[LTP] [PATCH v2] cgroup: Handle trailing new line in cgroup.controllers

[Petr Vorel]

Hi Richie,

Reviewed-by: Petr Vorel <pvorel@suse.cz>

> V2:
> * Add underscore
> * Add length check
> * Expand commit message
> * Use shorter syntax
+1

>  lib/tst_cgroup.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)

> diff --git a/lib/tst_cgroup.c b/lib/tst_cgroup.c
> index 5240aadaa..c5cb20505 100644
> --- a/lib/tst_cgroup.c
> +++ b/lib/tst_cgroup.c
> @@ -433,9 +433,20 @@ __attribute__ ((nonnull, warn_unused_result))
>  static struct cgroup_ctrl *cgroup_find_ctrl(const char *const ctrl_name)
>  {
>  	struct cgroup_ctrl *ctrl;
> +	int l = 0;
> +	char c = ctrl_name[l];
> +
> +	while (c == '_' || (c >= 'a' && c <= 'z'))
> +		c = ctrl_name[++l];
> +
> +	if (l > 32)
+1 for this check.
I would slightly prefer to add MAX_CGROUP_TYPE_NAMELEN definition into our
include/tst_cgroup.h, but it can stay as is.

BTW include/linux/cgroup-defs.h contains also MAX_CGROUP_ROOT_NAMELEN, there are
also other checks in C files (CGROUP_FILE_NAME_MAX) in case it makes sense to
have some checks for these (I have no idea).

Kind regards,
Petr

> +		tst_res(TWARN, "Subsys name len greater than max known value of MAX_CGROUP_TYPE_NAMELEN: %d > 32", l);

> +
> +	if (!(c == '\n' || c == '\0'))
> +		tst_brk(TBROK, "Unexpected char in %s: %c", ctrl_name, c);

>  	for_each_ctrl(ctrl) {
> -		if (!strcmp(ctrl_name, ctrl->ctrl_name))
> +		if (!strncmp(ctrl_name, ctrl->ctrl_name, l))
>  			return ctrl;
>  	}