On Wed, Dec 11, 2013 at 06:28:23AM -0600, [email protected] wrote:
> @@ -295,11 +301,17 @@ static int arch_build_bp_info(struct perf_event *bp)
> break;
> #endif
> default:
> - return -EINVAL;
> + if (!is_power_of_2(bp->attr.bp_len))
> + return -EINVAL;
> + if (!cpu_has_bpext)
> + return -EOPNOTSUPP;
> + info->mask = bp->attr.bp_len - 1;
> + info->len = X86_BREAKPOINT_LEN_1;
I think I asked this before but I can't remember. So dr7 must have
length as LEN_1 for breakpoint extension?