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2016-10-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds200-1061/+2300
Merge more updates from Andrew Morton: - a few block updates that fell in my lap - lib/ updates - checkpatch - autofs - ipc - a ton of misc other things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits) mm: split gfp_mask and mapping flags into separate fields fs: use mapping_set_error instead of opencoded set_bit treewide: remove redundant #include <linux/kconfig.h> hung_task: allow hung_task_panic when hung_task_warnings is 0 kthread: add kerneldoc for kthread_create() kthread: better support freezable kthread workers kthread: allow to modify delayed kthread work kthread: allow to cancel kthread work kthread: initial support for delayed kthread work kthread: detect when a kthread work is used by more workers kthread: add kthread_destroy_worker() kthread: add kthread_create_worker*() kthread: allow to call __kthread_create_on_node() with va_list args kthread/smpboot: do not park in kthread_create_on_cpu() kthread: kthread worker API cleanup kthread: rename probe_kthread_data() to kthread_probe_data() scripts/tags.sh: enable code completion in VIM mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping kdump, vmcoreinfo: report memory sections virtual addresses ipc/sem.c: add cond_resched in exit_sme ...
2016-10-11mm: split gfp_mask and mapping flags into separate fieldsMichal Hocko2-12/+11
mapping->flags currently encodes two different things into a single flag. It contains sticky gfp_mask for page cache allocations and AS_ codes used to report errors/enospace and other states which are mapping specific. Condensing the two semantically unrelated things saves few bytes but it also complicates other things. For one thing the gfp flags space is reduced and in fact we are already running out of available bits. It can be assumed that more gfp flags will be necessary later on. To not introduce the address_space grow (at least on x86_64) we can stick it right after private_lock because we have a hole there. struct address_space { struct inode * host; /* 0 8 */ struct radix_tree_root page_tree; /* 8 16 */ spinlock_t tree_lock; /* 24 4 */ atomic_t i_mmap_writable; /* 28 4 */ struct rb_root i_mmap; /* 32 8 */ struct rw_semaphore i_mmap_rwsem; /* 40 40 */ /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */ long unsigned int nrpages; /* 80 8 */ long unsigned int nrexceptional; /* 88 8 */ long unsigned int writeback_index; /* 96 8 */ const struct address_space_operations * a_ops; /* 104 8 */ long unsigned int flags; /* 112 8 */ spinlock_t private_lock; /* 120 4 */ /* XXX 4 bytes hole, try to pack */ /* --- cacheline 2 boundary (128 bytes) --- */ struct list_head private_list; /* 128 16 */ void * private_data; /* 144 8 */ /* size: 152, cachelines: 3, members: 14 */ /* sum members: 148, holes: 1, sum holes: 4 */ /* last cacheline: 24 bytes */ }; Link: http://lkml.kernel.org/r/20160912114852.GI14524@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11fs: use mapping_set_error instead of opencoded set_bitMichal Hocko7-14/+9
The mapping_set_error() helper sets the correct AS_ flag for the mapping so there is no reason to open code it. Use the helper directly. [akpm@linux-foundation.org: be honest about conversion from -ENXIO to -EIO] Link: http://lkml.kernel.org/r/20160912111608.2588-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11treewide: remove redundant #include <linux/kconfig.h>Masahiro Yamada96-112/+0
Kernel source files need not include <linux/kconfig.h> explicitly because the top Makefile forces to include it with: -include $(srctree)/include/linux/kconfig.h This commit removes explicit includes except the following: * arch/s390/include/asm/facilities_src.h * tools/testing/radix-tree/linux/kernel.h These two are used for host programs. Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11hung_task: allow hung_task_panic when hung_task_warnings is 0John Siddle1-14/+14
Previously hung_task_panic would not be respected if enabled after hung_task_warnings had already been decremented to 0. Permit the kernel to panic if hung_task_panic is enabled after hung_task_warnings has already been decremented to 0 and another task hangs for hung_task_timeout_secs seconds. Check if hung_task_panic is enabled so we don't return prematurely, and check if hung_task_warnings is non-zero so we don't print the warning unnecessarily. [akpm@linux-foundation.org: fix off-by-one] Link: http://lkml.kernel.org/r/1473450214-4049-1-git-send-email-jsiddle@redhat.com Signed-off-by: John Siddle <jsiddle@redhat.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: add kerneldoc for kthread_create()Jonathan Corbet1-0/+11
This macro is referenced in other kerneldoc comments, but lacks one of its own; fix that. Link: http://lkml.kernel.org/r/20160826072313.726a3485@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net> Reported-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: better support freezable kthread workersPetr Mladek2-9/+24
