bpf: Constify ctl_table argument of filter function

The sysctl core is moving to allow "struct ctl_table" in read-only memory.
As a preparation for that all functions handling "struct ctl_table" need
to be able to work with "const struct ctl_table".
As __cgroup_bpf_run_filter_sysctl() does not modify its table, it can be
adapted trivially.

Signed-off-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

Author: t-8ch

include/linux/bpf-cgroup.h

@@ -138,7 +138,7 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
 				      short access, enum cgroup_bpf_attach_type atype);
 
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
-				   struct ctl_table *table, int write,
+				   const struct ctl_table *table, int write,
 				   char **buf, size_t *pcount, loff_t *ppos,
 				   enum cgroup_bpf_attach_type atype);
 

kernel/bpf/cgroup.c

@@ -1691,7 +1691,7 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  * returned value != 1 during execution. In all other cases 0 is returned.
  */
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
-				   struct ctl_table *table, int write,
+				   const struct ctl_table *table, int write,
 				   char **buf, size_t *pcount, loff_t *ppos,
 				   enum cgroup_bpf_attach_type atype)
 {