From 2e9fb9953df91ef6310da22182ca8f4496907502 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Aug 2010 23:04:10 -0600 Subject: params: don't hand NULL values to param.set callbacks. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit An audit by Dongdong Deng revealed that most driver-author-written param calls don't handle val == NULL (which happens when parameters are specified with no =, eg "foo" instead of "foo=1"). The only real case to use this is boolean, so handle it specially for that case and remove a source of bugs for everyone else. Signed-off-by: Rusty Russell Cc: Dongdong Deng Cc: Américo Wang --- kernel/params.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index 0b30ecd53a5..3c4a9f1b095 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -58,6 +58,9 @@ static int parse_one(char *param, /* 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].set != param_set_bool) + return -EINVAL; DEBUGP("They are equal! Calling %p\n", params[i].set); return params[i].set(val, ¶ms[i]); @@ -181,7 +184,6 @@ int parse_args(const char *name, tmptype l; \ int ret; \ \ - if (!val) return -EINVAL; \ ret = strtolfn(val, 0, &l); \ if (ret == -EINVAL || ((type)l != l)) \ return -EINVAL; \ @@ -203,12 +205,6 @@ 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); @@ -309,12 +305,6 @@ 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 { @@ -381,10 +371,6 @@ 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); -- cgit v1.2.3-70-g09d2 From a14fe249a8f74269c9e636bcbaa78f5bdb354ce3 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Aug 2010 23:04:11 -0600 Subject: param: move the EXPORT_SYMBOL to after the definitions. This is modern style, and good to do before we start changing things. Signed-off-by: Rusty Russell Reviewed-by: Takashi Iwai Tested-by: Phil Carmody --- kernel/params.c | 39 +++++++++++++-------------------------- 1 file changed, 13 insertions(+), 26 deletions(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index 3c4a9f1b095..3e78fdb445e 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -193,7 +193,9 @@ int parse_args(const char *name, int param_get_##name(char *buffer, struct kernel_param *kp) \ { \ return sprintf(buffer, format, *((type *)kp->arg)); \ - } + } \ + EXPORT_SYMBOL(param_set_##name); \ + EXPORT_SYMBOL(param_get_##name) STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul); STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol); @@ -222,11 +224,13 @@ int param_set_charp(const char *val, struct kernel_param *kp) return 0; } +EXPORT_SYMBOL(param_set_charp); int param_get_charp(char *buffer, struct kernel_param *kp) { return sprintf(buffer, "%s", *((char **)kp->arg)); } +EXPORT_SYMBOL(param_get_charp); /* Actually could be a bool or an int, for historical reasons. */ int param_set_bool(const char *val, struct kernel_param *kp) @@ -254,6 +258,7 @@ 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) { @@ -266,6 +271,7 @@ 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); /* This one must be bool. */ int param_set_invbool(const char *val, struct kernel_param *kp) @@ -281,11 +287,13 @@ 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) { return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y'); } +EXPORT_SYMBOL(param_get_invbool); /* We break the rule and mangle the string. */ static int param_array(const char *name, @@ -346,6 +354,7 @@ int param_array_set(const char *val, struct kernel_param *kp) arr->elemsize, arr->set, kp->flags, arr->num ?: &temp_num); } +EXPORT_SYMBOL(param_array_set); int param_array_get(char *buffer, struct kernel_param *kp) { @@ -366,6 +375,7 @@ int param_array_get(char *buffer, struct kernel_param *kp) buffer[off] = '\0'; return off; } +EXPORT_SYMBOL(param_array_get); int param_set_copystring(const char *val, struct kernel_param *kp) { @@ -379,12 +389,14 @@ 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) { const struct kparam_string *kps = kp->str; return strlcpy(buffer, kps->string, kps->maxlen); } +EXPORT_SYMBOL(param_get_string); /* sysfs output in /sys/modules/XYZ/parameters/ */ #define to_module_attr(n) container_of(n, struct module_attribute, attr) @@ -754,28 +766,3 @@ 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); -- cgit v1.2.3-70-g09d2 From 9bbb9e5a33109b2832e2e63dcc7a132924ab374b Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Aug 2010 23:04:12 -0600 Subject: param: use ops in struct kernel_param, rather than get and set fns directly This is more kernel-ish, saves some space, and also allows us to expand the ops without breaking all the callers who are happy for the new members to be