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? -- 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
