NVMe: fix type warning on 32-bit

A recent change to the ioctl handling caused a new harmless
warning in the NVMe driver on all 32-bit machines:

drivers/block/nvme-core.c: In function 'nvme_submit_io':
drivers/block/nvme-core.c:1794:29: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

In order to shup up that warning, this introduces a new
temporary variable that uses a double cast to extract
the pointer from an __u64 structure member.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: a67a95134ff ("NVMe: Meta data handling through submit io ioctl")
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 85b8036..683dff2 100644 (file)
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1750,6 +1750,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        struct nvme_iod *iod;
        dma_addr_t meta_dma = 0;
        void *meta = NULL;
+       void __user *metadata;
 
        if (copy_from_user(&io, uio, sizeof(io)))
                return -EFAULT;
@@ -1763,6 +1764,8 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
                meta_len = 0;
        }
 
+       metadata = (void __user *)(unsigned long)io.metadata;
+
        write = io.opcode & 1;
 
        switch (io.opcode) {
@@ -1786,13 +1789,13 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        if (meta_len) {
                meta = dma_alloc_coherent(&dev->pci_dev->dev, meta_len,
                                                &meta_dma, GFP_KERNEL);
+
                if (!meta) {
                        status = -ENOMEM;
                        goto unmap;
                }
                if (write) {
-                       if (copy_from_user(meta, (void __user *)io.metadata,
-                                                               meta_len)) {
+                       if (copy_from_user(meta, metadata, meta_len)) {
                                status = -EFAULT;
                                goto unmap;
                        }
@@ -1819,8 +1822,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        nvme_free_iod(dev, iod);
        if (meta) {
                if (status == NVME_SC_SUCCESS && !write) {
-                       if (copy_to_user((void __user *)io.metadata, meta,
-                                                               meta_len))
+                       if (copy_to_user(metadata, meta, meta_len))
                                status = -EFAULT;
                }
                dma_free_coherent(&dev->pci_dev->dev, meta_len, meta, meta_dma);