release/4.8.27/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch

From foo@baz Wed Jan  3 20:37:21 CET 2018
From: Hugh Dickins <hughd@google.com>
Date: Sun, 3 Sep 2017 19:23:08 -0700
Subject: kaiser: tidied up kaiser_add/remove_mapping slightly

From: Hugh Dickins <hughd@google.com>


Yes, unmap_pud_range_nofree()'s declaration ought to be in a
header file really, but I'm not sure we want to use it anyway:
so for now just declare it inside kaiser_remove_mapping().
And there doesn't seem to be such a thing as unmap_p4d_range(),
even in a 5-level paging tree.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/mm/kaiser.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -285,8 +285,7 @@ void __init kaiser_init(void)
 				  __PAGE_KERNEL);
 }
 
-extern void unmap_pud_range_nofree(pgd_t *pgd, unsigned long start, unsigned long end);
-// add a mapping to the shadow-mapping, and synchronize the mappings
+/* Add a mapping to the shadow mapping, and synchronize the mappings */
 int kaiser_add_mapping(unsigned long addr, unsigned long size, unsigned long flags)
 {
 	return kaiser_add_user_map((const void *)addr, size, flags);
@@ -294,15 +293,13 @@ int kaiser_add_mapping(unsigned long add
 
 void kaiser_remove_mapping(unsigned long start, unsigned long size)
 {
+	extern void unmap_pud_range_nofree(pgd_t *pgd,
+				unsigned long start, unsigned long end);
 	unsigned long end = start + size;
 	unsigned long addr;
 
 	for (addr = start; addr < end; addr += PGDIR_SIZE) {
 		pgd_t *pgd = native_get_shadow_pgd(pgd_offset_k(addr));
-		/*
-		 * unmap_p4d_range() handles > P4D_SIZE unmaps,
-		 * so no need to trim 'end'.
-		 */
 		unmap_pud_range_nofree(pgd, addr, end);
 	}
 }