On 9 November 2018 at 20:03, Josh Poimboeuf <jpoim...@redhat.com> wrote: > On Fri, Nov 09, 2018 at 06:53:21PM +0100, Ard Biesheuvel wrote: >> > It's a bit fiddly since inline and out-of-line both use >> > arch_static_call_transform(), but what I need to do is basically: >> > >> > - for out-of-line, the trampoline needs to be patched into a >> > movn/movk/movk/br sequence if the target is too far >> > - for inline, the trampoline itself needs to be patched from >> > adrp/ldr/br (which does a load and a indirect branch) to >> > movn/movk/movk/br (which uses immediates), and the call sites need to >> > be patched into calls to the veneer if the target is out of range. >> > >> > So arch_static_call_transform() needs to know where the trampoline is >> > for this use case, so could we perhaps add a 'void *orig' in the key >> > struct that keeps track of the original value of 'addr' ? >> >> ... and pass it to arch_static_call_transform > > Ok. So in both cases, you need both the call site address and the tramp > address, right? We could add a 'tramp' pointer to the key struct -- I > assume that's what you mean? >
Yes. > And also change > > void arch_static_call_transform(unsigned long insn, void *dest) > > to > > void arch_static_call_transform(void *call_site, void *tramp, void *dest) > Indeed.
