From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>, Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Marco Elver <elver@google.com>,
Linux Embedded <linux-embedded@vger.kernel.org>,
John Ogness <john.ogness@linutronix.de>,
Randy Dunlap <rdunlap@infradead.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux IOMMU <iommu@lists.linux-foundation.org>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH 3/3] lib/vsprintf: Use pr_crit() instead of long fancy messages
Date: Mon, 17 May 2021 08:21:12 +0200 [thread overview]
Message-ID: <CAMuHMdXQArCn9BS_8p0iUAgomfEHWe8ypg=B_SGfvJu8c_L5vg@mail.gmail.com> (raw)
In-Reply-To: <20210331093104.383705-4-geert+renesas@glider.be>
On Wed, Mar 31, 2021 at 11:59 AM Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
> While long fancy messages have a higher probability of being seen than
> small messages, they may scroll of the screen fast, if visible at all,
> and may still be missed. In addition, they increase boot time and
> kernel size.
>
> The correct mechanism to increase importance of a kernel message is not
> to draw fancy boxes with more text, but to shout louder, i.e. increase
> the message's reporting level. Making sure the administrator of the
> system is aware of such a message is a system policy, and is the
> responsability of a user-space log daemon.
>
> Fix this by increasing the reporting level from KERN_WARNING to
> KERN_CRIT, and removing irrelevant text and graphics.
>
> This reduces kernel size by ca. 0.5 KiB.
>
> Fixes: 5ead723a20e0447b ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
No comments?
Unlike the cases handled by the other two patches in this series,
this one cannot be configured out.
Thanks!
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -2193,20 +2193,9 @@ static int __init no_hash_pointers_enable(char *str)
>
> no_hash_pointers = true;
>
> - pr_warn("**********************************************************\n");
> - pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
> - pr_warn("** **\n");
> - pr_warn("** This system shows unhashed kernel memory addresses **\n");
> - pr_warn("** via the console, logs, and other interfaces. This **\n");
> - pr_warn("** might reduce the security of your system. **\n");
> - pr_warn("** **\n");
> - pr_warn("** If you see this message and you are not debugging **\n");
> - pr_warn("** the kernel, report this immediately to your system **\n");
> - pr_warn("** administrator! **\n");
> - pr_warn("** **\n");
> - pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
> - pr_warn("**********************************************************\n");
> -
> + pr_crit("This system shows unhashed kernel memory addresses\n");
> + pr_crit("via the console, logs, and other interfaces. This\n");
> + pr_crit("might reduce the security of your system.\n");
> return 0;
> }
> early_param("no_hash_pointers", no_hash_pointers_enable);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-05-17 6:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-31 9:31 [PATCH 0/3] Use pr_crit() instead of long fancy messages Geert Uytterhoeven
2021-03-31 9:31 ` [PATCH 1/3] iommu: " Geert Uytterhoeven
2021-03-31 9:31 ` [PATCH 2/3] tracing: " Geert Uytterhoeven
2021-03-31 13:40 ` Steven Rostedt
2021-04-01 9:14 ` Petr Mladek via iommu
2021-04-01 9:39 ` Geert Uytterhoeven
2021-04-01 11:28 ` Robin Murphy
2021-03-31 9:31 ` [PATCH 3/3] lib/vsprintf: " Geert Uytterhoeven
2021-05-17 6:21 ` Geert Uytterhoeven [this message]
2021-05-20 12:51 ` Petr Mladek via iommu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAMuHMdXQArCn9BS_8p0iUAgomfEHWe8ypg=B_SGfvJu8c_L5vg@mail.gmail.com' \
--to=geert@linux-m68k.org \
--cc=akpm@linux-foundation.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=elver@google.com \
--cc=geert+renesas@glider.be \
--cc=iommu@lists.linux-foundation.org \
--cc=john.ogness@linutronix.de \
--cc=joro@8bytes.org \
--cc=linux-embedded@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=mingo@redhat.com \
--cc=pmladek@suse.com \
--cc=rdunlap@infradead.org \
--cc=rostedt@goodmis.org \
--cc=sergey.senozhatsky@gmail.com \
--cc=torvalds@linux-foundation.org \
--cc=vbabka@suse.cz \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).