From 22e48eaf587d044ba311a73c6fe0d0deaa8fdb63 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 16 Oct 2007 23:29:34 -0700 Subject: [PATCH] constify string/array kparam tracking structures .. in an effort to make read-only whatever can be made, so that CONFIG_DEBUG_RODATA can catch as many issues as possible. Signed-off-by: Jan Beulich Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/moduleparam.h | 18 +++++++++++------- kernel/params.c | 17 +++++++---------- 2 files changed, 18 insertions(+), 17 deletions(-) diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index c83588c8d08..13410b20600 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -38,7 +38,11 @@ struct kernel_param { unsigned int perm; param_set_fn set; param_get_fn get; - void *arg; + union { + void *arg; + const struct kparam_string *str; + const struct kparam_array *arr; + }; }; /* Special one for strings we want to copy into */ @@ -66,11 +70,11 @@ struct kparam_array /* Default value instead of permissions? */ \ static int __param_perm_check_##name __attribute__((unused)) = \ BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)); \ - static char __param_str_##name[] = prefix #name; \ + static const char __param_str_##name[] = prefix #name; \ static struct kernel_param const __param_##name \ __attribute_used__ \ __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ - = { __param_str_##name, perm, set, get, arg } + = { __param_str_##name, perm, set, get, { arg } } #define module_param_call(name, set, get, arg, perm) \ __module_param_call(MODULE_PARAM_PREFIX, name, set, get, arg, perm) @@ -88,10 +92,10 @@ struct kparam_array /* Actually copy string: maxlen param is usually sizeof(string). */ #define module_param_string(name, string, len, perm) \ - static struct kparam_string __param_string_##name \ + static const struct kparam_string __param_string_##name \ = { len, string }; \ module_param_call(name, param_set_copystring, param_get_string, \ - &__param_string_##name, perm); \ + .str = &__param_string_##name, perm); \ __MODULE_PARM_TYPE(name, "string") /* Called on module insert or kernel boot */ @@ -149,11 +153,11 @@ extern int param_get_invbool(char *buffer, struct kernel_param *kp); /* Comma-separated array: *nump is set to number they actually specified. */ #define module_param_array_named(name, array, type, nump, perm) \ - static struct kparam_array __param_arr_##name \ + static const struct kparam_array __param_arr_##name \ = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\ sizeof(array[0]), array }; \ module_param_call(name, param_array_set, param_array_get, \ - &__param_arr_##name, perm); \ + .arr = &__param_arr_##name, perm); \ __MODULE_PARM_TYPE(name, "array of " #type) #define module_param_array(name, type, nump, perm) \ diff --git a/kernel/params.c b/kernel/params.c index 4e57732fcfb..1d6aca288cd 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -252,8 +252,9 @@ int param_get_bool(char *buffer, struct kernel_param *kp) int param_set_invbool(const char *val, struct kernel_param *kp) { int boolval, ret; - struct kernel_param dummy = { .arg = &boolval }; + struct kernel_param dummy; + dummy.arg = &boolval; ret = param_set_bool(val, &dummy); if (ret == 0) *(int *)kp->arg = !boolval; @@ -262,11 +263,7 @@ int param_set_invbool(const char *val, struct kernel_param *kp) int param_get_invbool(char *buffer, struct kernel_param *kp) { - int val; - struct kernel_param dummy = { .arg = &val }; - - val = !*(int *)kp->arg; - return param_get_bool(buffer, &dummy); + return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'N' : 'Y'); } /* We break the rule and mangle the string. */ @@ -325,7 +322,7 @@ static int param_array(const char *name, int param_array_set(const char *val, struct kernel_param *kp) { - struct kparam_array *arr = kp->arg; + const struct kparam_array *arr = kp->arr; unsigned int temp_num; return param_array(kp->name, val, 1, arr->max, arr->elem, @@ -335,7 +332,7 @@ int param_array_set(const char *val, struct kernel_param *kp) int param_array_get(char *buffer, struct kernel_param *kp) { int i, off, ret; - struct kparam_array *arr = kp->arg; + const struct kparam_array *arr = kp->arr; struct kernel_param p; p = *kp; @@ -354,7 +351,7 @@ int param_array_get(char *buffer, struct kernel_param *kp) int param_set_copystring(const char *val, struct kernel_param *kp) { - struct kparam_string *kps = kp->arg; + const struct kparam_string *kps = kp->str; if (!val) { printk(KERN_ERR "%s: missing param set value\n", kp->name); @@ -371,7 +368,7 @@ int param_set_copystring(const char *val, struct kernel_param *kp) int param_get_string(char *buffer, struct kernel_param *kp) { - struct kparam_string *kps = kp->arg; + const struct kparam_string *kps = kp->str; return strlcpy(buffer, kps->string, kps->maxlen); }