From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH] kvm: vfio: silence GCC warning Date: Wed, 15 Jan 2014 12:02:10 +0100 Message-ID: <52D66AB2.6090601@redhat.com> References: <1389313726.2039.9.camel@x220> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , kvm@vger.kernel.org, linux-kernel@vger.kernel.org To: Paul Bolle Return-path: In-Reply-To: <1389313726.2039.9.camel@x220> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Il 10/01/2014 01:28, Paul Bolle ha scritto: > Building vfio.o triggers a GCC warning (when building for 32 bits x86): > arch/x86/kvm/../../../virt/kvm/vfio.c: In function 'kvm_vfio_set_group': > arch/x86/kvm/../../../virt/kvm/vfio.c:104:22: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] > void __user *argp = (void __user *)arg; > ^ > > Silence this warning by casting arg to unsigned long. > > argp's current type, "void __user *", is always casted to "int32_t > __user *". So its type might as well be changed to "int32_t __user *". > > Signed-off-by: Paul Bolle > --- > Compile tested on both 32 and 64 bits x86. I've no KVM capable hardware > that is already running v3.13-rc* at hand. Besides, I wouldn't know how > to test the codepaths I'm changing here. > > virt/kvm/vfio.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c > index ca4260e..b4f9507 100644 > --- a/virt/kvm/vfio.c > +++ b/virt/kvm/vfio.c > @@ -101,14 +101,14 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) > struct kvm_vfio *kv = dev->private; > struct vfio_group *vfio_group; > struct kvm_vfio_group *kvg; > - void __user *argp = (void __user *)arg; > + int32_t __user *argp = (int32_t __user *)(unsigned long)arg; > struct fd f; > int32_t fd; > int ret; > > switch (attr) { > case KVM_DEV_VFIO_GROUP_ADD: > - if (get_user(fd, (int32_t __user *)argp)) > + if (get_user(fd, argp)) > return -EFAULT; > > f = fdget(fd); > @@ -148,7 +148,7 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) > return 0; > > case KVM_DEV_VFIO_GROUP_DEL: > - if (get_user(fd, (int32_t __user *)argp)) > + if (get_user(fd, argp)) > return -EFAULT; > > f = fdget(fd); > Applied to kvm/queue, thanks. Paolo