[PATCH] x86/resctrl: Constify kernfs_ops

From: Rikard Falkeborn
Date: Tue Nov 10 2020 - 18:02:39 EST


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@xxxxxxxxx>
---
arch/x86/kernel/cpu/resctrl/internal.h | 2 +-
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 6cb068fcf501..5540b025880c 100644
--- 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 af323e2e3100..78dcbb8e0172 100644
--- 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,
};
--
2.29.2