Commit ed75098f authored by Steven Luo's avatar Steven Luo Committed by Greg Kroah-Hartman

Staging: TIDSPBRIDGE: Fix mmap to map the correct region of physical memory

Commit 559c71fe ("Staging: TIDSPBRIDGE: Use vm_iomap_memory for
mmap-ing instead of remap_pfn_range") had the effect of inadvertently
shifting the start of the physical memory area mapped by
pdata->phys_mempool_base.  Correct this by subtracting that shift before
calling vm_iomap_memory() and adding it back afterwards.
Reported-by: default avatarDheeraj CVR <cvr.dheeraj@gmail.com>
Signed-off-by: default avatarIvaylo Dimitrov <freemangordon@abv.bg>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 76981cf1
...@@ -258,6 +258,8 @@ static long bridge_ioctl(struct file *filp, unsigned int code, ...@@ -258,6 +258,8 @@ static long bridge_ioctl(struct file *filp, unsigned int code,
/* This function maps kernel space memory to user space memory. */ /* This function maps kernel space memory to user space memory. */
static int bridge_mmap(struct file *filp, struct vm_area_struct *vma) static int bridge_mmap(struct file *filp, struct vm_area_struct *vma)
{ {
unsigned long base_pgoff;
int status;
struct omap_dsp_platform_data *pdata = struct omap_dsp_platform_data *pdata =
omap_dspbridge_dev->dev.platform_data; omap_dspbridge_dev->dev.platform_data;
...@@ -269,9 +271,31 @@ static int bridge_mmap(struct file *filp, struct vm_area_struct *vma) ...@@ -269,9 +271,31 @@ static int bridge_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_start, vma->vm_end, vma->vm_page_prot, vma->vm_start, vma->vm_end, vma->vm_page_prot,
vma->vm_flags); vma->vm_flags);
return vm_iomap_memory(vma, /*
pdata->phys_mempool_base, * vm_iomap_memory() expects vma->vm_pgoff to be expressed as an offset
pdata->phys_mempool_size); * from the start of the physical memory pool, but we're called with
* a pfn (physical page number) stored there instead.
*
* To avoid duplicating lots of tricky overflow checking logic,
* temporarily convert vma->vm_pgoff to the offset vm_iomap_memory()
* expects, but restore the original value once the mapping has been
* created.
*/
base_pgoff = pdata->phys_mempool_base >> PAGE_SHIFT;
if (vma->vm_pgoff < base_pgoff)
return -EINVAL;
vma->vm_pgoff -= base_pgoff;
status = vm_iomap_memory(vma,
pdata->phys_mempool_base,
pdata->phys_mempool_size);
/* Restore the original value of vma->vm_pgoff */
vma->vm_pgoff += base_pgoff;
return status;
} }
static const struct file_operations bridge_fops = { static const struct file_operations bridge_fops = {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment