On Wed, Mar 09, 2016 at 11:13:05AM +0100, Jiri Kosina wrote: > On Wed, 9 Mar 2016, Torsten Duwe wrote: > > was my first choice. Arguments on the stack? I thought we'll deal with them > > once we get there (e.g. _really_ need to patch a varargs function or one > > with a silly signature). > > Well, the problem is, once such need arises, it's too late already. No, not if it's documented. > You need to be able to patch the kernels which are already out there, > running on machines potentially for ages once all of a sudden there is a > CVE for >8args / varargs function. Then you'd need a solution like I sent out yesterday, with a pre-prologue caller that pops the extra frame, so the replacement can be more straight- forward. Or you can just deal with the shifted offsets in the replacement. I'll try to demonstrate the alternative. That would then be required for _all_ replacement functions. Or can the live patching framework differentiate and tell ftrace_caller whether to place a stack frame or not? Miroslav? Petr? Can we have 2 sorts of replacement functions? Torsten -- 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
