Re: [PATCH 7/7] DWARF: add the config option

From: Andy Lutomirski
Date: Sat May 20 2017 - 17:57:31 EST


On Sat, May 20, 2017 at 1:16 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, May 19, 2017 at 10:23 PM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
>>
>> I personally like the idea of using real DWARF annotations in the
>> entry code because it makes gdb work better (not kgdb -- real gdb
>> attached to KVM). I bet that we could get entry asm annotations into
>> good shape if we really wanted to. OTOH, getting DWARF to work well
>> for inline asm is really nasty IIRC.
>
> No. I will NAK *any* attempt to make our asm contain the crazy
> shit-for-brains annotations.
>
> Been there, done that, got the T-shirt, and then doused the T-shirt in
> gasoline and put it on fire.
>
> The amount of unreadable crap and bugs it requires is not worth the
> pain. Not for *any* amount of gain, and the gain here is basically
> zero.

But what if objtool autogenerated the annotations, perhaps with a tiny
bit of help telling it "hardware frame goes here" or "pt_regs goes
here"?