Re: [PATCH v2] apparmor: add braces around optional statement

Serge E. Hallyn
2017-06-20T20:49:53Z

Quoting Arnd Bergmann (arnd@arndb.de):
> We get a warning when AA_BUG() compiles to an nothing:
>
> security/apparmor/label.c: In function '__label_update':
> security/apparmor/label.c:2055:3: error: suggest braces around empty body in an 'else' statement [-Werror=empty-body]
>
> There are two things we can do about this:
>
> - add the missing braces in the call site, which also
> brings the code in line with the regular Linux coding style
>
> - redefine the macro so it is not empty but instead uses
> no_printk() in AA_BUG_FMT() to perform format checking.
>
> Both seem like good ideas, so this does both at once.
>
> Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Serge Hallyn <serge@hallyn.com>

> --
> v2: actually include the second part of the patch
> ---
> security/apparmor/include/lib.h | 2 +-
> security/apparmor/label.c | 3 ++-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h
> index 436b3a722357..cbfb71c1ec88 100644
> --- a/security/apparmor/include/lib.h
> +++ b/security/apparmor/include/lib.h
> @@ -50,7 +50,7 @@
> #define AA_BUG_FMT(X, fmt, args...) \
> WARN((X), "AppArmor WARN %s: (" #X "): " fmt, __func__, ##args)
> #else
> -#define AA_BUG_FMT(X, fmt, args...)
> +#define AA_BUG_FMT(X, fmt, args...) no_printk("%s" fmt, __func__, ##args)
> #endif
>
> #define AA_ERROR(fmt, args...) \
> diff --git a/security/apparmor/label.c b/security/apparmor/label.c
> index e052eaba1cf6..f8e08d94a8a6 100644
> --- a/security/apparmor/label.c
> +++ b/security/apparmor/label.c
> @@ -2051,8 +2051,9 @@ static struct aa_label *__label_update(struct aa_label *label)
> write_lock_irqsave(&ls->lock, flags);
> goto remove;
> }
> - } else
> + } else {
> AA_BUG(labels_ns(label) != labels_ns(new));
> + }
>
> tmp = __label_insert(labels_set(label), new, true);
> remove:
> --
> 2.9.0