Merge branch 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (22 commits)
  param: don't deref arg in __same_type() checks
  param: update drivers/acpi/debug.c to new scheme
  param: use module_param in drivers/message/fusion/mptbase.c
  ide: use module_param_named rather than module_param_call
  param: update drivers/char/ipmi/ipmi_watchdog.c to new scheme
  param: lock if_sdio's lbs_helper_name and lbs_fw_name against sysfs changes.
  param: lock myri10ge_fw_name against sysfs changes.
  param: simple locking for sysfs-writable charp parameters
  param: remove unnecessary writable charp
  param: add kerneldoc to moduleparam.h
  param: locking for kernel parameters
  param: make param sections const.
  param: use free hook for charp (fix leak of charp parameters)
  param: add a free hook to kernel_param_ops.
  param: silence .init.text references from param ops
  Add param ops struct for hvc_iucv driver.
  nfs: update for module_param_named API change
  AppArmor: update for module_param_named API change
  param: use ops in struct kernel_param, rather than get and set fns directly
  param: move the EXPORT_SYMBOL to after the definitions.
  ...

1 files changed, 161 insertions, 72 deletions

diff --git a/kernel/params.c b/kernel/params.c
index 0b30ecd53a52..08107d181758 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -31,6 +31,42 @@
 #define DEBUGP(fmt, a...)
 #endif
 
+/* Protects all parameters, and incidentally kmalloced_param list. */
+static DEFINE_MUTEX(param_lock);
+
+/* This just allows us to keep track of which parameters are kmalloced. */
+struct kmalloced_param {
+        struct list_head list;
+        char val[];
+};
+static LIST_HEAD(kmalloced_params);
+
+static void *kmalloc_parameter(unsigned int size)
+{
+        struct kmalloced_param *p;
+
+        p = kmalloc(sizeof(*p) + size, GFP_KERNEL);
+        if (!p)
+                return NULL;
+
+        list_add(&p->list, &kmalloced_params);
+        return p->val;
+}
+
+/* Does nothing if parameter wasn't kmalloced above. */
+static void maybe_kfree_parameter(void *param)
+{
+        struct kmalloced_param *p;
+
+        list_for_each_entry(p, &kmalloced_params, list) {
+                if (p->val == param) {
+                        list_del(&p->list);
+                        kfree(p);
+                        break;
+                }
+        }
+}
+
 static inline char dash2underscore(char c)
 {
         if (c == '-')
@@ -49,18 +85,25 @@ static inline int parameq(const char *input, const char *paramname)
 
 static int parse_one(char *param,
                      char *val,
-                     struct kernel_param *params, 
+                     const struct kernel_param *params,
                      unsigned num_params,
                      int (*handle_unknown)(char *param, char *val))
 {
         unsigned int i;
+        int err;
 
         /* Find parameter */
         for (i = 0; i < num_params; i++) {
                 if (parameq(param, params[i].name)) {
+                        /* Noone handled NULL, so do it here. */
+                        if (!val && params[i].ops->set != param_set_bool)
+                                return -EINVAL;
                         DEBUGP("They are equal!  Calling %p\n",
-                               params[i].set);
-                        return params[i].set(val, &params[i]);
+                               params[i].ops->set);
+                        mutex_lock(&param_lock);
+                        err = params[i].ops->set(val, &params[i]);
+                        mutex_unlock(&param_lock);
+                        return err;
                 }
         }
 
@@ -128,7 +171,7 @@ static char *next_arg(char *args, char **param, char **val)
 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
 int parse_args(const char *name,
                char *args,
-               struct kernel_param *params,
+               const struct kernel_param *params,
                unsigned num,
                int (*unknown)(char *param, char *val))
 {
@@ -176,22 +219,29 @@ int parse_args(const char *name,
 
 /* Lazy bastard, eh? */
 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn)       \
-        int param_set_##name(const char *val, struct kernel_param *kp)  \
+        int param_set_##name(const char *val, const 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)     \
+        int param_get_##name(char *buffer, const struct kernel_param *kp) \
         {                                                               \
                 return sprintf(buffer, format, *((type *)kp->arg));     \
-        }
+        }                                                               \
+        struct kernel_param_ops param_ops_##name = {                    \
+                .set = param_set_##name,                                \
+                .get = param_get_##name,                                \
+        };                                                              \
+        EXPORT_SYMBOL(param_set_##name);                                \
+        EXPORT_SYMBOL(param_get_##name);                                \
+        EXPORT_SYMBOL(param_ops_##name)
+
 
 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
@@ -201,39 +251,50 @@ 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)
+int param_set_charp(const char *val, const 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;
         }
 
-        /* This is a hack.  We can't need to strdup in early boot, and we
+        maybe_kfree_parameter(*(char **)kp->arg);
+
+        /* This is a hack.  We can't kmalloc in early boot, and we
          * don't need to; this mangled commandline is preserved. */
         if (slab_is_available()) {
-                *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
+                *(char **)kp->arg = kmalloc_parameter(strlen(val)+1);
                 if (!*(char **)kp->arg)
                         return -ENOMEM;
+                strcpy(*(char **)kp->arg, val);
         } else
                 *(const char **)kp->arg = val;
 
         return 0;
 }
+EXPORT_SYMBOL(param_set_charp);
 
-int param_get_charp(char *buffer, struct kernel_param *kp)
+int param_get_charp(char *buffer, const struct kernel_param *kp)
 {
         return sprintf(buffer, "%s", *((char **)kp->arg));
 }
+EXPORT_SYMBOL(param_get_charp);
+
+static void param_free_charp(void *arg)
+{
+        maybe_kfree_parameter(*((char **)arg));
+}
+
+struct kernel_param_ops param_ops_charp = {
+        .set = param_set_charp,
+        .get = param_get_charp,
+        .free = param_free_charp,
+};
+EXPORT_SYMBOL(param_ops_charp);
 
 /* Actually could be a bool or an int, for historical reasons. */
-int param_set_bool(const char *val, struct kernel_param *kp)
+int param_set_bool(const char *val, const struct kernel_param *kp)
 {
         bool v;
 
@@ -258,8 +319,9 @@ int param_set_bool(const char *val, struct kernel_param *kp)
                 *(int *)kp->arg = v;
         return 0;
 }
+EXPORT_SYMBOL(param_set_bool);
 
-int param_get_bool(char *buffer, struct kernel_param *kp)
+int param_get_bool(char *buffer, const struct kernel_param *kp)
 {
         bool val;
         if (kp->flags & KPARAM_ISBOOL)
@@ -270,9 +332,16 @@ int param_get_bool(char *buffer, struct kernel_param *kp)
         /* Y and N chosen as being relatively non-coder friendly */
         return sprintf(buffer, "%c", val ? 'Y' : 'N');
 }
+EXPORT_SYMBOL(param_get_bool);
+
+struct kernel_param_ops param_ops_bool = {
+        .set = param_set_bool,
+        .get = param_get_bool,
+};
+EXPORT_SYMBOL(param_ops_bool);
 
 /* This one must be bool. */
-int param_set_invbool(const char *val, struct kernel_param *kp)
+int param_set_invbool(const char *val, const struct kernel_param *kp)
 {
         int ret;
         bool boolval;
@@ -285,18 +354,26 @@ int param_set_invbool(const char *val, struct kernel_param *kp)
                 *(bool *)kp->arg = !boolval;
         return ret;
 }
+EXPORT_SYMBOL(param_set_invbool);
 
-int param_get_invbool(char *buffer, struct kernel_param *kp)
+int param_get_invbool(char *buffer, const struct kernel_param *kp)
 {
         return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
 }
+EXPORT_SYMBOL(param_get_invbool);
+
+struct kernel_param_ops param_ops_invbool = {
+        .set = param_set_invbool,
+        .get = param_get_invbool,
+};
+EXPORT_SYMBOL(param_ops_invbool);
 
 /* 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),
+                       int (*set)(const char *, const struct kernel_param *kp),
                        u16 flags,
                        unsigned int *num)
 {
@@ -309,12 +386,6 @@ static int param_array(const char *name,
         kp.arg = elem;
         kp.flags = flags;
 
-        /* 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 {
@@ -330,6 +401,7 @@ static int param_array(const char *name,
                 /* nul-terminate and parse */
                 save = val[len];
                 ((char *)val)[len] = '\0';
+                BUG_ON(!mutex_is_locked(&param_lock));
                 ret = set(val, &kp);
 
                 if (ret != 0)
@@ -347,17 +419,17 @@ static int param_array(const char *name,
         return 0;
 }
 
-int param_array_set(const char *val, struct kernel_param *kp)
+static int param_array_set(const char *val, const 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, kp->flags,
+                           arr->elemsize, arr->ops->set, kp->flags,
                            arr->num ?: &temp_num);
 }
 
-int param_array_get(char *buffer, struct kernel_param *kp)
+static int param_array_get(char *buffer, const struct kernel_param *kp)
 {
         int i, off, ret;
         const struct kparam_array *arr = kp->arr;
@@ -368,7 +440,8 @@ int param_array_get(char *buffer, struct kernel_param *kp)
                 if (i)
                         buffer[off++] = ',';
                 p.arg = arr->elem + arr->elemsize * i;
-                ret = arr->get(buffer + off, &p);
+                BUG_ON(!mutex_is_locked(&param_lock));
+                ret = arr->ops->get(buffer + off, &p);
                 if (ret < 0)
                         return ret;
                 off += ret;
@@ -377,14 +450,27 @@ int param_array_get(char *buffer, struct kernel_param *kp)
         return off;
 }
 
