lkml.org 
[lkml]   [2016]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 2/3] modules: set mod->state to GOING before going notifiers are called
Date
Jessica Yu <jeyu@redhat.com> writes:
> In load_module(), the going notifiers are called during error handling
> when an error occurs after the coming notifiers have already been called.
> However, a module's state is still MODULE_STATE_COMING when the going
> notifiers are called in the error path. To be consistent, also set
> mod->state to MODULE_STATE_GOING before calling the going notifiers.
>
> Signed-off-by: Jessica Yu <jeyu@redhat.com>
> ---
> kernel/module.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/kernel/module.c b/kernel/module.c
> index 1981ae0..9e80576 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -3494,6 +3494,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
> return do_init_module(mod);
>
> coming_cleanup:
> + mutex_lock(&module_mutex);
> + mod->state = MODULE_STATE_GOING;
> + mutex_unlock(&module_mutex);
> blocking_notifier_call_chain(&module_notify_list,
> MODULE_STATE_GOING, mod);

Actually, reviewing this patch makes me realize it is wrong.

We rely on the state of the module being MODULE_STATE_COMING here:

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;

We will just have to document that the notifier can be called with
a module in MODULE_STATE_COMING if it never succeeded its
initialization.

Sorry for the previously false lead,
Rusty.

\
 
 \ /
  Last update: 2016-03-10 05:21    [W:0.072 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site