On Thu, 24 Nov 2016 10:38:04 +0100 Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Thursday, November 24, 2016 6:53:22 PM CET Nicholas Piggin wrote: > > > > > > > Google tells me > > > > Linus is not a neutral bystander on the topic of symbol versioning, so I'm > > > > bracing for a robust response (actually I don't much care either way, I'm > > > > happy to put a couple of bandaids on it and keep it going) > > > > > > There are tools that people are working on to make it more obvious where > > > API breaks happen by looking at the .o debug data instead of our crazy > > > current system (which is really better than nothing), perhaps we should > > > start using them instead? > > > > > > See here for more details about this: > > > https://kernel-recipes.org/en/2016/talks/would-an-abi-changes-visualization-tool-be-useful-to-linux-kernel-maintenance/ > > > > Hmm. I guess it's basically similar to modversions, so has downsides of not > > detecting a semantic change unless it changes the type. But still, if we could > > replace our custom code with a tool like this for modversions functionality, > > that alone would be a massive improvement. But requiring debug info might be > > a bit of a show stopper. I also don't know if that would handle asm functions. > > It's certainly not an option for v4.9 at this point. There is also no Yeah I wasn't suggesting that for 4.9, or 4.10 even. > realistic way we can get a correct asm/asm-prototypes.h for all the > other architectures in place. At the moment, powerpc is the only > one that actually works with modversions. > > We can either make CONFIG_MODVERSIONS a per-architecture opt-in > and let only the ones that have the header file select that, or > revert all of Al's original patches that moved the exports. alpha, m68k, s390, sparc, ia64 are affected and have no patch (or none I've been cc'ed on) for asm-prototypes.h. Doesn't seem infeasible to add them before 4.9, considering the fairly low risk of patch. Opt-in would be pointless IMO, might as well just revert the arch part of Al's patch instead. Thanks, Nick -- 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
