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2019-04-10x86/fpu: Remove fpu->initializedSebastian Andrzej Siewior12-121/+53
The struct fpu.initialized member is always set to one for user tasks and zero for kernel tasks. This avoids saving/restoring the FPU registers for kernel threads. The ->initialized = 0 case for user tasks has been removed in previous changes, for instance, by doing an explicit unconditional init at fork() time for FPU-less systems which was otherwise delayed until the emulated opcode. The context switch code (switch_fpu_prepare() + switch_fpu_finish()) can't unconditionally save/restore registers for kernel threads. Not only would it slow down the switch but also load a zeroed xcomp_bv for XSAVES. For kernel_fpu_begin() (+end) the situation is similar: EFI with runtime services uses this before alternatives_patched is true. Which means that this function is used too early and it wasn't the case before. For those two cases, use current->mm to distinguish between user and kernel thread. For kernel_fpu_begin() skip save/restore of the FPU registers. During the context switch into a kernel thread don't do anything. There is no reason to save the FPU state of a kernel thread. The reordering in __switch_to() is important because the current() pointer needs to be valid before switch_fpu_finish() is invoked so ->mm is seen of the new task instead the old one. N.B.: fpu__save() doesn't need to check ->mm because it is called by user tasks only. [ bp: Massage. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Babu Moger <Babu.Moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dmitry Safonov <dima@arista.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: kvm ML <kvm@vger.kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-8-bigeasy@linutronix.de
2019-04-10x86/fpu: Don't save fxregs for ia32 frames in copy_fpstate_to_sigframe()Sebastian Andrzej Siewior1-4/+0
In commit 72a671ced66db ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels") the 32bit and 64bit path of the signal delivery code were merged. The 32bit version: int save_i387_xstate_ia32(void __user *buf) … if (cpu_has_xsave) return save_i387_xsave(fp); if (cpu_has_fxsr) return save_i387_fxsave(fp); The 64bit version: int save_i387_xstate(void __user *buf) … if (user_has_fpu()) { if (use_xsave()) err = xsave_user(buf); else err = fxsave_user(buf); if (unlikely(err)) { __clear_user(buf, xstate_size); return err; The merge: int save_xstate_sig(void __user *buf, void __user *buf_fx, int size) … if (user_has_fpu()) { /* Save the live register state to the user directly. */ if (save_user_xstate(buf_fx)) return -1; /* Update the thread's fxstate to save the fsave header. */ if (ia32_fxstate) fpu_fxsave(&tsk->thread.fpu); I don't think that we needed to save the FPU registers to ->thread.fpu because the registers were stored in buf_fx. Today the state will be restored from buf_fx after the signal was handled (I assume that this was also the case with lazy-FPU). Since commit 66463db4fc560 ("x86, fpu: shift drop_init_fpu() from save_xstate_sig() to handle_signal()") it is ensured that the signal handler starts with clear/fresh set of FPU registers which means that the previous store is futile. Remove the copy_fxregs_to_kernel() call because task's FPU state is cleared later in handle_signal() via fpu__clear(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-7-bigeasy@linutronix.de
2019-04-09x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe()Sebastian Andrzej Siewior1-27/+8
With lazy-FPU support the (now named variable) ->initialized was set to true if the CPU's FPU registers were holding a valid state of the FPU registers for the active process. If it was set to false then the FPU state was saved in fpu->state and the FPU was deactivated. With lazy-FPU gone, ->initialized is always true for user threads and kernel threads never call this function so ->initialized is always true in copy_fpstate_to_sigframe(). The using_compacted_format() check is also a leftover from the lazy-FPU time. In the ->initialized == false case copy_to_user() would copy the compacted buffer while userland would expect the non-compacted format instead. So in order to save the FPU state in the non-compacted form it issues XSAVE to save the *current* FPU state. If the FPU is not enabled, the attempt raises the FPU trap, the trap restores the FPU contents and re-enables the FPU and XSAVE is invoked again and succeeds. *This* does not longer work since commit bef8b6da9522 ("x86/fpu: Handle #NM without FPU emulation as an error") Remove the check for ->initialized because it is always true and remove the false condition. Update the comment to reflect that the state is always live. [ bp: Massage. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-6-bigeasy@linutronix.de
2019-04-09x86/fpu: Always init the state in fpu__clear()Sebastian Andrzej Siewior3-7/+2
fpu__clear() only initializes the state if the CPU has FPU support. This initialisation is also required for FPU-less systems and takes place in math_emulate(). Since fpu__initialize() only performs the initialization if ->initialized is zero it does not matter that it is invoked each time an opcode is emulated. It makes the removal of ->initialized easier if the struct is also initialized in the FPU-less case at the same time. Move fpu__initialize() before the FPU feature check so it is also performed in the FPU-less case too. [ bp: Massage a bit. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Bill Metzenthen <billm@melbpc.org.au> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-5-bigeasy@linutronix.de
