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2006-11-03[PATCH] fill_tgid: fix task_struct leak and possible oopsOleg Nesterov
1. fill_tgid() forgets to do put_task_struct(first). 2. release_task(first) can happen after fill_tgid() drops tasklist_lock, it is unsafe to dereference first->signal. This is a temporary fix, imho the locking should be reworked. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@sgi.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2006-11-03[PATCH] posix-cpu-timers: prevent signal delivery starvationThomas Gleixner
The integer divisions in the timer accounting code can round the result down to 0. Adding 0 is without effect and the signal delivery stops. Clamp the division result to minimum 1 to avoid this. Problem was reported by Seongbae Park <spark@google.com>, who provided also an inital patch. Roland sayeth: I have had some more time to think about the problem, and to reproduce it using Toyo's test case. For the record, if my understanding of the problem is correct, this happens only in one very particular case. First, the expiry time has to be so soon that in cputime_t units (usually 1s/HZ ticks) it's < nthreads so the division yields zero. Second, it only affects each thread that is so new that its CPU time accumulation is zero so now+0 is still zero and ->it_*_expires winds up staying zero. For the VIRT and PROF clocks when cputime_t is tick granularity (or the SCHED clock on configurations where sched_clock's value only advances on clock ticks), this is not hard to arrange with new threads starting up and blocking before they accumulate a whole tick of CPU time. That's what happens in Toyo's test case. Note that in general it is fine for that division to round down to zero, and set each thread's expiry time to its "now" time. The problem only arises with thread's whose "now" value is still zero, so that now+0 winds up 0 and is interpreted as "not set" instead of ">= now". So it would be a sufficient and more precise fix to just use max(ticks, 1) inside the loop when setting each it_*_expires value. But, it does no harm to round the division up to one and always advance every thread's expiry time. If the thread didn't already fire timers for the expiry time of "now", there is no expectation that it will do so before the next tick anyway. So I followed Thomas's patch in lifting the max out of the loops. This patch also covers the reload cases, which are harder to write a test for (and I didn't try). I've tested it with Toyo's case and it fixes that. [toyoa@mvista.com: fix: min_t -> max_t] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Daniel Walker <dwalker@mvista.com> Cc: Toyo Abe <toyoa@mvista.com> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Seongbae Park <spark@google.com> Cc: Peter Mattis <pmattis@google.com> Cc: Rohit Seth <rohitseth@google.com> Cc: Martin Bligh <mbligh@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2006-10-13load_module: no BUG if module_subsys uninitializedEd Swierk
Invoking load_module() before param_sysfs_init() is called crashes in mod_sysfs_setup(), since the kset in module_subsys is not initialized yet. In my case, net-pf-1 is getting modprobed as a result of hotplug trying to create a UNIX socket. Calls to hotplug begin after the topology_init initcall. Another patch for the same symptom (module_subsys-initialize-earlier.patch) moves param_sysfs_init() to the subsys initcalls, but this is still not early enough in the boot process in some cases. In particular, topology_init() causes /sbin/hotplug to run, which requests net-pf-1 (the UNIX socket protocol) which can be compiled as a module. Moving param_sysfs_init() to the postcore initcalls fixes this particular race, but there might well be other cases where a usermodehelper causes a module to load earlier still. The patch makes load_module() return an error rather than crashing the kernel if invoked before module_subsys is initialized. Cc: Mark Huang <mlhuang@cs.princeton.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-13zone_reclaim: dynamic slab reclaimChristoph Lameter
