[kernel] r19377 - in dists/squeeze/linux-2.6/debian: . patches/bugfix/all patches/debian patches/series
Dann Frazier
dannf at alioth.debian.org
Tue Sep 11 05:15:40 UTC 2012
Author: dannf
Date: Tue Sep 11 05:15:38 2012
New Revision: 19377
Log:
Avoid leap second deadlock and early hrtimer/futex expiration issue
(Closes: #679882)
Added:
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0001-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0002-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0003-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0004-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0005-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0006-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0007-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0008-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0009-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0010-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/bugfix/all/0011-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
dists/squeeze/linux-2.6/debian/patches/debian/timer-Avoid_ABI-change-from-leap-second-fix.patch
Modified:
dists/squeeze/linux-2.6/debian/changelog
dists/squeeze/linux-2.6/debian/patches/series/46
Modified: dists/squeeze/linux-2.6/debian/changelog
==============================================================================
--- dists/squeeze/linux-2.6/debian/changelog Mon Sep 10 04:01:03 2012 (r19376)
+++ dists/squeeze/linux-2.6/debian/changelog Tue Sep 11 05:15:38 2012 (r19377)
@@ -30,6 +30,10 @@
* sky2: Add 'legacy_pme' option for PCI legacy power management
(Closes: #647560; works around regression introduced in 2.6.32-22)
+ [ dann frazier ]
+ * Avoid leap second deadlock and early hrtimer/futex expiration issue
+ (Closes: #679882)
+
-- Bastian Blank <waldi at debian.org> Mon, 07 May 2012 19:18:05 +0200
linux-2.6 (2.6.32-45) stable; urgency=high
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0001-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0001-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,335 @@
+From: John Stultz <john.stultz at linaro.org>
+
+This is a backport of 6b43ae8a619d17c4935c3320d2ef9e92bdeed05d
+
+This should have been backported when it was commited, but I
+mistook the problem as requiring the ntp_lock changes
+that landed in 3.4 in order for it to occur.
+
+Unfortunately the same issue can happen (with only one cpu)
+as follows:
+do_adjtimex()
+ write_seqlock_irq(&xtime_lock);
+ process_adjtimex_modes()
+ process_adj_status()
+ ntp_start_leap_timer()
+ hrtimer_start()
+ hrtimer_reprogram()
+ tick_program_event()
+ clockevents_program_event()
+ ktime_get()
+ seq = req_seqbegin(xtime_lock); [DEADLOCK]
+
+This deadlock will no always occur, as it requires the
+leap_timer to force a hrtimer_reprogram which only happens
+if its set and there's no sooner timer to expire.
+
+NOTE: This patch, being faithful to the original commit,
+introduces a bug (we don't update wall_to_monotonic),
+which will be resovled by backporting a following fix.
+
+Original commit message below:
+
+Since commit 7dffa3c673fbcf835cd7be80bb4aec8ad3f51168 the ntp
+subsystem has used an hrtimer for triggering the leapsecond
+adjustment. However, this can cause a potential livelock.
+
+Thomas diagnosed this as the following pattern:
+CPU 0 CPU 1
+do_adjtimex()
+ spin_lock_irq(&ntp_lock);
+ process_adjtimex_modes(); timer_interrupt()
+ process_adj_status(); do_timer()
+ ntp_start_leap_timer(); write_lock(&xtime_lock);
+ hrtimer_start(); update_wall_time();
+ hrtimer_reprogram(); ntp_tick_length()
+ tick_program_event() spin_lock(&ntp_lock);
+ clockevents_program_event()
+ ktime_get()
+ seq = req_seqbegin(xtime_lock);
+
+This patch tries to avoid the problem by reverting back to not using
+an hrtimer to inject leapseconds, and instead we handle the leapsecond
+processing in the second_overflow() function.
+
+The downside to this change is that on systems that support highres
+timers, the leap second processing will occur on a HZ tick boundary,
+(ie: ~1-10ms, depending on HZ) after the leap second instead of
+possibly sooner (~34us in my tests w/ x86_64 lapic).
+
+This patch applies on top of tip/timers/core.
+
+CC: Sasha Levin <levinsasha928 at gmail.com>
+CC: Thomas Gleixner <tglx at linutronix.de>
+Reported-by: Sasha Levin <levinsasha928 at gmail.com>
+Diagnoised-by: Thomas Gleixner <tglx at linutronix.de>
+Tested-by: Sasha Levin <levinsasha928 at gmail.com>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <john.stultz at linaro.org>
+---
+ include/linux/timex.h | 2 +-
+ kernel/time/ntp.c | 122 +++++++++++++++------------------------------
+ kernel/time/timekeeping.c | 12 ++---
+ 3 files changed, 44 insertions(+), 92 deletions(-)
+
+diff --git a/include/linux/timex.h b/include/linux/timex.h
+index e6967d1..3b587b4 100644
+--- a/include/linux/timex.h
++++ b/include/linux/timex.h
+@@ -271,7 +271,7 @@ static inline int ntp_synced(void)
+ /* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */
+ extern u64 tick_length;
+
+-extern void second_overflow(void);
++extern int second_overflow(unsigned long secs);
+ extern void update_ntp_one_tick(void);
+ extern int do_adjtimex(struct timex *);
+
+diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
+index 4800f93..dc76c9a 100644
+--- a/kernel/time/ntp.c
++++ b/kernel/time/ntp.c
+@@ -28,8 +28,6 @@ unsigned long tick_nsec;
+ u64 tick_length;
+ static u64 tick_length_base;
+
+-static struct hrtimer leap_timer;
+-
+ #define MAX_TICKADJ 500LL /* usecs */
+ #define MAX_TICKADJ_SCALED \
+ (((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
+@@ -180,60 +178,60 @@ void ntp_clear(void)
+ }
+
+ /*
+- * Leap second processing. If in leap-insert state at the end of the
+- * day, the system clock is set back one second; if in leap-delete
+- * state, the system clock is set ahead one second.
