From: jfannin@gmail.com (Joseph Fannin)
To: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@osdl.org>, Joseph Fannin <jfannin@gmail.com>,
linux-kernel@vger.kernel.org, arjan@infradead.org,
John Stultz <johnstul@us.ibm.com>
Subject: Re: [patch] lockdep: HPET/RTC fix
Date: Sat, 5 Aug 2006 17:59:34 -0400 [thread overview]
Message-ID: <20060805215934.GA8624@palmyra> (raw)
In-Reply-To: <20060711074541.GA5263@elte.hu>
On Tue, Jul 11, 2006 at 09:45:41AM +0200, Ingo Molnar wrote:
[Apologies for the very slow turn-around time on this. If patches
are written in the relatively-near future, I will test and report in a
more timely manner.]
> Subject: lockdep: HPET/RTC fix
> From: Ingo Molnar <mingo@elte.hu>
>
> Joseph Fannin reported that hpet_rtc_interrupt() enables hardirqs
> in irq context:
> --- linux.orig/drivers/char/rtc.c
> +++ linux/drivers/char/rtc.c
> @@ -1222,7 +1222,7 @@ static int rtc_proc_open(struct inode *i
>
> void rtc_get_rtc_time(struct rtc_time *rtc_tm)
> {
> - unsigned long uip_watchdog = jiffies;
> + unsigned long uip_watchdog = jiffies, flags;
> unsigned char ctrl;
> #ifdef CONFIG_MACH_DECSTATION
> unsigned int real_year;
> @@ -1249,7 +1249,7 @@ void rtc_get_rtc_time(struct rtc_time *r
> * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
> * only updated by the RTC when initially set to a non-zero value.
> */
> - spin_lock_irq(&rtc_lock);
> + spin_lock_irqsave(&rtc_lock, flags);
> rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
> rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
> rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
> @@ -1263,7 +1263,7 @@ void rtc_get_rtc_time(struct rtc_time *r
> real_year = CMOS_READ(RTC_DEC_YEAR);
> #endif
> ctrl = CMOS_READ(RTC_CONTROL);
> - spin_unlock_irq(&rtc_lock);
> + spin_unlock_irqrestore(&rtc_lock, flags);
>
> if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
> {
It seems this isn't enough:
[ 22.504000] EXT3 FS on sda3, internal journal
[ 22.892000] BUG: warning at kernel/lockdep.c:1803/trace_hardirqs_on()
[ 22.892000] [<c0104880>] show_trace_log_lvl+0x1a0/0x1d0
[ 22.892000] [<c0105a7b>] show_trace+0x1b/0x20
[ 22.892000] [<c0105aa4>] dump_stack+0x24/0x30
[ 22.892000] [<c01451e4>] trace_hardirqs_on+0xf4/0x180
[ 22.892000] [<c032e431>] _spin_unlock_irq+0x31/0x60
[ 22.892000] [<c0278a64>] rtc_get_rtc_time+0x44/0x1a0
[ 22.892000] [<c0118742>] hpet_rtc_interrupt+0x152/0x1b0
[ 22.892000] [<c015bb51>] handle_IRQ_event+0x31/0x70
[ 22.892000] [<c015bc29>] __do_IRQ+0x99/0x110
[ 22.892000] [<c0105ef7>] do_IRQ+0x47/0xa0
[ 22.892000] [<c0103eed>] common_interrupt+0x25/0x2c
[ 22.892000] [<c032f902>] do_page_fault+0x82/0x630
[ 22.892000] [<c0104085>] error_code+0x39/0x40
[ 22.892000] [<b7e8d060>] 0xb7e8d060
[ 22.892000] [<c0105a7b>] show_trace+0x1b/0x20
[ 22.892000] [<c0105aa4>] dump_stack+0x24/0x30
[ 22.892000] [<c01451e4>] trace_hardirqs_on+0xf4/0x180
[ 22.892000] [<c032e431>] _spin_unlock_irq+0x31/0x60
[ 22.892000] [<c0278a64>] rtc_get_rtc_time+0x44/0x1a0
[ 22.892000] [<c0118742>] hpet_rtc_interrupt+0x152/0x1b0
[ 22.892000] [<c015bb51>] handle_IRQ_event+0x31/0x70
[ 22.892000] [<c015bc29>] __do_IRQ+0x99/0x110
[ 22.892000] [<c0105ef7>] do_IRQ+0x47/0xa0
[ 22.892000] [<c0103eed>] common_interrupt+0x25/0x2c
[ 22.892000] [<c0104085>] error_code+0x39/0x40
This is from 2.6.18-rc3, but it's reproducable with pretty much
any kernel (the -rc3 backtrace is longer, it seems).
Should I file this in Bugzilla?
--
Joseph Fannin
jfannin@gmail.com
prev parent reply other threads:[~2006-08-05 22:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-09 5:05 [LOCKDEP] 2.6.18-rc1: inconsistent {hardirq-on-W} -> {in-hardirq-W} usage Joseph Fannin
2006-07-09 6:25 ` Andrew Morton
2006-07-09 7:45 ` Ingo Molnar
2006-07-11 5:11 ` Joseph Fannin
2006-07-11 7:45 ` [patch] lockdep: HPET/RTC fix Ingo Molnar
2006-07-14 3:57 ` [PATCH] remove unnecessary barrier in rtc_get_rtc_time Steven Rostedt
2006-08-05 21:59 ` Joseph Fannin [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20060805215934.GA8624@palmyra \
--to=jfannin@gmail.com \
--cc=akpm@osdl.org \
--cc=arjan@infradead.org \
--cc=johnstul@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.