Re: [PATCH] ext4: prefer strlcpy to strncpy

From: Theodore Y. Ts'o
Date: Wed May 30 2018 - 01:15:08 EST


On Mon, May 28, 2018 at 11:21:53PM -0700, Nick Desaulniers wrote:
> Fixes a stringop-truncation warning from gcc-8.
>
> Signed-off-by: Nick Desaulniers <nick.desaulniers@xxxxxxxxx>

I'll note that the ext4 superblock fields are *not* guaranteed to be
NULL terminated. Code that references them must, and do, deal with
this appropriately. See for example:

https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/tree/lib/e2p/ls.c#n436

GCC-8 may whine about it, but the whine is, in fact, not correct.
It's making assumptions about all strings being null terminated, which
is often, but not always, the case.

Cheers,

- Ted