_access to compute the exit qualification with XWR bit order. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@tencent.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-15KVM: VMX: Don't enable EPT A/D feature if EPT feature is disabledWanpeng Li
We can observe eptad kvm_intel module parameter is still Y even if ept is disabled which is weird. This patch will not enable EPT A/D feature if EPT feature is disabled. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-15KVM: x86: Fix load damaged SSEx MXCSR registerWanpeng Li
Reported by syzkaller: BUG: unable to handle kernel paging request at ffffffffc07f6a2e IP: report_bug+0x94/0x120 PGD 348e12067 P4D 348e12067 PUD 348e14067 PMD 3cbd84067 PTE 80000003f7e87161 Oops: 0003 [#1] SMP CPU: 2 PID: 7091 Comm: kvm_load_guest_ Tainted: G OE 4.11.0+ #8 task: ffff92fdfb525400 task.stack: ffffbda6c3d04000 RIP: 0010:report_bug+0x94/0x120 RSP: 0018:ffffbda6c3d07b20 EFLAGS: 00010202 do_trap+0x156/0x170 do_error_trap+0xa3/0x170 ? kvm_load_guest_fpu.part.175+0x12a/0x170 [kvm] ? mark_held_locks+0x79/0xa0 ? retint_kernel+0x10/0x10 ? trace_hardirqs_off_thunk+0x1a/0x1c do_invalid_op+0x20/0x30 invalid_op+0x1e/0x30 RIP: 0010:kvm_load_guest_fpu.part.175+0x12a/0x170 [kvm] ? kvm_load_guest_fpu.part.175+0x1c/0x170 [kvm] kvm_arch_vcpu_ioctl_run+0xed6/0x1b70 [kvm] kvm_vcpu_ioctl+0x384/0x780 [kvm] ? kvm_vcpu_ioctl+0x384/0x780 [kvm] ? sched_clock+0x13/0x20 ? __do_page_fault+0x2a0/0x550 do_vfs_ioctl+0xa4/0x700 ? up_read+0x1f/0x40 ? __do_page_fault+0x2a0/0x550 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc2 SDM mentioned that "The MXCSR has several reserved bits, and attempting to write a 1 to any of these bits will cause a general-protection exception(#GP) to be generated". The syzkaller forks' testcase overrides xsave area w/ random values and steps on the reserved bits of MXCSR register. The damaged MXCSR register values of guest will be restored to SSEx MXCSR register before vmentry. This patch fixes it by catching userspace override MXCSR register reserved bits w/ random values and bails out immediately. Reported-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-15kvm: nVMX: off by one in vmx_write_pml_buffer()Dan Carpenter
There are PML_ENTITY_NUM elements in the pml_address[] array so the > should be >= or we write beyond the end of the array when we do: pml_address[vmcs12->guest_pml_index--] = gpa; Fixes: c5f983f6e845 ("nVMX: Implement emulated Page Modification Logging") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-05-09nVMX: Advertise PML to L1 hypervisorBandan Das
Advertise the PML bit in vmcs12 but don't try to enable it in hardware when running L2 since L0 is emulating it. Also, preserve L0's settings for PML since it may still want to log writes. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-09nVMX: Implement emulated Page Modification LoggingBandan Das
With EPT A/D enabled, processor access to L2 guest paging structures will result in a write violation. When this happens, write the GUEST_PHYSICAL_ADDRESS to the pml buffer provided by L1 if the access is write and the dirty bit is being set. This patch also adds necessary checks during VMEntry if L1 has enabled PML. If the PML index overflows, we change the exit reason and run L1 to simulate a PML full event. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-09kvm: x86: Add a hook for arch specific dirty logging emulationBandan Das
When KVM updates accessed/dirty bits, this hook can be used to invoke an arch specific function that implements/emulates dirty logging such as PML. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-09kvm: nVMX: Validate CR3 target count on nested VM-entryJim Mattson
According to the SDM, the CR3-target count must not be greater than 4. Future processors may support a different number of CR3-target values. Software should read the VMX capability MSR IA32_VMX_MISC to determine the number of values supported. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-08Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - the rest of MM - various misc things - procfs updates - lib/ updates - checkpatch updates - kdump/kexec updates - add kvmalloc helpers, use them - time helper updates for Y2038 issues. We're almost ready to remove current_fs_time() but that awaits a btrfs merge. - add tracepoints to DAX * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits) drivers/staging/ccree/ssi_hash.c: fix build with gcc-4.4.4 selftests/vm: add a test for virtual address range mapping dax: add tracepoint to dax_insert_mapping() dax: add tracepoint to dax_writeback_one() dax: add tracepoints to dax_writeback_mapping_range() dax: add tracepoints to dax_load_hole() dax: add tracepoints to dax_pfn_mkwrite() dax: add tracepoints to dax_iomap_pte_fault() mtd: nand: nandsim: convert to memalloc_noreclaim_*() treewide: convert PF_MEMALLOC manipulations to new helpers mm: introduce memalloc_noreclaim_{save,restore} mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC mm/huge_memory.c: deposit a pgtable for DAX PMD faults when required mm/huge_memory.c: use zap_deposited_table() more time: delete CURRENT_TIME_SEC and CURRENT_TIME gfs2: replace CURRENT_TIME with current_time apparmorfs: replace CURRENT_TIME with current_time() lustre: replace CURRENT_TIME macro fs: ubifs: replace CURRENT_TIME_SEC with current_time fs: ufs: use ktime_get_real_ts64() for birthtime ...
2017-05-08mm: introduce kv[mz]alloc helpersMichal Hocko
Patch series "kvmalloc", v5. There are many open coded kmalloc with vmalloc fallback instances in the tree. Most of them are not careful enough or simply do not care about the underlying semantic of the kmalloc/page allocator which means that a) some vmalloc fallbacks are basically unreachable because the kmalloc part will keep retrying until it succeeds b) the page allocator can invoke a really disruptive steps like the OOM killer to move forward which doesn't sound appropriate when we consider that the vmalloc fallback is available. As it can be seen implementing kvmalloc requires quite an intimate knowledge if the page allocator and the memory reclaim internals which strongly suggests that a helper should be implemented in the memory subsystem proper. Most callers, I could find, have been converted to use the helper instead. This is patch 6. There are some more relying on __GFP_REPEAT in the networking stack which I have converted as well and Eric Dumazet was not opposed [2] to convert them as well. [1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org [2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com This patch (of 9): Using kmalloc with the vmalloc fallback for larger allocations is a common pattern in the kernel code. Yet we do not have any common helper for that and so users have invented their own helpers. Some of them are really creative when doing so. Let's just add kv[mz]alloc and make sure it is implemented properly. This implementation makes sure to not make a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also to not warn about allocation failures. This also rules out the OOM killer as the vmalloc is a more approapriate fallback than a disruptive user visible action. This patch also changes some existing users and removes helpers which are specific for them. In some cases this is not possible (e.g. ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and require GFP_NO{FS,IO} context which is not vmalloc compatible in general (note that the page table allocation is GFP_KERNEL). Those need to be fixed separately. While we are at it, document that __vmalloc{_node} about unsupported gfp mask because there seems to be a lot of confusion out there. kvmalloc_node will warn about GFP_KERNEL incompatible (which are not superset) flags to catch new abusers. Existing ones would have to die slowly. [sfr@canb.auug.org.au: f2fs fixup] Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Andreas Dilger <adilger@dilger.ca> [ext4 part] Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: John Hubbard <jhubbard@nvidia.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>