uio: replace deprecated mmap hook with mmap_prepare in uio_info

The f_op->mmap interface is deprecated, so update uio_info to use its
successor, mmap_prepare.

Therefore, replace the uio_info->mmap hook with a new
uio_info->mmap_prepare hook, and update its one user, target_core_user,
to both specify this new mmap_prepare hook and also to use the new
vm_ops->mapped() hook to continue to maintain a correct udev->kref
refcount.

Then update uio_mmap() to utilise the mmap_prepare compatibility layer to
invoke this callback from the uio mmap invocation.

Link: https://lkml.kernel.org/r/157583e4477705b496896c7acd4ac88a937b8fa6.1774045440.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bodo Stroesser <bostroesser@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Long Li <longli@microsoft.com>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index af95531ddd351e7986c990023d97fec92f685383..edc2afd5f4ee2c10b4bb84ee7290751c15a5e3b4 100644 (file)
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1860,6 +1860,17 @@ static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
        return NULL;
 }
 
+static int tcmu_vma_mapped(unsigned long start, unsigned long end, pgoff_t pgoff,
+                          const struct file *file, void **vm_private_data)
+{
+       struct tcmu_dev *udev = *vm_private_data;
+
+       pr_debug("vma_mapped\n");
+
+       kref_get(&udev->kref);
+       return 0;
+}
+
 static void tcmu_vma_open(struct vm_area_struct *vma)
 {
        struct tcmu_dev *udev = vma->vm_private_data;
@@ -1919,26 +1930,25 @@ static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
 }
 
 static const struct vm_operations_struct tcmu_vm_ops = {
+       .mapped = tcmu_vma_mapped,
        .open = tcmu_vma_open,
        .close = tcmu_vma_close,
        .fault = tcmu_vma_fault,
 };
 
-static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
+static int tcmu_mmap_prepare(struct uio_info *info, struct vm_area_desc *desc)
 {
        struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
 
-       vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
-       vma->vm_ops = &tcmu_vm_ops;
+       vma_desc_set_flags(desc, VMA_DONTEXPAND_BIT, VMA_DONTDUMP_BIT);
+       desc->vm_ops = &tcmu_vm_ops;
 
-       vma->vm_private_data = udev;
+       desc->private_data = udev;
 
        /* Ensure the mmap is exactly the right size */
-       if (vma_pages(vma) != udev->mmap_pages)
+       if (vma_desc_pages(desc) != udev->mmap_pages)
                return -EINVAL;
 
-       tcmu_vma_open(vma);
-
        return 0;
 }
 
@@ -2253,7 +2263,7 @@ static int tcmu_configure_device(struct se_device *dev)
        info->irqcontrol = tcmu_irqcontrol;
        info->irq = UIO_IRQ_CUSTOM;
 
-       info->mmap = tcmu_mmap;
+       info->mmap_prepare = tcmu_mmap_prepare;
        info->open = tcmu_open;
        info->release = tcmu_release;
 

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 5a4998e2caf87938fad21a5a03b1c81b15bfd891..1e4ade78ed8491220787b715b36001de023fcdf9 100644 (file)
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -850,8 +850,14 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
                goto out;
        }
 
-       if (idev->info->mmap) {
-               ret = idev->info->mmap(idev->info, vma);
+       if (idev->info->mmap_prepare) {
+               struct vm_area_desc desc;
+
+               compat_set_desc_from_vma(&desc, filep, vma);
+               ret = idev->info->mmap_prepare(idev->info, &desc);
+               if (ret)
+                       goto out;
+               ret = __compat_vma_mmap(&desc, vma);
                goto out;
        }
 

diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 334641e20fb12017ed0a3a78b5d2f40790cada73..02eaac47ac444a1b12654fcbc42fb1cde8a7be6b 100644 (file)
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -97,7 +97,7 @@ struct uio_device {
  * @irq_flags:         flags for request_irq()
  * @priv:              optional private data
  * @handler:           the device's irq handler
- * @mmap:              mmap operation for this uio device
+ * @mmap_prepare:      mmap_prepare operation for this uio device
  * @open:              open operation for this uio device
  * @release:           release operation for this uio device
  * @irqcontrol:                disable/enable irqs when 0/1 is written to /dev/uioX
@@ -112,7 +112,7 @@ struct uio_info {
        unsigned long           irq_flags;
        void                    *priv;
        irqreturn_t (*handler)(int irq, struct uio_info *dev_info);
-       int (*mmap)(struct uio_info *info, struct vm_area_struct *vma);
+       int (*mmap_prepare)(struct uio_info *info, struct vm_area_desc *desc);
        int (*open)(struct uio_info *info, struct inode *inode);
        int (*release)(struct uio_info *info, struct inode *inode);
        int (*irqcontrol)(struct uio_info *info, s32 irq_on);