++ * this routine handles the overflow of the microsecond field
++ *
++ * The tricky bits of code to handle the accurate clock support
++ * were provided by Dave Mills (Mills at UDEL.EDU) of NTP fame.
++ * They were originally developed for SUN and DEC kernels.
++ * All the kudos should go to Dave for this stuff.
++ *
++ * Also handles leap second processing, and returns leap offset
+ */
+-static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
++int second_overflow(unsigned long secs)
+ {
+- enum hrtimer_restart res = HRTIMER_NORESTART;
+-
+- write_seqlock(&xtime_lock);
++ int leap = 0;
++ s64 delta;
+
++ /*
++ * Leap second processing. If in leap-insert state at the end of the
++ * day, the system clock is set back one second; if in leap-delete
++ * state, the system clock is set ahead one second.
++ */
+ switch (time_state) {
+ case TIME_OK:
++ if (time_status & STA_INS)
++ time_state = TIME_INS;
++ else if (time_status & STA_DEL)
++ time_state = TIME_DEL;
+ break;
+ case TIME_INS:
+- timekeeping_leap_insert(-1);
+- time_state = TIME_OOP;
+- printk(KERN_NOTICE
+- "Clock: inserting leap second 23:59:60 UTC\n");
+- hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
+- res = HRTIMER_RESTART;
++ if (secs % 86400 == 0) {
++ leap = -1;
++ time_state = TIME_OOP;
++ printk(KERN_NOTICE
++ "Clock: inserting leap second 23:59:60 UTC\n");
++ }
+ break;
+ case TIME_DEL:
+- timekeeping_leap_insert(1);
+- time_tai--;
+- time_state = TIME_WAIT;
+- printk(KERN_NOTICE
+- "Clock: deleting leap second 23:59:59 UTC\n");
++ if ((secs + 1) % 86400 == 0) {
++ leap = 1;
++ time_tai--;
++ time_state = TIME_WAIT;
++ printk(KERN_NOTICE
++ "Clock: deleting leap second 23:59:59 UTC\n");
++ }
+ break;
+ case TIME_OOP:
+ time_tai++;
+ time_state = TIME_WAIT;
+- /* fall through */
++ break;
++
+ case TIME_WAIT:
+ if (!(time_status & (STA_INS | STA_DEL)))
+ time_state = TIME_OK;
+ break;
+ }
+
+- write_sequnlock(&xtime_lock);
+-
+- return res;
+-}
+-
+-/*
+- * this routine handles the overflow of the microsecond field
+- *
+- * The tricky bits of code to handle the accurate clock support
+- * were provided by Dave Mills (Mills at UDEL.EDU) of NTP fame.
+- * They were originally developed for SUN and DEC kernels.
+- * All the kudos should go to Dave for this stuff.
+- */
+-void second_overflow(void)
+-{
+- s64 delta;
+
+ /* Bump the maxerror field */
+ time_maxerror += MAXFREQ / NSEC_PER_USEC;
+@@ -253,23 +251,25 @@ void second_overflow(void)
+ tick_length += delta;
+
+ if (!time_adjust)
+- return;
++ goto out;
+
+ if (time_adjust > MAX_TICKADJ) {
+ time_adjust -= MAX_TICKADJ;
+ tick_length += MAX_TICKADJ_SCALED;
+- return;
++ goto out;
+ }
+
+ if (time_adjust < -MAX_TICKADJ) {
+ time_adjust += MAX_TICKADJ;
+ tick_length -= MAX_TICKADJ_SCALED;
+- return;
++ goto out;
+ }
+
+ tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
+ << NTP_SCALE_SHIFT;
+ time_adjust = 0;
++out:
++ return leap;
+ }
+
+ #ifdef CONFIG_GENERIC_CMOS_UPDATE
+@@ -331,27 +331,6 @@ static void notify_cmos_timer(void)
+ static inline void notify_cmos_timer(void) { }
+ #endif
+
+-/*
+- * Start the leap seconds timer:
+- */
+-static inline void ntp_start_leap_timer(struct timespec *ts)
+-{
+- long now = ts->tv_sec;
+-
+- if (time_status & STA_INS) {
+- time_state = TIME_INS;
+- now += 86400 - now % 86400;
+- hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
+-
+- return;
+- }
+-
+- if (time_status & STA_DEL) {
+- time_state = TIME_DEL;
+- now += 86400 - (now + 1) % 86400;
+- hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
+- }
+-}
+
+ /*
+ * Propagate a new txc->status value into the NTP state:
+@@ -374,22 +353,6 @@ static inline void process_adj_status(struct timex *txc, struct timespec *ts)
+ time_status &= STA_RONLY;
+ time_status |= txc->status & ~STA_RONLY;
+
+- switch (time_state) {
+- case TIME_OK:
+- ntp_start_leap_timer(ts);
+- break;
+- case TIME_INS:
+- case TIME_DEL:
+- time_state = TIME_OK;
+- ntp_start_leap_timer(ts);
+- case TIME_WAIT:
+- if (!(time_status & (STA_INS | STA_DEL)))
+- time_state = TIME_OK;
+- break;
+- case TIME_OOP:
+- hrtimer_restart(&leap_timer);
+- break;
+- }
+ }
+ /*
+ * Called with the xtime lock held, so we can access and modify
