[Xen-changelog] [xen-unstable] [IA64] Add support for enforcing singleshot mmap() semantics at the

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID 5b3ec078993b11433ba6345e0651143d350b488d
# Parent  d2e6a7be622d306528074b62ea21d0b672ebd0ea
[IA64] Add support for enforcing singleshot mmap() semantics at the
privcmd interface.
From: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
 linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c    |   14 ++++++++++++++
 linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c |   14 +++++++-------
 linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h |    1 +
 3 files changed, 22 insertions(+), 7 deletions(-)

diff -r d2e6a7be622d -r 5b3ec078993b 
linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c
--- a/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c   Thu Oct 12 11:44:53 
2006 +0100
+++ b/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c   Thu Oct 12 13:55:03 
2006 +0100
@@ -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 @@ static void
 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);
 }
@@ -722,6 +726,14 @@ xen_ia64_privcmd_vma_close(struct vm_are
                kfree(privcmd_range->res);
                vfree(privcmd_range);
        }
+}
+
+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
@@ -749,6 +761,8 @@ privcmd_mmap(struct file * file, struct 
        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 -r d2e6a7be622d -r 5b3ec078993b 
linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c
--- a/linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c        Thu Oct 12 
11:44:53 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/privcmd/privcmd.c        Thu Oct 12 
13:55:03 2006 +0100
@@ -35,14 +35,9 @@ static struct proc_dir_entry *privcmd_in
 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;
-#endif
-       return 1;
-}
+static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
+#endif
 
 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 * fi
 
        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 -r d2e6a7be622d -r 5b3ec078993b 
linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h        Thu Oct 12 
11:44:53 2006 +0100
+++ b/linux-2.6-xen-sparse/include/asm-ia64/hypervisor.h        Thu Oct 12 
13:55:03 2006 +0100
@@ -138,6 +138,7 @@ int direct_remap_pfn_range(struct vm_are
                           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
 

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