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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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2184a60de2
The 'len' variable was declared an unsigned and then checked for less than 0, which results in warnings on some compilers. Since len is assigned an int, make it an int. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
141 lines
3.6 KiB
C
141 lines
3.6 KiB
C
/*
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* Copyright (C) 2012 - Virtual Open Systems and Columbia University
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* Author: Christoffer Dall <c.dall@virtualopensystems.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include <linux/kvm_host.h>
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#include <asm/kvm_mmio.h>
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#include <asm/kvm_emulate.h>
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#include <trace/events/kvm.h>
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#include "trace.h"
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/**
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* kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
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* @vcpu: The VCPU pointer
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* @run: The VCPU run struct containing the mmio data
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*
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* This should only be called after returning from userspace for MMIO load
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* emulation.
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*/
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int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
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{
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unsigned long *dest;
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unsigned int len;
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int mask;
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if (!run->mmio.is_write) {
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dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt);
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*dest = 0;
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len = run->mmio.len;
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if (len > sizeof(unsigned long))
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return -EINVAL;
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memcpy(dest, run->mmio.data, len);
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trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
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*((u64 *)run->mmio.data));
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if (vcpu->arch.mmio_decode.sign_extend &&
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len < sizeof(unsigned long)) {
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mask = 1U << ((len * 8) - 1);
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*dest = (*dest ^ mask) - mask;
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}
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}
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return 0;
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}
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static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
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struct kvm_exit_mmio *mmio)
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{
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unsigned long rt;
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int len;
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bool is_write, sign_extend;
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if (kvm_vcpu_dabt_isextabt(vcpu)) {
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/* cache operation on I/O addr, tell guest unsupported */
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kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
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return 1;
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}
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if (kvm_vcpu_dabt_iss1tw(vcpu)) {
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/* page table accesses IO mem: tell guest to fix its TTBR */
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kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
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return 1;
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}
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len = kvm_vcpu_dabt_get_as(vcpu);
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if (unlikely(len < 0))
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return len;
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is_write = kvm_vcpu_dabt_iswrite(vcpu);
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sign_extend = kvm_vcpu_dabt_issext(vcpu);
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rt = kvm_vcpu_dabt_get_rd(vcpu);
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mmio->is_write = is_write;
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mmio->phys_addr = fault_ipa;
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mmio->len = len;
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vcpu->arch.mmio_decode.sign_extend = sign_extend;
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vcpu->arch.mmio_decode.rt = rt;
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/*
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* The MMIO instruction is emulated and should not be re-executed
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* in the guest.
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*/
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kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
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return 0;
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}
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int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
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phys_addr_t fault_ipa)
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{
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struct kvm_exit_mmio mmio;
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unsigned long rt;
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int ret;
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/*
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* Prepare MMIO operation. First stash it in a private
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* structure that we can use for in-kernel emulation. If the
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* kernel can't handle it, copy it into run->mmio and let user
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* space do its magic.
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*/
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if (kvm_vcpu_dabt_isvalid(vcpu)) {
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ret = decode_hsr(vcpu, fault_ipa, &mmio);
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if (ret)
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return ret;
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} else {
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kvm_err("load/store instruction decoding not implemented\n");
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return -ENOSYS;
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}
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rt = vcpu->arch.mmio_decode.rt;
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trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE :
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KVM_TRACE_MMIO_READ_UNSATISFIED,
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mmio.len, fault_ipa,
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(mmio.is_write) ? *vcpu_reg(vcpu, rt) : 0);
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if (mmio.is_write)
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memcpy(mmio.data, vcpu_reg(vcpu, rt), mmio.len);
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if (vgic_handle_mmio(vcpu, run, &mmio))
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return 1;
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kvm_prepare_mmio(run, &mmio);
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return 0;
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}
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