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Date:   Tue, 4 Feb 2020 11:16:20 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v1] printk: Declare log_wait as external variable
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References: <20200203131528.52825-1-andriy.shevchenko@linux.intel.com>
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On (20/02/03 15:15), Andy Shevchenko wrote:
> Static analyzer is not happy:
> 
> kernel/printk/printk.c:421:1: warning: symbol 'log_wait' was not declared. Should it be static?
> 
> This is due to usage of log_wait in the other module without announcing
> its declaration to the world. I wasn't able to dug into deep history of
> reasons why it is so, and thus decide to make less invasive change, i.e.
> declaring log_wait as external variable to make static analyzer happy.

[..]

> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index 633f41a11d75..43b5cb88c607 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -418,7 +418,14 @@ DEFINE_RAW_SPINLOCK(logbuf_lock);
>  	} while (0)
>
>  #ifdef CONFIG_PRINTK
> +
> +#ifdef CONFIG_PROC_FS
> +extern wait_queue_head_t log_wait;	/* Used in fs/proc/kmsg.c */
>  DECLARE_WAIT_QUEUE_HEAD(log_wait);
> +#else
> +static DECLARE_WAIT_QUEUE_HEAD(log_wait);
> +#endif /* CONFIG_PROC_FS */

[..]

Since we are now introducing CONFIG_PROC_FS dependency to printk (and
proc/kmsg already has CONFIG_PRINTK dependency), then I guess I wouldn't
mind it if fs/proc/kmsg would just relocate to printk, next to devksmg
implementation. Just saying.

	-ss