powerpc: Constify struct kobj_type

'struct kobj_type' is not modified. It is only used in
kobject_init_and_add()/kobject_init() which takes
a 'const struct kobj_type *ktype' parameter.

Constifying this structure moves some data to a read-only section,
so increase over all security.

On a x86_64, compiled with ppc64 defconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
   7145	    606	      0	   7751	   1e47	arch/powerpc/kernel/cacheinfo.o
   3663	    384	     16	   4063	    fdf	arch/powerpc/kernel/secvar-sysfs.o

After:
======
   text    data     bss     dec     hex filename
   7193	    558	      0	   7751	   1e47	arch/powerpc/kernel/cacheinfo.o
   3663	    384	     16	   4063	    fdf	arch/powerpc/kernel/secvar-sysfs.o

Signed-off-by: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240826150957.3500237-1-huangxiaojia2@huawei.com

diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c
index f502337dd37d64c56ec67fd16a6879323e5585b2..0fcc463b02e256049bc8a61af195dc7475a09266 100644 (file)
--- a/arch/powerpc/kernel/cacheinfo.c
+++ b/arch/powerpc/kernel/cacheinfo.c
@@ -735,7 +735,7 @@ static const struct sysfs_ops cache_index_ops = {
        .show = cache_index_show,
 };
 
-static struct kobj_type cache_index_type = {
+static const struct kobj_type cache_index_type = {
        .release = cache_index_release,
        .sysfs_ops = &cache_index_ops,
        .default_groups = cache_index_default_groups,

diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c
index eb3c053f323f7799ff8a60f36ebc04efa0b5946e..fbeb1cbac01b2c575cb7a71b16d214f2f822c489 100644 (file)
--- a/arch/powerpc/kernel/secvar-sysfs.c
+++ b/arch/powerpc/kernel/secvar-sysfs.c
@@ -125,7 +125,7 @@ static const struct attribute_group secvar_attr_group = {
 };
 __ATTRIBUTE_GROUPS(secvar_attr);
 
-static struct kobj_type secvar_ktype = {
+static const struct kobj_type secvar_ktype = {
        .sysfs_ops      = &kobj_sysfs_ops,
        .default_groups = secvar_attr_groups,
 };