Merge tag 'gpio-v5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux...

[sfrench/cifs-2.6.git] / arch / x86 / kvm / x86.c

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 93b0bd45ac738f6fefea3c7a834758d2e5d91340..91602d310a3fbf0be916d794d0eff9c3beb1b9b2 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5312,6 +5312,13 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
        /* kvm_write_guest_virt_system can pull in tons of pages. */
        vcpu->arch.l1tf_flush_l1d = true;
 
+       /*
+        * FIXME: this should call handle_emulation_failure if X86EMUL_IO_NEEDED
+        * is returned, but our callers are not ready for that and they blindly
+        * call kvm_inject_page_fault.  Ensure that they at least do not leak
+        * uninitialized kernel stack memory into cr2 and error code.
+        */
+       memset(exception, 0, sizeof(*exception));
        return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
                                           PFERR_WRITE_MASK, exception);
 }
@@ -6594,12 +6601,13 @@ restart:
                unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
                toggle_interruptibility(vcpu, ctxt->interruptibility);
                vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
-               kvm_rip_write(vcpu, ctxt->eip);
-               if (r == EMULATE_DONE && ctxt->tf)
-                       kvm_vcpu_do_singlestep(vcpu, &r);
                if (!ctxt->have_exception ||
-                   exception_type(ctxt->exception.vector) == EXCPT_TRAP)
+                   exception_type(ctxt->exception.vector) == EXCPT_TRAP) {
+                       kvm_rip_write(vcpu, ctxt->eip);
+                       if (r == EMULATE_DONE && ctxt->tf)
+                               kvm_vcpu_do_singlestep(vcpu, &r);
                        __kvm_set_rflags(vcpu, ctxt->eflags);
+               }
 
                /*
                 * For STI, interrupts are shadowed; so KVM_REQ_EVENT will