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module: Constify 'struct module_attribute'
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These structs are never modified, move them to read-only memory.
This makes the API clearer and also prepares for the constification of
'struct attribute' itself.

While at it, also constify 'modinfo_attrs_count'.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-3-3790b53e0abf@weissschuh.net
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
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@t-8ch @petrpavlu
t-8ch authored and petrpavlu committed Dec 31, 2024
1 parent 954fd68 commit 8a231a1
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Showing 5 changed files with 34 additions and 34 deletions.
8 changes: 4 additions & 4 deletions include/linux/module.h
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Original file line number Diff line number Diff line change
Expand Up @@ -52,9 +52,9 @@ struct module_kobject {

struct module_attribute {
struct attribute attr;
ssize_t (*show)(struct module_attribute *, struct module_kobject *,
ssize_t (*show)(const struct module_attribute *, struct module_kobject *,
char *);
ssize_t (*store)(struct module_attribute *, struct module_kobject *,
ssize_t (*store)(const struct module_attribute *, struct module_kobject *,
const char *, size_t count);
void (*setup)(struct module *, const char *);
int (*test)(struct module *);
Expand All @@ -67,10 +67,10 @@ struct module_version_attribute {
const char *version;
};

extern ssize_t __modver_version_show(struct module_attribute *,
extern ssize_t __modver_version_show(const struct module_attribute *,
struct module_kobject *, char *);

extern struct module_attribute module_uevent;
extern const struct module_attribute module_uevent;

/* These are either module local, or the kernel's dummy ones. */
extern int init_module(void);
Expand Down
4 changes: 2 additions & 2 deletions kernel/module/internal.h
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Original file line number Diff line number Diff line change
Expand Up @@ -47,8 +47,8 @@ struct kernel_symbol {
extern struct mutex module_mutex;
extern struct list_head modules;

extern struct module_attribute *modinfo_attrs[];
extern size_t modinfo_attrs_count;
extern const struct module_attribute *const modinfo_attrs[];
extern const size_t modinfo_attrs_count;

/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
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40 changes: 20 additions & 20 deletions kernel/module/main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -538,7 +538,7 @@ static void setup_modinfo_##field(struct module *mod, const char *s) \
{ \
mod->field = kstrdup(s, GFP_KERNEL); \
} \
static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
static ssize_t show_modinfo_##field(const struct module_attribute *mattr, \
struct module_kobject *mk, char *buffer) \
{ \
return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
Expand All @@ -552,7 +552,7 @@ static void free_modinfo_##field(struct module *mod) \
kfree(mod->field); \
mod->field = NULL; \
} \
static struct module_attribute modinfo_##field = { \
static const struct module_attribute modinfo_##field = { \
.attr = { .name = __stringify(field), .mode = 0444 }, \
.show = show_modinfo_##field, \
.setup = setup_modinfo_##field, \
Expand Down Expand Up @@ -842,13 +842,13 @@ void symbol_put_addr(void *addr)
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
static ssize_t show_refcnt(const struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
return sprintf(buffer, "%i\n", module_refcount(mk->mod));
}

static struct module_attribute modinfo_refcnt =
static const struct module_attribute modinfo_refcnt =
__ATTR(refcnt, 0444, show_refcnt, NULL);

void __module_get(struct module *module)
Expand Down Expand Up @@ -917,7 +917,7 @@ size_t module_flags_taint(unsigned long taints, char *buf)
return l;
}

static ssize_t show_initstate(struct module_attribute *mattr,
static ssize_t show_initstate(const struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
const char *state = "unknown";
Expand All @@ -938,10 +938,10 @@ static ssize_t show_initstate(struct module_attribute *mattr,
return sprintf(buffer, "%s\n", state);
}

static struct module_attribute modinfo_initstate =
static const struct module_attribute modinfo_initstate =
__ATTR(initstate, 0444, show_initstate, NULL);

static ssize_t store_uevent(struct module_attribute *mattr,
static ssize_t store_uevent(const struct module_attribute *mattr,
struct module_kobject *mk,
const char *buffer, size_t count)
{
Expand All @@ -951,10 +951,10 @@ static ssize_t store_uevent(struct module_attribute *mattr,
return rc ? rc : count;
}

struct module_attribute module_uevent =
const struct module_attribute module_uevent =
__ATTR(uevent, 0200, NULL, store_uevent);

static ssize_t show_coresize(struct module_attribute *mattr,
static ssize_t show_coresize(const struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
unsigned int size = mk->mod->mem[MOD_TEXT].size;
Expand All @@ -966,11 +966,11 @@ static ssize_t show_coresize(struct module_attribute *mattr,
return sprintf(buffer, "%u\n", size);
}

static struct module_attribute modinfo_coresize =
static const struct module_attribute modinfo_coresize =
__ATTR(coresize, 0444, show_coresize, NULL);

