diff options
| -rw-r--r-- | arch/x86/xen/p2m.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 9f5983b01ed9..4534320e66e4 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -566,6 +566,7 @@ static bool alloc_p2m(unsigned long pfn) /* Separately check the mid mfn level */ unsigned long missing_mfn; unsigned long mid_mfn_mfn; + unsigned long old_mfn; mid_mfn = alloc_p2m_page(); if (!mid_mfn) @@ -575,10 +576,13 @@ static bool alloc_p2m(unsigned long pfn) missing_mfn = virt_to_mfn(p2m_mid_missing_mfn); mid_mfn_mfn = virt_to_mfn(mid_mfn); - if (cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn) != missing_mfn) + old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn); + if (old_mfn != missing_mfn) { free_p2m_page(mid_mfn); - else + mid_mfn = mfn_to_virt(old_mfn); + } else { p2m_top_mfn_p[topidx] = mid_mfn; + } } if (p2m_top[topidx][mididx] == p2m_identity || |