On Fri, Jul 17, 2015 at 1:44 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > On Fri, Jul 17, 2015 at 01:39:09PM -0700, Andy Lutomirski wrote: >> 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? > > Wouldn't the "ENTRY" in ENTRY_FRAMEPTR_RETURN be confusing at the end of > a function? I meant ENTRY_FRAMEPTR_xyz and the beginning and ENDPROC_FRAMEPTR_xyz (ENTRY is debatable, but that's what we currently have). ENDPROC could easily be replaced with anything else. --Andy > > -- > 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
