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authorKay Sievers2007-02-02 16:39:12 +0100
committerGreg Kroah-Hartman2007-02-16 15:19:15 -0800
commitc353c3fb0700a3c17ea2b0237710a184232ccd7f (patch)
tree7b5fd590bd9b0a08bee8425ad074e993629683d1 /kernel/kmod.c
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>
Diffstat (limited to 'kernel/kmod.c')
-rw-r--r--kernel/kmod.c120
1 files changed, 120 insertions, 0 deletions
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 @@
#include <linux/resource.h>
#include <asm/uaccess.h>
+extern int delete_module(const char *name, unsigned int flags);
+
extern int max_threads;
static struct workqueue_struct *khelper_wq;
@@ -46,6 +48,7 @@ static struct workqueue_struct *khelper_wq;
modprobe_path is set via /proc/sys.
*/
char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
+struct module_kobject kmod_mk;
/**
* request_module - try to load a kernel module
@@ -75,6 +78,11 @@ int request_module(const char *fmt, ...)
static atomic_t kmod_concurrent = ATOMIC_INIT(0);
#define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */
static int kmod_loop_msg;
+ char modalias[16 + MODULE_NAME_LEN] = "MODALIAS=";
+ char *uevent_envp[2] = {
+ modalias,
+ NULL
+ };
va_start(args, fmt);
ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
@@ -82,6 +90,12 @@ int request_module(const char *fmt, ...)
if (ret >= MODULE_NAME_LEN)
return -ENAMETOOLONG;
+ strcpy(&modalias[strlen("MODALIAS=")], module_name);
+ kobject_uevent_env(&kmod_mk.kobj, KOBJ_CHANGE, uevent_envp);
+
+ if (modprobe_path[0] == '\0')
+ goto out;
+
/* If modprobe needs a service that is in a module, we get a recursive
* loop. Limit the number of running kmod threads to max_threads/2 or
* MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method
@@ -108,9 +122,115 @@ int request_module(const char *fmt, ...)
ret = call_usermodehelper(modprobe_path, argv, envp, 1);
atomic_dec(&kmod_concurrent);
+out:
return ret;
}
EXPORT_SYMBOL(request_module);
+
+static ssize_t store_mod_request(struct module_attribute *mattr,
+ struct module *mod,
+ const char *buffer, size_t count)
+{
+ char name[MODULE_NAME_LEN];
+ int ret;
+
+ if (count < 1 || count+1 > MODULE_NAME_LEN)
+ return -EINVAL;
+ memcpy(name, buffer, count);
+ name[count] = '\0';
+ if (name[count-1] == '\n')
+ name[count-1] = '\0';
+
+ ret = request_module(name);
+ if (ret < 0)
+ return ret;
+ return count;
+}
+
+static struct module_attribute mod_request = {
+ .attr = { .name = "mod_request", .mode = S_IWUSR, .owner = THIS_MODULE },
+ .store = store_mod_request,
+};
+
+#ifdef CONFIG_MODULE_UNLOAD
+static ssize_t store_mod_unload(struct module_attribute *mattr,
+ struct module *mod,
+ const char *buffer, size_t count)
+{
+ char name[MODULE_NAME_LEN];
+ int ret;
+
+ if (count < 1 || count+1 > MODULE_NAME_LEN)
+ return -EINVAL;
+ memcpy(name, buffer, count);
+ name[count] = '\0';
+ if (name[count-1] == '\n')
+ name[count-1] = '\0';
+
+ ret = delete_module(name, O_NONBLOCK);
+ if (ret < 0)
+ return ret;
+ return count;
+}
+
+static struct module_attribute mod_unload = {
+ .attr = { .name = "mod_unload", .mode = S_IWUSR, .owner = THIS_MODULE },
+ .store = store_mod_unload,
+};
+#endif
+
+static ssize_t show_mod_request_helper(struct module_attribute *mattr,
+ struct module *mod,
+ char *buffer)
+{
+ return sprintf(buffer, "%s\n", modprobe_path);
+}
+
+static ssize_t store_mod_request_helper(struct module_attribute *mattr,
+ struct module *mod,
+ const char *buffer, size_t count)
+{
+ if (count < 1 || count+1 > KMOD_PATH_LEN)
+ return -EINVAL;
+ memcpy(modprobe_path, buffer, count);
+ modprobe_path[count] = '\0';
+ if (modprobe_path[count-1] == '\n')
+ modprobe_path[count-1] = '\0';
+ return count;
+}
+
+static struct module_attribute mod_request_helper = {
+ .attr = {
+ .name = "mod_request_helper",
+ .mode = S_IWUSR | S_IRUGO,
+ .owner = THIS_MODULE
+ },
+ .show = show_mod_request_helper,
+ .store = store_mod_request_helper,
+};
+
+void __init kmod_sysfs_init(void)
+{
+ int ret;
+
+ kmod_mk.mod = THIS_MODULE;
+ kobj_set_kset_s(&kmod_mk, module_subsys);
+ kobject_set_name(&kmod_mk.kobj, "kmod");
+ kobject_init(&kmod_mk.kobj);
+ ret = kobject_add(&kmod_mk.kobj);
+ if (ret < 0)
+ goto out;
+
+ ret = sysfs_create_file(&kmod_mk.kobj, &mod_request_helper.attr);
+ ret = sysfs_create_file(&kmod_mk.kobj, &mod_request.attr);
+#ifdef CONFIG_MODULE_UNLOAD
+ ret = sysfs_create_file(&kmod_mk.kobj, &mod_unload.attr);
+#endif
+
+ kobject_uevent(&kmod_mk.kobj, KOBJ_ADD);
+out:
+ return;
+}
#endif /* CONFIG_KMOD */
struct subprocess_info {