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authorKay Sievers <kay.sievers@vrfy.org>2007-02-02 10:39:12 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2007-02-16 18:19:15 -0500
commitc353c3fb0700a3c17ea2b0237710a184232ccd7f (patch)
tree7b5fd590bd9b0a08bee8425ad074e993629683d1
parent89790fd789e024b23eb1fbccedd84a2015441ce0 (diff)
Driver core: let request_module() send a /sys/modules/kmod/-uevent
On recent systems, calls to /sbin/modprobe are handled by udev depending on the kind of device the kernel has discovered. This patch creates an uevent for the kernels internal request_module(), to let udev take control over the request, instead of forking the binary directly by the kernel. The direct execution of /sbin/modprobe can be disabled by setting: /sys/module/kmod/mod_request_helper (/proc/sys/kernel/modprobe) to an empty string, the same way /proc/sys/kernel/hotplug is disabled on an udev system. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--include/linux/kmod.h2
-rw-r--r--kernel/kmod.c120
-rw-r--r--kernel/module.c26
-rw-r--r--kernel/params.c1
4 files changed, 139 insertions, 10 deletions
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 10f505c8431d..cc8e674ae27a 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -28,8 +28,10 @@
28#ifdef CONFIG_KMOD 28#ifdef CONFIG_KMOD
29/* modprobe exit status on success, -ve on error. Return value 29/* modprobe exit status on success, -ve on error. Return value
30 * usually useless though. */ 30 * usually useless though. */
31extern void kmod_sysfs_init(void);
31extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2))); 32extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2)));
32#else 33#else
34static inline void kmod_sysfs_init(void) {};
33static inline int request_module(const char * name, ...) { return -ENOSYS; } 35static inline int request_module(const char * name, ...) { return -ENOSYS; }
34#endif 36#endif
35 37
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 796276141e51..9f923f8ce6a0 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -36,6 +36,8 @@
36#include <linux/resource.h> 36#include <linux/resource.h>
37#include <asm/uaccess.h> 37#include <asm/uaccess.h>
38 38
39extern int delete_module(const char *name, unsigned int flags);
40
39extern int max_threads; 41extern int max_threads;
40 42
41static struct workqueue_struct *khelper_wq; 43static struct workqueue_struct *khelper_wq;
@@ -46,6 +48,7 @@ static struct workqueue_struct *khelper_wq;
46 modprobe_path is set via /proc/sys. 48 modprobe_path is set via /proc/sys.
47*/ 49*/
48char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe"; 50char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
51struct module_kobject kmod_mk;
49 52
50/** 53/**
51 * request_module - try to load a kernel module 54 * request_module - try to load a kernel module
@@ -75,6 +78,11 @@ int request_module(const char *fmt, ...)
75 static atomic_t kmod_concurrent = ATOMIC_INIT(0); 78 static atomic_t kmod_concurrent = ATOMIC_INIT(0);
76#define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */ 79#define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */
77 static int kmod_loop_msg; 80 static int kmod_loop_msg;
81 char modalias[16 + MODULE_NAME_LEN] = "MODALIAS=";
82 char *uevent_envp[2] = {
83 modalias,
84 NULL
85 };
78 86
79 va_start(args, fmt); 87 va_start(args, fmt);
80 ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); 88 ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
@@ -82,6 +90,12 @@ int request_module(const char *fmt, ...)
82 if (ret >= MODULE_NAME_LEN) 90 if (ret >= MODULE_NAME_LEN)
83 return -ENAMETOOLONG; 91 return -ENAMETOOLONG;
84 92
93 strcpy(&modalias[strlen("MODALIAS=")], module_name);
94 kobject_uevent_env(&kmod_mk.kobj, KOBJ_CHANGE, uevent_envp);
95
96 if (modprobe_path[0] == '\0')
97 goto out;
98
85 /* If modprobe needs a service that is in a module, we get a recursive 99 /* If modprobe needs a service that is in a module, we get a recursive
86 * loop. Limit the number of running kmod threads to max_threads/2 or 100 * loop. Limit the number of running kmod threads to max_threads/2 or
87 * MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method 101 * MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method
@@ -108,9 +122,115 @@ int request_module(const char *fmt, ...)