2019-04-09x86/fpu: Remove preempt_disable() in fpu__clear()Sebastian Andrzej Siewior1-2/+0
The preempt_disable() section was introduced in commit a10b6a16cdad8 ("x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic") and it was said to be temporary. fpu__initialize() initializes the FPU struct to its initial value and then sets ->initialized to 1. The last part is the important one. The content of the state does not matter because it gets set via copy_init_fpstate_to_fpregs(). A preemption here has little meaning because the registers will always be set to the same content after copy_init_fpstate_to_fpregs(). A softirq with a kernel_fpu_begin() could also force to save FPU's registers after fpu__initialize() without changing the outcome here. Remove the preempt_disable() section in fpu__clear(), preemption here does not hurt. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-4-bigeasy@linutronix.de
2019-04-09x86/fpu: Remove fpu__restore()Sebastian Andrzej Siewior4-31/+2
There are no users of fpu__restore() so it is time to remove it. The comment regarding fpu__restore() and TS bit is stale since commit b3b0870ef3ffe ("i387: do not preload FPU state at task switch time") and has no meaning since. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Babu Moger <Babu.Moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dmitry Safonov <dima@arista.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: kvm ML <kvm@vger.kernel.org> Cc: linux-doc@vger.kernel.org Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-3-bigeasy@linutronix.de
2019-04-09x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig()Sebastian Andrzej Siewior3-29/+18
This is a preparation for the removal of the ->initialized member in the fpu struct. __fpu__restore_sig() is deactivating the FPU via fpu__drop() and then setting manually ->initialized followed by fpu__restore(). The result is that it is possible to manipulate fpu->state and the state of registers won't be saved/restored on a context switch which would overwrite fpu->state: fpu__drop(fpu): ... fpu->initialized = 0; preempt_enable(); <--- context switch Don't access the fpu->state while the content is read from user space and examined/sanitized. Use a temporary kmalloc() buffer for the preparation of the FPU registers and once the state is considered okay, load it. Should something go wrong, return with an error and without altering the original FPU registers. The removal of fpu__initialize() is a nop because fpu->initialized is already set for the user task. [ bp: Massage a bit. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-2-bigeasy@linutronix.de
2019-04-03x86/fpu: Fix __user annotationsJann Horn2-5/+5
In save_xstate_epilog(), use __user when type-casting userspace pointers. In setup_sigcontext() and x32_setup_rt_frame(), cast the userspace pointers to 'unsigned long __user *' before writing into them. These pointers are originally '__u32 __user *' or '__u64 __user *', causing sparse to complain when a userspace pointer is written into them. The casts are okay because the pointers always point to pointer-sized values. Thanks to Luc Van Oostenryck and Al Viro for explaining this to me. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mukesh Ojha <mojha@codeaurora.org> Cc: Qiaowei Ren <qiaowei.ren@intel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190329214652.258477-3-jannh@google.com
2019-03-31Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds9-55/+138
Pull KVM fixes from Paolo Bonzini: "A collection of x86 and ARM bugfixes, and some improvements to documentation. On top of this, a cleanup of kvm_para.h headers, which were exported by some architectures even though they not support KVM at all. This is responsible for all the Kbuild changes in the diffstat" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits) Documentation: kvm: clarify KVM_SET_USER_MEMORY_REGION KVM: doc: Document the life cycle of a VM and its resources KVM: selftests: complete IO before migrating guest state KVM: selftests: disable stack protector for all KVM tests KVM: selftests: explicitly disable PIE for tests KVM: selftests: assert on exit reason in CR4/cpuid sync test KVM: x86: update %rip after emulating IO x86/kvm/hyper-v: avoid spurious pending stimer on vCPU init kvm/x86: Move MSR_IA32_ARCH_CAPABILITIES to array emulated_msrs KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hosts kvm: don't redefine flags as something else kvm: mmu: Used range based flushing in slot_handle_level_range KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported KVM: x86: remove check on nr_mmu_pages in kvm_arch_commit_memory_region() kvm: nVMX: Add a vmentry check for HOST_SYSENTER_ESP and HOST_SYSENTER_EIP fields KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation) KVM: Reject device ioctls from processes other than the VM's creator KVM: doc: Fix incorrect word ordering regarding supported use of APIs KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size' KVM: nVMX: Do not inherit quadrant and invalid for the root shadow EPT ...
2019-03-31Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds8-22/+19
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A pile of x86 updates: - Prevent exceeding he valid physical address space in the /dev/mem limit checks. - Move all header content inside the header guard to prevent compile failures. - Fix the bogus __percpu annotation in this_cpu_has() which makes sparse very noisy. - Disable switch jump tables completely when retpolines are enabled. - Prevent leaking the trampoline address" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/realmode: Make set_real_mode_mem() static inline x86/cpufeature: Fix __percpu annotation in this_cpu_has() x86/mm: Don't exceed the valid physical address space x86/retpolines: Disable switch jump tables when retpolines are enabled x86/realmode: Don't leak the trampoline kernel address x86/boot: Fix incorrect ifdeffery scope x86/resctrl: Remove unused variable
2019-03-29x86/realmode: Make set_real_mode_mem() static inlineMatteo Croce3-10/+7
Remove the unused @size argument and move it into a header file, so it can be inlined. [ bp: Massage. ] Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-efi <linux-efi@vger.kernel.org> Cc: platform-driver-x86@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190328114233.27835-1-mcroce@redhat.com
2019-03-28KVM: x86: update %rip after emulating IOSean Christopherson2-10/+27
Most (all?) x86 platforms provide a port IO based reset mechanism, e.g. OUT 92h or CF9h. Userspace may emulate said mechanism, i.e. reset a vCPU in response to KVM_EXIT_IO, without explicitly announcing to KVM that it is doing a reset, e.g. Qemu jams vCPU state and resumes running. To avoid corruping %rip after such a reset, commit 0967b7bf1c22 ("KVM: Skip pio instruction when it is emulated, not executed") changed the behavior of PIO handlers, i.e. today's "fast" PIO handling to skip the instruction prior to exiting to userspace. Full emulation doesn't need such tricks becase re-emulating the instruction will naturally handle %rip being changed to point at the reset vector. Updating %rip prior to executing to userspace has several drawbacks: - Userspace sees the wrong %rip on the exit, e.g. if PIO emulation fails it will likely yell about the wrong address. - Single step exits to userspace for are effectively dropped as KVM_EXIT_DEBUG is overwritten with KVM_EXIT_IO. - Behavior of PIO emulation is different depending on whether it goes down the fast path or the slow path. Rather than skip the PIO instruction before exiting to userspace, snapshot the linear %rip and cancel PIO completion if the current value does not match the snapshot. For a 64-bit vCPU, i.e. the most common scenario, the snapshot and comparison has negligible overhead as VMCS.GUEST_RIP will be cached regardless, i.e. there is no extra VMREAD in this case. All other alternatives to snapshotting the linear %rip that don't rely on an explicit reset announcenment suffer from one corner case or another. For example, canceling PIO completion on any write to %rip fails if userspace does a save/restore of %rip, and attempting to avoid that issue by canceling PIO only if %rip changed then fails if PIO collides with the reset %rip. Attempting to zero in on the exact reset vector won't work for APs, which means adding more hooks such as the vCPU's MP_STATE, and so on and so forth. Checking for a linear %rip match technically suffers from corner cases, e.g. userspace could theoretically rewrite the underlying code page and expect a different instruction to execute, or the guest hardcodes a PIO reset at 0xfffffff0, but those are far, far outside of what can be considered normal operation. Fixes: 432baf60eee3 ("KVM: VMX: use kvm_fast_pio_in for handling IN I/O") Cc: <stable@vger.kernel.org> Reported-by: Jim Mattson <jmattson@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28x86/kvm/hyper-v: avoid spurious pending stimer on vCPU initVitaly Kuznetsov1-2/+7
When userspace initializes guest vCPUs it may want to zero all supported MSRs including Hyper-V related ones including HV_X64_MSR_STIMERn_CONFIG/ HV_X64_MSR_STIMERn_COUNT. With commit f3b138c5d89a ("kvm/x86: Update SynIC timers on guest entry only") we began doing stimer_mark_pending() unconditionally on every config change. The issue I'm observing manifests itself as following: - Qemu writes 0 to STIMERn_{CONFIG,COUNT} MSRs and marks all stimers as pending in stimer_pending_bitmap, arms KVM_REQ_HV_STIMER; - kvm_hv_has_stimer_pending() starts returning true; - kvm_vcpu_has_events() starts returning true; - kvm_arch_vcpu_runnable() starts returning true; - when kvm_arch_vcpu_ioctl_run() gets into (vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED) case: - kvm_vcpu_block() gets in 'kvm_vcpu_check_block(vcpu) < 0' and returns immediately, avoiding normal wait path; - -EAGAIN is returned from kvm_arch_vcpu_ioctl_run() immediately forcing userspace to retry. So instead of normal wait path we get a busy loop on all secondary vCPUs before they get INIT signal. This seems to be undesirable, especially given that this happens even when Hyper-V extensions are not used. Generally, it seems to be pointless to mark an stimer as pending in stimer_pending_bitmap and arm KVM_REQ_HV_STIMER as the only thing kvm_hv_process_stimers() will do is clear the corresponding bit. We may just not mark disabled timers as pending instead. Fixes: f3b138c5d89a ("kvm/x86: Update SynIC timers on guest entry only") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28kvm/x86: Move MSR_IA32_ARCH_CAPABILITIES to array emulated_msrsXiaoyao Li1-1/+2
