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Message-ID: <4856f28f-3da5-bf3e-161c-495aa837ae03@redhat.com>
Date:   Mon, 17 Oct 2022 09:26:53 +0200
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Subject: Re: [PATCH v3 1/4] module: Correct wake up of module_wq
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To:     Petr Pavlu <petr.pavlu@suse.com>, mcgrof@kernel.org
Cc:     pmladek@suse.com, linux-modules@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20221016123031.3963-1-petr.pavlu@suse.com>
 <20221016123031.3963-2-petr.pavlu@suse.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20221016123031.3963-2-petr.pavlu@suse.com>
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On 16.10.22 14:30, Petr Pavlu wrote:
> The module_wq wait queue has only non-exclusive waiters and all waits
> are interruptible, therefore for consistency use wake_up_interruptible()
> to wake its waiters.
> 
> Suggested-by: Petr Mladek <pmladek@suse.com>
> Reviewed-by: Petr Mladek <pmladek@suse.com>
> Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
> ---
>   kernel/module/main.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index d02d39c7174e..a12e177ea81f 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -764,7 +764,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
>   
>   	free_module(mod);
>   	/* someone could wait for the module in add_unformed_module() */
> -	wake_up_all(&module_wq);
> +	wake_up_interruptible(&module_wq);
>   	return 0;
>   out:
>   	mutex_unlock(&module_mutex);
> @@ -2522,7 +2522,7 @@ static noinline int do_init_module(struct module *mod)
>   		schedule_work(&init_free_wq);
>   
>   	mutex_unlock(&module_mutex);
> -	wake_up_all(&module_wq);
> +	wake_up_interruptible(&module_wq);
>   
>   	return 0;
>   
> @@ -2538,7 +2538,7 @@ static noinline int do_init_module(struct module *mod)
>   	klp_module_going(mod);
>   	ftrace_release_mod(mod);
>   	free_module(mod);
> -	wake_up_all(&module_wq);
> +	wake_up_interruptible(&module_wq);
>   	return ret;
>   }
>   
> @@ -2879,7 +2879,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
>   	/* Unlink carefully: kallsyms could be walking list. */
>   	list_del_rcu(&mod->list);
>   	mod_tree_remove(mod);
> -	wake_up_all(&module_wq);
> +	wake_up_interruptible(&module_wq);
>   	/* Wait for RCU-sched synchronizing before releasing mod->list. */
>   	synchronize_rcu();
>   	mutex_unlock(&module_mutex);

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb