On Fri, Jul 17, 2015 at 12:44:42PM -0700, Andy Lutomirski wrote: > On Fri, Jul 17, 2015 at 12:43 PM, Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > > > * Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > > >> ENTRY(aesni_set_key) > >> + FRAME > >> #ifndef __x86_64__ > >> pushl KEYP > >> movl 8(%esp), KEYP # ctx > >> @@ -1905,6 +1907,7 @@ ENTRY(aesni_set_key) > >> #ifndef __x86_64__ > >> popl KEYP > >> #endif > >> + ENDFRAME > >> ret > >> ENDPROC(aesni_set_key) > > > > So cannot we make this a bit more compact and less fragile? > > > > Instead of: > > > > ENTRY(aesni_set_key) > > FRAME > > ... > > ENDFRAME > > ret > > ENDPROC(aesni_set_key) > > > > > > How about writing this as: > > > > FUNCTION_ENTRY(aesni_set_key) > > ... > > FUNCTION_RETURN(aesni_set_key) > > > > which does the same thing in a short, symmetric construct? > > > > One potential problem with this approach would be that what 'looks' like an entry > > declaration, but it will now generate real code. > > > > OTOH if people find this intuitive enough then it's a lot harder to mess it up, > > and I think 'RETURN' makes it clear enough that there's a real instruction > > generated there. > > > > How about FUNCTION_PROLOGUE and FUNCTION_EPILOGUE? Perhaps the macro name should describe what the epilogue does, since frame pointers aren't required for _all_ functions, only those which don't have call instructions. What do you think about ENTRY_FRAME and ENDPROC_FRAME_RETURN? The ending macro is kind of long, but at least it a) matches the existing ENTRY/ENDPROC convention for asm functions; b) gives a clue that frame pointers are involved; and c) lets you know that the return is there. -- Josh -- 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
