svn commit: r294636 - in stable: 10/sys/ofed/include/linux 9/sys/ofed/include/linux

[John Baldwin]

Author: jhb
Date: Sat Jan 23 17:08:17 2016
New Revision: 294636
URL: https://svnweb.freebsd.org/changeset/base/294636

Log:
  MFC 294366:
  Initialize vm_page_prot to VM_MEMATTR_DEFAULT instead of 0.
  
  If a driver's Linux mmap callback passed vm_page_prot through unchanged,
  then linux_dev_mmap_single() would try to apply whatever VM_MEMATTR_xxx
  value 0 is to the mapping.  On x86, VM_MEMATTR_DEFAULT is the PAT value
  for write-back (WB) which is 6, while 0 maps to the PAT value for
  uncacheable (UC).  Thus, any mmap request that did not explicitly set
  page_prot was tried to map memory as UC triggering the warning in
  sg_pager_getpages().
  
  Sponsored by:	Chelsio Communications

Modified:
  stable/9/sys/ofed/include/linux/linux_compat.c
Directory Properties:
  stable/9/sys/   (props changed)

Changes in other areas also in this revision:
Modified:
  stable/10/sys/ofed/include/linux/linux_compat.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/9/sys/ofed/include/linux/linux_compat.c
==============================================================================
--- stable/9/sys/ofed/include/linux/linux_compat.c	Sat Jan 23 15:48:14 2016	(r294635)
+++ stable/9/sys/ofed/include/linux/linux_compat.c	Sat Jan 23 17:08:17 2016	(r294636)
@@ -434,7 +434,7 @@ linux_dev_mmap_single(struct cdev *dev, 
 	vma.vm_end = size;
 	vma.vm_pgoff = *offset / PAGE_SIZE;
 	vma.vm_pfn = 0;
-	vma.vm_page_prot = 0;
+	vma.vm_page_prot = VM_MEMATTR_DEFAULT;
 	if (filp->f_op->mmap) {
 		error = -filp->f_op->mmap(filp, &vma);
 		if (error == 0) {