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author | Christian Borntraeger <borntraeger@de.ibm.com> | 2014-12-07 22:01:59 +0100 |
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committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2015-01-19 14:14:20 +0100 |
commit | 1760f1eb7ec485197bd3a8a9c13e4160bb740275 (patch) | |
tree | 8582fadb1d21e4e55fbd48f2f572018d05949566 /arch/x86 | |
parent | da1a288d8562739aa8ba0273d4fb6b73b856c0d3 (diff) | |
download | op-kernel-dev-1760f1eb7ec485197bd3a8a9c13e4160bb740275.zip op-kernel-dev-1760f1eb7ec485197bd3a8a9c13e4160bb740275.tar.gz |
x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE
ACCESS_ONCE does not work reliably on non-scalar types. For
example gcc 4.6 and 4.7 might remove the volatile tag for such
accesses during the SRA (scalar replacement of aggregates) step
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145)
Change the p2m code to replace ACCESS_ONCE with READ_ONCE.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/xen/p2m.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index edbc7a6..cb71016 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -554,7 +554,7 @@ static bool alloc_p2m(unsigned long pfn) mid_mfn = NULL; } - p2m_pfn = pte_pfn(ACCESS_ONCE(*ptep)); + p2m_pfn = pte_pfn(READ_ONCE(*ptep)); if (p2m_pfn == PFN_DOWN(__pa(p2m_identity)) || p2m_pfn == PFN_DOWN(__pa(p2m_missing))) { /* p2m leaf page is missing */ |