108 122
109 ret = call_usermodehelper(modprobe_path, argv, envp, 1); 123 ret = call_usermodehelper(modprobe_path, argv, envp, 1);
110 atomic_dec(&kmod_concurrent); 124 atomic_dec(&kmod_concurrent);
125out:
111 return ret; 126 return ret;
112} 127}
113EXPORT_SYMBOL(request_module); 128EXPORT_SYMBOL(request_module);
129
130static ssize_t store_mod_request(struct module_attribute *mattr,
131 struct module *mod,
132 const char *buffer, size_t count)
133{
134 char name[MODULE_NAME_LEN];
135 int ret;
136
137 if (count < 1 || count+1 > MODULE_NAME_LEN)
138 return -EINVAL;
139 memcpy(name, buffer, count);
140 name[count] = '\0';
141 if (name[count-1] == '\n')
142 name[count-1] = '\0';
143
144 ret = request_module(name);
145 if (ret < 0)
146 return ret;
147 return count;
148}
149
150static struct module_attribute mod_request = {
151 .attr = { .name = "mod_request", .mode = S_IWUSR, .owner = THIS_MODULE },
152 .store = store_mod_request,
153};
154
155#ifdef CONFIG_MODULE_UNLOAD
156static ssize_t store_mod_unload(struct module_attribute *mattr,
157 struct module *mod,
158 const char *buffer, size_t count)
159{
160 char name[MODULE_NAME_LEN];
161 int ret;
162
163 if (count < 1 || count+1 > MODULE_NAME_LEN)
164 return -EINVAL;
165 memcpy(name, buffer, count);
166 name[count] = '\0';
167 if (name[count-1] == '\n')
168 name[count-1] = '\0';
169
170 ret = delete_module(name, O_NONBLOCK);
171 if (ret < 0)
172 return ret;
173 return count;
174}
175
176static struct module_attribute mod_unload = {
177 .attr = { .name = "mod_unload", .mode = S_IWUSR, .owner = THIS_MODULE },
178 .store = store_mod_unload,
179};
180#endif
181
182static ssize_t show_mod_request_helper(struct module_attribute *mattr,
183 struct module *mod,
184 char *buffer)
185{
186 return sprintf(buffer, "%s\n", modprobe_path);
187}
188
189static ssize_t store_mod_request_helper(struct module_attribute *mattr,
190 struct module *mod,
191 const char *buffer, size_t count)
192{
193 if (count < 1 || count+1 > KMOD_PATH_LEN)
194 return -EINVAL;
195 memcpy(modprobe_path, buffer, count);
196 modprobe_path[count] = '\0';
197 if (modprobe_path[count-1] == '\n')
198 modprobe_path[count-1] = '\0';
199 return count;
200}
201
202static struct module_attribute mod_request_helper = {
203 .attr = {
204 .name = "mod_request_helper",
205 .mode = S_IWUSR | S_IRUGO,
206 .owner = THIS_MODULE
207 },
208 .show = show_mod_request_helper,
209 .store = store_mod_request_helper,
210};
211
212void __init kmod_sysfs_init(void)
213{
214 int ret;
215
216 kmod_mk.mod = THIS_MODULE;
217 kobj_set_kset_s(&kmod_mk, module_subsys);
218 kobject_set_name(&kmod_mk.kobj, "kmod");
219 kobject_init(&kmod_mk.kobj);
220 ret = kobject_add(&kmod_mk.kobj);
221 if (ret < 0)
222 goto out;
223
224 ret = sysfs_create_file(&kmod_mk.kobj, &mod_request_helper.attr);
225 ret = sysfs_create_file(&kmod_mk.kobj, &mod_request.attr);
226#ifdef CONFIG_MODULE_UNLOAD
227 ret = sysfs_create_file(&kmod_mk.kobj, &mod_unload.attr);
228#endif
229
230 kobject_uevent(&kmod_mk.kobj, KOBJ_ADD);
231out:
232 return;
233}
114#endif /* CONFIG_KMOD */ 234#endif /* CONFIG_KMOD */
115 235
116struct subprocess_info { 236struct subprocess_info {
diff --git a/kernel/module.c b/kernel/module.c
index 8a94e054230c..225501f620ff 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -653,20 +653,11 @@ static void wait_for_zero_refcount(struct module *mod)
653 mutex_lock(&module_mutex); 653 mutex_lock(&module_mutex);
654} 654}
655 655
656asmlinkage long 656int delete_module(const char *name, unsigned int flags)
657sys_delete_module(const char __user *name_user, unsigned int flags)
658{ 657{
659 struct module *mod; 658 struct module *mod;
660 char name[MODULE_NAME_LEN];
661 int ret, forced = 0; 659 int ret, forced = 0;
662 660
663 if (!capable(CAP_SYS_MODULE))
664 return -EPERM;
665
666 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
667 return -EFAULT;
668 name[MODULE_NAME_LEN-1] = '\0';
669
670 if (mutex_lock_interruptible(&module_mutex) != 0) 661 if (mutex_lock_interruptible(&module_mutex) != 0)
671 return -EINTR; 662 return -EINTR;
672 663
@@ -727,6 +718,21 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
727 return ret; 718 return ret;
728} 719}
729 720
721asmlinkage long
722sys_delete_module(const char __user *name_user, unsigned int flags)
723{
724 char name[MODULE_NAME_LEN];
725
726 if (!capable(CAP_SYS_MODULE))
727 return -EPERM;
728
729 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
730 return -EFAULT;
731 name[MODULE_NAME_LEN-1] = '\0';
732
733 return delete_module(name, flags);
734}
735
730static void print_unload_info(struct seq_file *m, struct module *mod) 736static void print_unload_info(struct seq_file *m, struct module *mod)
731{ 737{
732 struct module_use *use; 738 struct module_use *use;
diff --git a/kernel/params.c b/kernel/params.c
index 553cf7d6a4be..7d231c6c1334 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -714,6 +714,7 @@ static int __init param_sysfs_init(void)
714 } 714 }
715 715
716 param_sysfs_builtin(); 716 param_sysfs_builtin();
717 kmod_sysfs_init();
717 718
718 return 0; 719 return 0;
719} 720}