On 19 November 2014 18:12, Nicolas Pitre <nicolas.pi...@linaro.org> wrote: > On Wed, 19 Nov 2014, Russell King - ARM Linux wrote: > >> On Wed, Nov 19, 2014 at 11:57:15AM -0500, Nicolas Pitre wrote: >> > On Wed, 19 Nov 2014, Russell King - ARM Linux wrote: >> > > I don't think I ever did, because its pretty much impossible to do as I >> > > explained in a follow up to this thread. >> > > >> > > We _used_ to do this with the userspace insmod methods, but since we got >> > > this kernel-side linker, it's been pretty much impossible to do without >> > > rewriting the module code. That's not going to happen on account of one >> > > quirky architecture which Linus doesn't particularly like. >> > >> > Still... We could try adding a hook in the generic module linker code >> > for a pre-relocation pass. Maybe only ARM would use it, but if the need >> > to load big modules is real then I imagine Linus could be amenable to a >> > compromise. >> >> So, how big a table would you allocate for the trampolines, based upon >> not knowing anything about the module being loaded? 4K? 8K? 64K? > > The idea of a pre-relocation pass is to determine that. That could be > something similar to calling apply_relocate() twice: once to determine > the number of trampoline entries, and a second time to perform the > actual relocation. >
Well, the veneers shouldn't take more than 3 words each, right? ldr ip, [pc] bx ip .long symbol and you would need at most one veneer per unique external symbol referenced by one or more R_ARM_CALL relocations. Is there no way to just add that to the static mem footprint as padding, and let the loader populate it as needed at module relocation time? -- Ard. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