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=0ff38490c836dc379ff7ec45b10a15a662f4e5f6 Currently one can enable slab reclaim by setting an explicit option in /proc/sys/vm/zone_reclaim_mode. Slab reclaim is then used as a final option if the freeing of unmapped file backed pages is not enough to free enough pages to allow a local allocation. However, that means that the slab can grow excessively and that most memory of a node may be used by slabs. We have had a case where a machine with 46GB of memory was using 40-42GB for slab. Zone reclaim was effective in dealing with pagecache pages. However, slab reclaim was only done during global reclaim (which is a bit rare on NUMA systems). This patch implements slab reclaim during zone reclaim. Zone reclaim occurs if there is a danger of an off node allocation. At that point we 1. Shrink the per node page cache if the number of pagecache pages is more than min_unmapped_ratio percent of pages in a zone. 2. Shrink the slab cache if the number of the nodes reclaimable slab pages (patch depends on earlier one that implements that counter) are more than min_slab_ratio (a new /proc/sys/vm tunable). The shrinking of the slab cache is a bit problematic since it is not node specific. So we simply calculate what point in the slab we want to reach (current per node slab use minus the number of pages that neeed to be allocated) and then repeately run the global reclaim until that is unsuccessful or we have reached the limit. I hope we will have zone based slab reclaim at some point which will make that easier. The default for the min_slab_ratio is 5% Also remove the slab option from /proc/sys/vm/zone_reclaim_mode. [akpm@osdl.org: cleanups] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-13Fix longstanding load balancing bug in the schedulerChristoph Lameter
The scheduler will stop load balancing if the most busy processor contains processes pinned via processor affinity. The scheduler currently only does one search for busiest cpu. If it cannot pull any tasks away from the busiest cpu because they were pinned then the scheduler goes into a corner and sulks leaving the idle processors idle. F.e. If you have processor 0 busy running four tasks pinned via taskset, there are none on processor 1 and one just started two processes on processor 2 then the scheduler will not move one of the two processes away from processor 2. This patch fixes that issue by forcing the scheduler to come out of its corner and retrying the load balancing by considering other processors for load balancing. This patch was originally developed by John Hawkes and discussed at http://marc.theaimsgroup.com/?l=linux-kernel&m=113901368523205&w=2. I have removed extraneous material and gone back to equipping struct rq with the cpu the queue is associated with since this makes the patch much easier and it is likely that others in the future will have the same difficulty of figuring out which processor owns which runqueue. The overhead added through these patches is a single word on the stack if the kernel is configured to support 32 cpus or less (32 bit). For 32 bit environments the maximum number of cpus that can be configued is 255 which would result in the use of 32 bytes additional on the stack. On IA64 up to 1k cpus can be configured which will result in the use of 128 additional bytes on the stack. The maximum additional cache footprint is one cacheline. Typically memory use will be much less than a cacheline and the additional cpumask will be placed on the stack in a cacheline that already contains other local variable. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: John Hawkes <hawkes@sgi.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-19[PATCH] genirq core: fix handle_level_irq()Ingo Molnar
while porting the -rt tree to 2.6.18-rc7 i noticed the following screaming-IRQ scenario on an SMP system: 2274 0Dn.:1 0.001ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.010ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.020ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.029ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.039ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.048ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.058ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.068ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.077ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.087ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) 2274 0Dn.:1 0.097ms: do_IRQ+0xc/0x103 <= (ret_from_intr+0x0/0xf) as it turns out, the bug is caused by handle_level_irq(), which if it races with another CPU already handling this IRQ, it _unmasks_ the IRQ line on the way out. This is not how 2.6.17 works, and we introduced this bug in one of the early genirq cleanups right before it went into -mm. (the bug was not in the genirq patchset for a long time, and we didnt notice the bug due to the lack of -rt rebase to the new genirq code. -rt, and hardirq-preemption in particular opens up such races much wider than anything else.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-16[PATCH] bug fix in kernel/kmod.cKenneth Lee
I think there is a bug in kmod.c: In __call_usermodehelper(), when kernel_thread(wait_for_helper, ...) return success, since wait_for_helper() might call complete() at any time, the sub_info should not be used any more. Normally wait_for_helper() take a long time to finish, you may not get problem for most of the case. But if you remove /sbin/modprobe, it may become easier for you to get a oop in khelper. Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-16[PATCH] genirq: fix typo in IRQ resendImre Deak
