Re: [PATCH] objtool: Fix GCC 8 cold function processing without -freorder-functions

From: Allan Xavier
Date: Wed Jun 27 2018 - 05:35:44 EST


Looks good overall, just one comment.

On 26/06/18 19:44, Josh Poimboeuf wrote:
> + /*
> + * Unfortunately, -fnoreorder-functions puts the child
> + * inside the parent. Remove the overlap so we can
> + * have sane assumptions.
> + */
> + if (sym->sec == pfunc->sec &&
> + sym->offset >= pfunc->offset &&
> + sym->offset < pfunc->offset + pfunc->len &&
> + sym->offset + sym->len == pfunc->offset + pfunc->len) {
> + pfunc->len -= sym->len;

It's a bit of a nit but I'd say you could drop the third condition of the if
since sym->offset would have to be less than pfunc->offset + pfunc->len for the
fourth condition to ever be true. The only situation it would have caught is
where sym->len == 0, which I think (hope?) is reasonable to assume wont happen
and wouldn't have had an effect on pfunc->len anyway.

if (sym->sec == pfunc->sec &&
sym->offset >= pfunc->offset &&
sym->offset + sym->len == pfunc->offset + pfunc->len)