summaryrefslogtreecommitdiff
path: root/kernel/params.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/params.c')
-rw-r--r--kernel/params.c721
1 files changed, 721 insertions, 0 deletions
diff --git a/kernel/params.c b/kernel/params.c
new file mode 100644
index 000000000000..5538608bd339
--- /dev/null
+++ b/kernel/params.c
@@ -0,0 +1,721 @@
+/* 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/config.h>
+#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>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt, a...)
+#endif
+
+static inline int 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;
+
+ /* Chew any extra spaces */
+ while (*args == ' ') args++;
+ 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;
+ 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);
+
+ while (*args) {
+ int ret;
+
+ args = next_arg(args, &param, &val);
+ ret = parse_one(param, val, params, num, unknown);
+ 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) \
+ { \
+ char *endp; \
+ tmptype l; \
+ \
+ if (!val) return -EINVAL; \
+ l = strtolfn(val, &endp, 0); \
+ if (endp == val || ((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, simple_strtoul);
+STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol);
+STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul);
+STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol);
+STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul);
+STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol);
+STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_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 = { .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)
+{
+ int val;
+ struct kernel_param dummy = { .arg = &val };
+
+ val = !*(int *)kp->arg;
+ return param_get_bool(buffer, &dummy);
+}
+
+/* We cheat here and temporarily mangle the string. */
+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),
+ 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)
+{
+ struct kparam_array *arr = kp->arg;
+
+ return param_array(kp->name, val, 1, arr->max, arr->elem,
+ arr->elemsize, arr->set, arr->num ?: &arr->max);
+}
+
+int param_array_get(char *buffer, struct kernel_param *kp)
+{
+ int i, off, ret;
+ struct kparam_array *arr = kp->arg;
+ 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)
+{
+ struct kparam_string *kps = kp->arg;
+
+ 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)
+{
+ struct kparam_string *kps = kp->arg;
+ return strlcpy(buffer, kps->string, kps->maxlen);
+}
+
+/* sysfs output in /sys/modules/XYZ/parameters/ */
+
+extern struct kernel_param __start___param[], __stop___param[];
+
+#define MAX_KBUILD_MODNAME KOBJ_NAME_LEN
+
+struct param_attribute
+{
+ struct module_attribute mattr;
+ struct kernel_param *param;
+};
+
+struct module_param_attrs
+{
+ struct attribute_group grp;
+ struct param_attribute attrs[0];
+};
+
+#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;
+}
+
+#ifdef CONFIG_MODULES
+#define __modinit
+#else
+#define __modinit __init
+#endif
+
+/*
+ * 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 = kmalloc(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.owner = mk->mod;
+ 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;
+
+ mk = kmalloc(sizeof(struct module_kobject), GFP_KERNEL);
+ memset(mk, 0, sizeof(struct module_kobject));
+
+ mk->mod = THIS_MODULE;
+ kobj_set_kset_s(mk, module_subsys);
+ kobject_set_name(&mk->kobj, name);
+ kobject_register(&mk->kobj);
+
+ /* no need to keep the kobject if no parameter is exported */
+ if (!param_sysfs_setup(mk, kparam, num_params, name_skip)) {
+ kobject_unregister(&mk->kobj);
+ kfree(mk);
+ }
+}
+
+/*
+ * 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[MAX_KBUILD_MODNAME + 1] = "";
+
+ for (i=0; i < __stop___param - __start___param; i++) {
+ char *dot;
+
+ kp = &__start___param[i];
+
+ /* We do not handle args without periods. */
+ dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME);
+ if (!dot) {
+ DEBUGP("couldn't find period in %s\n", 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 */
+#ifdef CONFIG_MODULES
+
+#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 -EPERM;
+
+ if (!try_module_get(mk->mod))
+ return -ENODEV;
+
+ ret = attribute->show(attribute, mk->mod, buf);
+
+ module_put(mk->mod);
+
+ 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 -EPERM;
+
+ if (!try_module_get(mk->mod))
+ return -ENODEV;
+
+ ret = attribute->store(attribute, mk->mod, buf, len);
+
+ module_put(mk->mod);
+
+ return ret;
+}
+
+static struct sysfs_ops module_sysfs_ops = {
+ .show = module_attr_show,
+ .store = module_attr_store,
+};
+
+#else
+static struct sysfs_ops module_sysfs_ops = {
+ .show = NULL,
+ .store = NULL,
+};
+#endif
+
+static struct kobj_type module_ktype = {
+ .sysfs_ops = &module_sysfs_ops,
+};
+
+decl_subsys(module, &module_ktype, NULL);
+
+/*
+ * param_sysfs_init - wrapper for built-in params support
+ */
+static int __init param_sysfs_init(void)
+{
+ subsystem_register(&module_subsys);
+
+ param_sysfs_builtin();
+
+ return 0;
+}
+__initcall(param_sysfs_init);
+
+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);
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-15 16:52:10 +0000