NULL. The few places which defined their own param types are changed to the new scheme (more which crept in recently fixed in following patches). Since we're touching them anyway, we change get() and set() to take a const struct kernel_param (which they really are). This causes some harmless warnings until we fix them (in following patches). To reduce churn, module_param_call creates the ops struct so the callers don't have to change (and casts the functions to reduce warnings). The modern version which takes an ops struct is called module_param_cb. Signed-off-by: Rusty Russell Reviewed-by: Takashi Iwai Tested-by: Phil Carmody Cc: "David S. Miller" Cc: Ville Syrjala Cc: Dmitry Torokhov Cc: Alessandro Rubini Cc: Michal Januszewski Cc: Trond Myklebust Cc: "J. Bruce Fields" Cc: Neil Brown Cc: linux-kernel@vger.kernel.org Cc: linux-input@vger.kernel.org Cc: linux-fbdev-devel@lists.sourceforge.net Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org --- drivers/input/misc/ati_remote2.c | 26 +++++--- drivers/input/mouse/psmouse-base.c | 14 +++-- drivers/video/uvesafb.c | 7 ++- fs/nfs/callback.c | 11 ++-- include/linux/moduleparam.h | 123 ++++++++++++++++++++++--------------- kernel/params.c | 90 ++++++++++++++++++--------- net/sunrpc/xprtsock.c | 26 ++++---- 7 files changed, 186 insertions(+), 111 deletions(-) (limited to 'kernel') diff --git a/drivers/input/misc/ati_remote2.c b/drivers/input/misc/ati_remote2.c index e148749b585..23257652b8e 100644 --- a/drivers/input/misc/ati_remote2.c +++ b/drivers/input/misc/ati_remote2.c @@ -38,7 +38,8 @@ enum { }; static int ati_remote2_set_mask(const char *val, - struct kernel_param *kp, unsigned int max) + const struct kernel_param *kp, + unsigned int max) { unsigned long mask; int ret; @@ -59,28 +60,31 @@ static int ati_remote2_set_mask(const char *val, } static int ati_remote2_set_channel_mask(const char *val, - struct kernel_param *kp) + const struct kernel_param *kp) { pr_debug("%s()\n", __func__); return ati_remote2_set_mask(val, kp, ATI_REMOTE2_MAX_CHANNEL_MASK); } -static int ati_remote2_get_channel_mask(char *buffer, struct kernel_param *kp) +static int ati_remote2_get_channel_mask(char *buffer, + const struct kernel_param *kp) { pr_debug("%s()\n", __func__); return sprintf(buffer, "0x%04x", *(unsigned int *)kp->arg); } -static int ati_remote2_set_mode_mask(const char *val, struct kernel_param *kp) +static int ati_remote2_set_mode_mask(const char *val, + const struct kernel_param *kp) { pr_debug("%s()\n", __func__); return ati_remote2_set_mask(val, kp, ATI_REMOTE2_MAX_MODE_MASK); } -static int ati_remote2_get_mode_mask(char *buffer, struct kernel_param *kp) +static int ati_remote2_get_mode_mask(char *buffer, + const struct kernel_param *kp) { pr_debug("%s()\n", __func__); @@ -89,15 +93,19 @@ static int ati_remote2_get_mode_mask(char *buffer, struct kernel_param *kp) static unsigned int channel_mask = ATI_REMOTE2_MAX_CHANNEL_MASK; #define param_check_channel_mask(name, p) __param_check(name, p, unsigned int) -#define param_set_channel_mask ati_remote2_set_channel_mask -#define param_get_channel_mask ati_remote2_get_channel_mask +static struct kernel_param_ops param_ops_channel_mask = { + .set = ati_remote2_set_channel_mask, + .get = ati_remote2_get_channel_mask, +}; module_param(channel_mask, channel_mask, 0644); MODULE_PARM_DESC(channel_mask, "Bitmask of channels to accept <15:Channel16>...<1:Channel2><0:Channel1>"); static unsigned int mode_mask = ATI_REMOTE2_MAX_MODE_MASK; #define param_check_mode_mask(name, p) __param_check(name, p, unsigned int) -#define param_set_mode_mask ati_remote2_set_mode_mask -#define param_get_mode_mask ati_remote2_get_mode_mask +static struct kernel_param_ops param_ops_mode_mask = { + .set = ati_remote2_set_mode_mask, + .get = ati_remote2_get_mode_mask, +}; module_param(mode_mask, mode_mask, 0644); MODULE_PARM_DESC(mode_mask, "Bitmask of modes to accept <4:PC><3:AUX4><2:AUX3><1:AUX2><0:AUX1>"); diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c index 979c5021528..73a7af2542a 100644 --- a/drivers/input/mouse/psmouse-base.c +++ b/drivers/input/mouse/psmouse-base.c @@ -39,11 +39,13 @@ MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL"); static unsigned int psmouse_max_proto = PSMOUSE_AUTO; -static int psmouse_set_maxproto(const char *val, struct kernel_param *kp); -static int psmouse_get_maxproto(char *buffer, struct kernel_param *kp); +static int psmouse_set_maxproto(const char *val, const struct kernel_param *); +static int psmouse_get_maxproto(char *buffer, const struct kernel_param *kp); +static struct kernel_param_ops