[RFC PATCH 11/11] driver/int3400_thermal: Fix prototype matching

joao
2022-04-20T00:44:13Z

From: Joao Moreira <joao@overdrivepizza.com>

The function attr_dev_show directly invokes functions from drivers
expecting an specific prototype. The driver for int3400_thermal
implements the given show function using a different prototype than what
is expected. This violates the prototype-based fine-grained CFI policy.

Make the function prototype compliant and cast the respective assignement
so it can be properly user together with fine-grained CFI.

(FWIIW, there should be a less ugly patch for this, but I don't know
enough about the touched source code).

Signed-off-by: Joao Moreira <joao@overdrivepizza.com>
---
.../thermal/intel/int340x_thermal/int3400_thermal.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
index 4954800b9850..4bd95a2016b7 100644
--- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
+++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
@@ -311,12 +311,13 @@ static int int3400_thermal_get_uuids(struct int3400_thermal_priv *priv)
return result;
}

-static ssize_t odvp_show(struct kobject *kobj, struct kobj_attribute *attr,
+static ssize_t odvp_show(struct device *kobj, struct device_attribute *attr,
char *buf)
{
+ struct kobj_attribute *kattr = (struct kobj_attribute *) attr;
struct odvp_attr *odvp_attr;

- odvp_attr = container_of(attr, struct odvp_attr, attr);
+ odvp_attr = container_of(kattr, struct odvp_attr, attr);

return sprintf(buf, "%d\n", odvp_attr->priv->odvp[odvp_attr->odvp]);
}
@@ -388,7 +389,10 @@ static int evaluate_odvp(struct int3400_thermal_priv *priv)
goto out_err;
}
odvp->attr.attr.mode = 0444;
- odvp->attr.show = odvp_show;
+ odvp->attr.show = (ssize_t (*)
+ (struct kobject *,
+ struct kobj_attribute *,
+ char *)) odvp_show;
odvp->attr.store = NULL;
ret = sysfs_create_file(&priv->pdev->dev.kobj,
&odvp->attr.attr);
--
2.35.1