-int param_set_copystring(const char *val, struct kernel_param *kp)
+static void param_array_free(void *arg)
+{
+        unsigned int i;
+        const struct kparam_array *arr = arg;
+
+        if (arr->ops->free)
+                for (i = 0; i < (arr->num ? *arr->num : arr->max); i++)
+                        arr->ops->free(arr->elem + arr->elemsize * i);
+}
+
+struct kernel_param_ops param_array_ops = {
+        .set = param_array_set,
+        .get = param_array_get,
+        .free = param_array_free,
+};
+EXPORT_SYMBOL(param_array_ops);
+
+int param_set_copystring(const char *val, const 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);
@@ -393,12 +479,20 @@ int param_set_copystring(const char *val, struct kernel_param *kp)
         strcpy(kps->string, val);
         return 0;
 }
+EXPORT_SYMBOL(param_set_copystring);
 
-int param_get_string(char *buffer, struct kernel_param *kp)
+int param_get_string(char *buffer, const struct kernel_param *kp)
 {
         const struct kparam_string *kps = kp->str;
         return strlcpy(buffer, kps->string, kps->maxlen);
 }
+EXPORT_SYMBOL(param_get_string);
+
+struct kernel_param_ops param_ops_string = {
+        .set = param_set_copystring,
+        .get = param_get_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)
@@ -409,7 +503,7 @@ extern struct kernel_param __start___param[], __stop___param[];
 struct param_attribute
 {
         struct module_attribute mattr;
-        struct kernel_param *param;
+        const struct kernel_param *param;
 };
 
 struct module_param_attrs
@@ -428,10 +522,12 @@ static ssize_t param_attr_show(struct module_attribute *mattr,
         int count;
         struct param_attribute *attribute = to_param_attr(mattr);
 
-        if (!attribute->param->get)
+        if (!attribute->param->ops->get)
                 return -EPERM;
 
-        count = attribute->param->get(buf, attribute->param);
+        mutex_lock(&param_lock);
+        count = attribute->param->ops->get(buf, attribute->param);
+        mutex_unlock(&param_lock);
         if (count > 0) {
                 strcat(buf, "\n");
                 ++count;
@@ -447,10 +543,12 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
         int err;
         struct param_attribute *attribute = to_param_attr(mattr);
 
-        if (!attribute->param->set)
+        if (!attribute->param->ops->set)
                 return -EPERM;
 
-        err = attribute->param->set(buf, attribute->param);
+        mutex_lock(&param_lock);
+        err = attribute->param->ops->set(buf, attribute->param);
+        mutex_unlock(&param_lock);
         if (!err)
                 return len;
         return err;
@@ -464,6 +562,18 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
 #endif
 
 #ifdef CONFIG_SYSFS
+void __kernel_param_lock(void)
+{
+        mutex_lock(&param_lock);
+}
+EXPORT_SYMBOL(__kernel_param_lock);
+
+void __kernel_param_unlock(void)
+{
+        mutex_unlock(&param_lock);
+}
+EXPORT_SYMBOL(__kernel_param_unlock);
+
 /*
  * add_sysfs_param - add a parameter to sysfs
  * @mk: struct module_kobject
@@ -475,7 +585,7 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
  * if there's an error.
  */
 static __modinit int add_sysfs_param(struct module_kobject *mk,
-                                     struct kernel_param *kp,
+                                     const struct kernel_param *kp,
                                      const char *name)
 {
         struct module_param_attrs *new;
@@ -557,7 +667,7 @@ static void free_module_param_attrs(struct module_kobject *mk)
  * /sys/module/[mod->name]/parameters/
  */
 int module_param_sysfs_setup(struct module *mod,
-                             struct kernel_param *kparam,
+                             const struct kernel_param *kparam,
                              unsigned int num_params)
 {
         int i, err;
@@ -602,7 +712,11 @@ void module_param_sysfs_remove(struct module *mod)
 
 void destroy_params(const struct kernel_param *params, unsigned num)
 {
-        /* FIXME: This should free kmalloced charp parameters.  It doesn't. */
+        unsigned int i;
+
+        for (i = 0; i < num; i++)
+                if (params[i].ops->free)
+                        params[i].ops->free(params[i].arg);
 }
 
 static void __init kernel_add_sysfs_param(const char *name,
@@ -768,28 +882,3 @@ static int __init param_sysfs_init(void)
 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);