Re: [PATCH 1/2] devcgroup: always show unsigned major/minor num

["Paul Menage" <menage@google.com>]

On Fri, Jul 4, 2008 at 10:39 PM, Li Zefan <lizf@cn.fujitsu.com> wrote:
>  # echo "b $((0x7fffffff)):$((0x80000000)) rwm" > devices.allow
>  # cat devices.list
>  b 214748364:-21474836 rwm
>
> though a major/minor number of 0x800000000 is meaningless, we
> should not cast it to a negative value.
>
> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> ---
>  security/device_cgroup.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/security/device_cgroup.c b/security/device_cgroup.c
> index fd764a0..1e2e28a 100644
> --- a/security/device_cgroup.c
> +++ b/security/device_cgroup.c
> @@ -222,7 +222,7 @@ static void devcgroup_destroy(struct cgroup_subsys *ss,
>  #define DEVCG_DENY 2
>  #define DEVCG_LIST 3
>
> -#define MAJMINLEN 10
> +#define MAJMINLEN 13
>  #define ACCLEN 4
>
>  static void set_access(char *acc, short access)
> @@ -254,7 +254,7 @@ static void set_majmin(char *str, unsigned m)
>        if (m == ~0)
>                sprintf(str, "*");

Can't this just be strcat(str, "*")?

>        else
> -               snprintf(str, MAJMINLEN, "%d", m);
> +               snprintf(str, MAJMINLEN, "%u", m);

I'm not sure that using snprintf() helps here over just sprintf() -
we're not actually basing it on the available space in the string,
we're just assuming there's enough space.

Paul