KVM: x86: emulate: correct page fault error code for NoWrite instructions

Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

kernel os linux

NoWrite instructions (e.g. cmp or test) never set the "write access"
bit in the error code, even if one of the operands is treated as a
destination.

Fixes: c205fb7d7d4f81e46fc577b707ceb9e356af1456
Cc: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo Bonzini 11 years ago d44e1212 ccd9e785

+2 -1

1 changed file

expand all

arch

x86

kvm

emulate.c

+2 -1

arch/x86/kvm/emulate.c

··· 4954 4954 rc = segmented_read(ctxt, ctxt->dst.addr.mem, 4955 4955 &ctxt->dst.val, ctxt->dst.bytes); 4956 4956 if (rc != X86EMUL_CONTINUE) { 4957 - if (rc == X86EMUL_PROPAGATE_FAULT && 4957 + if (!(ctxt->d & NoWrite) && 4958 + rc == X86EMUL_PROPAGATE_FAULT && 4958 4959 ctxt->exception.vector == PF_VECTOR) 4959 4960 ctxt->exception.error_code |= PFERR_WRITE_MASK; 4960 4961 goto done;