Re: [PATCH] powerpc/booke: Avoid link stack corruption in several places

Christophe Leroy
2021-08-23T17:07:24Z

Le 23/08/2021 à 17:58, Segher Boessenkool a écrit :
> On Mon, Aug 23, 2021 at 07:53:01AM +0000, Christophe Leroy wrote:
>> /* Be careful, this will clobber the lr register. */
>> #define LOAD_REG_ADDR_PIC(reg, name) \
>> - bl 0f; \
>> + bcl 20,31,0f \
>> 0: mflr reg; \
>> addis reg,reg,(name - 0b)@ha; \
>> addi reg,reg,(name - 0b)@l;
>
> The code ended each line with a semicolon before, for absolutely no
> reason that I can see, but still. Fixing that would be nice, but only
> doing it on one line isn't good.

Sure, forgetting the semicolon broke the build. That's because the backslash removes the newline.

The cleanest way I found to fix that quite of stuff is by using GAS macro, as I did for
LOAD_REG_IMMEDIATE() some time ago.

>
> Btw. Both the 7450 and the modern cores implementing this really need
> this to be $+4, so it is a lot clearer to write that instead of 1f or
> a named label.

I like that, removing unneeded labels will make it smoother and clearer. I'll do it.

Christophe