+@@ -469,9 +432,6 @@ int do_adjtimex(struct timex *txc)
+ (txc->tick < 900000/USER_HZ ||
+ txc->tick > 1100000/USER_HZ))
+ return -EINVAL;
+-
+- if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
+- hrtimer_cancel(&leap_timer);
+ }
+
+ getnstimeofday(&ts);
+@@ -549,6 +509,4 @@ __setup("ntp_tick_adj=", ntp_tick_adj_setup);
+ void __init ntp_init(void)
+ {
+ ntp_clear();
+- hrtimer_init(&leap_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
+- leap_timer.function = ntp_leap_second;
+ }
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index 4a71cff..00e2fae 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -183,14 +183,6 @@ void update_xtime_cache(u64 nsec)
+ ACCESS_ONCE(xtime_cache) = ts;
+ }
+
+-/* must hold xtime_lock */
+-void timekeeping_leap_insert(int leapsecond)
+-{
+- xtime.tv_sec += leapsecond;
+- wall_to_monotonic.tv_sec -= leapsecond;
+- update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
+-}
+-
+ #ifdef CONFIG_GENERIC_TIME
+
+ /**
+@@ -783,9 +775,11 @@ void update_wall_time(void)
+
+ timekeeper.xtime_nsec += timekeeper.xtime_interval;
+ if (timekeeper.xtime_nsec >= nsecps) {
++ int leap;
+ timekeeper.xtime_nsec -= nsecps;
+ xtime.tv_sec++;
+- second_overflow();
++ leap = second_overflow(xtime.tv_sec);
++ xtime.tv_sec += leap;
+ }
+
+ raw_time.tv_nsec += timekeeper.raw_interval;
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0002-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0002-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,46 @@
+From: Richard Cochran <richardcochran at gmail.com>
+
+This is a backport of dd48d708ff3e917f6d6b6c2b696c3f18c019feed
+
+When repeating a UTC time value during a leap second (when the UTC
+time should be 23:59:60), the TAI timescale should not stop. The kernel
+NTP code increments the TAI offset one second too late. This patch fixes
+the issue by incrementing the offset during the leap second itself.
+
+Signed-off-by: Richard Cochran <richardcochran at gmail.com>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <john.stultz at linaro.org>
+---
+ kernel/time/ntp.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
+index dc76c9a..c1c36a2 100644
+--- a/kernel/time/ntp.c
++++ b/kernel/time/ntp.c
+@@ -208,6 +208,7 @@ int second_overflow(unsigned long secs)
+ if (secs % 86400 == 0) {
+ leap = -1;
+ time_state = TIME_OOP;
++ time_tai++;
+ printk(KERN_NOTICE
+ "Clock: inserting leap second 23:59:60 UTC\n");
+ }
+@@ -222,7 +223,6 @@ int second_overflow(unsigned long secs)
+ }
+ break;
+ case TIME_OOP:
+- time_tai++;
+ time_state = TIME_WAIT;
+ break;
+
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0003-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0003-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,44 @@
+From: John Stultz <john.stultz at linaro.org>
+
+This is a backport of fad0c66c4bb836d57a5f125ecd38bed653ca863a
+which resolves a bug the previous commit.
+
+Commit 6b43ae8a61 (ntp: Fix leap-second hrtimer livelock) broke the
+leapsecond update of CLOCK_MONOTONIC. The missing leapsecond update to
+wall_to_monotonic causes discontinuities in CLOCK_MONOTONIC.
+
+Adjust wall_to_monotonic when NTP inserted a leapsecond.
+
+Reported-by: Richard Cochran <richardcochran at gmail.com>
+Signed-off-by: John Stultz <john.stultz at linaro.org>
+Tested-by: Richard Cochran <richardcochran at gmail.com>
+Link: http://lkml.kernel.org/r/1338400497-12420-1-git-send-email-john.stultz@linaro.org
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ kernel/time/timekeeping.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index 00e2fae..6d19a00 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -780,6 +780,7 @@ void update_wall_time(void)
+ xtime.tv_sec++;
+ leap = second_overflow(xtime.tv_sec);
+ xtime.tv_sec += leap;
++ wall_to_monotonic.tv_sec -= leap;
+ }
+
+ raw_time.tv_nsec += timekeeper.raw_interval;
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0004-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0004-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,72 @@
+From: Thomas Gleixner <tglx at linutronix.de>
+
+This is a backport of cc06268c6a87db156af2daed6e96a936b955cc82
+
+While not a bugfix itself, it allows following fixes to backport
+in a more straightforward manner.
