[PATCH 1/2] uio: provide vm access to UIO_MEM_PHYS maps

From: Uwe Kleine-KÃnig
Date: Fri Apr 26 2013 - 06:02:46 EST


This makes it possible to let gdb access mappings of the process that is
being debugged.

uio_mmap_logical was moved and uio_vm_ops renamed to group related code
and differentiate to new stuff.

Signed-off-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
---
drivers/uio/uio.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index c8b9262..f9c905a 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -629,12 +629,24 @@ static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
return 0;
}

-static const struct vm_operations_struct uio_vm_ops = {
+static const struct vm_operations_struct uio_logical_vm_ops = {
.open = uio_vma_open,
.close = uio_vma_close,
.fault = uio_vma_fault,
};

+static int uio_mmap_logical(struct vm_area_struct *vma)
+{
+ vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+ vma->vm_ops = &uio_vm_ops;
+ uio_vma_open(vma);
+ return 0;
+}
+
+static const struct vm_operations_struct uio_physical_vm_ops = {
+ .access = generic_access_phys,
+};
+
static int uio_mmap_physical(struct vm_area_struct *vma)
{
struct uio_device *idev = vma->vm_private_data;
@@ -642,6 +654,8 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
if (mi < 0)
return -EINVAL;

+ vma->vm_ops = &uio_physical_vm_ops;
+
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

return remap_pfn_range(vma,
@@ -651,14 +665,6 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
vma->vm_page_prot);
}

-static int uio_mmap_logical(struct vm_area_struct *vma)
-{
- vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
- vma->vm_ops = &uio_vm_ops;
- uio_vma_open(vma);
- return 0;
-}
-
static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
{
struct uio_listener *listener = filep->private_data;
--
1.8.2.rc2

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