Fix a bug where the IRQ_PENDING flag is never cleared and the ISR is called endlessly without an actual interrupt. Signed-off-by: Imre Deak <imre.deak@solidboot.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-13[PATCH] rcu_do_batch: make ->qlen decrement irq safeOleg Nesterov
rcu_do_batch() decrements rdp->qlen with irqs enabled. This is not good, it can also be modified by call_rcu() from interrupt. Decrement ->qlen once with irqs disabled, after a main loop. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-13[PATCH] lockdep: double the number of stack-trace entriesIngo Molnar
Miles Lane reported the "BUG: MAX_STACK_TRACE_ENTRIES too low!" message, which means that during normal use his system produced enough lockdep events so that the 128-thousand entries stack-trace array got exhausted. Double the size of the array. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Miles Lane <miles.lane@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-11[PATCH] audit: AUDIT_PERM supportAl Viro
add support for AUDIT_PERM predicate Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-09-11[PATCH] update audit rule change messagesAmy Griffis
Make the audit message for implicit rule removal more informative. Make the rule update message consistent with other messages. Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-09-11[PATCH] sanity check audit_bufferAmy Griffis
Add sanity checks for NULL audit_buffer consistent with other audit_log* routines. Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-09-11[PATCH] fix ppid bug in 2.6.18 kernelSteve Grubb
Hello, During some troubleshooting, I found that ppid was accidentally omitted from the legacy rule section. This resulted in EINVAL for any rule with ppid sent with AUDIT_ADD. Signed-off-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-09-08[PATCH] Use the correct restart option for futex_lock_piThomas Gleixner
The current implementation of futex_lock_pi returns -ERESTART_RESTARTBLOCK in case that the lock operation has been interrupted by a signal. This results in a return of -EINTR to userspace in case there is an handler for the signal. This is wrong, because userspace expects that the lock function does not return in any case of signal delivery. This was not caught by my insufficient test case, but triggered a nasty userspace problem in an high load application scenario. Unfortunately also glibc does not check for this invalid return value. Using -ERSTARTNOINTR makes sure, that the interrupted syscall is restarted. The restart block related code can be safely removed, as the possible timeout argument is an absolute time value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-06[PATCH] lockdep: do not touch console state when tainting the kernelIngo Molnar
Remove an unintended console_verbose() side-effect from add_taint(). Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-06[PATCH] prevent swsusp with PAEPavel Machek
PAE + swsusp results in hard-to-debug crash about 50% of time during resume. Cause is known, fix needs to be ported from x86-64 (but we can't make it to 2.6.18, and I'd like this to be worked around in 2.6.18). Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-06[PATCH] lockdep ifdef fixJarek Poplawski
With CONFIG_SMP=y CONFIG_PREEMPT=y CONFIG_LOCKDEP=y CONFIG_DEBUG_LOCK_ALLOC=y # CONFIG_PROVE_LOCKING is not set spin_unlock_irqrestore() goes through lockdep but spin_lock_irqsave() doesn't. Apparently, bad things happen. Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-02[PATCH] eligible_child: remove an obsolete ->tgid checkOleg Nesterov
It is not possible to find a sub-thread in ->children/->ptrace_children lists, ptrace_attach() does not allow to attach to sub-threads. Even if it was possible to ptrace the task from the same thread group, we can't allow to release ->group_leader while there are others (ptracer) threads in the same group. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-01[PATCH] kerneldoc for handle_bad_irq()Henrik Kretzschmar
Adds the description of the parameters from handle_bad_irq(). Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-01[PATCH] task delay accounting fixesShailabh Nagar