Since MSR_IA32_ARCH_CAPABILITIES is emualted unconditionally even if host doesn't suppot it. We should move it to array emulated_msrs from arry msrs_to_save, to report to userspace that guest support this msr. Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hostsSean Christopherson4-14/+13
The CPUID flag ARCH_CAPABILITIES is unconditioinally exposed to host userspace for all x86 hosts, i.e. KVM advertises ARCH_CAPABILITIES regardless of hardware support under the pretense that KVM fully emulates MSR_IA32_ARCH_CAPABILITIES. Unfortunately, only VMX hosts handle accesses to MSR_IA32_ARCH_CAPABILITIES (despite KVM_GET_MSRS also reporting MSR_IA32_ARCH_CAPABILITIES for all hosts). Move the MSR_IA32_ARCH_CAPABILITIES handling to common x86 code so that it's emulated on AMD hosts. Fixes: 1eaafe91a0df4 ("kvm: x86: IA32_ARCH_CAPABILITIES is always supported") Cc: stable@vger.kernel.org Reported-by: Xiaoyao Li <xiaoyao.li@linux.intel.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28kvm: mmu: Used range based flushing in slot_handle_level_rangeBen Gardon1-2/+5
Replace kvm_flush_remote_tlbs with kvm_flush_remote_tlbs_with_address in slot_handle_level_range. When range based flushes are not enabled kvm_flush_remote_tlbs_with_address falls back to kvm_flush_remote_tlbs. This changes the behavior of many functions that indirectly use slot_handle_level_range, iff the range based flushes are enabled. The only potential problem I see with this is that kvm->tlbs_dirty will be cleared less often, however the only caller of slot_handle_level_range that checks tlbs_dirty is kvm_mmu_notifier_invalidate_range_start which checks it and does a kvm_flush_remote_tlbs after calling kvm_unmap_hva_range anyway. Tested: Ran all kvm-unit-tests on a Intel Haswell machine with and without this patch. The patch introduced no new failures. Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28KVM: x86: remove check on nr_mmu_pages in kvm_arch_commit_memory_region()Wei Yang3-8/+4
* nr_mmu_pages would be non-zero only if kvm->arch.n_requested_mmu_pages is non-zero. * nr_mmu_pages is always non-zero, since kvm_mmu_calculate_mmu_pages() never return zero. Based on these two reasons, we can merge the two *if* clause and use the return value from kvm_mmu_calculate_mmu_pages() directly. This simplify the code and also eliminate the possibility for reader to believe nr_mmu_pages would be zero. Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28kvm: nVMX: Add a vmentry check for HOST_SYSENTER_ESP and HOST_SYSENTER_EIP ↵Krish Sadhukhan1-0/+5
fields According to section "Checks on VMX Controls" in Intel SDM vol 3C, the following check is performed on vmentry of L2 guests: On processors that support Intel 64 architecture, the IA32_SYSENTER_ESP field and the IA32_SYSENTER_EIP field must each contain a canonical address. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation)Singh, Brijesh4-3/+45
Errata#1096: On a nested data page fault when CR.SMAP=1 and the guest data read generates a SMAP violation, GuestInstrBytes field of the VMCB on a VMEXIT will incorrectly return 0h instead the correct guest instruction bytes . Recommend Workaround: To determine what instruction the guest was executing the hypervisor will have to decode the instruction at the instruction pointer. The recommended workaround can not be implemented for the SEV guest because guest memory is encrypted with the guest specific key, and instruction decoder will not be able to decode the instruction bytes. If we hit this errata in the SEV guest then log the message and request a guest shutdown. Reported-by: Venkatesh Srinivas <venkateshs@google.com> Cc: Jim Mattson <jmattson@google.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size'Sean Christopherson3-18/+28
The cr4_pae flag is a bit of a misnomer, its purpose is really to track whether the guest PTE that is being shadowed is a 4-byte entry or an 8-byte entry. Prior to supporting nested EPT, the size of the gpte was reflected purely by CR4.PAE. KVM fudged things a bit for direct sptes, but it was mostly harmless since the size of the gpte never mattered. Now that a spte may be tracking an indirect EPT entry, relying on CR4.PAE is wrong and ill-named. For direct shadow pages, force the gpte_size to '1' as they are always 8-byte entries; EPT entries can only be 8-bytes and KVM always uses 8-byte entries for NPT and its identity map (when running with EPT but not unrestricted guest). Likewise, nested EPT entries are always 8-bytes. Nested EPT presents a unique scenario as the size of the entries are not dictated by CR4.PAE, but neither is the shadow page a direct map. To handle this scenario, set cr0_wp=1 and smap_andnot_wp=1, an otherwise impossible combination, to denote a nested EPT shadow page. Use the information to avoid incorrectly zapping an unsync'd indirect page in __kvm_sync_page(). Providing a consistent and accurate gpte_size fixes a bug reported by Vitaly where fast_cr3_switch() always fails when switching from L2 to L1 as kvm_mmu_get_page() would force role.cr4_pae=0 for direct pages, whereas kvm_calc_mmu_role_common() would set it according to CR4.PAE. Fixes: 7dcd575520082 ("x86/kvm/mmu: check if tdp/shadow MMU reconfiguration is needed") Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28KVM: nVMX: Do not inherit quadrant and invalid for the root shadow EPTSean Christopherson1-4/+9
