From 6ec3cfeca04622e3d80c9270191cd7f5f88214af Mon Sep 17 00:00:00 2001 From: "Pallipadi, Venkatesh" Date: Mon, 13 Apr 2009 15:20:58 -0700 Subject: x86, irq: Remove IRQ_DISABLED check in process context IRQ move As discussed in the thread here: http://marc.info/?l=linux-kernel&m=123964468521142&w=2 Eric W. Biederman observed: > It looks like some additional bugs have slipped in since last I looked. > > set_irq_affinity does this: > ifdef CONFIG_GENERIC_PENDING_IRQ > if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { > cpumask_copy(desc->affinity, cpumask); > desc->chip->set_affinity(irq, cpumask); > } else { > desc->status |= IRQ_MOVE_PENDING; > cpumask_copy(desc->pending_mask, cpumask); > } > #else > > That IRQ_DISABLED case is a software state and as such it has nothing to > do with how safe it is to move an irq in process context. [...] > > The only reason we migrate MSIs in interrupt context today is that there > wasn't infrastructure for support migration both in interrupt context > and outside of it. Yes. The idea here was to force the MSI migration to happen in process context. One of the patches in the series did disable_irq(dev->irq); irq_set_affinity(dev->irq, cpumask_of(dev->cpu)); enable_irq(dev->irq); with the above patch adding irq/manage code check for interrupt disabled and moving the interrupt in process context. IIRC, there was no IRQ_MOVE_PCNTXT when we were developing this HPET code and we ended up having this ugly hack. IRQ_MOVE_PCNTXT was there when we eventually submitted the patch upstream. But, looks like I did a blind rebasing instead of using IRQ_MOVE_PCNTXT in hpet MSI code. Below patch fixes this. i.e., revert commit 932775a4ab622e3c99bd59f14cc and add PCNTXT to HPET MSI setup. Also removes copying of desc->affinity in generic code as set_affinity routines are doing it internally. Reported-by: "Eric W. Biederman" Signed-off-by: Venkatesh Pallipadi Acked-by: "Eric W. Biederman" Cc: "Li Shaohua" Cc: Gary Hade Cc: "lcm@us.ibm.com" Cc: suresh.b.siddha@intel.com LKML-Reference: <20090413222058.GB8211@linux-os.sc.intel.com> Signed-off-by: Ingo Molnar --- kernel/irq/manage.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 7e2e7dd4cd2f..2734eca59243 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -109,10 +109,9 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) spin_lock_irqsave(&desc->lock, flags); #ifdef CONFIG_GENERIC_PENDING_IRQ - if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { - cpumask_copy(desc->affinity, cpumask); + if (desc->status & IRQ_MOVE_PCNTXT) desc->chip->set_affinity(irq, cpumask); - } else { + else { desc->status |= IRQ_MOVE_PENDING; cpumask_copy(desc->pending_mask, cpumask); } -- cgit v1.2.3 From c8a250058656495be02c00de61e26b017c86ef00 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 17 Apr 2009 09:40:49 +0200 Subject: lockdep: more robust lockdep_map init sequence Steven Rostedt reported: > OK, I think I figured this bug out. This is a lockdep issue with respect > to tracepoints. > > The trace points in lockdep are called all the time. Outside the lockdep > logic. But if lockdep were to trigger an error / warning (which this run > did) we might be in trouble. For new locks, like the dentry->d_lock, that > are created, they will not get a name: > > void lockdep_init_map(struct lockdep_map *lock, const char *name, > struct lock_class_key *key, int subclass) > { > if (unlikely(!debug_locks)) > return; > > When a problem is found by lockdep, debug_locks becomes false. Thus we > stop allocating names for locks. This dentry->d_lock I had, now has no > name. Worse yet, I have CONFIG_DEBUG_VM set, that scrambles non > initialized memory. Thus, when the trace point was hit, it had junk for > the lock->name, and the machine crashed. Ah, nice catch. I think we should put at least the name in regardless. Ensure we at least initialize the trivial entries of the depmap so that they can be relied upon, even when lockdep itself decided to pack up and go home. [ Impact: fix lock tracing after lockdep warnings. ] Reported-by: Steven Rostedt Signed-off-by: Peter Zijlstra Acked-by: Steven Rostedt Cc: Andrew Morton Cc: Frederic Weisbecker LKML-Reference: <1239954049.23397.4156.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index b0f011866969..accb40cdb12a 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2490,13 +2490,20 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, void lockdep_init_map(struct lockdep_map *lock, const char *name, struct lock_class_key *key, int subclass) { - if (unlikely(!debug_locks)) + lock->class_cache = NULL; +#ifdef CONFIG_LOCK_STAT + lock->cpu = raw_smp_processor_id(); +#endif + + if (DEBUG_LOCKS_WARN_ON(!name)) { + lock->name = "NULL"; return; + } + + lock->name = name; if (DEBUG_LOCKS_WARN_ON(!key)) return; - if (DEBUG_LOCKS_WARN_ON(!name)) - return; /* * Sanity check, the lock-class key must be persistent: */ @@ -2505,12 +2512,11 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name, DEBUG_LOCKS_WARN_ON(1); return; } - lock->name = name; lock->key = key; - lock->class_cache = NULL; -#ifdef CONFIG_LOCK_STAT - lock->cpu = raw_smp_processor_id(); -#endif + + if (unlikely(!debug_locks)) + return; + if (subclass) register_lock_class(lock, subclass, 1); } -- cgit v1.2.3 From 24b6f16ecf37f918a1934d590e9e71c100d6388f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 18 Apr 2009 03:25:41 -0400 Subject: No need for crossing to mountpoint in audit_tag_tree() is_under() will DTRT anyway. And yes, is_subdir() behaviour is intentional. Signed-off-by: Al Viro --- kernel/audit_tree.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'kernel') diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index 917ab9525568..6e7351739a82 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -734,9 +734,6 @@ int audit_tag_tree(char *old, char *new) dentry = dget(path.dentry); path_put(&path); - if (dentry == tagged->mnt_root && dentry == mnt->mnt_root) - follow_up(&mnt, &dentry); - list_add_tail(&list, &tagged->mnt_list); mutex_lock(&audit_filter_mutex); -- cgit v1.2.3 From 8e19608e8b5c001e4a66ce482edc474f05fb7355 Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Tue, 21 Apr 2009 12:24:00 -0700 Subject: clocksource: pass clocksource to read() callback Pass clocksource pointer to the read() callback for clocksources. This allows us to share the callback between multiple instances. [hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods] [akpm@linux-foundation.org: cleanup] Signed-off-by: Magnus Damm Acked-by: John Stultz Cc: Thomas Gleixner Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/time/clocksource.c | 8 ++++---- kernel/time/jiffies.c | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index c46c931a7fe7..ecfd7b5187e0 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -181,12 +181,12 @@ static void clocksource_watchdog(unsigned long data) resumed = test_and_clear_bit(0, &watchdog_resumed); - wdnow = watchdog->read(); + wdnow = watchdog->read(watchdog); wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask); watchdog_last = wdnow; list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) { - csnow = cs->read(); + csnow = cs->read(cs); if (unlikely(resumed)) { cs->wd_last = csnow; @@ -247,7 +247,7 @@ static void clocksource_check_watchdog(struct clocksource *cs) list_add(&cs->wd_list, &watchdog_list); if (!started && watchdog) { - watchdog_last = watchdog->read(); + watchdog_last = watchdog->read(watchdog); watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask)); @@ -268,7 +268,7 @@ static void clocksource_check_watchdog(struct clocksource *cs) cse->flags &= ~CLOCK_SOURCE_WATCHDOG; /* Start if list is not empty */ if (!list_empty(&watchdog_list)) { - watchdog_last = watchdog->read(); + watchdog_last = watchdog->read(watchdog); watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; add_timer_on(&watchdog_timer, diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index 06f197560f3b..c3f6c30816e3 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -50,7 +50,7 @@ */ #define JIFFIES_SHIFT 8 -static cycle_t jiffies_read(void) +static cycle_t jiffies_read(struct clocksource *cs) { return (cycle_t) jiffies; } -- cgit v1.2.3 From 4614e6adafa2c5e6c3a9c245af2807fa7bc5117a Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Tue, 21 Apr 2009 12:24:02 -0700 Subject: clocksource: add enable() and disable() callbacks Add enable() and disable() callbacks for clocksources. This allows us to put unused clocksources in power save mode. The functions clocksource_enable() and clocksource_disable() wrap the callbacks and are inserted in the timekeeping code to enable before use and disable after switching to a new clocksource. Signed-off-by: Magnus Damm Acked-by: John Stultz Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/time/timekeeping.