This patch allows to make kthread worker freezable via a new @flags parameter. It will allow to avoid an init work in some kthreads. It currently does not affect the function of kthread_worker_fn() but it might help to do some optimization or fixes eventually. I currently do not know about any other use for the @flags parameter but I believe that we will want more flags in the future. Finally, I hope that it will not cause confusion with @flags member in struct kthread. Well, I guess that we will want to rework the basic kthreads implementation once all kthreads are converted into kthread workers or workqueues. It is possible that we will merge the two structures. Link: http://lkml.kernel.org/r/1470754545-17632-12-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: allow to modify delayed kthread workPetr Mladek2-0/+57
There are situations when we need to modify the delay of a delayed kthread work. For example, when the work depends on an event and the initial delay means a timeout. Then we want to queue the work immediately when the event happens. This patch implements kthread_mod_delayed_work() as inspired workqueues. It cancels the timer, removes the work from any worker list and queues it again with the given timeout. A very special case is when the work is being canceled at the same time. It might happen because of the regular kthread_cancel_delayed_work_sync() or by another kthread_mod_delayed_work(). In this case, we do nothing and let the other operation win. This should not normally happen as the caller is supposed to synchronize these operations a reasonable way. Link: http://lkml.kernel.org/r/1470754545-17632-11-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: allow to cancel kthread workPetr Mladek2-2/+135
We are going to use kthread workers more widely and sometimes we will need to make sure that the work is neither pending nor running. This patch implements cancel_*_sync() operations as inspired by workqueues. Well, we are synchronized against the other operations via the worker lock, we use del_timer_sync() and a counter to count parallel cancel operations. Therefore the implementation might be easier. First, we check if a worker is assigned. If not, the work has newer been queued after it was initialized. Second, we take the worker lock. It must be the right one. The work must not be assigned to another worker unless it is initialized in between. Third, we try to cancel the timer when it exists. The timer is deleted synchronously to make sure that the timer call back is not running. We need to temporary release the worker->lock to avoid a possible deadlock with the callback. In the meantime, we set work->canceling counter to avoid any queuing. Fourth, we try to remove the work from a worker list. It might be the list of either normal or delayed works. Fifth, if the work is running, we call kthread_flush_work(). It might take an arbitrary time. We need to release the worker-lock again. In the meantime, we again block any queuing by the canceling counter. As already mentioned, the check for a pending kthread work is done under a lock. In compare with workqueues, we do not need to fight for a single PENDING bit to block other operations. Therefore we do not suffer from the thundering storm problem and all parallel canceling jobs might use kthread_flush_work(). Any queuing is blocked until the counter gets zero. Link: http://lkml.kernel.org/r/1470754545-17632-10-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: initial support for delayed kthread workPetr Mladek2-0/+135
We are going to use kthread_worker more widely and delayed works will be pretty useful. The implementation is inspired by workqueues. It uses a timer to queue the work after the requested delay. If the delay is zero, the work is queued immediately. In compare with workqueues, each work is associated with a single worker (kthread). Therefore the implementation could be much easier. In particular, we use the worker->lock to synchronize all the operations with the work. We do not need any atomic operation with a flags variable. In fact, we do not need any state variable at all. Instead, we add a list of delayed works into the worker. Then the pending work is listed either in the list of queued or delayed works. And the existing check of pending works is the same even for the delayed ones. A work must not be assigned to another worker unless reinitialized. Therefore the timer handler might expect that dwork->work->worker is valid and it could simply take the lock. We just add some sanity checks to help with debugging a potential misuse. Link: http://lkml.kernel.org/r/1470754545-17632-9-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: detect when a kthread work is used by more workersPetr Mladek1-8/+20
Nothing currently prevents a work from queuing for a kthread worker when it is already running on another one. This means that the work might run in parallel on more than one worker. Also some operations are not reliable, e.g. flush. This problem will be even more visible after we add kthread_cancel_work() function. It will only have "work" as the parameter and will use worker->lock to synchronize with others. Well, normally this is not a problem because the API users are sane. But bugs might happen and users also might be crazy. This patch adds a warning when we try to insert the work for another worker. It does not fully prevent the misuse because it would make the code much more complicated without a big benefit. It adds the same warning also into kthread_flush_work() instead of the repeated attempts to get the right lock. A side effect is that one needs to explicitly reinitialize the work if it must be queued into another worker. This is needed, for example, when the worker is stopped and started again. It is a bit inconvenient. But it looks like a good compromise between the stability and complexity. I have double checked all existing users of the kthread worker API and they all seems to initialize the work after the worker gets started. Just for completeness, the patch adds a check that the work is not already in a queue. The patch also puts all the checks into a separate function. It will be reused when implementing delayed works. Link: http://lkml.kernel.org/r/1470754545-17632-8-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: add kthread_destroy_worker()Petr Mladek2-0/+25