Explicitly zero out quadrant and invalid instead of inheriting them from the root_mmu. Functionally, this patch is a nop as we (should) never set quadrant for a direct mapped (EPT) root_mmu and nested EPT is only allowed if EPT is used for L1, and the root_mmu will never be invalid at this point. Explicitly setting flags sets the stage for repurposing the legacy paging bits in role, e.g. nxe, cr0_wp, and sm{a,e}p_andnot_wp, at which point 'smm' would be the only flag to be inherited from root_mmu. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28x86/cpufeature: Fix __percpu annotation in this_cpu_has()Jann Horn1-2/+3
&cpu_info.x86_capability is __percpu, and the second argument of x86_this_cpu_test_bit() is expected to be __percpu. Don't cast the __percpu away and then implicitly add it again. This gets rid of 106 lines of sparse warnings with the kernel config I'm using. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Nadav Amit <namit@vmware.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190328154948.152273-1-jannh@google.com
2019-03-28x86/mm: Don't exceed the valid physical address spaceRalph Campbell1-1/+1
valid_phys_addr_range() is used to sanity check the physical address range of an operation, e.g., access to /dev/mem. It uses __pa(high_memory) internally. If memory is populated at the end of the physical address space, then __pa(high_memory) is outside of the physical address space because: high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; For the comparison in valid_phys_addr_range() this is not an issue, but if CONFIG_DEBUG_VIRTUAL is enabled, __pa() maps to __phys_addr(), which verifies that the resulting physical address is within the valid physical address space of the CPU. So in the case that memory is populated at the end of the physical address space, this is not true and triggers a VIRTUAL_BUG_ON(). Use __pa(high_memory - 1) to prevent the conversion from going beyond the end of valid physical addresses. Fixes: be62a3204406 ("x86/mm: Limit mmap() of /dev/mem to valid physical addresses") Signed-off-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Craig Bergstrom <craigb@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hans Verkuil <hans.verkuil@cisco.com> Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sander Eikelenboom <linux@eikelenboom.it> Cc: Sean Young <sean@mess.org> Link: https://lkml.kernel.org/r/20190326001817.15413-2-rcampbell@nvidia.com
2019-03-28x86/retpolines: Disable switch jump tables when retpolines are enabledDaniel Borkmann1-2/+6
Commit ce02ef06fcf7 ("x86, retpolines: Raise limit for generating indirect calls from switch-case") raised the limit under retpolines to 20 switch cases where gcc would only then start to emit jump tables, and therefore effectively disabling the emission of slow indirect calls in this area. After this has been brought to attention to gcc folks [0], Martin Liska has then fixed gcc to align with clang by avoiding to generate switch jump tables entirely under retpolines. This is taking effect in gcc starting from stable version 8.4.0. Given kernel supports compilation with older versions of gcc where the fix is not being available or backported anymore, we need to keep the extra KBUILD_CFLAGS around for some time and generally set the -fno-jump-tables to align with what more recent gcc is doing automatically today. More than 20 switch cases are not expected to be fast-path critical, but it would still be good to align with gcc behavior for versions < 8.4.0 in order to have consistency across supported gcc versions. vmlinux size is slightly growing by 0.27% for older gcc. This flag is only set to work around affected gcc, no change for clang. [0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86952 Suggested-by: Martin Liska <mliska@suse.cz> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Björn Töpel<bjorn.topel@intel.com> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: David S. Miller <davem@davemloft.net> Link: https://lkml.kernel.org/r/20190325135620.14882-1-daniel@iogearbox.net
2019-03-28x86/smp: Enforce CONFIG_HOTPLUG_CPU when SMP=yThomas Gleixner1-7/+1
The SMT disable 'nosmt' command line argument is not working properly when CONFIG_HOTPLUG_CPU is disabled. The teardown of the sibling CPUs which are required to be brought up due to the MCE issues, cannot work. The CPUs are then kept in a half dead state. As the 'nosmt' functionality has become popular due to the speculative hardware vulnerabilities, the half torn down state is not a proper solution to the problem. Enforce CONFIG_HOTPLUG_CPU=y when SMP is enabled so the full operation is possible. Reported-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Mukesh Ojha <mojha@codeaurora.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Rik van Riel <riel@surriel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Micheal Kelley <michael.h.kelley@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190326163811.598166056@linutronix.de
2019-03-27x86/realmode: Don't leak the trampoline kernel addressMatteo Croce1-2/+0
Since commit ad67b74d2469 ("printk: hash addresses printed with %p") at boot "____ptrval____" is printed instead of the trampoline addresses: Base memory trampoline at [(____ptrval____)] 99000 size 24576 Remove the print as we don't want to leak kernel addresses and this statement is not needed anymore. Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190326203046.20787-1-mcroce@redhat.com
2019-03-27x86/boot: Fix incorrect ifdeffery scopeBaoquan He1-2/+2
The declarations related to immovable memory handling are out of the BOOT_COMPRESSED_MISC_H #ifdef scope, wrap them inside. Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Chao Fan <fanc.fnst@cn.fujitsu.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190304055546.18566-1-bhe@redhat.com
2019-03-24x86/resctrl: Remove unused variablePeng Hao1-3/+0
