[IA64] Add support for enforcing singleshot mmap() semantics at the

privcmd interface.
From: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c b/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c
index 0b286047b9763be0f4c04a79bcb6f9ede077515e..93de4653641cb2d3f405baba15cb2b986f7ede62 100644 (file)
--- a/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c
+++ b/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c
@@ -546,6 +546,7 @@ struct xen_ia64_privcmd_range {
 };
 
 struct xen_ia64_privcmd_vma {
+       int                             is_privcmd_mmapped;
        struct xen_ia64_privcmd_range*  range;
 
        unsigned long                   num_entries;
@@ -684,12 +685,15 @@ __xen_ia64_privcmd_vma_open(struct vm_area_struct* vma,
 static void
 xen_ia64_privcmd_vma_open(struct vm_area_struct* vma)
 {
+       struct xen_ia64_privcmd_vma* old_privcmd_vma = (struct xen_ia64_privcmd_vma*)vma->vm_private_data;
        struct xen_ia64_privcmd_vma* privcmd_vma = (struct xen_ia64_privcmd_vma*)vma->vm_private_data;
        struct xen_ia64_privcmd_range* privcmd_range = privcmd_vma->range;
 
        atomic_inc(&privcmd_range->ref_count);
        // vm_op->open() can't fail.
        privcmd_vma = kmalloc(sizeof(*privcmd_vma), GFP_KERNEL | __GFP_NOFAIL);
+       // copy original value if necessary
+       privcmd_vma->is_privcmd_mmapped = old_privcmd_vma->is_privcmd_mmapped;
 
        __xen_ia64_privcmd_vma_open(vma, privcmd_vma, privcmd_range);
 }
@@ -724,6 +728,14 @@ xen_ia64_privcmd_vma_close(struct vm_area_struct* vma)
        }
 }
 
+int
+privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
+{
+       struct xen_ia64_privcmd_vma* privcmd_vma =
+               (struct xen_ia64_privcmd_vma *)vma->vm_private_data;
+       return (xchg(&privcmd_vma->is_privcmd_mmapped, 1) == 0);
+}
+
 int
 privcmd_mmap(struct file * file, struct vm_area_struct * vma)
 {
@@ -749,6 +761,8 @@ privcmd_mmap(struct file * file, struct vm_area_struct * vma)
        if (privcmd_vma == NULL) {
                goto out_enomem1;
        }
+       privcmd_vma->is_privcmd_mmapped = 0;
+
        res = kzalloc(sizeof(*res), GFP_KERNEL);
        if (res == NULL) {
                goto out_enomem1;

diff --git a/linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c b/linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c
index a17d0769003bb187790ef2e8c084d1acda260c00..9459229664ec86c95b67c4215fda78a75f80ec6c 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c
+++ b/linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c
@@ -35,14 +35,9 @@
 static struct proc_dir_entry *privcmd_intf;
 static struct proc_dir_entry *capabilities_intf;
 
-static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
-{
 #ifndef HAVE_ARCH_PRIVCMD_MMAP
-       if (xchg(&vma->vm_private_data, (void *)1) != NULL)
-               return 0;
+static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
 #endif
-       return 1;
-}
 
 static int privcmd_ioctl(struct inode *inode, struct file *file,
                         unsigned int cmd, unsigned long data)
@@ -255,6 +250,11 @@ static int privcmd_mmap(struct file * file, struct vm_area_struct * vma)
 
        return 0;
 }
+
+static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
+{
+       return (xchg(&vma->vm_private_data, (void *)1) == NULL);
+}
 #endif
 
 static struct file_operations privcmd_file_ops = {

diff --git a/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h b/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h
index 7b1a9a7fc9d6d588027630f00bdc71f169751e46..acdf51203adac63ccfbeceee6d0f4ba7ba231e0b 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h
+++ b/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h
@@ -138,6 +138,7 @@ int direct_remap_pfn_range(struct vm_area_struct *vma,
                           pgprot_t prot,
                           domid_t  domid);
 struct file;
+int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
 int privcmd_mmap(struct file * file, struct vm_area_struct * vma);
 #define HAVE_ARCH_PRIVCMD_MMAP