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 900f1b6598d1..687dff49f6e7 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -182,7 +182,7 @@ EXPORT_SYMBOL(do_settimeofday); */ static void change_clocksource(void) { - struct clocksource *new; + struct clocksource *new, *old; new = clocksource_get_next(); @@ -191,11 +191,16 @@ static void change_clocksource(void) clocksource_forward_now(); - new->raw_time = clock->raw_time; + if (clocksource_enable(new)) + return; + new->raw_time = clock->raw_time; + old = clock; clock = new; + clocksource_disable(old); + clock->cycle_last = 0; - clock->cycle_last = clocksource_read(new); + clock->cycle_last = clocksource_read(clock); clock->error = 0; clock->xtime_nsec = 0; clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); @@ -292,6 +297,7 @@ void __init timekeeping_init(void) ntp_init(); clock = clocksource_get_next(); + clocksource_enable(clock); clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); clock->cycle_last = clocksource_read(clock); -- cgit v1.2.3 From b48ccb095a0c9257241261ec2bd1cbb1bdabc48b Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 23 Apr 2009 09:36:52 +0200 Subject: locking: clarify kernel-taint warning message Andi Kleen reported this message triggering on non-lockdep kernels: Disabling lockdep due to kernel taint Clarify the message to say 'lock debugging' - debug_locks_off() turns off all things lock debugging, not just lockdep. [ Impact: change kernel warning message text ] Reported-by: Andi Kleen Cc: Peter Zijlstra Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/panic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/panic.c b/kernel/panic.c index 934fb377f4b3..3dcaa1661357 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -221,7 +221,7 @@ void add_taint(unsigned flag) * post-warning case. */ if (flag != TAINT_CRAP && flag != TAINT_WARN && __debug_locks_off()) - printk(KERN_WARNING "Disabling lockdep due to kernel taint\n"); + printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n"); set_bit(flag, &tainted_mask); } -- cgit v1.2.3 From 418df63c2d94f238ac7e1d1d53be35dd6b7a7252 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Wed, 22 Apr 2009 12:01:49 +0100 Subject: Delete slow-work timers properly Slow-work appears to delete its timer as soon as the first user unregisters, even though other users could be active. At the same time, it never seems to delete slow_work_oom_timer. Arrange for both to happen in the shutdown path. Signed-off-by: Jonathan Corbet Signed-off-by: David Howells Signed-off-by: Linus Torvalds --- kernel/slow-work.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/slow-work.c b/kernel/slow-work.c index cf2bc01186ef..b28d19135f43 100644 --- a/kernel/slow-work.c +++ b/kernel/slow-work.c @@ -609,14 +609,14 @@ void slow_work_unregister_user(void) if (slow_work_user_count == 0) { printk(KERN_NOTICE "Slow work thread pool: Shutting down\n"); slow_work_threads_should_exit = true; + del_timer_sync(&slow_work_cull_timer); + del_timer_sync(&slow_work_oom_timer); wake_up_all(&slow_work_thread_wq); wait_for_completion(&slow_work_last_thread_exited); printk(KERN_NOTICE "Slow work thread pool:" " Shut down complete\n"); } - del_timer_sync(&slow_work_cull_timer); - mutex_unlock(&slow_work_user_lock); } EXPORT_SYMBOL(slow_work_unregister_user); -- cgit v1.2.3 From 0c8454f56623505a99463405fd7d5664adfbb094 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 25 Apr 2009 00:16:06 +0200 Subject: PM/Hibernate: Fix waiting for image device to appear on resume Commit c751085943362143f84346d274e0011419c84202 ("PM/Hibernate: Wait