#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
static ssize_t show_datasize(struct module_attribute *mattr,
static ssize_t show_datasize(const struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
unsigned int size = 0;
Expand All @@ -980,11 +980,11 @@ static ssize_t show_datasize(struct module_attribute *mattr,
return sprintf(buffer, "%u\n", size);
}

static struct module_attribute modinfo_datasize =
static const struct module_attribute modinfo_datasize =
__ATTR(datasize, 0444, show_datasize, NULL);
#endif

static ssize_t show_initsize(struct module_attribute *mattr,
static ssize_t show_initsize(const struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
unsigned int size = 0;
Expand All @@ -994,10 +994,10 @@ static ssize_t show_initsize(struct module_attribute *mattr,
return sprintf(buffer, "%u\n", size);
}

static struct module_attribute modinfo_initsize =
static const struct module_attribute modinfo_initsize =
__ATTR(initsize, 0444, show_initsize, NULL);

static ssize_t show_taint(struct module_attribute *mattr,
static ssize_t show_taint(const struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
size_t l;
Expand All @@ -1007,10 +1007,10 @@ static ssize_t show_taint(struct module_attribute *mattr,
return l;
}

static struct module_attribute modinfo_taint =
static const struct module_attribute modinfo_taint =
__ATTR(taint, 0444, show_taint, NULL);

struct module_attribute *modinfo_attrs[] = {
const struct module_attribute *const modinfo_attrs[] = {
&module_uevent,
&modinfo_version,
&modinfo_srcversion,
Expand All @@ -1027,7 +1027,7 @@ struct module_attribute *modinfo_attrs[] = {
NULL,
};

size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
const size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);

static const char vermagic[] = VERMAGIC_STRING;

Expand Down Expand Up @@ -1681,7 +1681,7 @@ static void module_license_taint_check(struct module *mod, const char *license)

static void setup_modinfo(struct module *mod, struct load_info *info)
{
struct module_attribute *attr;
const struct module_attribute *attr;
int i;

for (i = 0; (attr = modinfo_attrs[i]); i++) {
Expand All @@ -1692,7 +1692,7 @@ static void setup_modinfo(struct module *mod, struct load_info *info)

static void free_modinfo(struct module *mod)
{
struct module_attribute *attr;
const struct module_attribute *attr;
int i;

for (i = 0; (attr = modinfo_attrs[i]); i++) {
Expand Down
4 changes: 2 additions & 2 deletions kernel/module/sysfs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -275,7 +275,7 @@ static int add_usage_links(struct module *mod)

static void module_remove_modinfo_attrs(struct module *mod, int end)
{
struct module_attribute *attr;
const struct module_attribute *attr;
int i;

for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
Expand All @@ -293,7 +293,7 @@ static void module_remove_modinfo_attrs(struct module *mod, int end)

static int module_add_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
const struct module_attribute *attr;
struct module_attribute *temp_attr;
int error = 0;
int i;
Expand Down
12 changes: 6 additions & 6 deletions kernel/params.c
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Original file line number Diff line number Diff line change
Expand Up @@ -538,7 +538,7 @@ const struct kernel_param_ops param_ops_string = {
EXPORT_SYMBOL(param_ops_string);

/* sysfs output in /sys/modules/XYZ/parameters/ */
#define to_module_attr(n) container_of(n, struct module_attribute, attr)
#define to_module_attr(n) container_of_const(n, struct module_attribute, attr)
#define to_module_kobject(n) container_of(n, struct module_kobject, kobj)

struct param_attribute
Expand All @@ -557,7 +557,7 @@ struct module_param_attrs
#ifdef CONFIG_SYSFS
#define to_param_attr(n) container_of_const(n, struct param_attribute, mattr)

static ssize_t param_attr_show(struct module_attribute *mattr,
static ssize_t param_attr_show(const struct module_attribute *mattr,
struct module_kobject *mk, char *buf)
{
int count;
Expand All @@ -573,7 +573,7 @@ static ssize_t param_attr_show(struct module_attribute *mattr,
}

/* sysfs always hands a nul-terminated string in buf. We rely on that. */
static ssize_t param_attr_store(struct module_attribute *mattr,
static ssize_t param_attr_store(const struct module_attribute *mattr,
struct module_kobject *mk,
const char *buf, size_t len)
{
Expand Down Expand Up @@ -857,7 +857,7 @@ static void __init param_sysfs_builtin(void)
}
}

ssize_t __modver_version_show(struct module_attribute *mattr,
ssize_t __modver_version_show(const struct module_attribute *mattr,
struct module_kobject *mk, char *buf)
{
const struct module_version_attribute *vattr =
Expand Down Expand Up @@ -892,7 +892,7 @@ static ssize_t module_attr_show(struct kobject *kobj,
struct attribute *attr,
char *buf)
{
struct module_attribute *attribute;
const struct module_attribute *attribute;
struct module_kobject *mk;
int ret;

Expand All @@ -911,7 +911,7 @@ static ssize_t module_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf, size_t len)
{
struct module_attribute *attribute;
const struct module_attribute *attribute;
struct module_kobject *mk;
int ret;

Expand Down

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