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authorDmitry Torokhov <dtor@vmware.com>2010-12-15 17:00:19 -0500
committerRusty Russell <rusty@rustcorp.com.au>2011-01-23 23:02:51 -0500
commite94965ed5beb23c6fabf7ed31f625e66d7ff28de (patch)
tree842e4cab961b568bcb98d8ab80d7d399110598a4 /kernel
parent1bae4ce27c9c90344f23c65ea6966c50ffeae2f5 (diff)
module: show version information for built-in modules in sysfs
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace. This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters. Signed-off-by: Dmitry Torokhov <dtor@vmware.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/params.c65
1 files changed, 54 insertions, 11 deletions
diff --git a/kernel/params.c b/kernel/params.c
index 08107d181758..0da1411222b9 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -719,9 +719,7 @@ void destroy_params(const struct kernel_param *params, unsigned num)
719 params[i].ops->free(params[i].arg); 719 params[i].ops->free(params[i].arg);
720} 720}
721 721
722static void __init kernel_add_sysfs_param(const char *name, 722static struct module_kobject * __init locate_module_kobject(const char *name)
723 struct kernel_param *kparam,
724 unsigned int name_skip)
725{ 723{
726 struct module_kobject *mk; 724 struct module_kobject *mk;
727 struct kobject *kobj; 725 struct kobject *kobj;
@@ -729,10 +727,7 @@ static void __init kernel_add_sysfs_param(const char *name,
729 727
730 kobj = kset_find_obj(module_kset, name); 728 kobj = kset_find_obj(module_kset, name);
731 if (kobj) { 729 if (kobj) {
732 /* We already have one. Remove params so we can add more. */
733 mk = to_module_kobject(kobj); 730 mk = to_module_kobject(kobj);
734 /* We need to remove it before adding parameters. */
735 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
736 } else { 731 } else {
737 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); 732 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
738 BUG_ON(!mk); 733 BUG_ON(!mk);
@@ -743,15 +738,36 @@ static void __init kernel_add_sysfs_param(const char *name,
743 "%s", name); 738 "%s", name);
744 if (err) { 739 if (err) {
745 kobject_put(&mk->kobj); 740 kobject_put(&mk->kobj);
746 printk(KERN_ERR "Module '%s' failed add to sysfs, " 741 printk(KERN_ERR
747 "error number %d\n", name, err); 742 "Module '%s' failed add to sysfs, error number %d\n",
748 printk(KERN_ERR "The system will be unstable now.\n"); 743 name, err);
749 return; 744 printk(KERN_ERR
745 "The system will be unstable now.\n");
746 return NULL;
750 } 747 }
751 /* So that exit path is even. */ 748
749 /* So that we hold reference in both cases. */
752 kobject_get(&mk->kobj); 750 kobject_get(&mk->kobj);
753 } 751 }
754 752
753 return mk;
754}
755
756static void __init kernel_add_sysfs_param(const char *name,
757 struct kernel_param *kparam,
758 unsigned int name_skip)
759{
760 struct module_kobject *mk;
761 int err;
762
763 mk = locate_module_kobject(name);
764 if (!mk)
765 return;
766
767 /* We need to remove old parameters before adding more. */
768 if (mk->mp)
769 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
770
755 /* These should not fail at boot. */ 771 /* These should not fail at boot. */
756 err = add_sysfs_param(mk, kparam, kparam->name + name_skip); 772 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
757 BUG_ON(err); 773 BUG_ON(err);
@@ -796,6 +812,32 @@ static void __init param_sysfs_builtin(void)
796 } 812 }
797} 813}
798 814
815ssize_t __modver_version_show(struct module_attribute *mattr,
816 struct module *mod, char *buf)
817{
818 struct module_version_attribute *vattr =
819 container_of(mattr, struct module_version_attribute, mattr);
820
821 return sprintf(buf, "%s\n", vattr->version);
822}
823
824extern struct module_version_attribute __start___modver[], __stop___modver[];
825
826static void __init version_sysfs_builtin(void)
827{
828 const struct module_version_attribute *vattr;
829 struct module_kobject *mk;
830 int err;
831
832 for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
833 mk = locate_module_kobject(vattr->module_name);
834 if (mk) {
835 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
836 kobject_uevent(&mk->kobj, KOBJ_ADD);
837 kobject_put(&mk->kobj);
838 }
839 }
840}
799 841
800/* module-related sysfs stuff */ 842/* module-related sysfs stuff */
801 843
@@ -875,6 +917,7 @@ static int __init param_sysfs_init(void)
875 } 917 }
876 module_sysfs_initialized = 1; 918 module_sysfs_initialized = 1;
877 919
920 version_sysfs_builtin();
878 param_sysfs_builtin(); 921 param_sysfs_builtin();
879 922
880 return 0; 923 return 0;