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Message-Id: <200903282354.00819.rusty@rustcorp.com.au>
Date: Sat, 28 Mar 2009 23:54:00 +1030
From: Rusty Russell <rusty@...tcorp.com.au>
To: linux-kernel@...r.kernel.org
Cc: Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH 4/5] module_param: allow 'bool' module_params to be bool, not just int.
Impact: API cleanup
For historical reasons, 'bool' parameters must be an int, not a bool.
But there are around 600 users, so a conversion seems like useless churn.
So we use __same_type() to distinguish, and handle both cases (we could
avoid this and treat every parameter as a bool, but that would break if any
arch had sizeof(bool) != sizeof(int).
Signed-off-by: Rusty Russell <rusty@...tcorp.com.au>
---
include/linux/moduleparam.h | 32 +++++++++++++++++++++++---------
kernel/params.c | 33 ++++++++++++++++++++++++++-------
2 files changed, 49 insertions(+), 16 deletions(-)
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -38,6 +38,7 @@ typedef int (*param_get_fn)(char *buffer
/* Flag bits for kernel_param.flags */
#define KPARAM_KMALLOCED 1
+#define KPARAM_ISBOOL 2
struct kernel_param {
const char *name;
@@ -83,7 +84,7 @@ struct kparam_array
parameters. perm sets the visibility in sysfs: 000 means it's
not there, read bits mean it's readable, write bits mean it's
writable. */
-#define __module_param_call(prefix, name, set, get, arg, perm) \
+#define __module_param_call(prefix, name, set, get, arg, isbool, perm) \
/* Default value instead of permissions? */ \
static int __param_perm_check_##name __attribute__((unused)) = \
BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \
@@ -92,10 +93,13 @@ struct kparam_array
static struct kernel_param __moduleparam_const __param_##name \
__used \
__attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
- = { __param_str_##name, perm, 0, set, get, { arg } }
+ = { __param_str_##name, perm, isbool ? KPARAM_ISBOOL : 0, \
+ set, get, { arg } }
#define module_param_call(name, set, get, arg, perm) \
- __module_param_call(MODULE_PARAM_PREFIX, name, set, get, arg, perm)
+ __module_param_call(MODULE_PARAM_PREFIX, \
+ name, set, get, arg, \
+ __same_type(*(arg), bool), perm)
/* Helper functions: type is byte, short, ushort, int, uint, long,
ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
@@ -124,15 +128,16 @@ struct kparam_array
#define core_param(name, var, type, perm) \
param_check_##type(name, &(var)); \
__module_param_call("", name, param_set_##type, param_get_##type, \
- &var, perm)
+ &var, __same_type(var, bool), perm)
#endif /* !MODULE */
/* Actually copy string: maxlen param is usually sizeof(string). */
#define module_param_string(name, string, len, perm) \
static const struct kparam_string __param_string_##name \
= { len, string }; \
- module_param_call(name, param_set_copystring, param_get_string, \
- .str = &__param_string_##name, perm); \
+ __module_param_call(MODULE_PARAM_PREFIX, name, \
+ param_set_copystring, param_get_string, \
+ .str = &__param_string_##name, 0, perm); \
__MODULE_PARM_TYPE(name, "string")
/* Called on module insert or kernel boot */
@@ -190,9 +195,16 @@ extern int param_get_charp(char *buffer,
extern int param_get_charp(char *buffer, struct kernel_param *kp);
#define param_check_charp(name, p) __param_check(name, p, char *)
+/* For historical reasons "bool" parameters can be (unsigned) "int". */
extern int param_set_bool(const char *val, struct kernel_param *kp);
extern int param_get_bool(char *buffer, struct kernel_param *kp);
-#define param_check_bool(name, p) __param_check(name, p, int)
+#define param_check_bool(name, p) \
+ static inline void __check_##name(void) \
+ { \
+ BUILD_BUG_ON(!__same_type(*(p), bool) && \
+ !__same_type(*(p), unsigned int) && \
+ !__same_type(*(p), int)); \
+ }
extern int param_set_invbool(const char *val, struct kernel_param *kp);
extern int param_get_invbool(char *buffer, struct kernel_param *kp);
@@ -203,8 +215,10 @@ extern int param_get_invbool(char *buffe
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, \
- .arr = &__param_arr_##name, perm); \
+ __module_param_call(MODULE_PARAM_PREFIX, name, \
+ param_array_set, param_array_get, \
+ .arr = &__param_arr_##name, \
+ __same_type(array[0], bool), 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
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -238,35 +238,54 @@ int param_get_charp(char *buffer, struct
return sprintf(buffer, "%s", *((char **)kp->arg));
}
+/* Actually could be a bool or an int, for historical reasons. */
int param_set_bool(const char *val, struct kernel_param *kp)
{
+ bool v;
+
/* No equals means "set"... */
if (!val) val = "1";
/* One of =[yYnN01] */
switch (val[0]) {
case 'y': case 'Y': case '1':
- *(int *)kp->arg = 1;
- return 0;
+ v = true;
+ break;
case 'n': case 'N': case '0':
- *(int *)kp->arg = 0;
- return 0;
+ v = false;
+ break;
+ default:
+ return -EINVAL;
}
- return -EINVAL;
+
+ if (kp->flags & KPARAM_ISBOOL)
+ *(bool *)kp->arg = v;
+ else
+ *(int *)kp->arg = v;
+ return 0;
}
int param_get_bool(char *buffer, struct kernel_param *kp)
{
+ bool val;
+ if (kp->flags & KPARAM_ISBOOL)
+ val = *(bool *)kp->arg;
+ else
+ val = *(int *)kp->arg;
+
/* Y and N chosen as being relatively non-coder friendly */
- return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
+ return sprintf(buffer, "%c", val ? 'Y' : 'N');
}
+/* This one must be bool. */
int param_set_invbool(const char *val, struct kernel_param *kp)
{
- int boolval, ret;
+ int ret;
+ bool boolval;
struct kernel_param dummy;
dummy.arg = &boolval;
+ dummy.flags = KPARAM_ISBOOL;
ret = param_set_bool(val, &dummy);
if (ret == 0)
*(bool *)kp->arg = !boolval;
--
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