From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-fsdevel@vger.kernel.org
Subject: Re: union: was: Re: [PATCH printk v1 05/18] printk: Add non-BKL console basic infrastructure
Date: Tue, 28 Mar 2023 11:48:06 +0206 [thread overview]
Message-ID: <87cz4tus9d.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <ZCKjSpDbiBVabbP5@alley>
On 2023-03-28, Petr Mladek <pmladek@suse.com> wrote:
>> A compilation check would be nice. Is that possible?
>
> I think the following might do the trick:
>
> static_assert(sizeof(struct cons_state) == sizeof(atomic_long_t));
I never realized the kernel code was allowed to have that. But it is
everywhere! :-) Thanks. I've added and tested the following:
/*
* The nbcon_state struct is used to easily create and interpret values that
* are stored in the console.nbcon_state variable. Make sure this struct stays
* within the size boundaries of that atomic variable's underlying type in
* order to avoid any accidental truncation.
*/
static_assert(sizeof(struct nbcon_state) <= sizeof(long));
Note that I am checking against sizeof(long), the underlying variable
type. We probably shouldn't assume sizeof(atomic_long_t) is always
sizeof(long).
John
next prev parent reply other threads:[~2023-03-28 9:45 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-02 19:56 [PATCH printk v1 00/18] threaded/atomic console support John Ogness
2023-03-02 19:56 ` [PATCH printk v1 01/18] kdb: do not assume write() callback available John Ogness
2023-03-07 14:57 ` Petr Mladek
2023-03-07 16:34 ` Doug Anderson
2023-03-09 10:52 ` Daniel Thompson
2023-03-09 11:26 ` Petr Mladek
2023-03-09 11:30 ` Daniel Thompson
2023-03-02 19:56 ` [PATCH printk v1 02/18] printk: Add NMI check to down_trylock_console_sem() John Ogness
2023-03-07 16:05 ` Petr Mladek
2023-03-17 11:37 ` John Ogness
2023-04-13 13:42 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 03/18] printk: Consolidate console deferred printing John Ogness
2023-03-08 13:15 ` Petr Mladek
2023-03-17 13:05 ` John Ogness
2023-04-13 15:15 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 04/18] printk: Add per-console suspended state John Ogness
2023-03-08 14:40 ` Petr Mladek
2023-03-17 13:22 ` John Ogness
2023-04-14 9:56 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 05/18] printk: Add non-BKL console basic infrastructure John Ogness
2023-03-09 14:08 ` global states: was: " Petr Mladek
2023-03-17 13:29 ` John Ogness
2023-03-09 15:32 ` naming: " Petr Mladek
2023-03-17 13:39 ` John Ogness
2023-03-21 16:04 ` union: was: " Petr Mladek
2023-03-27 16:28 ` John Ogness
2023-03-28 8:20 ` Petr Mladek
2023-03-28 9:42 ` John Ogness [this message]
2023-03-28 12:52 ` Petr Mladek
2023-03-28 13:47 ` Steven Rostedt
2023-03-02 19:56 ` [PATCH printk v1 06/18] printk: nobkl: Add acquire/release logic John Ogness
2023-03-06 9:07 ` Dan Carpenter
2023-03-06 9:39 ` John Ogness
2023-03-13 16:07 ` Petr Mladek
2023-03-17 14:56 ` John Ogness
2023-03-20 16:10 ` Petr Mladek
2023-03-17 17:34 ` simplify: was: " Petr Mladek
2023-03-21 15:36 ` Petr Mladek
2023-04-02 18:39 ` John Ogness
2023-03-02 19:56 ` [PATCH printk v1 07/18] printk: nobkl: Add buffer management John Ogness
2023-03-21 16:38 ` Petr Mladek
2023-03-23 13:38 ` John Ogness
2023-03-23 15:25 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 08/18] printk: nobkl: Add sequence handling John Ogness
2023-03-27 15:45 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 09/18] printk: nobkl: Add print state functions John Ogness
2023-03-29 13:58 ` buffer write race: " Petr Mladek
2023-03-29 14:33 ` John Ogness
2023-03-30 11:54 ` Petr Mladek
2023-03-29 14:05 ` misc details: was: " Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 10/18] printk: nobkl: Add emit function and callback functions for atomic printing John Ogness
2023-03-03 0:19 ` kernel test robot
2023-03-03 10:55 ` John Ogness
2023-03-31 10:29 ` dropped handling: was: " Petr Mladek
2023-03-31 10:36 ` semantic: " Petr Mladek
[not found] ` <87edp29kvq.fsf@jogness.linutronix.de>
[not found] ` <ZCraqrkqFtsfLWuP@alley>
[not found] ` <87ilecsrvl.fsf@jogness.linutronix.de>
2023-04-04 14:09 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 11/18] printk: nobkl: Introduce printer threads John Ogness
2023-03-03 1:23 ` kernel test robot
2023-03-03 10:56 ` John Ogness
2023-04-05 10:48 ` boot console: was: " Petr Mladek
2023-04-06 8:09 ` wakeup synchronization: " Petr Mladek
2023-04-06 9:46 ` port lock: " Petr Mladek
2023-04-20 9:55 ` Petr Mladek
2023-04-20 10:33 ` John Ogness
2023-04-20 13:33 ` Petr Mladek
2023-04-21 16:15 ` Petr Mladek
2023-04-06 13:19 ` misc: " Petr Mladek
2023-04-13 13:28 ` (k)thread: " Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 12/18] printk: nobkl: Add printer thread wakeups John Ogness
2023-04-12 9:38 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 13/18] printk: nobkl: Add write context storage for atomic writes John Ogness
2023-03-02 19:56 ` [PATCH printk v1 14/18] printk: nobkl: Provide functions for atomic write enforcement John Ogness
2023-04-12 14:53 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 15/18] printk: nobkl: Stop threads on shutdown/reboot John Ogness
2023-04-13 9:03 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 16/18] kernel/panic: Add atomic write enforcement to warn/panic John Ogness
2023-04-13 10:08 ` Petr Mladek
2023-04-13 12:13 ` John Ogness
2023-04-14 10:10 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 17/18] rcu: Add atomic write enforcement for rcu stalls John Ogness
2023-04-13 12:10 ` Petr Mladek
2023-03-02 19:56 ` [PATCH printk v1 18/18] printk: Perform atomic flush in console_flush_on_panic() John Ogness
2023-04-13 12:20 ` Petr Mladek
2023-03-02 19:58 ` [PATCH printk v1 00/18] serial: 8250: implement non-BKL console John Ogness
2023-03-28 13:33 ` locking API: was: " Petr Mladek
2023-03-28 13:57 ` John Ogness
2023-03-28 15:10 ` Petr Mladek
2023-03-28 21:47 ` John Ogness
2023-03-29 8:03 ` Petr Mladek
2023-03-28 13:59 ` [PATCH printk v1 00/18] POC: serial: 8250: implement nbcon console John Ogness
2023-03-09 10:55 ` [PATCH printk v1 00/18] threaded/atomic console support Daniel Thompson
2023-03-09 11:14 ` John Ogness
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