Cleanup allocation and freeing of tsk->delays used by delay accounting. This solves two problems reported for delay accounting: 1. oops in __delayacct_blkio_ticks http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1844.html Currently tsk->delays is getting freed too early in task exit which can cause a NULL tsk->delays to get accessed via reading of /proc/<tgid>/stats. The patch fixes this problem by freeing tsk->delays closer to when task_struct itself is freed up. As a result, it also eliminates the use of tsk->delays_lock which was only being used (inadequately) to safeguard access to tsk->delays while a task was exiting. 2. Possible memory leak in kernel/delayacct.c http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1389.html The patch cleans up tsk->delays allocations after a bad fork which was missing earlier. The patch has been tested to fix the problems listed above and stress tested with rapid calls to delay accounting's taskstats command interface (which is the other path that can access the same data, besides the /proc interface causing the oops above). Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] cpuset: oom panic fixNick Piggin
cpuset_excl_nodes_overlap always returns 0 if current is exiting. This caused customer's systems to panic in the OOM killer when processes were having trouble getting memory for the final put_user in mm_release. Even though there were lots of processes to kill. Change to returning 1 in this case. This achieves parity with !CONFIG_CPUSETS case, and was observed to fix the problem. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] cpuset: top_cpuset tracks hotplug changes to cpu_online_mapPaul Jackson
Change the list of cpus allowed to tasks in the top (root) cpuset to dynamically track what cpus are online, using a CPU hotplug notifier. Make this top cpus file read-only. On systems that have cpusets configured in their kernel, but that aren't actively using cpusets (for some distros, this covers the majority of systems) all tasks end up in the top cpuset. If that system does support CPU hotplug, then these tasks cannot make use of CPUs that are added after system boot, because the CPUs are not allowed in the top cpuset. This is a surprising regression over earlier kernels that didn't have cpusets enabled. In order to keep the behaviour of cpusets consistent between systems actively making use of them and systems not using them, this patch changes the behaviour of the 'cpus' file in the top (root) cpuset, making it read only, and making it automatically track the value of cpu_online_map. Thus tasks in the top cpuset will have automatic use of hot plugged CPUs allowed by their cpuset. Thanks to Anton Blanchard and Nathan Lynch for reporting this problem, driving the fix, and earlier versions of this patch. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: Nathan Lynch <ntl@pobox.com> Cc: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] Remove redundant up() in stop_machine()Yingchao Zhou
An up() is called in kernel/stop_machine.c on failure, and also in the caller (unconditionally). Signed-off-by: Zhou Yingchao <yingchao.zhou@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] futex_find_get_task(): remove an obscure EXIT_ZOMBIE checkOleg Nesterov
futex_find_get_task: if (p->state == EXIT_ZOMBIE || p->exit_state == EXIT_ZOMBIE) return NULL; I can't understand this. First, p->state can't be EXIT_ZOMBIE. The ->exit_state check looks strange too. Sub-threads or tasks whose ->parent ignores SIGCHLD go directly to EXIT_DEAD state (I am ignoring a ptrace case). Why EXIT_DEAD tasks should be ok? Yes, EXIT_ZOMBIE is more important (a task may stay zombie for a long time), but this doesn't mean we should explicitely ignore other EXIT_XXX states. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] revert "Drop tasklist lock in do_sched_setscheduler"Oleg Nesterov
sched_setscheduler() looks at ->signal->rlim[]. It is unsafe do dereference ->signal unless tasklist_lock or ->siglock is held (or p == current). We pin the task structure, but this can't prevent from release_task()->__exit_signal() which sets ->signal = NULL. Restore tasklist_lock across the setscheduler call. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-14[PATCH] workqueue: remove lock_cpu_hotplug()Andrew Morton
Use a private lock instead. It protects all per-cpu data structures in workqueue.c, including the workqueues list. Fix a bug in schedule_on_each_cpu(): it was forgetting to lock down the per-cpu resources. Unfixed long-standing bug: if someone unplugs the CPU identified by `singlethread_cpu' the kernel will get very sick. Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14[PATCH] futex_handle_fault always failsjohn stultz