+
+CC: Thomas Gleixner <tglx at linutronix.de>
+CC: Eric Dumazet <eric.dumazet at gmail.com>
+CC: Richard Cochran <richardcochran at gmail.com>
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <john.stultz at linaro.org>
+---
+ kernel/time/timekeeping.c | 20 ++++++++++++++------
+ 1 file changed, 14 insertions(+), 6 deletions(-)
+
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index 6d19a00..a969adf 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -166,6 +166,18 @@ static struct timespec total_sleep_time;
+ */
+ struct timespec raw_time;
+
++/* must hold write on xtime_lock */
++static void timekeeping_update(bool clearntp)
++{
++ if (clearntp) {
++ timekeeper.ntp_error = 0;
++ ntp_clear();
++ }
++ update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
++}
++
++
++
+ /* flag for if timekeeping is suspended */
+ int __read_mostly timekeeping_suspended;
+
+@@ -341,10 +353,7 @@ int do_settimeofday(struct timespec *tv)
+
+ update_xtime_cache(0);
+
+- timekeeper.ntp_error = 0;
+- ntp_clear();
+-
+- update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
++ timekeeping_update(true);
+
+ write_sequnlock_irqrestore(&xtime_lock, flags);
+
+@@ -832,8 +841,7 @@ void update_wall_time(void)
+ nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift);
+ update_xtime_cache(nsecs);
+
+- /* check to see if there is a new clocksource to use */
+- update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
++ timekeeping_update(false);
+ }
+
+ /**
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0005-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0005-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,120 @@
+This is a backport of f55a6faa384304c89cfef162768e88374d3312cb
+
+clock_was_set() cannot be called from hard interrupt context because
+it calls on_each_cpu().
+
+For fixing the widely reported leap seconds issue it is necessary to
+call it from hard interrupt context, i.e. the timer tick code, which
+does the timekeeping updates.
+
+Provide a new function which denotes it in the hrtimer cpu base
+structure of the cpu on which it is called and raise the hrtimer
+softirq. We then execute the clock_was_set() notificiation from
+softirq context in run_hrtimer_softirq(). The hrtimer softirq is
+rarely used, so polling the flag there is not a performance issue.
+
+[ tglx: Made it depend on CONFIG_HIGH_RES_TIMERS. We really should get
+ rid of all this ifdeffery ASAP ]
+
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+Reported-by: Jan Engelhardt <jengelh at inai.de>
+Reviewed-by: Ingo Molnar <mingo at kernel.org>
+Acked-by: Peter Zijlstra <a.p.zijlstra at chello.nl>
+Acked-by: Prarit Bhargava <prarit at redhat.com>
+Cc: stable at vger.kernel.org
+Link: http://lkml.kernel.org/r/1341960205-56738-2-git-send-email-johnstul@us.ibm.com
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ include/linux/hrtimer.h | 7 +++++++
+ kernel/hrtimer.c | 20 ++++++++++++++++++++
+ 2 files changed, 27 insertions(+)
+
+diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
+index 040b679..a7f48af 100644
+--- a/include/linux/hrtimer.h
++++ b/include/linux/hrtimer.h
+@@ -159,6 +159,7 @@ struct hrtimer_clock_base {
+ * and timers
+ * @clock_base: array of clock bases for this cpu
+ * @curr_timer: the timer which is executing a callback right now
++ * @clock_was_set: Indicates that clock was set from irq context.
+ * @expires_next: absolute time of the next event which was scheduled
+ * via clock_set_next_event()
+ * @hres_active: State of high resolution mode
+@@ -171,6 +172,7 @@ struct hrtimer_clock_base {
+ struct hrtimer_cpu_base {
+ spinlock_t lock;
+ struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
++ unsigned int clock_was_set;
+ #ifdef CONFIG_HIGH_RES_TIMERS
+ ktime_t expires_next;
+ int hres_active;
+@@ -280,6 +282,8 @@ extern void hrtimer_peek_ahead_timers(void);
+ # define MONOTONIC_RES_NSEC HIGH_RES_NSEC
+ # define KTIME_MONOTONIC_RES KTIME_HIGH_RES
+
++extern void clock_was_set_delayed(void);
++
+ #else
+
+ # define MONOTONIC_RES_NSEC LOW_RES_NSEC
+@@ -308,6 +312,9 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer)
+ {
+ return 0;
+ }
++
++static inline void clock_was_set_delayed(void) { }
++
+ #endif
+
+ extern ktime_t ktime_get(void);
+diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
+index a6e9d00..c4acec7 100644
+--- a/kernel/hrtimer.c
++++ b/kernel/hrtimer.c
+@@ -738,6 +738,19 @@ static int hrtimer_switch_to_hres(void)
+ return 1;
+ }
+
++/*
++ * Called from timekeeping code to reprogramm the hrtimer interrupt
++ * device. If called from the timer interrupt context we defer it to
++ * softirq context.
