* Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > On Fri, Jul 17, 2015 at 9:47 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > These patches fix many of the warnings reported by stackvalidate. > > They're based on top of the "Compile-time stack validation" v7 patch set > > [1]. > > > > They've been compile-tested and boot tested in a VM, but I haven't > > attempted any meaningful testing for most of them. This should give an > > idea of what kinds of changes I think are needed. > > > > [1] https://lkml.kernel.org/r/cover.1436893563.git.jpoimboe@xxxxxxxxxx > > > > Nothing here looks all that bad, but I think the extra frame pointers > staring us in the face (as opposed to the ones that gcc adds > transparently) might serve as added incentive to suck it up and get > CFI unwinding working. So there are two aspects to frame pointers staring us in the face: - Syntactically there's extra debuginfo cruft added to the source code. Not good but very fixable: I already made a couple of suggestions of how to trim all that in a way that improves general readability as well over what we have today. - Instruction wise in the generated code. I'm afraid the 'transparent' frame pointers added by GCC are staring me in the face in perf top/report disassembly output just as much! ;-) But naming details aside, I like the direction of these patches a lot better than that of any previous debuginfo approach, because the approach is very proactive. ( Which it really has to be, given that deep down these patches are motivated by enabling more complex models of live kernel patching. But that's a win-win. ) Once the cleanliness of the annotations is improved and we have a reasonable path towards having no warnings on a regular kernel build, I plan on starting to apply the patches. So if anyone has any deep objections that were kept close to the vest so far, please holler now. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
