Re: [PATCH 2/4] dm verity: separate function for parsing opt args

From: Kees Cook
Date: Tue Nov 17 2015 - 17:33:30 EST


On Wed, Nov 4, 2015 at 6:02 PM, Sami Tolvanen <samitolvanen@xxxxxxxxxx> wrote:
> Move optional argument parsing into a separate function to make it
> easier to add more of them without making verity_ctr even longer.
>
> Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
> drivers/md/dm-verity.c | 31 ++++++++++++++++++++++---------
> 1 file changed, 22 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
> index 487cb66..da76f77 100644
> --- a/drivers/md/dm-verity.c
> +++ b/drivers/md/dm-verity.c
> @@ -34,6 +34,8 @@
> #define DM_VERITY_OPT_LOGGING "ignore_corruption"
> #define DM_VERITY_OPT_RESTART "restart_on_corruption"
>
> +#define DM_VERITY_OPTS_MAX 1
> +
> static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE;
>
> module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO | S_IWUSR);
> @@ -725,6 +727,21 @@ static void verity_dtr(struct dm_target *ti)
> kfree(v);
> }
>
> +static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
> + const char *opt_string)
> +{
> + if (!strcasecmp(opt_string, DM_VERITY_OPT_LOGGING)) {
> + v->mode = DM_VERITY_MODE_LOGGING;
> + return 0;
> + } else if (!strcasecmp(opt_string, DM_VERITY_OPT_RESTART)) {
> + v->mode = DM_VERITY_MODE_RESTART;
> + return 0;
> + }
> +
> + v->ti->error = "Invalid feature arguments";
> + return -EINVAL;
> +}
> +
> /*
> * Target parameters:
> * <version> The current format is version 1.
> @@ -752,7 +769,7 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
> char dummy;
>
> static struct dm_arg _args[] = {
> - {0, 1, "Invalid number of feature args"},
> + {0, DM_VERITY_OPTS_MAX, "Invalid number of feature args"},
> };
>
> v = kzalloc(sizeof(struct dm_verity), GFP_KERNEL);
> @@ -912,15 +929,11 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
> goto bad;
> }
>
> - if (!strcasecmp(opt_string, DM_VERITY_OPT_LOGGING))
> - v->mode = DM_VERITY_MODE_LOGGING;
> - else if (!strcasecmp(opt_string, DM_VERITY_OPT_RESTART))
> - v->mode = DM_VERITY_MODE_RESTART;
> - else {
> - ti->error = "Invalid feature arguments";
> - r = -EINVAL;
> + r = verity_parse_opt_args(&as, v, opt_string);
> + if (r < 0)
> goto bad;
> - }
> +
> + opt_params -= r;
> }
> }
>
> --
> 2.6.0.rc2.230.g3dd15c0
>



--
Kees Cook
Chrome OS Security
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