linux-kernel - [PATCH v2 4/4] printk/sound: Handle more message headers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1478695291-12169-5-git-send-email-pmladek@suse.com>
Date:   Wed,  9 Nov 2016 13:41:31 +0100
From:   Petr Mladek <pmladek@...e.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Joe Perches <joe@...ches.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Jason Wessel <jason.wessel@...driver.com>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>, Chris Mason <clm@...com>,
        Josef Bacik <jbacik@...com>, David Sterba <dsterba@...e.com>,
        linux-kernel@...r.kernel.org, Petr Mladek <pmladek@...e.com>
Subject: [PATCH v2 4/4] printk/sound: Handle more message headers

The commit 4bcc595ccd80decb4245096e ("printk: reinstate KERN_CONT for
printing continuation lines") allows to define more message headers
for a single message. The motivation is that continuous lines might
get mixed. Therefore it make sense to define the right log level
for every piece of a cont line.

This patch allows to copy only the real message level. We should
ignore KERN_CONT because <filename:line> is added for each message.
By other words, we want to know where each piece of the line comes
from.

Signed-off-by: Petr Mladek <pmladek@...e.com>
---
 sound/core/misc.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/sound/core/misc.c b/sound/core/misc.c
index f2e8226c88fb..45f03b1d4102 100644
--- a/sound/core/misc.c
+++ b/sound/core/misc.c
@@ -71,6 +71,7 @@ void __snd_printk(unsigned int level, const char *path, int line,
 	int kern_level;
 	struct va_format vaf;
 	char verbose_fmt[] = KERN_DEFAULT "ALSA %s:%d %pV";
+	bool level_found = false;
 #endif
 
 #ifdef CONFIG_SND_DEBUG
@@ -83,15 +84,22 @@ void __snd_printk(unsigned int level, const char *path, int line,
 	vaf.fmt = format;
 	vaf.va = &args;
 
-	kern_level = printk_get_level(format);
-	if (kern_level) {
-		const char *end_of_header = printk_skip_level(format);
-		memcpy(verbose_fmt, format, end_of_header - format);
+	while ((kern_level = printk_get_level(vaf.fmt)) != 0) {
+		const char *end_of_header = printk_skip_level(vaf.fmt);
+
+		/* Ignore KERN_CONT. We print filename:line for each piece. */
+		if (kern_level >= '0' || kern_level <= '7') {
+			memcpy(verbose_fmt, vaf.fmt, end_of_header - vaf.fmt);
+			level_found = true;
+		}
+
 		vaf.fmt = end_of_header;
-	} else if (level)
+	}
+
+	if (!level_found && level)
 		memcpy(verbose_fmt, KERN_DEBUG, sizeof(KERN_DEBUG) - 1);
-	printk(verbose_fmt, sanity_file_name(path), line, &vaf);
 
+	printk(verbose_fmt, sanity_file_name(path), line, &vaf);
 #else
 	vprintk(format, args);
 #endif
-- 
1.8.5.6