Re: [Xen-devel] [PATCH v2 05/12] x86emul: use eflags definitions in x86-defns.h

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 31.01.17 at 12:08, <wei.liu2@xxxxxxxxxx> wrote:
> @@ -5016,20 +5004,20 @@ x86_emulate(
>  
>          /*
>           * SYSCALL (unlike most instructions) evaluates its singlestep action
> -         * based on the resulting EFLG_TF, not the starting EFLG_TF.
> +         * based on the resulting X86_EFLAGS_TF, not the starting 
> X86_EFLAGS_TF.
>           *
>           * As the #DB is raised after the CPL change and before the OS can
>           * switch stack, it is a large risk for privilege escalation.
>           *
> -         * 64bit kernels should mask EFLG_TF in MSR_FMASK to avoid any
> +         * 64bit kernels should mask X86_EFLAGS_TF in MSR_FMASK to avoid any
>           * vulnerability.  Running the #DB handler on an IST stack is also a
>           * mitigation.
>           *
> -         * 32bit kernels have no ability to mask EFLG_TF at all.  Their only
> -         * mitigation is to use a task gate for handling #DB (or to not use
> -         * enable EFER.SCE to start with).
> +         * 32bit kernels have no ability to mask X86_EFLAGS_TF at all.
> +         * Their only mitigation is to use a task gate for handling
> +         * #DB (or to not use enable EFER.SCE to start with).

Please use EFLAGS.TF instead here, matching e.g. EFER.SCE.

With this taken care of and the #include style matching whatever
is chosen as the final model in the earlier patch,
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
However, I'd appreciate if you took the opportunity to add blanks
around binary operators as mandated by our coding style, on the
lines that you touch anyway.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel