Initial commit

kernel/params.c

@@ -0,0 +1,743 @@
+/* Helpers for initial module or kernel cmdline parsing
+   Copyright (C) 2001 Rusty Russell.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt, a...)
+#endif
+
+static inline char dash2underscore(char c)
+{
+	if (c == '-')
+		return '_';
+	return c;
+}
+
+static inline int parameq(const char *input, const char *paramname)
+{
+	unsigned int i;
+	for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
+		if (input[i] == '\0')
+			return 1;
+	return 0;
+}
+
+static int parse_one(char *param,
+		     char *val,
+		     struct kernel_param *params, 
+		     unsigned num_params,
+		     int (*handle_unknown)(char *param, char *val))
+{
+	unsigned int i;
+
+	/* Find parameter */
+	for (i = 0; i < num_params; i++) {
+		if (parameq(param, params[i].name)) {
+			DEBUGP("They are equal!  Calling %p\n",
+			       params[i].set);
+			return params[i].set(val, &params[i]);
+		}
+	}
+
+	if (handle_unknown) {
+		DEBUGP("Unknown argument: calling %p\n", handle_unknown);
+		return handle_unknown(param, val);
+	}
+
+	DEBUGP("Unknown argument `%s'\n", param);
+	return -ENOENT;
+}
+
+/* You can use " around spaces, but can't escape ". */
+/* Hyphens and underscores equivalent in parameter names. */
+static char *next_arg(char *args, char **param, char **val)
+{
+	unsigned int i, equals = 0;
+	int in_quote = 0, quoted = 0;
+	char *next;
+
+	if (*args == '"') {
+		args++;
+		in_quote = 1;
+		quoted = 1;
+	}
+
+	for (i = 0; args[i]; i++) {
+		if (args[i] == ' ' && !in_quote)
+			break;
+		if (equals == 0) {
+			if (args[i] == '=')
+				equals = i;
+		}
+		if (args[i] == '"')
+			in_quote = !in_quote;
+	}
+
+	*param = args;
+	if (!equals)
+		*val = NULL;
+	else {
+		args[equals] = '\0';
+		*val = args + equals + 1;
+
+		/* Don't include quotes in value. */
+		if (**val == '"') {
+			(*val)++;
+			if (args[i-1] == '"')
+				args[i-1] = '\0';
+		}
+		if (quoted && args[i-1] == '"')
+			args[i-1] = '\0';
+	}
+
+	if (args[i]) {
+		args[i] = '\0';
+		next = args + i + 1;
+	} else
+		next = args + i;
+
+	/* Chew up trailing spaces. */
+	while (*next == ' ')
+		next++;
+	return next;
+}
+
+/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
+int parse_args(const char *name,
+	       char *args,
+	       struct kernel_param *params,
+	       unsigned num,
+	       int (*unknown)(char *param, char *val))
+{
+	char *param, *val;
+
+	DEBUGP("Parsing ARGS: %s\n", args);
+
+	/* Chew leading spaces */
+	while (*args == ' ')
+		args++;
+
+	while (*args) {
+		int ret;
+		int irq_was_disabled;
+
+		args = next_arg(args, &param, &val);
+		irq_was_disabled = irqs_disabled();
+		ret = parse_one(param, val, params, num, unknown);
+		if (irq_was_disabled && !irqs_disabled()) {
+			printk(KERN_WARNING "parse_args(): option '%s' enabled "
+					"irq's!\n", param);
+		}
+		switch (ret) {
+		case -ENOENT:
+			printk(KERN_ERR "%s: Unknown parameter `%s'\n",
+			       name, param);
+			return ret;
+		case -ENOSPC:
+			printk(KERN_ERR
+			       "%s: `%s' too large for parameter `%s'\n",
+			       name, val ?: "", param);
+			return ret;
+		case 0:
+			break;
+		default:
+			printk(KERN_ERR
+			       "%s: `%s' invalid for parameter `%s'\n",
+			       name, val ?: "", param);
+			return ret;
+		}
+	}
+
+	/* All parsed OK. */
+	return 0;
+}
+
+/* Lazy bastard, eh? */
+#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn)      	\
+	int param_set_##name(const char *val, struct kernel_param *kp)	\
+	{								\
+		tmptype l;						\
+		int ret;						\
+									\
+		if (!val) return -EINVAL;				\
+		ret = strtolfn(val, 0, &l);				\
+		if (ret == -EINVAL || ((type)l != l))			\
+			return -EINVAL;					\
+		*((type *)kp->arg) = l;					\
+		return 0;						\
+	}								\
+	int param_get_##name(char *buffer, struct kernel_param *kp)	\
+	{								\
+		return sprintf(buffer, format, *((type *)kp->arg));	\
+	}
+
+STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
+STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
+STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
+STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
+STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
+STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
+STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
+
+int param_set_charp(const char *val, struct kernel_param *kp)
+{
+	if (!val) {
+		printk(KERN_ERR "%s: string parameter expected\n",
+		       kp->name);
+		return -EINVAL;
+	}
+
+	if (strlen(val) > 1024) {
+		printk(KERN_ERR "%s: string parameter too long\n",
+		       kp->name);
+		return -ENOSPC;
+	}
+
+	*(char **)kp->arg = (char *)val;
+	return 0;
+}
+
+int param_get_charp(char *buffer, struct kernel_param *kp)
+{
+	return sprintf(buffer, "%s", *((char **)kp->arg));
+}
+
+int param_set_bool(const char *val, struct kernel_param *kp)
+{
+	/* 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;
+	case 'n': case 'N': case '0':
+		*(int *)kp->arg = 0;
+		return 0;
+	}
+	return -EINVAL;
+}
+
+int param_get_bool(char *buffer, struct kernel_param *kp)
+{
+	/* Y and N chosen as being relatively non-coder friendly */
+	return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
+}
+
+int param_set_invbool(const char *val, struct kernel_param *kp)
+{
+	int boolval, ret;
+	struct kernel_param dummy;
+
+	dummy.arg = &boolval;
+	ret = param_set_bool(val, &dummy);
+	if (ret == 0)
+		*(int *)kp->arg = !boolval;
+	return ret;
+}
+
+int param_get_invbool(char *buffer, struct kernel_param *kp)
+{
+	return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'N' : 'Y');
+}
+
+/* We break the rule and mangle the string. */
+static int param_array(const char *name,
+		       const char *val,
+		       unsigned int min, unsigned int max,
+		       void *elem, int elemsize,
+		       int (*set)(const char *, struct kernel_param *kp),
+		       unsigned int *num)
+{
+	int ret;
+	struct kernel_param kp;
+	char save;
+
+	/* Get the name right for errors. */
+	kp.name = name;
+	kp.arg = elem;
+
+	/* No equals sign? */
+	if (!val) {
+		printk(KERN_ERR "%s: expects arguments\n", name);
+		return -EINVAL;
+	}
+
+	*num = 0;
+	/* We expect a comma-separated list of values. */
+	do {
+		int len;
+
+		if (*num == max) {
+			printk(KERN_ERR "%s: can only take %i arguments\n",
+			       name, max);
+			return -EINVAL;
+		}
+		len = strcspn(val, ",");
+
+		/* nul-terminate and parse */
+		save = val[len];
+		((char *)val)[len] = '\0';
+		ret = set(val, &kp);
+
+		if (ret != 0)
+			return ret;
+		kp.arg += elemsize;
+		val += len+1;
+		(*num)++;
+	} while (save == ',');
+
+	if (*num < min) {
+		printk(KERN_ERR "%s: needs at least %i arguments\n",
+		       name, min);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int param_array_set(const char *val, struct kernel_param *kp)
+{
+	const struct kparam_array *arr = kp->arr;
+	unsigned int temp_num;
+
+	return param_array(kp->name, val, 1, arr->max, arr->elem,
+			   arr->elemsize, arr->set, arr->num ?: &temp_num);
+}
+
+int param_array_get(char *buffer, struct kernel_param *kp)
+{
+	int i, off, ret;
+	const struct kparam_array *arr = kp->arr;
+	struct kernel_param p;
+
+	p = *kp;
+	for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
+		if (i)
+			buffer[off++] = ',';
+		p.arg = arr->elem + arr->elemsize * i;
+		ret = arr->get(buffer + off, &p);
+		if (ret < 0)
+			return ret;
+		off += ret;
+	}
+	buffer[off] = '\0';
+	return off;
+}
+
+int param_set_copystring(const char *val, struct kernel_param *kp)
+{
+	const struct kparam_string *kps = kp->str;
+
+	if (!val) {
+		printk(KERN_ERR "%s: missing param set value\n", kp->name);
+		return -EINVAL;
+	}
+	if (strlen(val)+1 > kps->maxlen) {
+		printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
+		       kp->name, kps->maxlen-1);
+		return -ENOSPC;
+	}
+	strcpy(kps->string, val);
+	return 0;
+}
+
+int param_get_string(char *buffer, struct kernel_param *kp)
+{
+	const struct kparam_string *kps = kp->str;
+	return strlcpy(buffer, kps->string, kps->maxlen);
+}
+
+/* sysfs output in /sys/modules/XYZ/parameters/ */
+
+extern struct kernel_param __start___param[], __stop___param[];
+
+struct param_attribute
+{
+	struct module_attribute mattr;
+	struct kernel_param *param;
+};
+
+struct module_param_attrs
+{
+	struct attribute_group grp;
+	struct param_attribute attrs[0];
+};
+
+#ifdef CONFIG_SYSFS
+#define to_param_attr(n) container_of(n, struct param_attribute, mattr);
+
+static ssize_t param_attr_show(struct module_attribute *mattr,
+			       struct module *mod, char *buf)
+{
+	int count;
+	struct param_attribute *attribute = to_param_attr(mattr);
+
+	if (!attribute->param->get)
+		return -EPERM;
+
+	count = attribute->param->get(buf, attribute->param);
+	if (count > 0) {
+		strcat(buf, "\n");
+		++count;
+	}
+	return count;
+}
+
+/* sysfs always hands a nul-terminated string in buf.  We rely on that. */
+static ssize_t param_attr_store(struct module_attribute *mattr,
+				struct module *owner,
+				const char *buf, size_t len)
+{
+ 	int err;
+	struct param_attribute *attribute = to_param_attr(mattr);
+
+	if (!attribute->param->set)
+		return -EPERM;
+
+	err = attribute->param->set(buf, attribute->param);
+	if (!err)
+		return len;
+	return err;
+}
+#endif
+
+#ifdef CONFIG_MODULES
+#define __modinit
+#else
+#define __modinit __init
+#endif
+
+#ifdef CONFIG_SYSFS
+/*
+ * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME
+ * @mk: struct module_kobject (contains parent kobject)
+ * @kparam: array of struct kernel_param, the actual parameter definitions
+ * @num_params: number of entries in array
+ * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules"
+ *
+ * Create a kobject for a (per-module) group of parameters, and create files
+ * in sysfs. A pointer to the param_kobject is returned on success,
+ * NULL if there's no parameter to export, or other ERR_PTR(err).
+ */
+static __modinit struct module_param_attrs *
+param_sysfs_setup(struct module_kobject *mk,
+		  struct kernel_param *kparam,
+		  unsigned int num_params,
+		  unsigned int name_skip)
+{
+	struct module_param_attrs *mp;
+	unsigned int valid_attrs = 0;
+	unsigned int i, size[2];
+	struct param_attribute *pattr;
+	struct attribute **gattr;
+	int err;
+
+	for (i=0; i<num_params; i++) {
+		if (kparam[i].perm)
+			valid_attrs++;
+	}
+
+	if (!valid_attrs)
+		return NULL;
+
+	size[0] = ALIGN(sizeof(*mp) +
+			valid_attrs * sizeof(mp->attrs[0]),
+			sizeof(mp->grp.attrs[0]));
+	size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);
+
+	mp = kzalloc(size[0] + size[1], GFP_KERNEL);
+	if (!mp)
+		return ERR_PTR(-ENOMEM);
+
+	mp->grp.name = "parameters";
+	mp->grp.attrs = (void *)mp + size[0];
+
+	pattr = &mp->attrs[0];
+	gattr = &mp->grp.attrs[0];
+	for (i = 0; i < num_params; i++) {
+		struct kernel_param *kp = &kparam[i];
+		if (kp->perm) {
+			pattr->param = kp;
+			pattr->mattr.show = param_attr_show;
+			pattr->mattr.store = param_attr_store;
+			pattr->mattr.attr.name = (char *)&kp->name[name_skip];
+			pattr->mattr.attr.mode = kp->perm;
+			*(gattr++) = &(pattr++)->mattr.attr;
+		}
+	}
+	*gattr = NULL;
+
+	if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
+		kfree(mp);
+		return ERR_PTR(err);
+	}
+	return mp;
+}
+
+#ifdef CONFIG_MODULES
+/*
+ * module_param_sysfs_setup - setup sysfs support for one module
+ * @mod: module
+ * @kparam: module parameters (array)
+ * @num_params: number of module parameters
+ *
+ * Adds sysfs entries for module parameters, and creates a link from
+ * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/
+ */
+int module_param_sysfs_setup(struct module *mod,
+			     struct kernel_param *kparam,
+			     unsigned int num_params)
+{
+	struct module_param_attrs *mp;
+
+	mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
+	if (IS_ERR(mp))
+		return PTR_ERR(mp);
+
+	mod->param_attrs = mp;
+	return 0;
+}
+
+/*
+ * module_param_sysfs_remove - remove sysfs support for one module
+ * @mod: module
+ *
+ * Remove sysfs entries for module parameters and the corresponding
+ * kobject.
+ */
+void module_param_sysfs_remove(struct module *mod)
+{
+	if (mod->param_attrs) {
+		sysfs_remove_group(&mod->mkobj.kobj,
+				   &mod->param_attrs->grp);
+		/* We are positive that no one is using any param
+		 * attrs at this point.  Deallocate immediately. */
+		kfree(mod->param_attrs);
+		mod->param_attrs = NULL;
+	}
+}
+#endif
+
+/*
+ * kernel_param_sysfs_setup - wrapper for built-in params support
+ */
+static void __init kernel_param_sysfs_setup(const char *name,
+					    struct kernel_param *kparam,
+					    unsigned int num_params,
+					    unsigned int name_skip)
+{
+	struct module_kobject *mk;
+	int ret;
+
+	mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
+	BUG_ON(!mk);
+
+	mk->mod = THIS_MODULE;
+	mk->kobj.kset = module_kset;
+	ret = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, "%s", name);
+	if (ret) {
+		kobject_put(&mk->kobj);
+		printk(KERN_ERR "Module '%s' failed to be added to sysfs, "
+		      "error number %d\n", name, ret);
+		printk(KERN_ERR	"The system will be unstable now.\n");
+		return;
+	}
+	param_sysfs_setup(mk, kparam, num_params, name_skip);
+	kobject_uevent(&mk->kobj, KOBJ_ADD);
+}
+
+/*
+ * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
+ *
+ * Add module_parameters to sysfs for "modules" built into the kernel.
+ *
+ * The "module" name (KBUILD_MODNAME) is stored before a dot, the
+ * "parameter" name is stored behind a dot in kernel_param->name. So,
+ * extract the "module" name for all built-in kernel_param-eters,
+ * and for all who have the same, call kernel_param_sysfs_setup.
