On Fri, Jul 17, 2015 at 1:37 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > 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. > This really is about frame pointers, right? How about ENTRY_FRAMEPTR_xyz where xyz can be prologue, epilogue, return, whatever? > -- > Josh -- Andy Lutomirski AMA Capital Management, LLC -- 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