Variable "struct rdt_resource *r" is set but not used. So remove it. Signed-off-by: Peng Hao <peng.hao2@zte.com.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1552152584-26087-1-git-send-email-peng.hao2@zte.com.cn
2019-03-23x86/gart: Exclude GART aperture from kcoreKairui Song1-7/+13
On machines where the GART aperture is mapped over physical RAM, /proc/kcore contains the GART aperture range. Accessing the GART range via /proc/kcore results in a kernel crash. vmcore used to have the same issue, until it was fixed with commit 2a3e83c6f96c ("x86/gart: Exclude GART aperture from vmcore")', leveraging existing hook infrastructure in vmcore to let /proc/vmcore return zeroes when attempting to read the aperture region, and so it won't read from the actual memory. Apply the same workaround for kcore. First implement the same hook infrastructure for kcore, then reuse the hook functions introduced in the previous vmcore fix. Just with some minor adjustment, rename some functions for more general usage, and simplify the hook infrastructure a bit as there is no module usage yet. Suggested-by: Baoquan He <bhe@redhat.com> Signed-off-by: Kairui Song <kasong@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jiri Bohac <jbohac@suse.cz> Acked-by: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Omar Sandoval <osandov@fb.com> Cc: Dave Young <dyoung@redhat.com> Link: https://lkml.kernel.org/r/20190308030508.13548-1-kasong@redhat.com
2019-03-22Merge branch 'x86/cpu' into x86/urgentThomas Gleixner1-16/+15
Merge the forgotten cleanup patch for the new file, so the mess does not propagate further.
2019-03-22x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return ↵Nathan Chancellor1-0/+1
an error When building with -Wsometimes-uninitialized, Clang warns: arch/x86/kernel/hw_breakpoint.c:355:2: warning: variable 'align' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized] The default cannot be reached because arch_build_bp_info() initializes hw->len to one of the specified cases. Nevertheless the warning is valid and returning -EINVAL makes sure that this cannot be broken by future modifications. Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: clang-built-linux@googlegroups.com Link: https://github.com/ClangBuiltLinux/linux/issues/392 Link: https://lkml.kernel.org/r/20190307212756.4648-1-natechancellor@gmail.com
2019-03-22x86/mm/pti: Make local symbols staticValdis Kletnieks1-2/+2
With 'make C=2 W=1', sparse and gcc both complain: CHECK arch/x86/mm/pti.c arch/x86/mm/pti.c:84:3: warning: symbol 'pti_mode' was not declared. Should it be static? arch/x86/mm/pti.c:605:6: warning: symbol 'pti_set_kernel_image_nonglobal' was not declared. Should it be static? CC arch/x86/mm/pti.o arch/x86/mm/pti.c:605:6: warning: no previous prototype for 'pti_set_kernel_image_nonglobal' [-Wmissing-prototypes] 605 | void pti_set_kernel_image_nonglobal(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ pti_set_kernel_image_nonglobal() is only used locally. 'pti_mode' exists in drivers/hwtracing/intel_th/pti.c as well, but it's a completely unrelated local (static) symbol. Make both static. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/27680.1552376873@turing-police
2019-03-21x86/cpu/cyrix: Remove {get,set}Cx86_old macros used for Cyrix processorsMatthew Whitehead1-21/+0
The getCx86_old() and setCx86_old() macros have been replaced with correctly working getCx86() and setCx86(), so remove these unused macros. Signed-off-by: Matthew Whitehead <tedheadster@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: luto@kernel.org Link: https://lkml.kernel.org/r/1552596361-8967-3-git-send-email-tedheadster@gmail.com
2019-03-21x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processorsMatthew Whitehead1-7/+7
There are comments in processor-cyrix.h advising you to _not_ make calls using the deprecated macros in this style: setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80); This is because it expands the macro into a non-functioning calling sequence. The calling order must be: outb(CX86_CCR2, 0x22); inb(0x23); From the comments: * When using the old macros a line like * setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88); * gets expanded to: * do { * outb((CX86_CCR2), 0x22); * outb((({ * outb((CX86_CCR2), 0x22); * inb(0x23); * }) | 0x88), 0x23); * } while (0); The new macros fix this problem, so use them instead. Tested on an actual Geode processor. Signed-off-by: Matthew Whitehead <tedheadster@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: luto@kernel.org Link: https://lkml.kernel.org/r/1552596361-8967-2-git-send-email-tedheadster@gmail.com
2019-03-21x86/microcode: Announce reload operation's completionBorislav Petkov1-0/+2
By popular demand, issue a single line to dmesg after the reload operation completes to let the user know that a reload has at least been attempted. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190313110022.8229-1-bp@alien8.de
2019-03-21x86/hyperv: Prevent potential NULL pointer dereferenceKangjie Lu1-1/+5
The page allocation in hv_cpu_init() can fail, but the code does not have a check for that. Add a check and return -ENOMEM when the allocation fails. [ tglx: Massaged changelog ] Signed-off-by: Kangjie Lu <kjlu@umn.edu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Acked-by: "K. Y. Srinivasan" <kys@microsoft.com> Cc: pakki001@umn.edu Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sasha Levin <sashal@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: linux-hyperv@vger.kernel.org Link: https://lkml.kernel.org/r/20190314054651.1315-1-kjlu@umn.edu
2019-03-21x86/hpet: Prevent potential NULL pointer dereferenceAditya Pakki1-0/+2
