On Tue, Dec 15, 2020 at 8:43 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> From: Francis Laniel <laniel_francis@xxxxxxxxxxxxxxxxxxx>
> Subject: string.h: add FORTIFY coverage for strscpy()
>
> The fortified version of strscpy ensures the following [..]
So I've taken this, because it follows the pattern of what we already
have, but I have to say that the "fortify" stuff is now about half of
string.h.
I think it should probably be split out into its own header file, and
then string.h could just do
#if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) &&
defined(CONFIG_FORTIFY_SOURCE)
#include <linux/fortify-string.h>
#endif
or similar.
That won't help my merge window build times (I build with
allmodconfig, so I'll have CONFIG_FORTIFY_SOURCE=y and so my poor
compiler will end up always going off and seeing all that every time
somebody glances at string.h), but I think it would be a cleanup
regardless.
And people who _don't_ build with FORTIFY_SOURCE wouldn't have to read
and parse that big chunk every time <linux/string.h> gets included.
(And yes, just reading the source file and tokenizing it - even if
it's all inside an #ifdef that turns off all the other phases - is
actually quite noticeable overhead in a C compiler. Surprisingly so)
Linus
