On 03/12/2018 04:44 PM, Luis R. Rodriguez wrote: > On Mon, Mar 12, 2018 at 04:15:39PM -0400, Waiman Long wrote: >> When minimum/maximum values are specified for a sysctl parameter in >> the ctl_table structure with proc_dointvec_minmax() handler, update >> to that parameter will fail with error if the given value is outside >> of the required range. >> >> There are use cases where it may be better to clamp the value of >> the sysctl parameter to the given range without failing the update, >> especially if the users are not aware of the actual range limits. >> Reading the value back after the update will now be a good practice >> to see if the provided value exceeds the range limits. >> >> To provide this less restrictive form of range checking, a new flags >> field is added to the ctl_table structure. >> >> When the CTL_FLAGS_CLAMP_RANGE flag is set in the ctl_table >> entry, any update from the userspace will be clamped to the given >> range without error if either the proc_dointvec_minmax() or the >> proc_douintvec_minmax() handlers is used. > You keep missing to document both on commit log and kdoc which > end on the range is selected if you happen to go over. To be clear > it is unclear from reading the commit log if a default is set if > you go over if you pick another value. In this case it is conditional > if you go over we pick the high range max, and if you go below the > lower range minimum set allowed. > > What happens if no low range is set and that is what the issue in > terms of range triggers? Sorry for missing that. If a minimum value is not specified, no minimum checking and clamping will be done. Similarly for maximum. I will clarify that. Cheers, Longman
