From 07ad8ff3b84771257b36545af8192171eabbd8ac Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Tue, 20 Oct 2020 15:19:23 +0200 Subject: [PATCH] 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 master commit: 08e6c6f80b018878476adc2c4e5679d2ce5cb4b1 master date: 2020-10-20 14:19:31 +0200 --- 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 fd734ff947..f6df0a41f1 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -5112,6 +5112,7 @@ 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); \ @@ -5132,7 +5133,8 @@ 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 && @@ -5218,7 +5220,7 @@ 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, @@ -5247,7 +5249,7 @@ int map_pages_to_xen( pl2e = virt_to_xen_l2e(virt); if ( !pl2e ) - return -ENOMEM; + goto out; if ( ((((virt >> PAGE_SHIFT) | mfn) & ((1u << PAGETABLE_ORDER) - 1)) == 0) && @@ -5289,7 +5291,7 @@ 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 ) { @@ -5315,7 +5317,7 @@ 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], @@ -5458,7 +5460,10 @@ int map_pages_to_xen( #undef flush_flags - return 0; + rc = 0; + + out: + return rc; } int populate_pt_range(unsigned long virt, unsigned long mfn, -- 2.39.5