hpet_virt_address may be NULL when ioremap_nocache fail, but the code lacks a check. Add a check to prevent NULL pointer dereference. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: kjlu@umn.edu Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Joe Perches <joe@perches.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Roland Dreier <roland@purestorage.com> Link: https://lkml.kernel.org/r/20190319021958.17275-1-pakki001@umn.edu
2019-03-21x86/lib: Fix indentation issue, remove extra tabColin Ian King1-1/+1
The increment of buff is indented one level too deeply, clean this up by removing a tab. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: kernel-janitors@vger.kernel.org Link: https://lkml.kernel.org/r/20190314230838.18256-1-colin.king@canonical.com
2019-03-21x86/boot: Restrict header scope to make Clang happyNick Desaulniers1-1/+2
The inclusion of <linux/kernel.h> was causing issue as the definition of __arch_hweight64 from arch/x86/include/asm/arch_hweight.h eventually gets included. The definition is problematic when compiled with -m16 (all code in arch/x86/boot/ is) as the "D" inline assembly constraint is rejected by both compilers when passed an argument of type long long (regardless of signedness, anything smaller is fine). Because GCC performs inlining before semantic analysis, and __arch_hweight64 is dead in this translation unit, GCC does not report any issues at compile time. Clang does the semantic analysis in the front end, before inlining (run in the middle) can determine the code is dead. I consider this another case of PR33587, which I think we can do more work to solve. It turns out that arch/x86/boot/string.c doesn't actually need linux/kernel.h, simply linux/limits.h and linux/compiler.h. Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Cc: bp@alien8.de Cc: niravd@google.com Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Chao Fan <fanc.fnst@cn.fujitsu.com> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://bugs.llvm.org/show_bug.cgi?id=33587 Link: https://github.com/ClangBuiltLinux/linux/issues/347 Link: https://lkml.kernel.org/r/20190314221458.83047-1-ndesaulniers@google.com
2019-03-19x86/mm: Don't leak kernel addressesMatteo Croce1-2/+2
Since commit: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") at boot "____ptrval____" is printed instead of actual addresses: found SMP MP-table at [mem 0x000f5cc0-0x000f5ccf] mapped at [(____ptrval____)] Instead of changing the print to "%px", and leaking a kernel addresses, just remove the print completely, like in: 071929dbdd865f77 ("arm64: Stop printing the virtual memory layout"). Signed-off-by: Matteo Croce <mcroce@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-03-17Merge tag 'kbuild-v5.1-2' of ↵Linus Torvalds1-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - add more Build-Depends to Debian source package - prefix header search paths with $(srctree)/ - make modpost show verbose section mismatch warnings - avoid hard-coded CROSS_COMPILE for h8300 - fix regression for Debian make-kpkg command - add semantic patch to detect missing put_device() - fix some warnings of 'make deb-pkg' - optimize NOSTDINC_FLAGS evaluation - add warnings about redundant generic-y - clean up Makefiles and scripts * tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove stale lxdialog/.gitignore kbuild: force all architectures except um to include mandatory-y kbuild: warn redundant generic-y Revert "modsign: Abort modules_install when signing fails" kbuild: Make NOSTDINC_FLAGS a simply expanded variable kbuild: deb-pkg: avoid implicit effects coccinelle: semantic code search for missing put_device() kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIG kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddeb kbuild: deb-pkg: add CONFIG_ prefix to kernel config options kbuild: add workaround for Debian make-kpkg kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG} unicore32: simplify linker script generation for decompressor h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux- kbuild: move archive command to scripts/Makefile.lib modpost: always show verbose warning for section mismatch ia64: prefix header search path with $(srctree)/ libfdt: prefix header search paths with $(srctree)/ deb-pkg: generate correct build dependencies
2019-03-17Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds3-125/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Thomas Gleixner: "Two cleanup patches removing dead conditionals and unused code" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Remove unused __constant_c_x_memset() macro and inlines x86/asm: Remove dead __GNUC__ conditionals
2019-03-17Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "Three fixes for the fallout from the TSX errata workaround: - Prevent memory corruption caused by a unchecked out of bound array index. - Two trivial fixes to address compiler warnings" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Make dev_attr_allow_tsx_force_abort static perf/x86: Fixup typo in stub functions perf/x86/intel: Fix memory corruption
2019-03-17perf/x86/intel: Make dev_attr_allow_tsx_force_abort statickbuild test robot1-1/+1
Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort") Signed-off-by: kbuild test robot <lkp@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: kbuild-all@01.org Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190313184243.GA10820@lkp-sb-ep06
2019-03-17kbuild: force all architectures except um to include mandatory-yMasahiro Yamada1-2/+0
Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes the common Kbuild.asm file. Factor out the duplicated include directives to scripts/Makefile.asm-generic so that no architecture would opt out of the mandatory-y mechanism. um is not forced to include mandatory-y since it is a very exceptional case which does not support UAPI. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-17kbuild: warn redundant generic-yMasahiro Yamada1-1/+0
The generic-y is redundant under the following condition: - arch has its own implementation - the same header is added to generated-y - the same header is added to mandatory-y If a redundant generic-y is found, the warning like follows is displayed: scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h I fixed up arch Kbuild files found by this. Suggested-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-16Merge tag 'pidfd-v5.1-rc1' of ↵Linus Torvalds2-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull pidfd system call from Christian Brauner: "This introduces the ability to use file descriptors from /proc/<pid>/ as stable handles on struct pid. Even if a pid is recycled the handle will not change. For a start these fds can be used to send signals to the processes they refer to. With the ability to use /proc/<pid> fds as stable handles on struct pid we can fix a long-standing issue where after a process has exited its pid can be reused by another process. If a caller sends a signal to a reused pid it will end up signaling the wrong process. With this patchset we enable a variety of use cases. One obvious example is that we can now safely delegate an important part of process management - sending signals - to processes other than the parent of a given process by sending file descriptors around via scm rights and not fearing that the given process will have been recycled in the meantime. It also allows for easy testing whether a given process is still alive or not by sending signal 0 to a pidfd which is quite handy. There has been some interest in this feature e.g. from systems management (systemd, glibc) and container managers. I have requested and gotten comments from glibc to make sure that this syscall is suitable for their needs as well. In the future I expect it to take on most other pid-based signal syscalls. But such features are left for the future once they are needed. This has been sitting in linux-next for quite a while and has not caused any issues. It comes with selftests which verify basic functionality and also test that a recycled pid cannot be signaled via a pidfd. Jon has written about a prior version of this patchset. It should cover the basic functionality since not a lot has changed since then: https://lwn.net/Articles/773459/ The commit message for the syscall itself is extensively documenting the syscall, including it's functionality and extensibility" * tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: selftests: add tests for pidfd_send_signal() signal: add pidfd_send_signal() syscall
2019-03-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds21-602/+677
Pull KVM updates from Paolo Bonzini: "ARM: - some cleanups - direct physical timer assignment - cache sanitization for 32-bit guests s390: - interrupt cleanup - introduction of the Guest Information Block - preparation for processor subfunctions in cpu models PPC: - bug fixes and improvements, especially related to machine checks and protection keys x86: - many, many cleanups, including removing a bunch of MMU code for unnecessary optimizations - AVIC fixes Generic: - memcg accounting" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits) kvm: vmx: fix formatting of a comment KVM: doc: Document the life cycle of a VM and its resources MAINTAINERS: Add KVM selftests to existing KVM entry Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()" KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char() KVM: PPC: Fix compilation when KVM is not enabled KVM: Minor cleanups for kvm_main.c KVM: s390: add debug logging for cpu model subfunctions KVM: s390: implement subfunction processor calls arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2 KVM: arm/arm64: Remove unused timer variable KVM: PPC: Book3S: Improve KVM reference counting KVM: PPC: Book3S HV: Fix build failure without IOMMU support Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()" x86: kvmguest: use TSC clocksource if invariant TSC is exposed KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes() KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children ...
2019-03-15kvm: vmx: fix formatting of a commentPaolo Bonzini1-5/+5
Eliminate a gratuitous conflict with 5.0. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-15Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"Ben Gardon1-13/+3
This reverts commit 71883a62fcd6c70639fa12cda733378b4d997409. The above commit contains an optimization to kvm_zap_gfn_range which uses gfn-limited TLB flushes, if enabled. If using these limited flushes, kvm_zap_gfn_range passes lock_flush_tlb=false to slot_handle_level_range which creates a race when the function unlocks to call cond_resched. See an example of this race below: CPU 0 CPU 1 CPU 3 // zap_direct_gfn_range mmu_lock() // *ptep == pte_1 *ptep = 0 if (lock_flush_tlb) flush_tlbs() mmu_unlock() // In invalidate range // MMU notifier mmu_lock() if (pte != 0) *ptep = 0 flush = true if (flush) flush_remote_tlbs() mmu_unlock() return // Host MM reallocates // page previously // backing guest memory. // Guest accesses // invalid page // through pte_1 // in its TLB!! Tested: Ran all kvm-unit-tests on a Intel Haswell machine with and without this patch. The patch introduced no new failures. Signed-off-by: Ben Gardon <bgardon@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>