for SCSI devices scan to complete during resume") added a call to scsi_complete_async_scans() to software_resume(), so that it waited for the SCSI scanning to complete, but the call was added at a wrong place. Namely, it should have been added after wait_for_device_probe(), which is called only if the image partition hasn't been specified yet. Also, it's reasonable to check if the image partition is present and only wait for the device probing and SCSI scanning to complete if it is not the case. Additionally, since noresume is checked right at the beginning of software_resume() and the function returns immediately if it's set, it doesn't make sense to check it once again later. Signed-off-by: Rafael J. Wysocki Signed-off-by: Linus Torvalds --- kernel/power/disk.c | 51 +++++++++++++++++++++++++++------------------------ 1 file changed, 27 insertions(+), 24 deletions(-) (limited to 'kernel') diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 0854770b63b9..e71ca9cd81b2 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -645,13 +645,6 @@ static int software_resume(void) if (noresume) return 0; - /* - * We can't depend on SCSI devices being available after loading one of - * their modules if scsi_complete_async_scans() is not called and the - * resume device usually is a SCSI one. - */ - scsi_complete_async_scans(); - /* * name_to_dev_t() below takes a sysfs buffer mutex when sysfs * is configured into the kernel. Since the regular hibernate @@ -663,32 +656,42 @@ static int software_resume(void) * here to avoid lockdep complaining. */ mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING); + + if (swsusp_resume_device) + goto Check_image; + + if (!strlen(resume_file)) { + error = -ENOENT; + goto Unlock; + } + + pr_debug("PM: Checking image partition %s\n", resume_file); + + /* Check if the device is there */ + swsusp_resume_device = name_to_dev_t(resume_file); if (!swsusp_resume_device) { - if (!strlen(resume_file)) { - mutex_unlock(&pm_mutex); - return -ENOENT; - } /* * Some device discovery might still be in progress; we need * to wait for this to finish. */ wait_for_device_probe(); + /* + * We can't depend on SCSI devices being available after loading + * one of their modules until scsi_complete_async_scans() is + * called and the resume device usually is a SCSI one. + */ + scsi_complete_async_scans(); + swsusp_resume_device = name_to_dev_t(resume_file); - pr_debug("PM: Resume from partition %s\n", resume_file); - } else { - pr_debug("PM: Resume from partition %d:%d\n", - MAJOR(swsusp_resume_device), - MINOR(swsusp_resume_device)); + if (!swsusp_resume_device) { + error = -ENODEV; + goto Unlock; + } } - if (noresume) { - /** - * FIXME: If noresume is specified, we need to find the - * partition and reset it back to normal swap space. - */ - mutex_unlock(&pm_mutex); - return 0; - } + Check_image: + pr_debug("PM: Resume from partition %d:%d\n", + MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); pr_debug("PM: Checking hibernation image.\n"); error = swsusp_check(); -- cgit v1.2.3 From cad81bc2529ab8c62b6fdc83a1c0c7f4a87209eb Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 27 Apr 2009 01:41:34 +0200 Subject: ptrace: ptrace_attach: fix the usage of ->cred_exec_mutex ptrace_attach() needs task->cred_exec_mutex, not current->cred_exec_mutex. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Acked-by: David Howells Signed-off-by: James Morris --- kernel/ptrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index dfcd83ceee3b..0692ab5a0d67 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -188,7 +188,7 @@ int ptrace_attach(struct task_struct *task) /* Protect exec's credential calculations against our interference; * SUID, SGID and LSM creds get determined differently under ptrace. */ - retval = mutex_lock_interruptible(¤t->cred_exec_mutex); + retval = mutex_lock_interruptible(&task->cred_exec_mutex); if (retval < 0) goto out; @@ -232,7 +232,7 @@ repeat: bad: write_unlock_irqrestore(&tasklist_lock, flags); task_unlock(task); - mutex_unlock(¤t->cred_exec_mutex); + mutex_unlock(&task->cred_exec_mutex); out: return retval; } -- cgit v1.2.3