linux-kernel - Re: PATCH: /proc/acpi/alarm: handle day-of-month wraparound on readback

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: <20081202102925.GA3194@dose.home.local>
Date:	Tue, 2 Dec 2008 11:29:25 +0100
From:	Tino Keitel <tino.keitel@....de>
To:	Mark Lord <lkml@....ca>
Cc:	Len Brown <lenb@...nel.org>,
	Alessandro Zummo <a.zummo@...ertech.it>,
	David Brownell <david-b@...bell.net>,
	lkml <linux-kernel@...r.kernel.org>, rtc-linux@...glegroups.com,
	linux-acpi@...r.kernel.org
Subject: Re: PATCH: /proc/acpi/alarm: handle day-of-month wraparound on
	readback

On Mon, Dec 01, 2008 at 12:02:06 -0500, Mark Lord wrote:
> Mark Lord wrote:
>> Fix month wrap issue with readback from /proc/acpi/alarm
>> This bug has been around *forever*.
>>
>> $ echo '2008-12-01 10:36:20' > /proc/acpi/alarm
>> $ cat /proc/acpi/alarm
>> 2008-11-01 10:36:20
>>
>> Note how the readback above shows the month incorrectly.
>> But with this patch applied, it shows the correct month (12).
> ..
>
> I should add, that the above test requires that the alarm
> be set for any day of the *next* month from the current month.
> My MythTV box does a readback test any time it programs a wakeup,
> and noticed the bug over this past weekend (2008-11-30).

Why not just use the new RTC drivers and /sys/class/rtc/rtc0/wakealarm?
MythTV already provides seconds since epoch for the wakeup time, so you
can use this value without converting it:

$ cat /usr/local/bin/myth-setwaketime
#!/bin/sh

SYSFS_WAKE_FILE="/sys/class/rtc/rtc0/wakealarm"

echo -n "Wakeup time is "
date -d @$1

if ! test -w "$SYSFS_WAKE_FILE" ; then
	exit 1
fi

echo 0 > "$SYSFS_WAKE_FILE"
echo "$1" > "$SYSFS_WAKE_FILE"
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/