From ddd3d4081ffa806ffef28eaeefde757ba2b6812a Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 11 Apr 2018 10:35:41 +0800 Subject: [PATCH] vhost: return bool from *_access_ok() functions 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 Signed-off-by: Stefan Hajnoczi Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- drivers/vhost/vhost.c | 66 +++++++++++++++++++++---------------------- drivers/vhost/vhost.h | 4 +-- 2 files changed, 35 insertions(+), 35 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 9a18535fafba..f3bd8e941224 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); } 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, -- 2.30.2