On Wed 2015-04-15 01:01:39, Minfei Huang wrote: > On 04/14/15 at 06:27pm, Petr Mladek wrote: > > On Tue 2015-04-14 23:55:36, Minfei Huang wrote: > > > On 04/14/15 at 10:11P, Josh Poimboeuf wrote: > > > > On Tue, Apr 14, 2015 at 01:45:49PM +0800, Minfei Huang wrote: > > > > > On 04/14/15 at 12:32P, Josh Poimboeuf wrote: > > > > > > On Tue, Apr 14, 2015 at 01:29:50PM +0800, Minfei Huang wrote: > > > > > > > > > > > > > > For end user, they may know litter about restriction of kallsyms and > > > > > > > livepatch. How can they know the restriction that function name is > > > > > > > limited to 127? > > > > > > > > > > > > As I mentioned above, I think kallsyms.c should fail the build if it > > > > > > encounters a symbol longer than KSYM_NAME_LEN. > > > > > > > > > > > > > > > > I dont think it is a good idea to handle this case like that. The > > > > > function name is only for human recognization. Why the compiler fails > > > > > to build it? > > > > > > > > Well, the function name isn't only for human recognition. kpatch-build > > > > generates patch modules automatically. It assumes that the compiled > > > > function name matches the kallsyms name. And I'd guess that a lot of > > > > other code (both in-kernel and user space tools) make the same > > > > assumption. > > > > > > > > Not to mention that most humans would also make the same assumption... > > > > > > Yes. The assumption is correct for most case. > > > > > > It is significance for livepatch to support extra module, because in my > > > opinion kernel is more stable than the third module. > > > > > > So it is more important, if the livepatch can patch all sorts of patch. > > > For dynamic function name, I think it is simple to avoid it. > > > > Do you have some really existing module with such a crazy long > > function names or is this debate pure theoretical, please? > > > > No, I do not have such running module which function name is exceed to > 127. > > Again, we can not predict what end user do to name the function name. I > think the overlength function name is valid for linux kernel, if the > module can be installed. My position on this is that using >127 length function names is insane. I would be scared to use such a module on a production system. If we refuse patching, we actually do a favor for the user. Instead of fixing live patch for such a scenario, we should suggest the user to use more trustful modules. Best Regards, Petr -- 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