++ */
++void clock_was_set_delayed(void)
++{
++ struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
++
++ cpu_base->clock_was_set = 1;
++ __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
++}
++
+ #else
+
+ static inline int hrtimer_hres_active(void) { return 0; }
+@@ -1393,6 +1406,13 @@ void hrtimer_peek_ahead_timers(void)
+
+ static void run_hrtimer_softirq(struct softirq_action *h)
+ {
++ struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
++
++ if (cpu_base->clock_was_set) {
++ cpu_base->clock_was_set = 0;
++ clock_was_set();
++ }
++
+ hrtimer_peek_ahead_timers();
+ }
+
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0006-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0006-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,56 @@
+This is a backport of 4873fa070ae84a4115f0b3c9dfabc224f1bc7c51
+
+The timekeeping code misses an update of the hrtimer subsystem after a
+leap second happened. Due to that timers based on CLOCK_REALTIME are
+either expiring a second early or late depending on whether a leap
+second has been inserted or deleted until an operation is initiated
+which causes that update. Unless the update happens by some other
+means this discrepancy between the timekeeping and the hrtimer data
+stays forever and timers are expired either early or late.
+
+The reported immediate workaround - $ data -s "`date`" - is causing a
+call to clock_was_set() which updates the hrtimer data structures.
+See: http://www.sheeri.com/content/mysql-and-leap-second-high-cpu-and-fix
+
+Add the missing clock_was_set() call to update_wall_time() in case of
+a leap second event. The actual update is deferred to softirq context
+as the necessary smp function call cannot be invoked from hard
+interrupt context.
+
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+Reported-by: Jan Engelhardt <jengelh at inai.de>
+Reviewed-by: Ingo Molnar <mingo at kernel.org>
+Acked-by: Peter Zijlstra <a.p.zijlstra at chello.nl>
+Acked-by: Prarit Bhargava <prarit at redhat.com>
+Cc: stable at vger.kernel.org
+Link: http://lkml.kernel.org/r/1341960205-56738-3-git-send-email-johnstul@us.ibm.com
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ kernel/time/timekeeping.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index a969adf..1e9808d 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -790,6 +790,8 @@ void update_wall_time(void)
+ leap = second_overflow(xtime.tv_sec);
+ xtime.tv_sec += leap;
+ wall_to_monotonic.tv_sec -= leap;
++ if (leap)
++ clock_was_set_delayed();
+ }
+
+ raw_time.tv_nsec += timekeeper.raw_interval;
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0007-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0007-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,104 @@
+From: Thomas Gleixner <tglx at linutronix.de>
+
+This is a backport of 5b9fe759a678e05be4937ddf03d50e950207c1c0
+
+We need to update the hrtimer clock offsets from the hrtimer interrupt
+context. To avoid conversions from timespec to ktime_t maintain a
+ktime_t based representation of those offsets in the timekeeper. This
+puts the conversion overhead into the code which updates the
+underlying offsets and provides fast accessible values in the hrtimer
+interrupt.
+
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+Reviewed-by: Ingo Molnar <mingo at kernel.org>
+Acked-by: Peter Zijlstra <a.p.zijlstra at chello.nl>
+Acked-by: Prarit Bhargava <prarit at redhat.com>
+Cc: stable at vger.kernel.org
+Link: http://lkml.kernel.org/r/1341960205-56738-4-git-send-email-johnstul@us.ibm.com
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ kernel/time/timekeeping.c | 25 ++++++++++++++++++++++++-
+ 1 file changed, 24 insertions(+), 1 deletion(-)
+
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index 1e9808d..c7fbc9f 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -161,18 +161,34 @@ struct timespec xtime __attribute__ ((aligned (16)));
+ struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
+ static struct timespec total_sleep_time;
+
++/* Offset clock monotonic -> clock realtime */
++static ktime_t offs_real;
++
++/* Offset clock monotonic -> clock boottime */
++static ktime_t offs_boot;
++
+ /*
+ * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
+ */
+ struct timespec raw_time;
+
+ /* must hold write on xtime_lock */
++static void update_rt_offset(void)
++{
++ struct timespec tmp, *wtm = &wall_to_monotonic;
++
++ set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
++ offs_real = timespec_to_ktime(tmp);
++}
++
++/* must hold write on xtime_lock */
+ static void timekeeping_update(bool clearntp)
+ {
+ if (clearntp) {
+ timekeeper.ntp_error = 0;
+ ntp_clear();
+ }
++ update_rt_offset();
+ update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
+ }
+
+@@ -576,6 +592,7 @@ void __init timekeeping_init(void)
+ set_normalized_timespec(&wall_to_monotonic,
+ -boot.tv_sec, -boot.tv_nsec);
+ update_xtime_cache(0);
++ update_rt_offset();
+ total_sleep_time.tv_sec = 0;
+ total_sleep_time.tv_nsec = 0;
+ write_sequnlock_irqrestore(&xtime_lock, flags);
+@@ -584,6 +601,12 @@ void __init timekeeping_init(void)
+ /* time in seconds when suspend began */
+ static struct timespec timekeeping_suspend_time;
+
++static void update_sleep_time(struct timespec t)
++{
++ total_sleep_time = t;
++ offs_boot = timespec_to_ktime(t);
++}
++
+ /**
+ * timekeeping_resume - Resumes the generic timekeeping subsystem.
