提交 c49c759f 编写于 作者: N Nadav Amit 提交者: Paolo Bonzini

KVM: x86: Emulator performs code segment checks on read access

When read access is performed using a readable code segment, the "conforming"
and "non-conforming" checks should not be done.  As a result, read using
non-conforming readable code segment fails.

This is according to Intel SDM 5.6.1 ("Accessing Data in Code Segments").

The fix is not to perform the "non-conforming" checks if the access is not a
fetch; the relevant checks are already done when loading the segment.
Signed-off-by: NNadav Amit <namit@cs.technion.ac.il>
Reviewed-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
上级 0e8a0996
......@@ -703,8 +703,8 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
if (size > *max_size)
goto bad;
cpl = ctxt->ops->cpl(ctxt);
if (!(desc.type & 8)) {
/* data segment */
if (!fetch) {
/* data segment or readable code segment */
if (cpl > desc.dpl)
goto bad;
} else if ((desc.type & 8) && !(desc.type & 4)) {
......
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