| Message ID | 20180411023541.15776-3-stefanha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Apr 11, 2018 at 10:35:41AM +0800, Stefan Hajnoczi wrote: > Currently vhost *_access_ok() functions return int. This is error-prone > because there are two popular conventions: > > 1. 0 means failure, 1 means success > 2. -errno means failure, 0 means success > > Although vhost mostly uses #1, it does not do so consistently. > umem_access_ok() uses #2. > > This patch changes the return type from int to bool so that false means > failure and true means success. This eliminates a potential source of > errors. > > Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/vhost/vhost.h | 4 ++-- > drivers/vhost/vhost.c | 66 +++++++++++++++++++++++++-------------------------- > 2 files changed, 35 insertions(+), 35 deletions(-) > > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index d8ee85ae8fdc..6c844b90a168 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -178,8 +178,8 @@ void vhost_dev_cleanup(struct vhost_dev *); > void vhost_dev_stop(struct vhost_dev *); > long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); > long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); > -int vhost_vq_access_ok(struct vhost_virtqueue *vq); > -int vhost_log_access_ok(struct vhost_dev *); > +bool vhost_vq_access_ok(struct vhost_virtqueue *vq); > +bool vhost_log_access_ok(struct vhost_dev *); > > int vhost_get_vq_desc(struct vhost_virtqueue *, > struct iovec iov[], unsigned int iov_count, > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index fc805b7fad9d..0fcb51a9940c 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -641,14 +641,14 @@ void vhost_dev_cleanup(struct vhost_dev *dev) > } > EXPORT_SYMBOL_GPL(vhost_dev_cleanup); > > -static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) > +static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) > { > u64 a = addr / VHOST_PAGE_SIZE / 8; > > /* Make sure 64 bit math will not overflow. */ > if (a > ULONG_MAX - (unsigned long)log_base || > a + (unsigned long)log_base > ULONG_MAX) > - return 0; > + return false; > > return access_ok(VERIFY_WRITE, log_base + a, > (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); > @@ -661,30 +661,30 @@ static bool vhost_overflow(u64 uaddr, u64 size) > } > > /* Caller should have vq mutex and device mutex. */ > -static int vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, > - int log_all) > +static bool vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, > + int log_all) > { > struct vhost_umem_node *node; > > if (!umem) > - return 0; > + return false; > > list_for_each_entry(node, &umem->umem_list, link) { > unsigned long a = node->userspace_addr; > > if (vhost_overflow(node->userspace_addr, node->size)) > - return 0; > + return false; > > > if (!access_ok(VERIFY_WRITE, (void __user *)a, > node->size)) > - return 0; > + return false; > else if (log_all && !log_access_ok(log_base, > node->start, > node->size)) > - return 0; > + return false; > } > - return 1; > + return true; > } > > static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, > @@ -701,13 +701,13 @@ static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, > > /* Can we switch to this memory table? */ > /* Caller should have device mutex but not vq mutex */ > -static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, > - int log_all) > +static bool memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, > + int log_all) > { > int i; > > for (i = 0; i < d->nvqs; ++i) { > - int ok; > + bool ok; > bool log; > > mutex_lock(&d->vqs[i]->mutex); > @@ -717,12 +717,12 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, > ok = vq_memory_access_ok(d->vqs[i]->log_base, > umem, log); > else > - ok = 1; > + ok = true; > mutex_unlock(&d->vqs[i]->mutex); > if (!ok) > - return 0; > + return false; > } > - return 1; > + return true; > } > > static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, > @@ -959,21 +959,21 @@ static void vhost_iotlb_notify_vq(struct vhost_dev *d, > spin_unlock(&d->iotlb_lock); > } > > -static int umem_access_ok(u64 uaddr, u64 size, int access) > +static bool umem_access_ok(u64 uaddr, u64 size, int access) > { > unsigned long a = uaddr; > > /* Make sure 64 bit math will not overflow. */ > if (vhost_overflow(uaddr, size)) > - return -EFAULT; > + return false; > > if ((access & VHOST_ACCESS_RO) && > !access_ok(VERIFY_READ, (void __user *)a, size)) > - return -EFAULT; > + return false; > if ((access & VHOST_ACCESS_WO) && > !access_ok(VERIFY_WRITE, (void __user *)a, size)) > - return -EFAULT; > - return 0; > + return false; > + return true; > } > > static int vhost_process_iotlb_msg(struct vhost_dev *dev, > @@ -988,7 +988,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev, > ret = -EFAULT; > break; > } > - if (umem_access_ok(msg->uaddr, msg->size, msg->perm)) { > + if (!umem_access_ok(msg->uaddr, msg->size, msg->perm)) { > ret = -EFAULT; > break; > } > @@ -1135,10 +1135,10 @@ static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) > return 0; > } > > -static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, > - struct vring_desc __user *desc, > - struct vring_avail __user *avail, > - struct vring_used __user *used) > +static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, > + struct vring_desc __user *desc, > + struct vring_avail __user *avail, > + struct vring_used __user *used) > > { > size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; > @@ -1161,8 +1161,8 @@ static void vhost_vq_meta_update(struct vhost_virtqueue *vq, > vq->meta_iotlb[type] = node; > } > > -static int iotlb_access_ok(struct vhost_virtqueue *vq, > - int access, u64 addr, u64 len, int type) > +static bool iotlb_access_ok(struct vhost_virtqueue *vq, > + int access, u64 addr, u64 len, int type) > { > const struct vhost_umem_node *node; > struct vhost_umem *umem = vq->iotlb; > @@ -1220,7 +1220,7 @@ EXPORT_SYMBOL_GPL(vq_iotlb_prefetch); > > /* Can we log writes? */ > /* Caller should have device mutex but not vq mutex */ > -int vhost_log_access_ok(struct vhost_dev *dev) > +bool vhost_log_access_ok(struct vhost_dev *dev) > { > return memory_access_ok(dev, dev->umem, 1); > } > @@ -1228,8 +1228,8 @@ EXPORT_SYMBOL_GPL(vhost_log_access_ok); > > /* Verify access for write logging. */ > /* Caller should have vq mutex and device mutex */ > -static int vq_log_access_ok(struct vhost_virtqueue *vq, > - void __user *log_base) > +static bool vq_log_access_ok(struct vhost_virtqueue *vq, > + void __user *log_base) > { > size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; > > @@ -1242,14 +1242,14 @@ static int vq_log_access_ok(struct vhost_virtqueue *vq, > > /* Can we start vq? */ > /* Caller should have vq mutex and device mutex */ > -int vhost_vq_access_ok(struct vhost_virtqueue *vq) > +bool vhost_vq_access_ok(struct vhost_virtqueue *vq) > { > if (!vq_log_access_ok(vq, vq->log_base)) > - return 0; > + return false; > > /* Access validation occurs at prefetch time with IOTLB */ > if (vq->iotlb) > - return 1; > + return true; > > return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); > } > -- > 2.14.3
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index d8ee85ae8fdc..6c844b90a168 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -178,8 +178,8 @@ void vhost_dev_cleanup(struct vhost_dev *); void vhost_dev_stop(struct vhost_dev *); long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); -int vhost_vq_access_ok(struct vhost_virtqueue *vq); -int vhost_log_access_ok(struct vhost_dev *); +bool vhost_vq_access_ok(struct vhost_virtqueue *vq); +bool vhost_log_access_ok(struct vhost_dev *); int vhost_get_vq_desc(struct vhost_virtqueue *, struct iovec iov[], unsigned int iov_count, diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index fc805b7fad9d..0fcb51a9940c 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -641,14 +641,14 @@ void vhost_dev_cleanup(struct vhost_dev *dev) } EXPORT_SYMBOL_GPL(vhost_dev_cleanup); -static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) +static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) { u64 a = addr / VHOST_PAGE_SIZE / 8; /* Make sure 64 bit math will not overflow. */ if (a > ULONG_MAX - (unsigned long)log_base || a + (unsigned long)log_base > ULONG_MAX) - return 0; + return false; return access_ok(VERIFY_WRITE, log_base + a, (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); @@ -661,30 +661,30 @@ static bool vhost_overflow(u64 uaddr, u64 size) } /* Caller should have vq mutex and device mutex. */ -static int vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, - int log_all) +static bool vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, + int log_all) { struct vhost_umem_node *node; if (!umem) - return 0; + return false; list_for_each_entry(node, &umem->umem_list, link) { unsigned long a = node->userspace_addr; if (vhost_overflow(node->userspace_addr, node->size)) - return 0; + return false; if (!access_ok(VERIFY_WRITE, (void __user *)a, node->size)) - return 0; + return false; else if (log_all && !log_access_ok(log_base, node->start, node->size)) - return 0; + return false; } - return 1; + return true; } static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, @@ -701,13 +701,13 @@ static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, /* Can we switch to this memory table? */ /* Caller should have device mutex but not vq mutex */ -static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, - int log_all) +static bool memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, + int log_all) { int i; for (i = 0; i < d->nvqs; ++i) { - int ok; + bool ok; bool log; mutex_lock(&d->vqs[i]->mutex); @@ -717,12 +717,12 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, ok = vq_memory_access_ok(d->vqs[i]->log_base, umem, log); else - ok = 1; + ok = true; mutex_unlock(&d->vqs[i]->mutex); if (!ok) - return 0; + return false; } - return 1; + return true; } static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, @@ -959,21 +959,21 @@ static void vhost_iotlb_notify_vq(struct vhost_dev *d, spin_unlock(&d->iotlb_lock); } -static int umem_access_ok(u64 uaddr, u64 size, int access) +static bool umem_access_ok(u64 uaddr, u64 size, int access) { unsigned long a = uaddr; /* Make sure 64 bit math will not overflow. */ if (vhost_overflow(uaddr, size)) - return -EFAULT; + return false; if ((access & VHOST_ACCESS_RO) && !access_ok(VERIFY_READ, (void __user *)a, size)) - return -EFAULT; + return false; if ((access & VHOST_ACCESS_WO) && !access_ok(VERIFY_WRITE, (void __user *)a, size)) - return -EFAULT; - return 0; + return false; + return true; } static int vhost_process_iotlb_msg(struct vhost_dev *dev, @@ -988,7 +988,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev, ret = -EFAULT; break; } - if (umem_access_ok(msg->uaddr, msg->size, msg->perm)) { + if (!umem_access_ok(msg->uaddr, msg->size, msg->perm)) { ret = -EFAULT; break; } @@ -1135,10 +1135,10 @@ static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) return 0; } -static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, - struct vring_desc __user *desc, - struct vring_avail __user *avail, - struct vring_used __user *used) +static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, + struct vring_desc __user *desc, + struct vring_avail __user *avail, + struct vring_used __user *used) { size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; @@ -1161,8 +1161,8 @@ static void vhost_vq_meta_update(struct vhost_virtqueue *vq, vq->meta_iotlb[type] = node; } -static int iotlb_access_ok(struct vhost_virtqueue *vq, - int access, u64 addr, u64 len, int type) +static bool iotlb_access_ok(struct vhost_virtqueue *vq, + int access, u64 addr, u64 len, int type) { const struct vhost_umem_node *node; struct vhost_umem *umem = vq->iotlb; @@ -1220,7 +1220,7 @@ EXPORT_SYMBOL_GPL(vq_iotlb_prefetch); /* Can we log writes? */ /* Caller should have device mutex but not vq mutex */ -int vhost_log_access_ok(struct vhost_dev *dev) +bool vhost_log_access_ok(struct vhost_dev *dev) { return memory_access_ok(dev, dev->umem, 1); } @@ -1228,8 +1228,8 @@ EXPORT_SYMBOL_GPL(vhost_log_access_ok); /* Verify access for write logging. */ /* Caller should have vq mutex and device mutex */ -static int vq_log_access_ok(struct vhost_virtqueue *vq, - void __user *log_base) +static bool vq_log_access_ok(struct vhost_virtqueue *vq, + void __user *log_base) { size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; @@ -1242,14 +1242,14 @@ static int vq_log_access_ok(struct vhost_virtqueue *vq, /* Can we start vq? */ /* Caller should have vq mutex and device mutex */ -int vhost_vq_access_ok(struct vhost_virtqueue *vq) +bool vhost_vq_access_ok(struct vhost_virtqueue *vq) { if (!vq_log_access_ok(vq, vq->log_base)) - return 0; + return false; /* Access validation occurs at prefetch time with IOTLB */ if (vq->iotlb) - return 1; + return true; return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); }
Currently vhost *_access_ok() functions return int. This is error-prone because there are two popular conventions: 1. 0 means failure, 1 means success 2. -errno means failure, 0 means success Although vhost mostly uses #1, it does not do so consistently. umem_access_ok() uses #2. This patch changes the return type from int to bool so that false means failure and true means success. This eliminates a potential source of errors. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- drivers/vhost/vhost.h | 4 ++-- drivers/vhost/vhost.c | 66 +++++++++++++++++++++++++-------------------------- 2 files changed, 35 insertions(+), 35 deletions(-)