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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-09-04 15:45:17 -0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-09-05 09:47:41 -0400 |
| commit | 50e900417b8096939d12a46848f965e27a905e36 (patch) | |
| tree | 1bd5945867f1071965665381bbe96ef0cd878e37 /arch/x86 | |
| parent | c96aae1f7f393387d160211f60398d58463a7e65 (diff) | |
| download | linux-50e900417b8096939d12a46848f965e27a905e36.tar.bz2 | |
xen/p2m: Fix one-off error in checking the P2M tree directory.
We would traverse the full P2M top directory (from 0->MAX_DOMAIN_PAGES
inclusive) when trying to figure out whether we can re-use some of the
P2M middle leafs.
Which meant that if the kernel was compiled with MAX_DOMAIN_PAGES=512
we would try to use the 512th entry. Fortunately for us the p2m_top_index
has a check for this:
BUG_ON(pfn >= MAX_P2M_PFN);
which we hit and saw this:
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.1.2-OVM x86_64 debug=n Tainted: C ]----
(XEN) CPU: 0
(XEN) RIP: e033:[<ffffffff819cadeb>]
(XEN) RFLAGS: 0000000000000212 EM: 1 CONTEXT: pv guest
(XEN) rax: ffffffff81db5000 rbx: ffffffff81db4000 rcx: 0000000000000000
(XEN) rdx: 0000000000480211 rsi: 0000000000000000 rdi: ffffffff81db4000
(XEN) rbp: ffffffff81793db8 rsp: ffffffff81793d38 r8: 0000000008000000
(XEN) r9: 4000000000000000 r10: 0000000000000000 r11: ffffffff81db7000
(XEN) r12: 0000000000000ff8 r13: ffffffff81df1ff8 r14: ffffffff81db6000
(XEN) r15: 0000000000000ff8 cr0: 000000008005003b cr4: 00000000000026f0
(XEN) cr3: 0000000661795000 cr2: 0000000000000000
Fixes-Oracle-Bug: 14570662
CC: stable@vger.kernel.org # only for v3.5
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.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 d4b255463253..76ba0e97e530 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -599,7 +599,7 @@ bool __init early_can_reuse_p2m_middle(unsigned long set_pfn, unsigned long set_ if (p2m_index(set_pfn)) return false; - for (pfn = 0; pfn <= MAX_DOMAIN_PAGES; pfn += P2M_PER_PAGE) { + for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_PER_PAGE) { topidx = p2m_top_index(pfn); if (!p2m_top[topidx]) |