Commit 3c6c065a authored Oct 26, 2015 by Mitko Haralanov Committed by Greg Kroah-Hartman Oct 27, 2015

staging/rdma/hfi1: Wrong cast breaks desired pointer arithmetic



The address being mapped into a process's memory for notification events was
improperly calculated due to cast that was happening too early. dd->events is a
pointer and should have been casted to unsigned long after the pointer
arithmetic was done, not before.

As a result, processes were looking at the wrong place and not seeing their
notification events.

Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b9fb6318

drivers/staging/rdma/hfi1/file_ops.c

+3 −3

Original line number	Original line	Diff line number	Diff line
	@@ -607,7 +607,7 @@ static int hfi1_file_mmap(struct file fp, struct vm_area_struct vma)
	* Use the page where this context's flags are. User level		* Use the page where this context's flags are. User level
	* knows where it's own bitmap is within the page.		* knows where it's own bitmap is within the page.
	*/		*/
	memaddr = ((unsigned long)dd->events +		memaddr = (unsigned long)(dd->events +
	((uctxt->ctxt - dd->first_user_ctxt) *		((uctxt->ctxt - dd->first_user_ctxt) *
	HFI1_MAX_SHARED_CTXTS)) & PAGE_MASK;		HFI1_MAX_SHARED_CTXTS)) & PAGE_MASK;
	memlen = PAGE_SIZE;		memlen = PAGE_SIZE;