Re: [PATCH 0/8] Rework KERN_<LEVEL>

From: Joe Perches
Date: Tue Jun 05 2012 - 20:07:30 EST


On Tue, 2012-06-05 at 16:58 -0700, Andrew Morton wrote:
> echo "\0014Hello Joe" > /dev/kmsg

# echo -e "\x014Hello Me" > /dev/kmsg
gives:
12,778,4057982669;Hello Me

#echo -e "\x011Hello Me_2" > /dev/kmsg
gives:
12,779,4140452093;Hello Me_2

I didn't change devkmsg_writev so the
original parsing style for "<.>" is
unchanged.

from printk.c:

static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
[...]
int level = default_message_loglevel;
[...]
if (line[0] == '<') {
char *endp = NULL;

i = simple_strtoul(line+1, &endp, 10);
if (endp && endp[0] == '>') {
level = i & 7;
if (i >> 3)
facility = i >> 3;
endp++;
len -= endp - line;
line = endp;
}
}
line[len] = '\0';

printk_emit(facility, level, NULL, 0, "%s", line);
[]

level is what matters.

from dmesg -r

<12>[ 2462.339252] \001Hello Andrew
<9>[ 2516.023444] Hello Andrew
<12>[ 3046.752764] \x01Hello Kay
<12>[ 3940.871850] \x01Hello Kay
<12>[ 4057.982669] Hello Me
<12>[ 4140.452093] Hello Me_2


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