+ * @dev: unused
+@@ -607,7 +630,7 @@ static int timekeeping_resume(struct sys_device *dev)
+ ts = timespec_sub(ts, timekeeping_suspend_time);
+ xtime = timespec_add_safe(xtime, ts);
+ wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
+- total_sleep_time = timespec_add_safe(total_sleep_time, ts);
++ update_sleep_time(timespec_add_safe(total_sleep_time, ts));
+ }
+ update_xtime_cache(0);
+ /* re-base the last cycle value */
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0008-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0008-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,66 @@
+From: Thomas Gleixner <tglx at linutronix.de>
+
+This is a backport of 196951e91262fccda81147d2bcf7fdab08668b40
+
+We need to update the base offsets from this code and we need to do
+that under base->lock. Move the lock held region around the
+ktime_get() calls. The ktime_get() calls are going to be replaced with
+a function which gets the time and the offsets atomically.
+
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Reviewed-by: Ingo Molnar <mingo at kernel.org>
+Acked-by: Peter Zijlstra <a.p.zijlstra at chello.nl>
+Acked-by: Prarit Bhargava <prarit at redhat.com>
+Cc: stable at vger.kernel.org
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+Link: http://lkml.kernel.org/r/1341960205-56738-6-git-send-email-johnstul@us.ibm.com
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ kernel/hrtimer.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
+index c4acec7..8ba6d31 100644
+--- a/kernel/hrtimer.c
++++ b/kernel/hrtimer.c
+@@ -1263,11 +1263,10 @@ void hrtimer_interrupt(struct clock_event_device *dev)
+ cpu_base->nr_events++;
+ dev->next_event.tv64 = KTIME_MAX;
+
++ spin_lock(&cpu_base->lock);
+ entry_time = now = ktime_get();
+ retry:
+ expires_next.tv64 = KTIME_MAX;
+-
+- spin_lock(&cpu_base->lock);
+ /*
+ * We set expires_next to KTIME_MAX here with cpu_base->lock
+ * held to prevent that a timer is enqueued in our queue via
+@@ -1342,6 +1341,7 @@ retry:
+ * interrupt routine. We give it 3 attempts to avoid
+ * overreacting on some spurious event.
+ */
++ spin_lock(&cpu_base->lock);
+ now = ktime_get();
+ cpu_base->nr_retries++;
+ if (++retries < 3)
+@@ -1354,6 +1354,7 @@ retry:
+ */
+ cpu_base->nr_hangs++;
+ cpu_base->hang_detected = 1;
++ spin_unlock(&cpu_base->lock);
+ delta = ktime_sub(now, entry_time);
+ if (delta.tv64 > cpu_base->max_hang_time.tv64)
+ cpu_base->max_hang_time = delta;
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0009-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0009-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,91 @@
+From: Thomas Gleixner <tglx at linutronix.de>
+
+This is a backport of f6c06abfb3972ad4914cef57d8348fcb2932bc3b
+
+To finally fix the infamous leap second issue and other race windows
+caused by functions which change the offsets between the various time
+bases (CLOCK_MONOTONIC, CLOCK_REALTIME and CLOCK_BOOTTIME) we need a
+function which atomically gets the current monotonic time and updates
+the offsets of CLOCK_REALTIME and CLOCK_BOOTTIME with minimalistic
+overhead. The previous patch which provides ktime_t offsets allows us
+to make this function almost as cheap as ktime_get() which is going to
+be replaced in hrtimer_interrupt().
+
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Reviewed-by: Ingo Molnar <mingo at kernel.org>
+Acked-by: Peter Zijlstra <a.p.zijlstra at chello.nl>
+Acked-by: Prarit Bhargava <prarit at redhat.com>
+Cc: stable at vger.kernel.org
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+Link: http://lkml.kernel.org/r/1341960205-56738-7-git-send-email-johnstul@us.ibm.com
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ include/linux/hrtimer.h | 2 +-
+ kernel/time/timekeeping.c | 32 ++++++++++++++++++++++++++++++++
+ 2 files changed, 33 insertions(+), 1 deletion(-)
+
+diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
+index a7f48af..b4f0b3f 100644
+--- a/include/linux/hrtimer.h
++++ b/include/linux/hrtimer.h
+@@ -319,7 +319,7 @@ static inline void clock_was_set_delayed(void) { }
+
+ extern ktime_t ktime_get(void);
+ extern ktime_t ktime_get_real(void);
+-
++extern ktime_t ktime_get_update_offsets(ktime_t *offs_real);
+
+ DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
+
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index c7fbc9f..6054b94 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -943,3 +943,35 @@ struct timespec get_monotonic_coarse(void)
+ now.tv_nsec + mono.tv_nsec);
+ return now;
+ }
++
++#ifdef CONFIG_HIGH_RES_TIMERS
++/**
++ * ktime_get_update_offsets - hrtimer helper
++ * @real: pointer to storage for monotonic -> realtime offset
++ *
++ * Returns current monotonic time and updates the offsets
++ * Called from hrtimer_interupt() or retrigger_next_event()
++ */
++ktime_t ktime_get_update_offsets(ktime_t *real)
++{
++ ktime_t now;
++ unsigned int seq;
++ u64 secs, nsecs;
++
++ do {
++ seq = read_seqbegin(&xtime_lock);
++
++ secs = xtime.tv_sec;
++ nsecs = xtime.tv_nsec;
++ nsecs += timekeeping_get_ns();
++ /* If arch requires, add in gettimeoffset() */
++ nsecs += arch_gettimeoffset();
++
++ *real = offs_real;
++ } while (read_seqretry(&xtime_lock, seq));
++
++ now = ktime_add_ns(ktime_set(secs, 0), nsecs);
++ now = ktime_sub(now, *real);
++ return now;
++}
++#endif
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0010-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0010-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,130 @@
+This is a backport of 5baefd6d84163443215f4a99f6a20f054ef11236
+
+The update of the hrtimer base offsets on all cpus cannot be made
+atomically from the timekeeper.lock held and interrupt disabled region
+as smp function calls are not allowed there.
