From bac155310be35e0fa64b066d47625d2a12a75122 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Mon, 26 Jan 2015 09:32:26 +0200 Subject: 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 Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 10 +++++++--- arch/x86/kvm/x86.c | 2 ++ 2 files changed, 9 insertions(+), 3 deletions(-) (limited to 'arch/x86/kvm') 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; } -- cgit v1.2.3-59-g8ed1b