• Michael S. Tsirkin's avatar
    KVM: make processes waiting on vcpu mutex killable · 9fc77441
    Michael S. Tsirkin authored
    vcpu mutex can be held for unlimited time so
    taking it with mutex_lock on an ioctl is wrong:
    one process could be passed a vcpu fd and
    call this ioctl on the vcpu used by another process,
    it will then be unkillable until the owner exits.
    Call mutex_lock_killable instead and return status.
    Note: mutex_lock_interruptible would be even nicer,
    but I am not sure all users are prepared to handle EINTR
    from these ioctls. They might misinterpret it as an error.
    Cleanup paths expect a vcpu that can't be used by
    any userspace so this will always succeed - catch bugs
    by calling BUG_ON.
    Catch callers that don't check return state by adding
    Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
    Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>