From ff5c2c0316ff0e3e2dba3ca14167d994453df093 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Sun, 4 Dec 2011 19:36:29 +0200 Subject: KVM: Use memdup_user instead of kmalloc/copy_from_user Switch to using memdup_user when possible. This makes code more smaller and compact, and prevents errors. Signed-off-by: Sasha Levin Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 82 +++++++++++++++++++++++------------------------------ virt/kvm/kvm_main.c | 29 ++++++++----------- 2 files changed, 47 insertions(+), 64 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 03042d60a8f..0a646e2b57c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1309,12 +1309,11 @@ static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data) if (page_num >= blob_size) goto out; r = -ENOMEM; - page = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!page) + page = memdup_user(blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE); + if (IS_ERR(page)) { + r = PTR_ERR(page); goto out; - r = -EFAULT; - if (copy_from_user(page, blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE)) - goto out_free; + } if (kvm_write_guest(kvm, page_addr, page, PAGE_SIZE)) goto out_free; r = 0; @@ -1988,15 +1987,12 @@ static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs, if (msrs.nmsrs >= MAX_IO_MSRS) goto out; - r = -ENOMEM; size = sizeof(struct kvm_msr_entry) * msrs.nmsrs; - entries = kmalloc(size, GFP_KERNEL); - if (!entries) + entries = memdup_user(user_msrs->entries, size); + if (IS_ERR(entries)) { + r = PTR_ERR(entries); goto out; - - r = -EFAULT; - if (copy_from_user(entries, user_msrs->entries, size)) - goto out_free; + } r = n = __msr_io(vcpu, &msrs, entries, do_msr); if (r < 0) @@ -2533,13 +2529,12 @@ long kvm_arch_vcpu_ioctl(struct file *filp, r = -EINVAL; if (!vcpu->arch.apic) goto out; - u.lapic = kmalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL); - r = -ENOMEM; - if (!u.lapic) - goto out; - r = -EFAULT; - if (copy_from_user(u.lapic, argp, sizeof(struct kvm_lapic_state))) + u.lapic = memdup_user(argp, sizeof(*u.lapic)); + if (IS_ERR(u.lapic)) { + r = PTR_ERR(u.lapic); goto out; + } + r = kvm_vcpu_ioctl_set_lapic(vcpu, u.lapic); if (r) goto out; @@ -2718,14 +2713,11 @@ long kvm_arch_vcpu_ioctl(struct file *filp, break; } case KVM_SET_XSAVE: { - u.xsave = kzalloc(sizeof(struct kvm_xsave), GFP_KERNEL); - r = -ENOMEM; - if (!u.xsave) - break; - - r = -EFAULT; - if (copy_from_user(u.xsave, argp, sizeof(struct kvm_xsave))) - break; + u.xsave = memdup_user(argp, sizeof(*u.xsave)); + if (IS_ERR(u.xsave)) { + r = PTR_ERR(u.xsave); + goto out; + } r = kvm_vcpu_ioctl_x86_set_xsave(vcpu, u.xsave); break; @@ -2746,15 +2738,11 @@ long kvm_arch_vcpu_ioctl(struct file *filp, break; } case KVM_SET_XCRS: { - u.xcrs = kzalloc(sizeof(struct kvm_xcrs), GFP_KERNEL); - r = -ENOMEM; - if (!u.xcrs) - break; - - r = -EFAULT; - if (copy_from_user(u.xcrs, argp, - sizeof(struct kvm_xcrs))) - break; + u.xcrs = memdup_user(argp, sizeof(*u.xcrs)); + if (IS_ERR(u.xcrs)) { + r = PTR_ERR(u.xcrs); + goto out; + } r = kvm_vcpu_ioctl_x86_set_xcrs(vcpu, u.xcrs); break; @@ -3190,14 +3178,14 @@ long kvm_arch_vm_ioctl(struct file *filp, } case KVM_GET_IRQCHIP: { /* 0: PIC master, 1: PIC slave, 2: IOAPIC */ - struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL); + struct kvm_irqchip *chip; - r = -ENOMEM; - if (!chip) + chip = memdup_user(argp, sizeof(*chip)); + if (IS_ERR(chip)) { + r = PTR_ERR(chip); goto out; - r = -EFAULT; - if (copy_from_user(chip, argp, sizeof *chip)) - goto get_irqchip_out; + } + r = -ENXIO; if (!irqchip_in_kernel(kvm)) goto get_irqchip_out; @@ -3216,14 +3204,14 @@ long kvm_arch_vm_ioctl(struct file *filp, } case KVM_SET_IRQCHIP: { /* 0: PIC master, 1: PIC slave, 2: IOAPIC */ - struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL); + struct kvm_irqchip *chip; - r = -ENOMEM; - if (!chip) + chip = memdup_user(argp, sizeof(*chip)); + if (IS_ERR(chip)) { + r = PTR_ERR(chip); goto out; - r = -EFAULT; - if (copy_from_user(chip, argp, sizeof *chip)) - goto set_irqchip_out; + } + r = -ENXIO; if (!irqchip_in_kernel(kvm)) goto set_irqchip_out; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a6e612fced7..d8bac075166 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1821,12 +1821,11 @@ out_free1: struct kvm_regs *kvm_regs; r = -ENOMEM; - kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL); - if (!kvm_regs) + kvm_regs = memdup_user(argp, sizeof(*kvm_regs)); + if (IS_ERR(kvm_regs)) { + r = PTR_ERR(kvm_regs); goto out; - r = -EFAULT; - if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs))) - goto out_free2; + } r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs); if (r) goto out_free2; @@ -1850,13 +1849,11 @@ out_free2: break; } case KVM_SET_SREGS: { - kvm_sregs = kmalloc(sizeof(struct kvm_sregs), GFP_KERNEL); - r = -ENOMEM; - if (!kvm_sregs) - goto out; - r = -EFAULT; - if (copy_from_user(kvm_sregs, argp, sizeof(struct kvm_sregs))) + kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs)); + if (IS_ERR(kvm_sregs)) { + r = PTR_ERR(kvm_sregs); goto out; + } r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs); if (r) goto out; @@ -1952,13 +1949,11 @@ out_free2: break; } case KVM_SET_FPU: { - fpu = kmalloc(sizeof(struct kvm_fpu), GFP_KERNEL); - r = -ENOMEM; - if (!fpu) - goto out; - r = -EFAULT; - if (copy_from_user(fpu, argp, sizeof(struct kvm_fpu))) + fpu = memdup_user(argp, sizeof(*fpu)); + if (IS_ERR(fpu)) { + r = PTR_ERR(fpu); goto out; + } r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu); if (r) goto out; -- cgit v1.2.3-18-g5258