x86/resctrl: Constify kernfs_ops

The only usage of the kf_ops field in the rftype struct is to pass
it as argument to __kernfs_create_file(), which accepts a pointer to
const. Make it a pointer to const. This makes it possible to make
rdtgroup_kf_single_ops and kf_mondata_ops const, which allows the
compiler to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/20201110230228.801785-1-rikard.falkeborn@gmail.com

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 6cb068f..5540b02 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -264,7 +264,7 @@ void __exit rdtgroup_exit(void);
 struct rftype {
        char                    *name;
        umode_t                 mode;
-       struct kernfs_ops       *kf_ops;
+       const struct kernfs_ops *kf_ops;
        unsigned long           flags;
        unsigned long           fflags;
 

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index af323e2..78dcbb8 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -240,13 +240,13 @@ static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
        return -EINVAL;
 }
 
-static struct kernfs_ops rdtgroup_kf_single_ops = {
+static const struct kernfs_ops rdtgroup_kf_single_ops = {
        .atomic_write_len       = PAGE_SIZE,
        .write                  = rdtgroup_file_write,
        .seq_show               = rdtgroup_seqfile_show,
 };
 
-static struct kernfs_ops kf_mondata_ops = {
+static const struct kernfs_ops kf_mondata_ops = {
        .atomic_write_len       = PAGE_SIZE,
        .seq_show               = rdtgroup_mondata_show,
 };