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| author | Marc Zyngier <marc.zyngier@arm.com> | 2018-06-17 10:16:21 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-06-21 17:17:50 +0100 |
| commit | 7ddfd3e0df29106c728dda2a6bd6591ee43a4e3c (patch) | |
| tree | 881292b233bf620c55ae432583778e59a18f4591 /virt/kvm/kvm_main.c | |
| parent | 47a91b7232fa25abc7e0b7fc1c69ae4f81061594 (diff) | |
| download | lwn-7ddfd3e0df29106c728dda2a6bd6591ee43a4e3c.tar.gz lwn-7ddfd3e0df29106c728dda2a6bd6591ee43a4e3c.zip | |
KVM: Enforce error in ioctl for compat tasks when !KVM_COMPAT
The current behaviour of the compat ioctls is a bit odd.
We provide a compat_ioctl method when KVM_COMPAT is set, and NULL
otherwise. But NULL means that the normal, non-compat ioctl should
be used directly for compat tasks, and there is no way to actually
prevent a compat task from issueing KVM ioctls.
This patch changes this behaviour, by always registering a compat_ioctl
method, even if KVM_COMPAT is not selected. In that case, the callback
will always return -EINVAL.
Fixes: de8e5d744051568c8aad ("KVM: Disable compat ioctl for s390")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ada21f47f22b..8b47507faab5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -116,6 +116,11 @@ static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, #ifdef CONFIG_KVM_COMPAT static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); +#define KVM_COMPAT(c) .compat_ioctl = (c) +#else +static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl, + unsigned long arg) { return -EINVAL; } +#define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl #endif static int hardware_enable_all(void); static void hardware_disable_all(void); @@ -2396,11 +2401,9 @@ static int kvm_vcpu_release(struct inode *inode, struct file *filp) static struct file_operations kvm_vcpu_fops = { .release = kvm_vcpu_release, .unlocked_ioctl = kvm_vcpu_ioctl, -#ifdef CONFIG_KVM_COMPAT - .compat_ioctl = kvm_vcpu_compat_ioctl, -#endif .mmap = kvm_vcpu_mmap, .llseek = noop_llseek, + KVM_COMPAT(kvm_vcpu_compat_ioctl), }; /* @@ -2824,10 +2827,8 @@ static int kvm_device_release(struct inode *inode, struct file *filp) static const struct file_operations kvm_device_fops = { .unlocked_ioctl = kvm_device_ioctl, -#ifdef CONFIG_KVM_COMPAT - .compat_ioctl = kvm_device_ioctl, -#endif .release = kvm_device_release, + KVM_COMPAT(kvm_device_ioctl), }; struct kvm_device *kvm_device_from_filp(struct file *filp) @@ -3165,10 +3166,8 @@ static long kvm_vm_compat_ioctl(struct file *filp, static struct file_operations kvm_vm_fops = { .release = kvm_vm_release, .unlocked_ioctl = kvm_vm_ioctl, -#ifdef CONFIG_KVM_COMPAT - .compat_ioctl = kvm_vm_compat_ioctl, -#endif .llseek = noop_llseek, + KVM_COMPAT(kvm_vm_compat_ioctl), }; static int kvm_dev_ioctl_create_vm(unsigned long type) @@ -3259,8 +3258,8 @@ out: static struct file_operations kvm_chardev_ops = { .unlocked_ioctl = kvm_dev_ioctl, - .compat_ioctl = kvm_dev_ioctl, .llseek = noop_llseek, + KVM_COMPAT(kvm_dev_ioctl), }; static struct miscdevice kvm_dev = { |