diff options
| -rw-r--r-- | arch/x86/xen/p2m.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index d1b3da2960ab..b456b048eca9 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -532,12 +532,13 @@ static bool alloc_p2m(unsigned long pfn) unsigned topidx, mididx; unsigned long ***top_p, **mid; unsigned long *top_mfn_p, *mid_mfn; + unsigned long *p2m_orig; topidx = p2m_top_index(pfn); mididx = p2m_mid_index(pfn); top_p = &p2m_top[topidx]; - mid = *top_p; + mid = ACCESS_ONCE(*top_p); if (mid == p2m_mid_missing) { /* Mid level is missing, allocate a new one */ @@ -552,7 +553,7 @@ static bool alloc_p2m(unsigned long pfn) } top_mfn_p = &p2m_top_mfn[topidx]; - mid_mfn = p2m_top_mfn_p[topidx]; + mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]); BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p); @@ -579,11 +580,10 @@ static bool alloc_p2m(unsigned long pfn) } } - if (p2m_top[topidx][mididx] == p2m_identity || - p2m_top[topidx][mididx] == p2m_missing) { + p2m_orig = ACCESS_ONCE(p2m_top[topidx][mididx]); + if (p2m_orig == p2m_identity || p2m_orig == p2m_missing) { /* p2m leaf page is missing */ unsigned long *p2m; - unsigned long *p2m_orig = p2m_top[topidx][mididx]; p2m = alloc_p2m_page(); if (!p2m) |