+
+clock_was_set(), which enforces the update on all cpus, is called
+either from preemptible process context in case of do_settimeofday()
+or from the softirq context when the offset modification happened in
+the timer interrupt itself due to a leap second.
+
+In both cases there is a race window for an hrtimer interrupt between
+dropping timekeeper lock, enabling interrupts and clock_was_set()
+issuing the updates. Any interrupt which arrives in that window will
+see the new time but operate on stale offsets.
+
+So we need to make sure that an hrtimer interrupt always sees a
+consistent state of time and offsets.
+
+ktime_get_update_offsets() allows us to get the current monotonic time
+and update the per cpu hrtimer base offsets from hrtimer_interrupt()
+to capture a consistent state of monotonic time and the offsets. The
+function replaces the existing ktime_get() calls in hrtimer_interrupt().
+
+The overhead of the new function vs. ktime_get() is minimal as it just
+adds two store operations.
+
+This ensures that any changes to realtime or boottime offsets are
+noticed and stored into the per-cpu hrtimer base structures, prior to
+any hrtimer expiration and guarantees that timers are not expired early.
+
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+Reviewed-by: Ingo Molnar <mingo at kernel.org>
+Acked-by: Peter Zijlstra <a.p.zijlstra at chello.nl>
+Acked-by: Prarit Bhargava <prarit at redhat.com>
+Cc: stable at vger.kernel.org
+Link: http://lkml.kernel.org/r/1341960205-56738-8-git-send-email-johnstul@us.ibm.com
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ kernel/hrtimer.c | 27 ++++++++++++---------------
+ 1 file changed, 12 insertions(+), 15 deletions(-)
+
+diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
+index 8ba6d31..2818422 100644
+--- a/kernel/hrtimer.c
++++ b/kernel/hrtimer.c
+@@ -603,6 +603,12 @@ static int hrtimer_reprogram(struct hrtimer *timer,
+ return res;
+ }
+
++static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
++{
++ ktime_t *offs_real = &base->clock_base[CLOCK_REALTIME].offset;
++
++ return ktime_get_update_offsets(offs_real);
++}
+
+ /*
+ * Retrigger next event is called after clock was set
+@@ -612,26 +618,15 @@ static int hrtimer_reprogram(struct hrtimer *timer,
+ static void retrigger_next_event(void *arg)
+ {
+ struct hrtimer_cpu_base *base;
+- struct timespec realtime_offset;
+- unsigned long seq;
+
+ if (!hrtimer_hres_active())
+ return;
+
+- do {
+- seq = read_seqbegin(&xtime_lock);
+- set_normalized_timespec(&realtime_offset,
+- -wall_to_monotonic.tv_sec,
+- -wall_to_monotonic.tv_nsec);
+- } while (read_seqretry(&xtime_lock, seq));
+-
+ base = &__get_cpu_var(hrtimer_bases);
+
+ /* Adjust CLOCK_REALTIME offset */
+ spin_lock(&base->lock);
+- base->clock_base[CLOCK_REALTIME].offset =
+- timespec_to_ktime(realtime_offset);
+-
++ hrtimer_update_base(base);
+ hrtimer_force_reprogram(base, 0);
+ spin_unlock(&base->lock);
+ }
+@@ -731,7 +726,6 @@ static int hrtimer_switch_to_hres(void)
+ base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES;
+
+ tick_setup_sched_timer();
+-
+ /* "Retrigger" the interrupt to get things going */
+ retrigger_next_event(NULL);
+ local_irq_restore(flags);
+@@ -1264,7 +1258,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
+ dev->next_event.tv64 = KTIME_MAX;
+
+ spin_lock(&cpu_base->lock);
+- entry_time = now = ktime_get();
++ entry_time = now = hrtimer_update_base(cpu_base);
+ retry:
+ expires_next.tv64 = KTIME_MAX;
+ /*
+@@ -1340,9 +1334,12 @@ retry:
+ * We need to prevent that we loop forever in the hrtimer
+ * interrupt routine. We give it 3 attempts to avoid
+ * overreacting on some spurious event.
++ *
++ * Acquire base lock for updating the offsets and retrieving
++ * the current time.
