1 files changed, 45 insertions, 27 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8d45d35f8aad..7dc0597e2381 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1630,6 +1630,15 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	struct kvm *kvm = filp->private_data;
 	void __user *argp = (void __user *)arg;
 	int r = -EINVAL;
+	/*
+	 * This union makes it completely explicit to gcc-3.x
+	 * that these two variables' stack usage should be
+	 * combined, not added together.
+	 */
+	union {
+		struct kvm_pit_state ps;
+		struct kvm_memory_alias alias;
+	} u;
 
 	switch (ioctl) {
 	case KVM_SET_TSS_ADDR:
@@ -1661,17 +1670,14 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	case KVM_GET_NR_MMU_PAGES:
 		r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
 		break;
-	case KVM_SET_MEMORY_ALIAS: {
-		struct kvm_memory_alias alias;
-
+	case KVM_SET_MEMORY_ALIAS:
 		r = -EFAULT;
-		if (copy_from_user(&alias, argp, sizeof alias))
+		if (copy_from_user(&u.alias, argp, sizeof(struct kvm_memory_alias)))
 			goto out;
-		r = kvm_vm_ioctl_set_memory_alias(kvm, &alias);
+		r = kvm_vm_ioctl_set_memory_alias(kvm, &u.alias);
 		if (r)
 			goto out;
 		break;
-	}
 	case KVM_CREATE_IRQCHIP:
 		r = -ENOMEM;
 		kvm->arch.vpic = kvm_create_pic(kvm);
@@ -1713,65 +1719,77 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	}
 	case KVM_GET_IRQCHIP: {
 		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
-		struct kvm_irqchip chip;
+		struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL);
 
-		r = -EFAULT;
-		if (copy_from_user(&chip, argp, sizeof chip))
+		r = -ENOMEM;
+		if (!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 out;
-		r = kvm_vm_ioctl_get_irqchip(kvm, &chip);
+			goto get_irqchip_out;
+		r = kvm_vm_ioctl_get_irqchip(kvm, chip);
 		if (r)
-			goto out;
+			goto get_irqchip_out;
 		r = -EFAULT;
-		if (copy_to_user(argp, &chip, sizeof chip))
-			goto out;
+		if (copy_to_user(argp, chip, sizeof *chip))
+			goto get_irqchip_out;
 		r = 0;
+	get_irqchip_out:
+		kfree(chip);
+		if (r)
+			goto out;
 		break;
 	}
 	case KVM_SET_IRQCHIP: {
 		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
-		struct kvm_irqchip chip;
+		struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL);
 
-		r = -EFAULT;
-		if (copy_from_user(&chip, argp, sizeof chip))
+		r = -ENOMEM;
+		if (!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 out;
-		r = kvm_vm_ioctl_set_irqchip(kvm, &chip);
+			goto set_irqchip_out;
+		r = kvm_vm_ioctl_set_irqchip(kvm, chip);
 		if (r)
-			goto out;
+			goto set_irqchip_out;
 		r = 0;
+	set_irqchip_out:
+		kfree(chip);
+		if (r)
+			goto out;
 		break;
 	}
 	case KVM_GET_PIT: {
-		struct kvm_pit_state ps;
 		r = -EFAULT;
-		if (copy_from_user(&ps, argp, sizeof ps))
+		if (copy_from_user(&u.ps, argp, sizeof(struct kvm_pit_state)))
 			goto out;
 		r = -ENXIO;
 		if (!kvm->arch.vpit)
 			goto out;
-		r = kvm_vm_ioctl_get_pit(kvm, &ps);
+		r = kvm_vm_ioctl_get_pit(kvm, &u.ps);
 		if (r)
 			goto out;
 		r = -EFAULT;
-		if (copy_to_user(argp, &ps, sizeof ps))
+		if (copy_to_user(argp, &u.ps, sizeof(struct kvm_pit_state)))
 			goto out;
 		r = 0;
 		break;
 	}
 	case KVM_SET_PIT: {
-		struct kvm_pit_state ps;
 		r = -EFAULT;
-		if (copy_from_user(&ps, argp, sizeof ps))
+		if (copy_from_user(&u.ps, argp, sizeof u.ps))
 			goto out;
 		r = -ENXIO;
 		if (!kvm->arch.vpit)
 			goto out;
-		r = kvm_vm_ioctl_set_pit(kvm, &ps);
+		r = kvm_vm_ioctl_set_pit(kvm, &u.ps);
 		if (r)
 			goto out;
 		r = 0;