We found this issue last week w/ the -RT kernel, but it seems the same issue is in mainline as well. Basically it is possible for futex_unlock_pi to return without actually freeing the lock. This is due to buggy logic in the use of futex_handle_fault() and its attempt argument in a failure case. Looking at futex.c the logic is as follows: 1) In futex_unlock_pi() we start w/ ret=0 and we go down to the first futex_atomic_cmpxchg_inatomic(), where we find uval==-EFAULT. We then jump to the pi_faulted label. 2) From pi_faulted: We increment attempt, unlock the sem and hit the retry label. 3) From the retry label, with ret still zero, we again hit EFAULT on the first futex_atomic_cmpxchg_inatomic(), and again goto the pi_faulted label. 4) Again from pi_faulted: we increment attempt and enter the conditional, where we call futex_handle_fault. 5) futex_handle_fault fails, and we goto the out_unlock_release_sem label. 6) From out_unlock_release_sem we return, and since ret is still zero, we return without error, while never actually unlocking the lock. Issue #1: at the first futex_atomic_cmpxchg_inatomic() we should probably be setting ret=-EFAULT before jumping to pi_faulted: However in our case this doesn't really affect anything, as the glibc we're using ignores the error value from futex_unlock_pi(). Issue #2: Look at futex_handle_fault(), its first conditional will return -EFAULT if attempt is >= 2. However, from the "if(attempt++) futex_handle_fault(attempt)" logic above, we'll *never* call futex_handle_fault when attempt is less then two. So we never get a chance to even try to fault the page in. The following patch addresses these two issues by 1) Always setting ret to -EFAULT if futex_handle_fault fails, and 2) Removing the = in futex_handle_fault's (attempt >= 2) check. I'm really not sure this is the right fix, but wanted to bring it up so folks knew the issue is alive and well in the current -git tree. From looking at the git logs the logic was first introduced (then later copied to other places) in the following commit almost a year ago: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=4732efbeb997189d9f9b04708dc26bf8613ed721;hp=5b039e681b8c5f30aac9cc04385cc94be45d0823 Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14[PATCH] sys_getppid oopses on debug kernelKirill Korotaev
sys_getppid() optimization can access a freed memory. On kernels with DEBUG_SLAB turned ON, this results in Oops. As Dave Hansen noted, this optimization is also unsafe for memory hotplug. So this patch always takes the lock to be safe. [oleg@tv-sign.ru: simplifications] Signed-off-by: Kirill Korotaev <dev@openvz.org> Cc: <stable@kernel.org> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14[PATCH] panic.c build fixAndrew Morton
kernel/panic.c: In function 'add_taint': kernel/panic.c:176: warning: implicit declaration of function 'debug_locks_off' Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14[PATCH] fix hrtimer percpu usage typoJan Blunck
The percpu variable is used incorrectly in switch_hrtimer_base(). Signed-off-by: Jan Blunck <jblunck@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-06[PATCH] futex: Apply recent futex fixes to futex_compatThomas Gleixner
The recent fixups in futex.c need to be applied to futex_compat.c too. Fixes a hang reported by Olaf. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Olaf Hering <olh@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06[PATCH] memory hotadd fixes: find_next_system_ram catch range fixKAMEZAWA Hiroyuki
find_next_system_ram() is used to find available memory resource at onlining newly added memory. This patch fixes following problem. find_next_system_ram() cannot catch this case. Resource: (start)-------------(end) Section : (start)-------------(end) Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Keith Mannthey <kmannth@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06[PATCH] memory hotadd fixes: change find_next_system_ram's return value mannerKAMEZAWA Hiroyuki
find_next_system_ram() returns valid memory range which meets requested area, only used by memory-hot-add. This function always rewrite requested resource even if returned area is not fully fit in requested one. And sometimes the returnd resource is larger than requested area. This annoyes the caller. This patch changes the returned value to fit in requested area. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Keith Mannthey <kmannth@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06[PATCH] vt: printk: Fix framebuffer console triggering might_sleep assertionAntonino A. Daplas
Reported by: Dave Jones Whilst printk'ing to both console and serial console, I got this... (2.6.18rc1) BUG: sleeping function called from invalid context at kernel/sched.c:4438 in_atomic():0, irqs_disabled():1 Call Trace: [<ffffffff80271db8>] show_trace+0xaa/0x23d [<ffffffff80271f60>] dump_stack+0x15/0x17 [<ffffffff8020b9f8>] __might_sleep+0xb2/0xb4 [<ffffffff8029232e>] __cond_resched+0x15/0x55 [<ffffffff80267eb8>] cond_resched+0x3b/0x42 [<ffffffff80268c64>] console_conditional_schedule+0x12/0x14 [<ffffffff80368159>] fbcon_redraw+0xf6/0x160 [<ffffffff80369c58>] fbcon_scroll+0x5d9/0xb52 [<ffffffff803a43c4>] scrup+0x6b/0xd6 [<ffffffff803a4453>] lf+0x24/0x44 [<ffffffff803a7ff8>] vt_console_print+0x166/0x23d [<ffffffff80295528>] __call_console_drivers+0x65/0x76 [<ffffffff80295597>] _call_console_drivers+0x5e/0x62 [<ffffffff80217e3f>] release_console_sem+0x14b/0x232 [<ffffffff8036acd6>] fb_flashcursor+0x279/0x2a6 [<ffffffff80251e3f>] run_workqueue+0xa8/0xfb [<ffffffff8024e5e0>] worker_thread+0xef/0x122 [<ffffffff8023660f>] kthread+0x100/0x136 [<ffffffff8026419e>] child_rip+0x8/0x12 This can occur when release_console_sem() is called but the log buffer still has contents that need to be flushed. The console drivers are called while the console_may_schedule flag is still true. The might_sleep() is triggered when fbcon calls console_conditional_schedule(). Fix by setting console_may_schedule to zero earlier, before the call to the console drivers. Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06[PATCH] ptrace: make pid of child process available for PTRACE_EVENT_VFORK_DONEChuck Ebbert
When delivering PTRACE_EVENT_VFORK_DONE, provide pid of the child process when tracer calls ptrace(PTRACE_GETEVENTMSG). This is already (accidentally) available when the tracer is tracing VFORK in addition to VFORK_DONE. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Cc: Daniel Jacobowitz <dan@debian.org> Cc: Albert Cahalan <acahalan@gmail.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06[PATCH] bug in futex unqueue_meChristian Borntraeger
This patch adds a barrier() in futex unqueue_me to avoid aliasing of two pointers. On my s390x system I saw the following oops: Unable to handle kernel pointer dereference at virtual kernel address 0000000000000000 Oops: 0004 [#1] CPU: 0 Not tainted Process mytool (pid: 13613, task: 000000003ecb6ac0, ksp: 00000000366bdbd8) Krnl PSW : 0704d00180000000 00000000003c9ac2 (_spin_lock+0xe/0x30) Krnl GPRS: 00000000ffffffff 000000003ecb6ac0 0000000000000000 0700000000000000 0000000000000000 0000000000000000 000001fe00002028 00000000000c091f 000001fe00002054 000001fe00002054 0000000000000000 00000000366bddc0 00000000005ef8c0 00000000003d00e8 0000000000144f91 00000000366bdcb8 Krnl Code: ba 4e 20 00 12 44 b9 16 00 3e a7 84 00 08 e3 e0 f0 88 00 04 Call Trace: ([<0000000000144f90>] unqueue_me+0x40/0xe4) [<0000000000145a0c>] do_futex+0x33c/0xc40 [<000000000014643e>] sys_futex+0x12e/0x144 [<000000000010bb00>] sysc_noemu+0x10/0x16 [<000002000003741c>] 0x2000003741c The code in question is: static int unqueue_me(struct futex_q *q) { int ret = 0; spinlock_t *lock_ptr; /* In the common case we don't take the spinlock, which is nice. */ retry: lock_ptr = q->lock_ptr; if (lock_ptr != 0) { spin_lock(lock_ptr); /* * q->lock_ptr can change between reading it and * spin_lock(), causing us to take the wrong lock. This * corrects the race condition. [...] and my compiler (gcc 4.1.0) makes the following out of it: 00000000000003c8 <unqueue_me>: 3c8: eb bf f0 70 00 24 stmg %r11,%r15,112(%r15) 3ce: c0 d0 00 00 00 00 larl %r13,3ce <unqueue_me+0x6> 3d0: R_390_PC32DBL .rodata+0x2a 3d4: a7 f1 1e 00 tml %r15,7680 3d8: a7 84 00 01 je 3da <unqueue_me+0x12> 3dc: b9 04 00 ef lgr %r14,%r15 3e0: a7 fb ff d0 aghi %r15,-48 3e4: b9 04 00 b2 lgr %r11,%r2 3e8: e3 e0 f0 98 00 24 stg %r14,152(%r15) 3ee: e3 c0 b0 28 00 04 lg %r12,40(%r11) /* write q->lock_ptr in r12 */ 3f4: b9 02 00 cc ltgr %r12,%r12 3f8: a7 84 00 4b je 48e <unqueue_me+0xc6> /* if r12 is zero then jump over the code.... */ 3fc: e3 20 b0 28 00 04 lg %r2,40(%r11) /* write q->lock_ptr in r2 */ 402: c0 e5 00 00 00 00 brasl %r14,402 <unqueue_me+0x3a> 404: R_390_PC32DBL _spin_lock+0x2 /* use r2 as parameter for spin_lock */ So the code becomes more or less: if (q->lock_ptr != 0) spin_lock(q->lock_ptr) instead of if (lock_ptr != 0) spin_lock(lock_ptr) Which caused the oops from above. After adding a barrier gcc creates code without this problem: [...] (the same) 3ee: e3 c0 b0 28 00 04 lg %r12,40(%r11) 3f4: b9 02 00 cc ltgr %r12,%r12 3f8: b9 04 00 2c lgr %r2,%r12 3fc: a7 84 00 48 je 48c <unqueue_me+0xc4> 400: c0 e5 00 00 00 00 brasl %r14,400 <unqueue_me+0x38> 402: R_390_PC32DBL _spin_lock+0x2 As a general note, this code of unqueue_me seems a bit fishy. The retry logic of unqueue_me only works if we can guarantee, that the original value of q->lock_ptr is always a spinlock (Otherwise we overwrite kernel memory). We know that q->lock_ptr can change. I dont know what happens with the original spinlock, as I am not an expert with the futex code. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@timesys.com> Signed-off-by: Christian Borntraeger <borntrae@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06[PATCH] Make suspend possible with a traced process at a breakpointRafael J. Wysocki
It should be possible to suspend, either to RAM or to disk, if there's a traced process that has just reached a breakpoint. However, this is a special case, because its parent process might have been frozen already and then we are unable to deliver the "freeze" signal to the traced process. If this happens, it's better to cancel the freezing of the traced process. Ref. http://bugzilla.kernel.org/show_bug.cgi?id=6787 Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-03[PATCH] take filling ->pid, etc. out of audit_get_context()Al Viro
