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

drivers/staging/tidspbridge/rmgr/drv_interface.c

+27 −3
Original line number Diff line number Diff line
@@ -258,6 +258,8 @@ static long bridge_ioctl(struct file *filp, unsigned int code, 
/* This function maps kernel space memory to user space memory. */

static int bridge_mmap(struct file *filp, struct vm_area_struct *vma)

{

	unsigned long base_pgoff;

	int status;

	struct omap_dsp_platform_data *pdata =

					omap_dspbridge_dev->dev.platform_data;
@@ -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_flags);



	return vm_iomap_memory(vma,

	/*

	 * vm_iomap_memory() expects vma->vm_pgoff to be expressed as an offset

	 * 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 = {