Re: [PATCH] erofs: Eliminate usage of uninitialized_var() macro

From: Gao Xiang
Date: Mon Jun 15 2020 - 03:25:46 EST


Hi Jason,

On Mon, Jun 15, 2020 at 12:01:41PM +0800, Jason Yan wrote:
> This is an effort to eliminate the uninitialized_var() macro[1].
>
> The use of this macro is the wrong solution because it forces off ANY
> analysis by the compiler for a given variable. It even masks "unused
> variable" warnings.
>
> Quoted from Linus[2]:
>
> "It's a horrible thing to use, in that it adds extra cruft to the
> source code, and then shuts up a compiler warning (even the _reliable_
> warnings from gcc)."
>
> The gcc option "-Wmaybe-uninitialized" has been disabled and this change
> will not produce any warnnings even with "make W=1".
>
> [1] https://github.com/KSPP/linux/issues/81
> [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@xxxxxxxxxxxxxx/
>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Chao Yu <yuchao0@xxxxxxxxxx>
> Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx>
> ---

I'm fine with the patch since "-Wmaybe-uninitialized" has been disabled and
I've also asked Kees for it in private previously.

I still remembered that Kees sent out a treewide patch. Sorry about that
I don't catch up it... But what is wrong with the original patchset?

Thanks,
Gao Xiang