From b3e0d4e37b7902533a463812374947d4d6d2e463 Mon Sep 17 00:00:00 2001
From: Wei Liu <wei.liu2@citrix.com>
Date: Sat, 11 Jan 2020 21:57:41 +0000
Subject: [PATCH 1/3] x86/mm: Refactor map_pages_to_xen to have only a single
exit path
We will soon need to perform clean-ups before returning.
No functional change.
This is part of XSA-345.
Reported-by: Hongyan Xia <hongyxia@amazon.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Hongyan Xia <hongyxia@amazon.com>
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
xen/arch/x86/mm.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 30dffb68e8..133a393875 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5187,6 +5187,7 @@ int map_pages_to_xen(
l2_pgentry_t *pl2e, ol2e;
l1_pgentry_t *pl1e, ol1e;
unsigned int i;
+ int rc = -ENOMEM;
#define flush_flags(oldf) do { \
unsigned int o_ = (oldf); \
@@ -5207,7 +5208,8 @@ int map_pages_to_xen(
l3_pgentry_t ol3e, *pl3e = virt_to_xen_l3e(virt);
if ( !pl3e )
- return -ENOMEM;
+ goto out;
+
ol3e = *pl3e;
if ( cpu_has_page1gb &&
@@ -5295,7 +5297,7 @@ int map_pages_to_xen(
pl2e = alloc_xen_pagetable();
if ( pl2e == NULL )
- return -ENOMEM;
+ goto out;
for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
l2e_write(pl2e + i,
@@ -5324,7 +5326,7 @@ int map_pages_to_xen(
pl2e = virt_to_xen_l2e(virt);
if ( !pl2e )
- return -ENOMEM;
+ goto out;
if ( ((((virt >> PAGE_SHIFT) | mfn_x(mfn)) &
((1u << PAGETABLE_ORDER) - 1)) == 0) &&
@@ -5367,7 +5369,7 @@ int map_pages_to_xen(
{
pl1e = virt_to_xen_l1e(virt);
if ( pl1e == NULL )
- return -ENOMEM;
+ goto out;
}
else if ( l2e_get_flags(*pl2e) & _PAGE_PSE )
{
@@ -5394,7 +5396,7 @@ int map_pages_to_xen(
pl1e = alloc_xen_pagetable();
if ( pl1e == NULL )
- return -ENOMEM;
+ goto out;
for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
l1e_write(&pl1e[i],
@@ -5538,7 +5540,10 @@ int map_pages_to_xen(
#undef flush_flags
- return 0;
+ rc = 0;
+
+ out:
+ return rc;
}
int populate_pt_range(unsigned long virt, unsigned long nr_mfns)
--
2.25.1
|