+ */
+ spin_lock(&cpu_base->lock);
+- now = ktime_get();
++ now = hrtimer_update_base(cpu_base);
+ cpu_base->nr_retries++;
+ if (++retries < 3)
+ goto retry;
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/bugfix/all/0011-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/bugfix/all/0011-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,57 @@
+From: Thomas Gleixner <tglx at linutronix.de>
+
+This is a backport of 3e997130bd2e8c6f5aaa49d6e3161d4d29b43ab0
+
+The leap second rework unearthed another issue of inconsistent data.
+
+On timekeeping_resume() the timekeeper data is updated, but nothing
+calls timekeeping_update(), so now the update code in the timer
+interrupt sees stale values.
+
+This has been the case before those changes, but then the timer
+interrupt was using stale data as well so this went unnoticed for quite
+some time.
+
+Add the missing update call, so all the data is consistent everywhere.
+
+Reported-by: Andreas Schwab <schwab at linux-m68k.org>
+Reported-and-tested-by: "Rafael J. Wysocki" <rjw at sisk.pl>
+Reported-and-tested-by: Martin Steigerwald <Martin at lichtvoll.de>
+Cc: LKML <linux-kernel at vger.kernel.org>
+Cc: Linux PM list <linux-pm at vger.kernel.org>
+Cc: John Stultz <johnstul at us.ibm.com>
+Cc: Ingo Molnar <mingo at kernel.org>
+Cc: Peter Zijlstra <a.p.zijlstra at chello.nl>,
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: stable at vger.kernel.org
+Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
+Cc: Prarit Bhargava <prarit at redhat.com>
+Cc: Thomas Gleixner <tglx at linutronix.de>
+Cc: Linux Kernel <linux-kernel at vger.kernel.org>
+Signed-off-by: John Stultz <johnstul at us.ibm.com>
+---
+ kernel/time/timekeeping.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
+index 6054b94..3f7e53f 100644
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -637,6 +637,7 @@ static int timekeeping_resume(struct sys_device *dev)
+ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
+ timekeeper.ntp_error = 0;
+ timekeeping_suspended = 0;
++ timekeeping_update(false);
+ write_sequnlock_irqrestore(&xtime_lock, flags);
+
+ touch_softlockup_watchdog();
+--
+1.7.9.5
+
+--
+To unsubscribe from this list: send the line "unsubscribe stable" in
+the body of a message to majordomo at vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
+
Added: dists/squeeze/linux-2.6/debian/patches/debian/timer-Avoid_ABI-change-from-leap-second-fix.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/squeeze/linux-2.6/debian/patches/debian/timer-Avoid_ABI-change-from-leap-second-fix.patch Tue Sep 11 05:15:38 2012 (r19377)
@@ -0,0 +1,34 @@
+diff -urpN a/include/linux/hrtimer.h b/include/linux/hrtimer.h
+--- a/include/linux/hrtimer.h 2012-09-09 17:27:07.607070035 -0600
++++ b/include/linux/hrtimer.h 2012-09-09 17:30:51.185934452 -0600
+@@ -159,7 +159,6 @@ struct hrtimer_clock_base {
+ * and timers
+ * @clock_base: array of clock bases for this cpu
+ * @curr_timer: the timer which is executing a callback right now
+- * @clock_was_set: Indicates that clock was set from irq context.
+ * @expires_next: absolute time of the next event which was scheduled
+ * via clock_set_next_event()
+ * @hres_active: State of high resolution mode
+@@ -168,11 +167,11 @@ struct hrtimer_clock_base {
+ * @nr_retries: Total number of hrtimer interrupt retries
+ * @nr_hangs: Total number of hrtimer interrupt hangs
+ * @max_hang_time: Maximum time spent in hrtimer_interrupt
++ * @clock_was_set: Indicates that clock was set from irq context.
+ */
+ struct hrtimer_cpu_base {
+ spinlock_t lock;
+ struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
+- unsigned int clock_was_set;
+ #ifdef CONFIG_HIGH_RES_TIMERS
+ ktime_t expires_next;
+ int hres_active;
+@@ -182,6 +181,9 @@ struct hrtimer_cpu_base {
+ unsigned long nr_hangs;
+ ktime_t max_hang_time;
+ #endif
++#ifndef __GENKSYMS__
++ unsigned int clock_was_set;
++#endif
+ };
+
+ static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
Modified: dists/squeeze/linux-2.6/debian/patches/series/46
==============================================================================
--- dists/squeeze/linux-2.6/debian/patches/series/46 Mon Sep 10 04:01:03 2012 (r19376)
+++ dists/squeeze/linux-2.6/debian/patches/series/46 Tue Sep 11 05:15:38 2012 (r19377)
@@ -20,3 +20,15 @@
+ bugfix/all/drm-radeon-kms-fix-MSI-re-arm-on-rv370.patch
+ features/all/sky2/0057-sky2-override-for-PCI-legacy-power-management.patch
+ features/arm/ahci-Add-JMicron-362-device-IDs.patch
++ bugfix/all/0001-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0002-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0003-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0004-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0005-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0006-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0007-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0008-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0009-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0010-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ bugfix/all/0011-Fix-for-leap-second-deadlock-and-hrtimer-futex-issue.patch
++ debian/timer-Avoid_ABI-change-from-leap-second-fix.patch
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