On Mon, Feb 28, 2022 at 11:27:43AM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > During a patch discussion, Linus brought up the option of changing > the C standard version from gnu89 to gnu99, which allows using variable > declaration inside of a for() loop. While the C99, C11 and later standards > introduce many other features, most of these are already available in > gnu89 as GNU extensions as well. The downside is that backporting affected patches to older kernel branches now fails with error messages such as mm/kfence/core.c: In function ‘kfence_init_pool’: mm/kfence/core.c:595:2: error: ‘for’ loop initial declarations are only allowed in C99 or C11 mode Just something to keep in mind when writing patches. Guenter
