On 6/28/23 08:59, Cindy Lu wrote:
From: Your Name <[email protected]>
Add the operation for mmap, The user space APP will
use this function to map the pages to userspace
Signed-off-by: Cindy Lu <[email protected]>
---
drivers/vdpa/vdpa_user/vduse_dev.c | 49 ++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c
b/drivers/vdpa/vdpa_user/vduse_dev.c
index f845dc46b1db..1b833bf0ae37 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -1313,6 +1313,54 @@ static struct vduse_dev *vduse_dev_get_from_minor(int
minor)
return dev;
}
+
+static vm_fault_t vduse_vm_fault(struct vm_fault *vmf)
+{
+ struct vduse_dev *dev = vmf->vma->vm_file->private_data;
+ struct vm_area_struct *vma = vmf->vma;
+ u16 index = vma->vm_pgoff;
+
+ struct vdpa_reconnect_info *info;
+ info = &dev->reconnect_info[index];
+
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ if (remap_pfn_range(vma, vmf->address & PAGE_MASK, PFN_DOWN(info->addr),
+ PAGE_SIZE, vma->vm_page_prot))
+ return VM_FAULT_SIGBUS;
+ return VM_FAULT_NOPAGE;
+}
+
+static const struct vm_operations_struct vduse_vm_ops = {
+ .fault = vduse_vm_fault,
+};
+
+static int vduse_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct vduse_dev *dev = file->private_data;
+ struct vdpa_reconnect_info *info;
+ unsigned long index = vma->vm_pgoff;
+
+ if (vma->vm_end - vma->vm_start != PAGE_SIZE)
+ return -EINVAL;
+ if ((vma->vm_flags & VM_SHARED) == 0)
+ return -EINVAL;
+
+ if (index > 65535)
+ return -EINVAL;
You declare an array of 64 entries in patch 1, so it can overflow.
+
+ info = &dev->reconnect_info[index];
+ if (info->addr & (PAGE_SIZE - 1))
+ return -EINVAL;
+ if (vma->vm_end - vma->vm_start != info->size) {
+ return -ENOTSUPP;
+ }
+
+ vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
+ vma->vm_ops = &vduse_vm_ops;
+
+ return 0;
+}
+
static int vduse_dev_open(struct inode *inode, struct file *file)
{
int ret;
@@ -1345,6 +1393,7 @@ static const struct file_operations vduse_dev_fops = {
.unlocked_ioctl = vduse_dev_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.llseek = noop_llseek,
+ .mmap = vduse_mmap,
};
static struct vduse_dev *vduse_dev_create(void)
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