* PaX Team <pageexec@xxxxxxxxxxx> wrote: > On 29 Nov 2015 at 9:08, Ingo Molnar wrote: > > > > > * PaX Team <pageexec@xxxxxxxxxxx> wrote: > > > > > i don't see the compile time vs. runtime detection as 'competing' approaches, > > > both have their own role. [...] > > > > That's true - but only as long as 'this can be solved in tooling!' is not used as > > an excuse to oppose the runtime solution and we end up doing neither. > > actually, i already voiced my opinion elsewhere in the constify thread on the > kernel hardening list that adding/using __read_only is somewhat premature > without also adding the compile time verification part (as part of the constify > plugin for example). right now its use on the embedded vdso image is simple and > easy to verify but once people begin to add it to variables that the compiler > knows and cares about (say, the ops structures) then things can become fragile > without compile checking. so yes, i'd also advise to get such tooling in > *before* more __read_only usage is added. I think you are mistaken there: if we add the page fault fixup to make sure we don't crash if a read-only variable is accessed, then we'll have most of the benefits of read-only mappings and no fragility - without having to wait for tooling. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