param_ops_proto_abbrev = { + .set = psmouse_set_maxproto, + .get = psmouse_get_maxproto, +}; #define param_check_proto_abbrev(name, p) __param_check(name, p, unsigned int) -#define param_set_proto_abbrev psmouse_set_maxproto -#define param_get_proto_abbrev psmouse_get_maxproto module_param_named(proto, psmouse_max_proto, proto_abbrev, 0644); MODULE_PARM_DESC(proto, "Highest protocol extension to probe (bare, imps, exps, any). Useful for KVM switches."); @@ -1679,7 +1681,7 @@ static ssize_t psmouse_attr_set_resolution(struct psmouse *psmouse, void *data, } -static int psmouse_set_maxproto(const char *val, struct kernel_param *kp) +static int psmouse_set_maxproto(const char *val, const struct kernel_param *kp) { const struct psmouse_protocol *proto; @@ -1696,7 +1698,7 @@ static int psmouse_set_maxproto(const char *val, struct kernel_param *kp) return 0; } -static int psmouse_get_maxproto(char *buffer, struct kernel_param *kp) +static int psmouse_get_maxproto(char *buffer, const struct kernel_param *kp) { int type = *((unsigned int *)kp->arg); diff --git a/drivers/video/uvesafb.c b/drivers/video/uvesafb.c index 7b8839ebf3c..52ec0959d46 100644 --- a/drivers/video/uvesafb.c +++ b/drivers/video/uvesafb.c @@ -1977,8 +1977,7 @@ static void __devexit uvesafb_exit(void) module_exit(uvesafb_exit); -#define param_get_scroll NULL -static int param_set_scroll(const char *val, struct kernel_param *kp) +static int param_set_scroll(const char *val, const struct kernel_param *kp) { ypan = 0; @@ -1993,7 +1992,9 @@ static int param_set_scroll(const char *val, struct kernel_param *kp) return 0; } - +static struct kernel_param_ops param_ops_scroll = { + .set = param_set_scroll, +}; #define param_check_scroll(name, p) __param_check(name, p, void) module_param_named(scroll, ypan, scroll, 0); diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c index 36dfdae9512..e17b49e2eab 100644 --- a/fs/nfs/callback.c +++ b/fs/nfs/callback.c @@ -45,7 +45,7 @@ unsigned short nfs_callback_tcpport; unsigned short nfs_callback_tcpport6; #define NFS_CALLBACK_MAXPORTNR (65535U) -static int param_set_portnr(const char *val, struct kernel_param *kp) +static int param_set_portnr(const char *val, const struct kernel_param *kp) { unsigned long num; int ret; @@ -58,11 +58,10 @@ static int param_set_portnr(const char *val, struct kernel_param *kp) *((unsigned int *)kp->arg) = num; return 0; } - -static int param_get_portnr(char *buffer, struct kernel_param *kp) -{ - return param_get_uint(buffer, kp); -} +static struct kernel_param_ops param_ops_portnr = { + .set = param_set_portnr, + .get = param_get_uint, +}; #define param_check_portnr(name, p) __param_check(name, p, unsigned int); module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644); diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 82a9124f7d7..02e5090ce32 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -31,20 +31,21 @@ static const char __module_cat(name,__LINE__)[] \ struct kernel_param; -/* Returns 0, or -errno. arg is in kp->arg. */ -typedef int (*param_set_fn)(const char *val, struct kernel_param *kp); -/* Returns length written or -errno. Buffer is 4k (ie. be short!) */ -typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp); +struct kernel_param_ops { + /* Returns 0, or -errno. arg is in kp->arg. */ + int (*set)(const char *val, const struct kernel_param *kp); + /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ + int (*get)(char *buffer, const struct kernel_param *kp); +}; /* Flag bits for kernel_param.flags */ #define KPARAM_ISBOOL 2 struct kernel_param { const char *name; + const struct kernel_param_ops *ops; u16 perm; u16 flags; - param_set_fn set; - param_get_fn get; union { void *arg; const struct kparam_string *str; @@ -63,8 +64,7 @@ struct kparam_array { unsigned int max; unsigned int *num; - param_set_fn set; - param_get_fn get; + const struct kernel_param_ops *ops; unsigned int elemsize; void *elem; }; @@ -83,7 +83,7 @@ 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, isbool, perm) \ +#define __module_param_call(prefix, name, ops, 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)) \ @@ -92,20 +92,37 @@ struct kparam_array static struct kernel_param __moduleparam_const __param_##name \ __used \ __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ - = { __param_str_##name, perm, isbool ? KPARAM_ISBOOL : 0, \ - set, get, { arg } } + = { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0, \ + { arg } } + +/* Obsolete - use module_param_cb() */ +#define module_param_call(name, set, get, arg, perm) \ + static struct kernel_param_ops __param_ops_##name = \ + { (void *)set, (void *)get }; \ + __module_param_call(MODULE_PARAM_PREFIX, \ + name, &__param_ops_##name, arg, \ + __same_type(*(arg), bool), \ + (perm) + sizeof(__check_old_set_param(set))*0) + +/* We don't get oldget: it's often a new-style param_get_uint, etc. */ +static inline int +__check_old_set_param(int (*oldset)(const char *, struct kernel_param *)) +{ + return 0; +} -#define module_param_call(name, set, get, arg, perm) \ +#define module_param_cb(name, ops, arg, perm) \ __module_param_call(MODULE_PARAM_PREFIX, \ - name, set, get, arg, \ - __same_type(*(arg), bool), perm) + name, ops, 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, - param_set_XXX and param_check_XXX. */ +/* + * Helper functions: type is byte, short, ushort, int, uint, long, + * ulong, charp, bool or invbool, or XXX if you define param_ops_XXX + * and param_check_XXX. + */ #define module_param_named(name, value, type, perm) \ param_check_##type(name, &(value)); \ - module_param_call(name, param_set_##type, param_get_##type, &value, perm); \ + module_param_cb(name, ¶m_ops_##type, &value, perm); \ __MODULE_PARM_TYPE(name, #type) #define module_param(name, type, perm) \ @@ -126,7 +143,7 @@ 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, \ + __module_param_call("", name, ¶m_ops_##type, \ &var, __same_type(var, bool), perm) #endif /* !MODULE */ @@ -135,7 +152,7 @@ struct kparam_array static const struct kparam_string __param_string_##name \ = { len, string }; \ __module_param_call(MODULE_PARAM_PREFIX, name, \ - param_set_copystring, param_get_string, \ + ¶m_ops_string, \ .str = &__param_string_##name, 0, perm); \ __MODULE_PARM_TYPE(name, "string") @@ -162,41 +179,50 @@ static inline void destroy_params(const struct kernel_param *params, #define __param_check(name, p, type) \ static inline type *__check_##name(void) { return(p); } -extern int param_set_byte(const char *val, struct kernel_param *kp); -extern int param_get_byte(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_byte; +extern int param_set_byte(const char *val, const struct kernel_param *kp); +extern int param_get_byte(char *buffer, const struct kernel_param *kp); #define param_check_byte(name, p) __param_check(name, p, unsigned char) -extern int param_set_short(const char *val, struct kernel_param *kp); -extern int param_get_short(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_short; +extern int param_set_short(const char *val, const struct kernel_param *kp); +extern int param_get_short(char *buffer, const struct kernel_param *kp); #define param_check_short(name, p) __param_check(name, p, short) -extern int param_set_ushort(const char *val, struct kernel_param *kp); -extern int param_get_ushort(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_ushort; +extern int param_set_ushort(const char *val, const struct kernel_param *kp); +extern int param_get_ushort(char *buffer, const struct kernel_param *kp); #define param_check_ushort(name, p) __param_check(name, p, unsigned short) -extern int param_set_int(const char *val, struct kernel_param *kp); -extern int param_get_int(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_int; +extern int param_set_int(const char *val, const struct kernel_param *kp); +extern int param_get_int(char *buffer, const struct kernel_param *kp); #define param_check_int(name, p) __param_check(name, p, int) -extern int param_set_uint(const char *val, struct kernel_param *kp); -extern int param_get_uint(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_uint; +extern int param_set_uint(const char *val, const struct kernel_param *kp); +extern int param_get_uint(char *buffer, const struct kernel_param *kp); #define param_check_uint(name, p) __param_check(name, p, unsigned int) -extern int param_set_long(const char *val, struct kernel_param *kp); -extern int param_get_long(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_long; +extern int param_set_long(const char *val, const struct kernel_param *kp); +extern int param_get_long(char *buffer, const struct kernel_param *kp); #define param_check_long(name, p) __param_check(name, p, long) -extern int param_set_ulong(const char *val, struct kernel_param *kp); -extern int param_get_ulong(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_ulong; +extern int param_set_ulong(const char *val, const struct kernel_param *kp); +extern int param_get_ulong(char *buffer, const struct kernel_param *kp); #define param_check_ulong(name, p) __param_check(name, p, unsigned long) -extern int param_set_charp(const char *val, struct kernel_param *kp); -extern int param_get_charp(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_charp; +extern int param_set_charp(const char *val, const struct kernel_param *kp); +extern int param_get_charp(char *buffer, const 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); +extern struct kernel_param_ops param_ops_bool; +extern int param_set_bool(const char *val, const struct kernel_param *kp); +extern int param_get_bool(char *buffer, const struct kernel_param *kp); #define param_check_bool(name, p) \ static inline void __check_##name(void) \ { \ @@ -205,17 +231,18 @@ extern int param_get_bool(char *buffer, struct kernel_param *kp); !