linux-kernel - Re: [PATCH 1/1] ensure we don't use bootconsoles after init has been released

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Message-Id: <200708201314.57801.rgetz@blackfin.uclinux.org>
Date:	Mon, 20 Aug 2007 13:14:57 -0400
From:	Robin Getz <rgetz@...ckfin.uclinux.org>
To:	"Paul Mundt" <lethal@...ux-sh.org>
Cc:	"Mike Frysinger" <vapier.adi@...il.com>,
	"Andrew Morton" <akpm@...ux-foundation.org>,
	torvalds@...ux-foundation.org, linux-kernel@...r.kernel.org,
	"Gerd Hoffmann" <kraxel@...hat.com>
Subject: Re: [PATCH 1/1] ensure we don't use bootconsoles after init has been released

Try #3...

From: Robin Getz <rgetz@...ckfin.uclinux.org>
 
This is a followup to the cleanups for earlyprintk patch from Gerd Hoffmann
 
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=69331af79cf29e26d1231152a172a1a10c2df511
 
This ensures that a bootconsole is unregistered if it is not replaced.
The current implementation spews garbage out the bootconsole in this case,
since the bootconsole structure is normally in the init section, and is
freed, but still used.
 
Signed-off-by: Robin Getz <rgetz@...ckfin.uclinux.org>
CC: Gerd Hoffmann <kraxel@...hat.com>
CC: Paul Mundt <lethal@...ux-sh.org>
CC: Mike Frysinger <vapier.adi@...il.com>
---
 printk.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)


Index: linux-2.6.x/kernel/printk.c
===================================================================
--- linux-2.6.x/kernel/printk.c
+++ linux-2.6.x/kernel/printk.c
@@ -1104,6 +1104,19 @@
 }
 EXPORT_SYMBOL(unregister_console);
 
+static int __init disable_boot_consoles(void)
+{
+	printk(KERN_INFO "here\n");
+
+	if (console_drivers->flags & CON_BOOT) {
+		printk(KERN_INFO "turn off boot console %s%d\n",
+			console_drivers->name, console_drivers->index);
+		return unregister_console(console_drivers);
+	}
+	return 0;
+}
+late_initcall(disable_boot_consoles);
+
 /**
  * tty_write_message - write a message to a certain tty, not just the console.
  * @tty: the destination tty_struct
-
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