Re: lib/crypto/chacha.c:65:1: warning: the frame size of 1604 bytes is larger than 1024 bytes

From: Joe Perches
Date: Mon Oct 19 2020 - 11:47:25 EST


On Mon, 2020-10-19 at 03:13 +0800, kernel test robot wrote:
> Hi Ard,
>
> First bad commit (maybe != root cause):
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 9d9af1007bc08971953ae915d88dc9bb21344b53
> commit: 5fb8ef25803ef33e2eb60b626435828b937bed75 crypto: chacha - move existing library code into lib/crypto
> date: 11 months ago
> config: i386-randconfig-r023-20201019 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
> reproduce (this is a W=1 build):
> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5fb8ef25803ef33e2eb60b626435828b937bed75
> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout 5fb8ef25803ef33e2eb60b626435828b937bed75
> # save the attached .config to linux build tree
> make W=1 ARCH=i386
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>):
>
> lib/crypto/chacha.c: In function 'chacha_permute':
> > > lib/crypto/chacha.c:65:1: warning: the frame size of 1604 bytes is larger than 1024 bytes [-Wframe-larger-than=]
> 65 | }
> | ^
>
> vim +65 lib/crypto/chacha.c

This seems to come from function tracing overhead.

It it really useful to add function tracing to what
should be a single instruction?

AFAIK:

There isn't a good way to turn function tracing off
on a per-function basis.

Adding notrace doesn't work for that. Should it?