__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); +extern struct kernel_param_ops param_ops_invbool; +extern int param_set_invbool(const char *val, const struct kernel_param *kp); +extern int param_get_invbool(char *buffer, const struct kernel_param *kp); #define param_check_invbool(name, p) __param_check(name, p, bool) /* Comma-separated array: *nump is set to number they actually specified. */ #define module_param_array_named(name, array, type, nump, perm) \ static const struct kparam_array __param_arr_##name \ - = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\ + = { ARRAY_SIZE(array), nump, ¶m_ops_##type, \ sizeof(array[0]), array }; \ __module_param_call(MODULE_PARAM_PREFIX, name, \ - param_array_set, param_array_get, \ + ¶m_array_ops, \ .arr = &__param_arr_##name, \ __same_type(array[0], bool), perm); \ __MODULE_PARM_TYPE(name, "array of " #type) @@ -223,11 +250,11 @@ extern int param_get_invbool(char *buffer, struct kernel_param *kp); #define module_param_array(name, type, nump, perm) \ module_param_array_named(name, name, type, nump, perm) -extern int param_array_set(const char *val, struct kernel_param *kp); -extern int param_array_get(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_array_ops; -extern int param_set_copystring(const char *val, struct kernel_param *kp); -extern int param_get_string(char *buffer, struct kernel_param *kp); +extern struct kernel_param_ops param_ops_string; +extern int param_set_copystring(const char *val, const struct kernel_param *); +extern int param_get_string(char *buffer, const struct kernel_param *kp); /* for exporting parameters in /sys/parameters */ @@ -235,13 +262,13 @@ struct module; #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) extern int module_param_sysfs_setup(struct module *mod, - struct kernel_param *kparam, + const struct kernel_param *kparam, unsigned int num_params); extern void module_param_sysfs_remove(struct module *mod); #else static inline int module_param_sysfs_setup(struct module *mod, - struct kernel_param *kparam, + const struct kernel_param *kparam, unsigned int num_params) { return 0; diff --git a/kernel/params.c b/kernel/params.c index 3e78fdb445e..a550698ae02 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -59,11 +59,11 @@ static int parse_one(char *param, for (i = 0; i < num_params; i++) { if (parameq(param, params[i].name)) { /* Noone handled NULL, so do it here. */ - if (!val && params[i].set != param_set_bool) + 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, ¶ms[i]); + params[i].ops->set); + return params[i].ops->set(val, ¶ms[i]); } } @@ -179,7 +179,7 @@ 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; \ @@ -190,12 +190,18 @@ int parse_args(const char *name, *((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_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); @@ -205,7 +211,7 @@ 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 (strlen(val) > 1024) { printk(KERN_ERR "%s: string parameter too long\n", @@ -226,14 +232,20 @@ int param_set_charp(const char *val, struct kernel_param *kp) } 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); +struct kernel_param_ops param_ops_charp = { + .set = param_set_charp, + .get = param_get_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; @@ -260,7 +272,7 @@ int param_set_bool(const char *val, struct kernel_param *kp) } 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) @@ -273,8 +285,14 @@ int param_get_bool(char *buffer, struct kernel_param *kp) } 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; @@ -289,18 +307,24 @@ int param_set_invbool(const char *val, struct kernel_param *kp) } 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) { @@ -345,18 +369,17 @@ 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); } -EXPORT_SYMBOL(param_array_set); -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; @@ -367,7 +390,7 @@ 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); + ret = arr->ops->get(buffer + off, &p); if (ret < 0) return ret; off += ret; @@ -375,9 +398,14 @@ int param_array_get(char *buffer, struct kernel_param *kp) buffer[off] = '\0'; return off; } -EXPORT_SYMBOL(param_array_get); -int param_set_copystring(const char *val, struct kernel_param *kp) +struct kernel_param_ops param_array_ops = { + .set = param_array_set, + .get = param_array_get, +}; +EXPORT_SYMBOL(param_array_ops); + +int param_set_copystring(const char *val, const struct kernel_param *kp) { const struct kparam_string *kps = kp->str; @@ -391,13 +419,19 @@ int param_set_copystring(const char *val, struct kernel_param *kp) } 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) #define to_module_kobject(n) container_of(n, struct module_kobject, kobj) @@ -407,7 +441,7 @@ 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 @@ -426,10 +460,10 @@ 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); + count = attribute->param->ops->get(buf, attribute->param); if (count > 0) { strcat(buf, "\n"); ++count; @@ -445,10 +479,10 @@ 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); + err = attribute->param->ops->set(buf, attribute->param); if (!err) return len; return err; @@ -473,7 +507,7 @@ 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; @@ -555,7 +589,7 @@ 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; diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 7ca65c7005e..49a62f0c4b8 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2577,7 +2577,8 @@ void cleanup_socket_xprt(void) xprt_unregister_transport(&xs_bc_tcp_transport); } -static int param_set_uint_minmax(const char *val, struct kernel_param *kp, +static int param_set_uint_minmax(const char *val, + const struct kernel_param *kp, unsigned int min, unsigned int max) { unsigned long num; @@ -2592,34 +2593,37 @@ static int param_set_uint_minmax(const char *val, struct kernel_param *kp, return 0; } -static int param_set_portnr(const char *val, struct kernel_param *kp) +static int param_set_portnr(const char *val, const struct kernel_param *kp) { return param_set_uint_minmax(val, kp, RPC_MIN_RESVPORT, RPC_MAX_RESVPORT); } -static int param_get_portnr(char *buffer, struct kernel_param *kp) -{ - return param_get_uint(buffer, kp); -} +static struct kernel_param_ops param_ops_portnr = { + .set = param_set_portnr, + .get = param_get_uint, +}; + #define param_check_portnr(name, p) \ __param_check(name, p, unsigned int); module_param_named(min_resvport, xprt_min_resvport, portnr, 0644); module_param_named(max_resvport, xprt_max_resvport, portnr, 0644); -static int param_set_slot_table_size(const char *val, struct kernel_param *kp) +static int param_set_slot_table_size(const char *val, + const struct kernel_param *kp) { return param_set_uint_minmax(val, kp, RPC_MIN_SLOT_TABLE, RPC_MAX_SLOT_TABLE); } -static int param_get_slot_table_size(char *buffer, struct kernel_param *kp) -{ - return param_get_uint(buffer, kp); -} +static struct kernel_param_ops param_ops_slot_table_size = { + .set = param_set_slot_table_size, + .get = param_get_uint, +}; + #define param_check_slot_table_size(name, p) \ __param_check(name, p, unsigned int); -- cgit v1.2.3-70-g09d2 From e6df34a4429b77fdffb6e05adf263468a3dcda33 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Aug 2010 23:04:17 -0600 Subject: param: add a free hook to kernel_param_ops. This allows us to generalize the KPARAM_KMALLOCED flag, by calling a function on every parameter when a module is unloaded. Signed-off-by: Rusty Russell Reviewed-by: Takashi Iwai Tested-by: Phil Carmody --- include/linux/moduleparam.h | 2 ++ kernel/params.c | 17 ++++++++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 02e5090ce32..9f51568f51c 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -36,6 +36,8 @@ struct kernel_param_ops { int (*set)(const char *val, const struct kernel_param *kp); /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ int (*get)(char *buffer, const struct kernel_param *kp); + /* Optional function to free kp->arg when module unloaded. */ + void (*free)(void *arg); }; /* Flag bits for kernel_param.flags */ diff --git a/kernel/params.c b/kernel/params.c index a550698ae02..458a09b886c 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -399,9 +399,20 @@ static int param_array_get(char *buffer, const struct kernel_param *kp) return off; } +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); @@ -634,7 +645,11 @@ 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, -- cgit v1.2.3-70-g09d2 From a1054322afc8120ea5a50bc84e5beeda54571862 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Aug 2010 23:04:18 -0600 Subject: param: use free hook for charp (fix leak of charp parameters) Instead of using a "I kmalloced this" flag, we keep track of the kmalloced strings and use that list to check if we need to kfree (in practice, the list is very short). This means that kparams can be const again, and plugs a leak. This is important for drivers/usb/gadget/nokia.c which gets modprobe/rmmod'ed frequently on the N9000. Signed-off-by: Rusty Russell Reviewed-by: Takashi Iwai Cc: Artem Bityutskiy Tested-by: Phil Carmody --- kernel/params.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 50 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index 458a09b886c..ef60db14fae 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -31,6 +31,45 @@ #define DEBUGP(fmt, a...) #endif +/* This just allows us to keep track of which parameters are kmalloced. */ +struct kmalloced_param { + struct list_head list; + char val[]; +}; +static DEFINE_MUTEX(param_lock); +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; + + mutex_lock(¶m_lock); + list_add(&p->list, &kmalloced_params); + mutex_unlock(¶m_lock); + + return p->val; +} + +/* Does nothing if parameter wasn't kmalloced above. */ +static void maybe_kfree_parameter(void *param) +{ + struct kmalloced_param *p; + + mutex_lock(¶m_lock); + list_for_each_entry(p, &kmalloced_params, list) { + if (p->val == param) { + list_del(&p->list); + kfree(p); + break; + } + } + mutex_unlock(¶m_lock); +} + static inline char dash2underscore(char c) { if (c == '-') @@ -219,12 +258,15 @@ int param_set_charp(const char *val, const struct kernel_param *kp) 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; @@ -238,9 +280,15 @@ int param_get_charp(char *buffer, const struct kernel_param *kp) } 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); -- cgit v1.2.3-70-g09d2 From 914dcaa84c53f2c3efa6016efcae13fd92a8a17c Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Aug 2010 23:04:18 -0600 Subject: param: make param sections const. Since this section can be read-only (they're in .rodata), they should always have been const. Minor flow-through various functions. Signed-off-by: Rusty Russell Tested-by: Phil Carmody --- include/linux/moduleparam.h | 2 +- init/main.c | 8 ++++---- kernel/params.c | 4 ++-- 3 files changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 9f51568f51c..6d48831fe7d 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -161,7 +161,7 @@ __check_old_set_param(int (*oldset)(const char *, struct kernel_param *)) /* Called on module insert or kernel boot */ extern 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)); diff --git a/init/main.c b/init/main.c index 86cbfd085b0..22d61cb06f9 100644 --- a/init/main.c +++ b/init/main.c @@ -201,11 +201,11 @@ static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; static const char *panic_later, *panic_param; -extern struct obs_kernel_param __setup_start[], __setup_end[]; +extern const struct obs_kernel_param __setup_start[], __setup_end[]; static int __init obsolete_checksetup(char *line) { - struct obs_kernel_param *p; + const struct obs_kernel_param *p; int had_early_param = 0; p = __setup_start; @@ -458,7 +458,7 @@ static noinline void __init_refok rest_init(void) /* Check for early params. */ static int __init do_early_param(char *param, char *val) { - struct obs_kernel_param *p; + const struct obs_kernel_param *p; for (p = __setup_start; p < __setup_end; p++) { if ((p->early && strcmp(param, p->str) == 0) || @@ -536,7 +536,7 @@ static void __init mm_init(void) asmlinkage void __init start_kernel(void) { char * command_line; - extern struct kernel_param __start___param[], __stop___param[]; + extern const struct kernel_param __start___param[], __stop___param[]; smp_setup_processor_id(); diff --git a/kernel/params.c b/kernel/params.c index ef60db14fae..a3eeeefc947 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -88,7 +88,7 @@ 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)) { @@ -170,7 +170,7 @@ 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)) { -- cgit v1.2.3-70-g09d2 From 907b29eb41aa604477a655bff7345731da94514d Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Aug 2010 23:04:19 -0600 Subject: param: locking for kernel parameters There may be cases (most obviously, sysfs-writable charp parameters) where a module needs to prevent sysfs access to parameters. Rather than express this in terms of a big lock, the functions are expressed in terms of what they protect against. This is clearer, esp. if the implementation changes to a module-level or even param-level lock. Signed-off-by: Rusty Russell Reviewed-by: Takashi Iwai Tested-by: Phil Carmody --- include/linux/moduleparam.h | 56 +++++++++++++++++++++++++++++++++++++++++++++ kernel/params.c | 33 ++++++++++++++++++++------ 2 files changed, 82 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 6d48831fe7d..ca74a3402d6 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -130,6 +130,62 @@ __check_old_set_param(int (*oldset)(const char *, struct kernel_param *)) #define module_param(name, type, perm) \ module_param_named(name, name, type, perm) +/** + * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs. + * @name: the name of the parameter + * + * There's no point blocking write on a paramter that isn't writable via sysfs! + */ +#define kparam_block_sysfs_write(name) \ + do { \ + BUG_ON(!(__param_##name.perm & 0222)); \ + __kernel_param_lock(); \ + } while (0) + +/** + * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again. + * @name: the name of the parameter + */ +#define kparam_unblock_sysfs_write(name) \ + do { \ + BUG_ON(!(__param_##name.perm & 0222)); \ + __kernel_param_unlock(); \ + } while (0) + +/** + * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs. + * @name: the name of the parameter + * + * This also blocks sysfs writes. + */ +#define kparam_block_sysfs_read(name) \ + do { \ + BUG_ON(!(__param_##name.perm & 0444)); \ + __kernel_param_lock(); \ + } while (0) + +/** + * kparam_unblock_sysfs_read - allows sysfs to read a parameter again. + * @name: the name of the parameter + */ +#define kparam_unblock_sysfs_read(name) \ + do { \ + BUG_ON(!(__param_##name.perm & 0444)); \ + __kernel_param_unlock(); \ + } while (0) + +#ifdef CONFIG_SYSFS +extern void __kernel_param_lock(void); +extern void __kernel_param_unlock(void); +#else +static inline void __kernel_param_lock(void) +{ +} +static inline void __kernel_param_unlock(void) +{ +} +#endif + #ifndef MODULE /** * core_param - define a historical core kernel parameter. diff --git a/kernel/params.c b/kernel/params.c index a3eeeefc947..08107d18175 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -31,12 +31,14 @@ #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 DEFINE_MUTEX(param_lock); static LIST_HEAD(kmalloced_params); static void *kmalloc_parameter(unsigned int size) @@ -47,10 +49,7 @@ static void *kmalloc_parameter(unsigned int size) if (!p) return NULL; - mutex_lock(¶m_lock); list_add(&p->list, &kmalloced_params); - mutex_unlock(¶m_lock); - return p->val; } @@ -59,7 +58,6 @@ static void maybe_kfree_parameter(void *param) { struct kmalloced_param *p; - mutex_lock(¶m_lock); list_for_each_entry(p, &kmalloced_params, list) { if (p->val == param) { list_del(&p->list); @@ -67,7 +65,6 @@ static void maybe_kfree_parameter(void *param) break; } } - mutex_unlock(¶m_lock); } static inline char dash2underscore(char c) @@ -93,6 +90,7 @@ static int parse_one(char *param, int (*handle_unknown)(char *param, char *val)) { unsigned int i; + int err; /* Find parameter */ for (i = 0; i < num_params; i++) { @@ -102,7 +100,10 @@ static int parse_one(char *param, return -EINVAL; DEBUGP("They are equal! Calling %p\n", params[i].ops->set); - return params[i].ops->set(val, ¶ms[i]); + mutex_lock(¶m_lock); + err = params[i].ops->set(val, ¶ms[i]); + mutex_unlock(¶m_lock); + return err; } } @@ -400,6 +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(¶m_lock)); ret = set(val, &kp); if (ret != 0) @@ -438,6 +440,7 @@ static int param_array_get(char *buffer, const struct kernel_param *kp) if (i) buffer[off++] = ','; p.arg = arr->elem + arr->elemsize * i; + BUG_ON(!mutex_is_locked(¶m_lock)); ret = arr->ops->get(buffer + off, &p); if (ret < 0) return ret; @@ -522,7 +525,9 @@ static ssize_t param_attr_show(struct module_attribute *mattr, if (!attribute->param->ops->get) return -EPERM; + mutex_lock(¶m_lock); count = attribute->param->ops->get(buf, attribute->param); + mutex_unlock(¶m_lock); if (count > 0) { strcat(buf, "\n"); ++count; @@ -541,7 +546,9 @@ static ssize_t param_attr_store(struct module_attribute *mattr, if (!attribute->param->ops->set) return -EPERM; + mutex_lock(¶m_lock); err = attribute->param->ops->set(buf, attribute->param); + mutex_unlock(¶m_lock); if (!err) return len; return err; @@ -555,6 +562,18 @@ static ssize_t param_attr_store(struct module_attribute *mattr, #endif #ifdef CONFIG_SYSFS +void __kernel_param_lock(void) +{ + mutex_lock(¶m_lock); +} +EXPORT_SYMBOL(__kernel_param_lock); + +void __kernel_param_unlock(void) +{ + mutex_unlock(¶m_lock); +} +EXPORT_SYMBOL(__kernel_param_unlock); + /* * add_sysfs_param - add a parameter to sysfs * @mk: struct module_kobject -- cgit v1.2.3-70-g09d2