From b3e0d4e37b7902533a463812374947d4d6d2e463 Mon Sep 17 00:00:00 2001 From: Wei Liu 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 Signed-off-by: Wei Liu Signed-off-by: Hongyan Xia Signed-off-by: George Dunlap Acked-by: Jan Beulich --- 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