move that stuff downstream and into the only branch where it'll be used. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03[PATCH] don't bother with aux entires for dummy contextAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03[PATCH] mark context of syscall entered with no rules as dummyAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03[PATCH] introduce audit rules counterAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03[PATCH] fix audit oops with invalid operatorAmy Griffis
Michael C Thompson wrote: [Tue Aug 01 2006, 02:36:36PM EDT] > The trigger for this oops is: > # auditctl -a exit,always -S pread64 -F 'inode<1' Setting the err value will fix it. Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03[PATCH] fix oops with CONFIG_AUDIT and !CONFIG_AUDITSYSCALLAmy Griffis
Always initialize the audit_inode_hash[] so we don't oops on list rules. Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03[PATCH] fix missed create event for directory auditAmy Griffis
When an object is created via a symlink into an audited directory, audit misses the event due to not having collected the inode data for the directory. Modify __audit_inode_child() to copy the parent inode data if a parent wasn't found in audit_names[]. Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03[PATCH] fix faulty inode data collection for open() with O_CREATAmy Griffis
When the specified path is an existing file or when it is a symlink, audit collects the wrong inode number, which causes it to miss the open() event. Adding a second hook to the open() path fixes this. Also add audit_copy_inode() to consolidate some code. Signed-off-by: Amy Griffis <amy.griffis@hp.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-02Fix force_sig_info() semantics after cleanupsLinus Torvalds
Suresh points out that commit b0423a0d9cc836b2c3d796623cd19236bfedfe63 broke the semantics of a synchronous signal like SIGSEGV occurring recursively inside its own handler handler (or, indeed, any other context when the signal was blocked). That was unintentional, and this fixes things up by reinstating the old semantics, but without reverting the cleanups. Cc: Paul E. McKenney <paulmck@us.ibm.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31[PATCH] timer: Fix tvec_bases initializerJosh Triplett
kernel/timer.c defines a (per-cpu) pointer to tvec_base_t, but initializes it using { &a_tvec_base_t }, which sparse warns about; change this to just &a_tvec_base_t. Signed-off-by: Josh Triplett <josh@freedesktop.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31[PATCH] reference rt-mutex-design in rtmutex.cSteven Rostedt
In order to prevent Doc Rot, this patch adds a reference to the design document for rtmutex.c in rtmutex.c. So when someone needs to update or change the design of that file they will know that a document actually exists that explains the design (helping them change it), and hopefully that they will update the document if they too change the design. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31[PATCH] Reducing local_bh_enable/disable overhead in irqtraceTim Chen
The recent changes from irqtrace feature has added overheads to local_bh_disable and local_bh_enable that reduces UDP performance across x86_64 and IA64, even though IA64 does not support the irqtrace feature. Patch in question is [PATCH]lockdep: irqtrace subsystem, core http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=c ommit;h=de30a2b355ea85350ca2f58f3b9bf4e5bc007986 Prior to this patch, local_bh_disable was a short macro. Now it is a function which calls __local_bh_disable with added irq flags save and restore. The irq flags save and restore were also added to local_bh_enable, probably for injecting the trace irqs code. This overhead is on the generic code path across all architectures. On a IA_64 test machine (Itanium-2 1.6 GHz) running a benchmark like netperf's UDP streaming test, the added overhead results in a drop of 3% in throughput, as udp_sendmsg calls the local_bh_enable/disable several times. Other workloads that have heavy usages of local_bh_enable/disable could also be affected. The patch ideally should not have affected IA-64 performance as it does not have IRQ tracing support. A significant portion of the overhead is in the added irq flags save and restore, which I think is not needed if IRQ tracing is unused. A suggested patch is attached below that recovers the lost performance. However, the "ifdef"s in the patch are a bit ugly. Signed-off-by: Tim Chen <tim.c.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>