Messages in this thread | | | Date | Sun, 2 Nov 2014 12:13:37 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86, cpu: trivial printk formatting fixes |
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On Sun, Nov 02, 2014 at 04:03:52AM +0000, Steven Honeyman wrote: > Hmm - the difference is to do with the source of the kernel ring > buffer. The old output format be obtained using the latest dmesg by > adding "-S", which uses syslog(2) rather than /dev/kmsg. > (added in commit 7af230601ab) > > The klogctl version interprets the \n and adds the timestamp > afterwards, but /dev/kmsg changes the '\n' to "\x0a" resulting in: > 4,355,10557,-;ENERGY_PERF_BIAS: Set to 'normal', was > 'performance'\x0aENERGY_P... > > It looks as though it's just a matter of opinion/preference whether > control characters are printed (rfc5424)
Right, I see what you mean. There's this in the /dev/kmsg code
--- * /dev/kmsg exports the structured data in the following line format: * "level,sequnum,timestamp;<message text>\n" * * The optional key/value pairs are attached as continuation lines starting * with a space character and terminated by a newline. All possible * non-prinatable characters are escaped in the "\xff" notation. * * Users of the export format should ignore possible additional values * separated by ',', and find the message after the ';' character. */ --
and also
--- /* escape non-printable characters */ for (i = 0; i < msg->text_len; i++) { unsigned char c = log_text(msg)[i];
if (c < ' ' || c >= 127 || c == '\\') len += sprintf(user->buf + len, "\\x%02x", c); else user->buf[len++] = c; } --
in devkmsg_read().
Hmm, so this all looks like an agreed upon thing or whatever. Oh, and btw, if you don't enable printk timestamping, you won't see the issue.
I'd say the simplest solution - and this is only me and I like practical - is to accept your patch after all and stop wasting time with this :-)
Only after you fix it, though, to *not* change log levels for the other printk message. FWIW, your change even improves the readability a bit of those printks.
Thanks.
-- Regards/Gruss, Boris.
Sent from a fat crate under my desk. Formatting is fine. --
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