Right now we don't check for valid module parameter value for
block size, that allows user to set negative values.
Add a callback to error out when block size value is set < 1 before
module is loaded.
Signed-off-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
---
drivers/block/null_blk/main.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index f55d88ebd7e6..d8d79c66a7aa 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -190,8 +190,23 @@ static int g_gb = 250;
device_param_cb(gb, &null_gb_param_ops, &g_gb, 0444);
MODULE_PARM_DESC(gb, "Size in GB");
+static int null_set_bs(const char *s, const struct kernel_param *kp)
+{
+ int ret;
+
+ ret = null_param_store_int(s, kp->arg, 512, INT_MAX);
+ if (ret)
+ pr_err("valid range for bs value [512 ... %d]\n", INT_MAX);
+ return ret;
+}
+
+static const struct kernel_param_ops null_bs_param_ops = {
+ .set = null_set_bs,
+ .get = param_get_int,
+};
+
static int g_bs = 512;
-module_param_named(bs, g_bs, int, 0444);
+device_param_cb(bs, &null_bs_param_ops, &g_bs, 0444);
MODULE_PARM_DESC(bs, "Block size (in bytes)");
static int g_max_sectors;
--
2.29.0
