aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--drivers/block/virtio_blk.c7
-rw-r--r--include/linux/module.h10
-rw-r--r--kernel/debug/kdb/kdb_main.c2
-rw-r--r--kernel/module.c154
-rw-r--r--lib/bug.c1
5 files changed, 122 insertions, 52 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 9d8409c0208..8ad21a25bc0 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -889,6 +889,7 @@ static void virtblk_remove(struct virtio_device *vdev)
{
struct virtio_blk *vblk = vdev->priv;
int index = vblk->index;
+ int refc;
/* Prevent config work handler from accessing the device. */
mutex_lock(&vblk->config_lock);
@@ -903,11 +904,15 @@ static void virtblk_remove(struct virtio_device *vdev)
flush_work(&vblk->config_work);
+ refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
put_disk(vblk->disk);
mempool_destroy(vblk->pool);
vdev->config->del_vqs(vdev);
kfree(vblk);
- ida_simple_remove(&vd_index_ida, index);
+
+ /* Only free device id if we don't have any users */
+ if (refc == 1)
+ ida_simple_remove(&vd_index_ida, index);
}
#ifdef CONFIG_PM
diff --git a/include/linux/module.h b/include/linux/module.h
index 7760c6d344a..1375ee3f03a 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -199,11 +199,11 @@ struct module_use {
struct module *source, *target;
};
-enum module_state
-{
- MODULE_STATE_LIVE,
- MODULE_STATE_COMING,
- MODULE_STATE_GOING,
+enum module_state {
+ MODULE_STATE_LIVE, /* Normal state. */
+ MODULE_STATE_COMING, /* Full formed, running module_init. */
+ MODULE_STATE_GOING, /* Going away. */
+ MODULE_STATE_UNFORMED, /* Still setting it up. */
};
/**
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 4d5f8d5612f..8875254120b 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1970,6 +1970,8 @@ static int kdb_lsmod(int argc, const char **argv)
kdb_printf("Module Size modstruct Used by\n");
list_for_each_entry(mod, kdb_modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
kdb_printf("%-20s%8u 0x%p ", mod->name,
mod->core_size, (void *)mod);
diff --git a/kernel/module.c b/kernel/module.c
index b10b048367e..d25e359279a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -188,6 +188,7 @@ struct load_info {
ongoing or failed initialization etc. */
static inline int strong_try_module_get(struct module *mod)
{
+ BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
if (mod && mod->state == MODULE_STATE_COMING)
return -EBUSY;
if (try_module_get(mod))
@@ -343,6 +344,9 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
#endif
};
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+
if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
return true;
}
@@ -450,16 +454,24 @@ const struct kernel_symbol *find_symbol(const char *name,
EXPORT_SYMBOL_GPL(find_symbol);
/* Search for module by name: must hold module_mutex. */
-struct module *find_module(const char *name)
+static struct module *find_module_all(const char *name,
+ bool even_unformed)
{
struct module *mod;
list_for_each_entry(mod, &modules, list) {
+ if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (strcmp(mod->name, name) == 0)
return mod;
}
return NULL;
}
+
+struct module *find_module(const char *name)
+{
+ return find_module_all(name, false);
+}
EXPORT_SYMBOL_GPL(find_module);
#ifdef CONFIG_SMP
@@ -525,6 +537,8 @@ bool is_module_percpu_address(unsigned long addr)
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (!mod->percpu_size)
continue;
for_each_possible_cpu(cpu) {
@@ -1048,6 +1062,8 @@ static ssize_t show_initstate(struct module_attribute *mattr,
case MODULE_STATE_GOING:
state = "going";
break;
+ default:
+ BUG();
}
return sprintf(buffer, "%s\n", state);
}
@@ -1786,6 +1802,8 @@ void set_all_modules_text_rw(void)
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if ((mod->module_core) && (mod->core_text_size)) {
set_page_attributes(mod->module_core,
mod->module_core + mod->core_text_size,
@@ -1807,6 +1825,8 @@ void set_all_modules_text_ro(void)
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if ((mod->module_core) && (mod->core_text_size)) {
set_page_attributes(mod->module_core,
mod->module_core + mod->core_text_size,
@@ -2527,6 +2547,13 @@ static int copy_module_from_fd(int fd, struct load_info *info)
err = -EFBIG;
goto out;
}
+
+ /* Don't hand 0 to vmalloc, it whines. */
+ if (stat.size == 0) {
+ err = -EINVAL;
+ goto out;
+ }
+
info->hdr = vmalloc(stat.size);
if (!info->hdr) {
err = -ENOMEM;
@@ -2990,8 +3017,9 @@ static bool finished_loading(const char *name)
bool ret;
mutex_lock(&module_mutex);
- mod = find_module(name);
- ret = !mod || mod->state != MODULE_STATE_COMING;
+ mod = find_module_all(name, true);
+ ret = !mod || mod->state == MODULE_STATE_LIVE
+ || mod->state == MODULE_STATE_GOING;
mutex_unlock(&module_mutex);
return ret;
@@ -3136,6 +3164,32 @@ static int load_module(struct load_info *info, const char __user *uargs,
goto free_copy;
}
+ /*
+ * We try to place it in the list now to make sure it's unique
+ * before we dedicate too many resources. In particular,
+ * temporary percpu memory exhaustion.
+ */
+ mod->state = MODULE_STATE_UNFORMED;
+again:
+ mutex_lock(&module_mutex);
+ if ((old = find_module_all(mod->name, true)) != NULL) {
+ if (old->state == MODULE_STATE_COMING
+ || old->state == MODULE_STATE_UNFORMED) {
+ /* Wait in case it fails to load. */
+ mutex_unlock(&module_mutex);
+ err = wait_event_interruptible(module_wq,
+ finished_loading(mod->name));
+ if (err)
+ goto free_module;
+ goto again;
+ }
+ err = -EEXIST;
+ mutex_unlock(&module_mutex);
+ goto free_module;
+ }
+ list_add_rcu(&mod->list, &modules);
+ mutex_unlock(&module_mutex);
+
#ifdef CONFIG_MODULE_SIG
mod->sig_ok = info->sig_ok;
if (!mod->sig_ok)
@@ -3145,7 +3199,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
/* Now module is in final location, initialize linked lists, etc. */
err = module_unload_init(mod);
if (err)
- goto free_module;
+ goto unlink_mod;
/* Now we've got everything in the final locations, we can
* find optional sections. */
@@ -3180,54 +3234,33 @@ static int load_module(struct load_info *info, const char __user *uargs,
goto free_arch_cleanup;
}
- /* Mark state as coming so strong_try_module_get() ignores us. */
- mod->state = MODULE_STATE_COMING;
-
- /* Now sew it into the lists so we can get lockdep and oops
- * info during argument parsing. No one should access us, since
- * strong_try_module_get() will fail.
- * lockdep/oops can run asynchronous, so use the RCU list insertion
- * function to insert in a way safe to concurrent readers.
- * The mutex protects against concurrent writers.
- */
-again:
- mutex_lock(&module_mutex);
- if ((old = find_module(mod->name)) != NULL) {
- if (old->state == MODULE_STATE_COMING) {
- /* Wait in case it fails to load. */
- mutex_unlock(&module_mutex);
- err = wait_event_interruptible(module_wq,
- finished_loading(mod->name));
- if (err)
- goto free_arch_cleanup;
- goto again;
- }
- err = -EEXIST;
- goto unlock;
- }
-
- /* This has to be done once we're sure module name is unique. */
dynamic_debug_setup(info->debug, info->num_debug);
- /* Find duplicate symbols */
+ mutex_lock(&module_mutex);
+ /* Find duplicate symbols (must be called under lock). */
err = verify_export_symbols(mod);
if (err < 0)
- goto ddebug;
+ goto ddebug_cleanup;
+ /* This relies on module_mutex for list integrity. */
module_bug_finalize(info->hdr, info->sechdrs, mod);
- list_add_rcu(&mod->list, &modules);
+
+ /* Mark state as coming so strong_try_module_get() ignores us,
+ * but kallsyms etc. can see us. */
+ mod->state = MODULE_STATE_COMING;
+
mutex_unlock(&module_mutex);
/* Module is ready to execute: parsing args may do that. */
err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
-32768, 32767, &ddebug_dyndbg_module_param_cb);
if (err < 0)
- goto unlink;
+ goto bug_cleanup;
/* Link in to syfs. */
err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
if (err < 0)
- goto unlink;
+ goto bug_cleanup;
/* Get rid of temporary copy. */
free_copy(info);
@@ -3237,16 +3270,13 @@ again:
return do_init_module(mod);
- unlink:
+ bug_cleanup:
+ /* module_bug_cleanup needs module_mutex protection */
mutex_lock(&module_mutex);
- /* Unlink carefully: kallsyms could be walking list. */
- list_del_rcu(&mod->list);
module_bug_cleanup(mod);
- wake_up_all(&module_wq);
- ddebug:
- dynamic_debug_remove(info->debug);
- unlock:
mutex_unlock(&module_mutex);
+ ddebug_cleanup:
+ dynamic_debug_remove(info->debug);
synchronize_sched();
kfree(mod->args);
free_arch_cleanup:
@@ -3255,6 +3285,12 @@ again:
free_modinfo(mod);
free_unload:
module_unload_free(mod);
+ unlink_mod:
+ mutex_lock(&module_mutex);
+ /* Unlink carefully: kallsyms could be walking list. */
+ list_del_rcu(&mod->list);
+ wake_up_all(&module_wq);
+ mutex_unlock(&module_mutex);
free_module:
module_deallocate(mod, info);
free_copy:
@@ -3377,6 +3413,8 @@ const char *module_address_lookup(unsigned long addr,
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (within_module_init(addr, mod) ||
within_module_core(addr, mod)) {
if (modname)
@@ -3400,6 +3438,8 @@ int lookup_module_symbol_name(unsigned long addr, char *symname)
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (within_module_init(addr, mod) ||
within_module_core(addr, mod)) {
const char *sym;
@@ -3424,6 +3464,8 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (within_module_init(addr, mod) ||
within_module_core(addr, mod)) {
const char *sym;
@@ -3451,6 +3493,8 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (symnum < mod->num_symtab) {
*value = mod->symtab[symnum].st_value;
*type = mod->symtab[symnum].st_info;
@@ -3493,9 +3537,12 @@ unsigned long module_kallsyms_lookup_name(const char *name)
ret = mod_find_symname(mod, colon+1);
*colon = ':';
} else {
- list_for_each_entry_rcu(mod, &modules, list)
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if ((ret = mod_find_symname(mod, name)) != 0)
break;
+ }
}
preempt_enable();
return ret;
@@ -3510,6 +3557,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
int ret;
list_for_each_entry(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
for (i = 0; i < mod->num_symtab; i++) {
ret = fn(data, mod->strtab + mod->symtab[i].st_name,
mod, mod->symtab[i].st_value);
@@ -3525,6 +3574,7 @@ static char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
+ BUG_ON(mod->state == MODULE_STATE_UNFORMED);
if (mod->taints ||
mod->state == MODULE_STATE_GOING ||
mod->state == MODULE_STATE_COMING) {
@@ -3566,6 +3616,10 @@ static int m_show(struct seq_file *m, void *p)
struct module *mod = list_entry(p, struct module, list);
char buf[8];
+ /* We always ignore unformed modules. */
+ if (mod->state == MODULE_STATE_UNFORMED)
+ return 0;
+
seq_printf(m, "%s %u",
mod->name, mod->init_size + mod->core_size);
print_unload_info(m, mod);
@@ -3626,6 +3680,8 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (mod->num_exentries == 0)
continue;
@@ -3674,10 +3730,13 @@ struct module *__module_address(unsigned long addr)
if (addr < module_addr_min || addr > module_addr_max)
return NULL;
- list_for_each_entry_rcu(mod, &modules, list)
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
if (within_module_core(addr, mod)
|| within_module_init(addr, mod))
return mod;
+ }
return NULL;
}
EXPORT_SYMBOL_GPL(__module_address);
@@ -3730,8 +3789,11 @@ void print_modules(void)
printk(KERN_DEFAULT "Modules linked in:");
/* Most callers should already have preempt disabled, but make sure */
preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list)
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
printk(" %s%s", mod->name, module_flags(mod, buf));
+ }
preempt_enable();
if (last_unloaded_module[0])
printk(" [last unloaded: %s]", last_unloaded_module);
diff --git a/lib/bug.c b/lib/bug.c
index a28c1415357..d0cdf14c651 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -55,6 +55,7 @@ static inline unsigned long bug_addr(const struct bug_entry *bug)
}
#ifdef CONFIG_MODULES
+/* Updates are protected by module mutex */
static LIST_HEAD(module_bug_list);
static const struct bug_entry *module_find_bug(unsigned long bugaddr)
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-26 07:45:31 +0000