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authorNadav Amit <namit@cs.technion.ac.il>2015-01-26 09:32:26 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2015-01-26 12:15:18 +0100
commitbac155310be35e0fa64b066d47625d2a12a75122 (patch)
tree14dd9f7eae1b56432132c6d89c30eeb4b9f846b6 /arch
parent2b42fce6954d1730edaf479d02378703e7b821cb (diff)
downloadblackbird-op-linux-bac155310be35e0fa64b066d47625d2a12a75122.tar.gz
blackbird-op-linux-bac155310be35e0fa64b066d47625d2a12a75122.zip
KVM: x86: 32-bit wraparound read/write not emulated correctly
If we got a wraparound of 32-bit operand, and the limit is 0xffffffff, read and writes should be successful. It just needs to be done in two segments. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/emulate.c10
-rw-r--r--arch/x86/kvm/x86.c2
2 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 997c9ebb70ef..c3b07574942f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -684,9 +684,13 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
}
if (addr.ea > lim)
goto bad;
- *max_size = min_t(u64, ~0u, (u64)lim + 1 - addr.ea);
- if (size > *max_size)
- goto bad;
+ if (lim == 0xffffffff)
+ *max_size = ~0u;
+ else {
+ *max_size = (u64)lim + 1 - addr.ea;
+ if (size > *max_size)
+ goto bad;
+ }
la &= (u32)-1;
break;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cdd6606e4c54..1e10e3f7f516 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4495,6 +4495,8 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr,
if (rc != X86EMUL_CONTINUE)
return rc;
addr += now;
+ if (ctxt->mode != X86EMUL_MODE_PROT64)
+ addr = (u32)addr;
val += now;
bytes -= now;
}
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