Attachment 310139 Details for Bug 448603 – patch to make proc file creation / module ownership atomic for any module that wants it

[patch] patch to make proc file creation / module ownership atomic for any module that wants it

open_refcnt.patch (text/plain), 2.24 KB, created by Neil Horman on 2008-06-24 13:22:58 UTC

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Creator: Neil Horman

Created: 2008-06-24 13:22:58 UTC

Size: 2.24 KB

patch

obsolete

>--- linux-2.6.9/kernel/module.c.orig	2008-06-24 06:36:43.000000000 -0400
>+++ linux-2.6.9/kernel/module.c	2008-06-24 06:56:51.000000000 -0400
>@@ -1918,6 +1918,9 @@
> 			free_module(mod);
> 			up(&module_mutex);
> 		}
>+		down(&noitify_mutex);
>+		notifier_call_chain(&module_notify_list, MODULE_STATE_FAILED, mod);
>+		up(&notifier_mutex);
> 		return ret;
> 	}
> 
>@@ -1932,6 +1935,10 @@
> 	mod->init_text_size = 0;
> 	up(&module_mutex);
> 
>+	down(&noitify_mutex);
>+	notifier_call_chain(&module_notify_list, MODULE_STATE_LIVE, mod);
>+	up(&notify_mutex);
>+
> 	return 0;
> }
> 
>--- linux-2.6.9/fs/proc/inode.c.orig	2008-06-24 06:38:30.000000000 -0400
>+++ linux-2.6.9/fs/proc/inode.c	2008-06-24 07:01:15.000000000 -0400
>@@ -69,6 +69,8 @@
> 	/* Let go of any associated proc directory entry */
> 	de = PROC_I(inode)->pde;
> 	if (de) {
>+		if (de->owner)
>+			module_put(de->owner);
> 		de_put(de);
> 	}
> 	clear_inode(inode);
>@@ -186,6 +188,36 @@
> 	return 1;
> }
> 
>+static struct notifier_block module_load_nb = {
>+	.notifier_call = module_load_notify,
>+};
>+
>+static spinlock_t module_get_lock = SPIN_LOCK_UNLOCKED;
>+
>+static int module_load_notify(struct notifier_block * self, unsigned long val, void * data)
>+{
>+#ifdef CONFIG_MODULES
>+	switch (val) {
>+		case MODULE_STATE_COMING:
>+			spin_lock(&module_get_lock);
>+			break;
>+		case MODULE_STATE_LIVE:
>+		case MODULE_STATE_FAILED:
>+			spin_unlock(&module_get_lock);
>+			break;
>+		default:
>+			return 0;
>+	}
>+#endif
>+        return 0;
>+}
>+
>+
>+int __init proc_init_notifiers(void)
>+{
>+	return register_module_notifier(&module_load_nb);
>+}
>+
> struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
> 				struct proc_dir_entry *de)
> {
>@@ -213,6 +245,12 @@
> 			inode->i_size = de->size;
> 		if (de->nlink)
> 			inode->i_nlink = de->nlink;
>+		spin_lock(&module_get_lock);
>+		if (!try_module_get(de->owner)) {
>+			spin_unlock(&module_get_lock);
>+			goto out_fail;
>+		}
>+		spin_unlock(&module_get_lock);
> 		if (de->proc_iops)
> 			inode->i_op = de->proc_iops;
> 		if (de->proc_fops)
>--- linux-2.6.9/include/linux/module.h.orig	2008-06-24 06:36:08.000000000 -0400
>+++ linux-2.6.9/include/linux/module.h	2008-06-24 06:56:00.000000000 -0400
>@@ -206,6 +206,7 @@
> 	MODULE_STATE_LIVE,
> 	MODULE_STATE_COMING,
> 	MODULE_STATE_GOING,
>+	MODULE_STATE_FAILED,
> };
> 
> /* sysfs stuff */

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Attachments on bug 448603: 309114 | 309292 | 309776 | 310139 | 310142 | 316894 | 316952 | 317720