+ */
+static void __init param_sysfs_builtin(void)
+{
+	struct kernel_param *kp, *kp_begin = NULL;
+	unsigned int i, name_len, count = 0;
+	char modname[MODULE_NAME_LEN + 1] = "";
+
+	for (i=0; i < __stop___param - __start___param; i++) {
+		char *dot;
+		size_t max_name_len;
+
+		kp = &__start___param[i];
+		max_name_len =
+			min_t(size_t, MODULE_NAME_LEN, strlen(kp->name));
+
+		dot = memchr(kp->name, '.', max_name_len);
+		if (!dot) {
+			DEBUGP("couldn't find period in first %d characters "
+			       "of %s\n", MODULE_NAME_LEN, kp->name);
+			continue;
+		}
+		name_len = dot - kp->name;
+
+ 		/* new kbuild_modname? */
+		if (strlen(modname) != name_len
+		    || strncmp(modname, kp->name, name_len) != 0) {
+			/* add a new kobject for previous kernel_params. */
+			if (count)
+				kernel_param_sysfs_setup(modname,
+							 kp_begin,
+							 count,
+							 strlen(modname)+1);
+
+			strncpy(modname, kp->name, name_len);
+			modname[name_len] = '\0';
+			count = 0;
+			kp_begin = kp;
+		}
+		count++;
+	}
+
+	/* last kernel_params need to be registered as well */
+	if (count)
+		kernel_param_sysfs_setup(modname, kp_begin, count,
+					 strlen(modname)+1);
+}
+
+
+/* module-related sysfs stuff */
+
+#define to_module_attr(n) container_of(n, struct module_attribute, attr);
+#define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
+
+static ssize_t module_attr_show(struct kobject *kobj,
+				struct attribute *attr,
+				char *buf)
+{
+	struct module_attribute *attribute;
+	struct module_kobject *mk;
+	int ret;
+
+	attribute = to_module_attr(attr);
+	mk = to_module_kobject(kobj);
+
+	if (!attribute->show)
+		return -EIO;
+
+	ret = attribute->show(attribute, mk->mod, buf);
+
+	return ret;
+}
+
+static ssize_t module_attr_store(struct kobject *kobj,
+				struct attribute *attr,
+				const char *buf, size_t len)
+{
+	struct module_attribute *attribute;
+	struct module_kobject *mk;
+	int ret;
+
+	attribute = to_module_attr(attr);
+	mk = to_module_kobject(kobj);
+
+	if (!attribute->store)
+		return -EIO;
+
+	ret = attribute->store(attribute, mk->mod, buf, len);
+
+	return ret;
+}
+
+static struct sysfs_ops module_sysfs_ops = {
+	.show = module_attr_show,
+	.store = module_attr_store,
+};
+
+static int uevent_filter(struct kset *kset, struct kobject *kobj)
+{
+	struct kobj_type *ktype = get_ktype(kobj);
+
+	if (ktype == &module_ktype)
+		return 1;
+	return 0;
+}
+
+static struct kset_uevent_ops module_uevent_ops = {
+	.filter = uevent_filter,
+};
+
+struct kset *module_kset;
+int module_sysfs_initialized;
+
+struct kobj_type module_ktype = {
+	.sysfs_ops =	&module_sysfs_ops,
+};
+
+/*
+ * param_sysfs_init - wrapper for built-in params support
+ */
+static int __init param_sysfs_init(void)
+{
+	module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
+	if (!module_kset) {
+		printk(KERN_WARNING "%s (%d): error creating kset\n",
+			__FILE__, __LINE__);
+		return -ENOMEM;
+	}
+	module_sysfs_initialized = 1;
+
+	param_sysfs_builtin();
+
+	return 0;
+}
+subsys_initcall(param_sysfs_init);
+
+#endif /* CONFIG_SYSFS */
+
+EXPORT_SYMBOL(param_set_byte);
+EXPORT_SYMBOL(param_get_byte);
+EXPORT_SYMBOL(param_set_short);
+EXPORT_SYMBOL(param_get_short);
+EXPORT_SYMBOL(param_set_ushort);
+EXPORT_SYMBOL(param_get_ushort);
+EXPORT_SYMBOL(param_set_int);
+EXPORT_SYMBOL(param_get_int);
+EXPORT_SYMBOL(param_set_uint);
+EXPORT_SYMBOL(param_get_uint);
+EXPORT_SYMBOL(param_set_long);
+EXPORT_SYMBOL(param_get_long);
+EXPORT_SYMBOL(param_set_ulong);
+EXPORT_SYMBOL(param_get_ulong);
+EXPORT_SYMBOL(param_set_charp);
+EXPORT_SYMBOL(param_get_charp);
+EXPORT_SYMBOL(param_set_bool);
+EXPORT_SYMBOL(param_get_bool);
+EXPORT_SYMBOL(param_set_invbool);
+EXPORT_SYMBOL(param_get_invbool);
+EXPORT_SYMBOL(param_array_set);
+EXPORT_SYMBOL(param_array_get);
+EXPORT_SYMBOL(param_set_copystring);
+EXPORT_SYMBOL(param_get_string);