diff options
| -rw-r--r-- | include/linux/module.h | 4 | ||||
| -rw-r--r-- | kernel/module.c | 79 |
2 files changed, 51 insertions, 32 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index 6914fca..680db9e 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -359,7 +359,9 @@ struct module #ifdef CONFIG_MODULE_UNLOAD /* What modules depend on me? */ - struct list_head modules_which_use_me; + struct list_head source_list; + /* What modules do I depend on? */ + struct list_head target_list; /* Who is waiting for us to be unloaded */ struct task_struct *waiter; diff --git a/kernel/module.c b/kernel/module.c index 0129769..be18c3e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -523,7 +523,8 @@ static void module_unload_init(struct module *mod) { int cpu; - INIT_LIST_HEAD(&mod->modules_which_use_me); + INIT_LIST_HEAD(&mod->source_list); + INIT_LIST_HEAD(&mod->target_list); for_each_possible_cpu(cpu) { per_cpu_ptr(mod->refptr, cpu)->incs = 0; per_cpu_ptr(mod->refptr, cpu)->decs = 0; @@ -538,8 +539,9 @@ static void module_unload_init(struct module *mod) /* modules using other modules */ struct module_use { - struct list_head list; - struct module *module_which_uses; + struct list_head source_list; + struct list_head target_list; + struct module *source, *target; }; /* Does a already use b? */ @@ -547,8 +549,8 @@ static int already_uses(struct module *a, struct module *b) { struct module_use *use; - list_for_each_entry(use, &b->modules_which_use_me, list) { - if (use->module_which_uses == a) { + list_for_each_entry(use, &b->source_list, source_list) { + if (use->source == a) { DEBUGP("%s uses %s!\n", a->name, b->name); return 1; } @@ -557,6 +559,33 @@ static int already_uses(struct module *a, struct module *b) return 0; } +/* + * Module a uses b + * - we add 'a' as a "source", 'b' as a "target" of module use + * - the module_use is added to the list of 'b' sources (so + * 'b' can walk the list to see who sourced them), and of 'a' + * targets (so 'a' can see what modules it targets). + */ +static int add_module_usage(struct module *a, struct module *b) +{ + int no_warn; + struct module_use *use; + + DEBUGP("Allocating new usage for %s.\n", a->name); + use = kmalloc(sizeof(*use), GFP_ATOMIC); + if (!use) { + printk(KERN_WARNING "%s: out of memory loading\n", a->name); + return -ENOMEM; + } + + use->source = a; + use->target = b; + list_add(&use->source_list, &b->source_list); + list_add(&use->target_list, &a->target_list); + no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name); + return 0; +} + /* Module a uses b */ int use_module(struct module *a, struct module *b) { @@ -578,17 +607,11 @@ int use_module(struct module *a, struct module *b) if (err) return 0; - DEBUGP("Allocating new usage for %s.\n", a->name); - use = kmalloc(sizeof(*use), GFP_ATOMIC); - if (!use) { - printk("%s: out of memory loading\n", a->name); + err = add_module_usage(a, b); + if (err) { module_put(b); return 0; } - - use->module_which_uses = a; - list_add(&use->list, &b->modules_which_use_me); - no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name); return 1; } EXPORT_SYMBOL_GPL(use_module); @@ -596,22 +619,16 @@ EXPORT_SYMBOL_GPL(use_module); /* Clear the unload stuff of the module. */ static void module_unload_free(struct module *mod) { - struct module *i; - - list_for_each_entry(i, &modules, list) { - struct module_use *use; + struct module_use *use, *tmp; - list_for_each_entry(use, &i->modules_which_use_me, list) { - if (use->module_which_uses == mod) { - DEBUGP("%s unusing %s\n", mod->name, i->name); - module_put(i); - list_del(&use->list); - kfree(use); - sysfs_remove_link(i->holders_dir, mod->name); - /* There can be at most one match. */ - break; - } - } + list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { + struct module *i = use->target; + DEBUGP("%s unusing %s\n", mod->name, i->name); + module_put(i); + list_del(&use->source_list); + list_del(&use->target_list); + kfree(use); + sysfs_remove_link(i->holders_dir, mod->name); } } @@ -735,7 +752,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, goto out; } - if (!list_empty(&mod->modules_which_use_me)) { + if (!list_empty(&mod->source_list)) { /* Other modules depend on us: get rid of them first. */ ret = -EWOULDBLOCK; goto out; @@ -799,9 +816,9 @@ static inline void print_unload_info(struct seq_file *m, struct module *mod) /* Always include a trailing , so userspace can differentiate between this and the old multi-field proc format. */ - list_for_each_entry(use, &mod->modules_which_use_me, list) { + list_for_each_entry(use, &mod->source_list, source_list) { printed_something = 1; - seq_printf(m, "%s,", use->module_which_uses->name); + seq_printf(m, "%s,", use->source->name); } if (mod->init != NULL && mod->exit == NULL) { |