The current kthread worker users call flush() and stop() explicitly. This function does the same plus it frees the kthread_worker struct in one call. It is supposed to be used together with kthread_create_worker*() that allocates struct kthread_worker. Link: http://lkml.kernel.org/r/1470754545-17632-7-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: add kthread_create_worker*()Petr Mladek2-10/+110
Kthread workers are currently created using the classic kthread API, namely kthread_run(). kthread_worker_fn() is passed as the @threadfn parameter. This patch defines kthread_create_worker() and kthread_create_worker_on_cpu() functions that hide implementation details. They enforce using kthread_worker_fn() for the main thread. But I doubt that there are any plans to create any alternative. In fact, I think that we do not want any alternative main thread because it would be hard to support consistency with the rest of the kthread worker API. The naming and function of kthread_create_worker() is inspired by the workqueues API like the rest of the kthread worker API. The kthread_create_worker_on_cpu() variant is motivated by the original kthread_create_on_cpu(). Note that we need to bind per-CPU kthread workers already when they are created. It makes the life easier. kthread_bind() could not be used later for an already running worker. This patch does _not_ convert existing kthread workers. The kthread worker API need more improvements first, e.g. a function to destroy the worker. IMPORTANT: kthread_create_worker_on_cpu() allows to use any format of the worker name, in compare with kthread_create_on_cpu(). The good thing is that it is more generic. The bad thing is that most users will need to pass the cpu number in two parameters, e.g. kthread_create_worker_on_cpu(cpu, "helper/%d", cpu). To be honest, the main motivation was to avoid the need for an empty va_list. The only legal way was to create a helper function that would be called with an empty list. Other attempts caused compilation warnings or even errors on different architectures. There were also other alternatives, for example, using #define or splitting __kthread_create_worker(). The used solution looked like the least ugly. Link: http://lkml.kernel.org/r/1470754545-17632-6-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: allow to call __kthread_create_on_node() with va_list argsPetr Mladek1-30/+42
kthread_create_on_node() implements a bunch of logic to create the kthread. It is already called by kthread_create_on_cpu(). We are going to extend the kthread worker API and will need to call kthread_create_on_node() with va_list args there. This patch does only a refactoring and does not modify the existing behavior. Link: http://lkml.kernel.org/r/1470754545-17632-5-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread/smpboot: do not park in kthread_create_on_cpu()Petr Mladek2-2/+11
kthread_create_on_cpu() was added by the commit 2a1d446019f9a5983e ("kthread: Implement park/unpark facility"). It is currently used only when enabling new CPU. For this purpose, the newly created kthread has to be parked. The CPU binding is a bit tricky. The kthread is parked when the CPU has not been allowed yet. And the CPU is bound when the kthread is unparked. The function would be useful for more per-CPU kthreads, e.g. bnx2fc_thread, fcoethread. For this purpose, the newly created kthread should stay in the uninterruptible state. This patch moves the parking into smpboot. It binds the thread already when created. Then the function might be used universally. Also the behavior is consistent with kthread_create() and kthread_create_on_node(). Link: http://lkml.kernel.org/r/1470754545-17632-4-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: kthread worker API cleanupPetr Mladek18-92/+93
A good practice is to prefix the names of functions by the name of the subsystem. The kthread worker API is a mix of classic kthreads and workqueues. Each worker has a dedicated kthread. It runs a generic function that process queued works. It is implemented as part of the kthread subsystem. This patch renames the existing kthread worker API to use the corresponding name from the workqueues API prefixed by kthread_: __init_kthread_worker() -> __kthread_init_worker() init_kthread_worker() -> kthread_init_worker() init_kthread_work() -> kthread_init_work() insert_kthread_work() -> kthread_insert_work() queue_kthread_work() -> kthread_queue_work() flush_kthread_work() -> kthread_flush_work() flush_kthread_worker() -> kthread_flush_worker() Note that the names of DEFINE_KTHREAD_WORK*() macros stay as they are. It is common that the "DEFINE_" prefix has precedence over the subsystem names. Note that INIT() macros and init() functions use different naming scheme. There is no good solution. There are several reasons for this solution: + "init" in the function names stands for the verb "initialize" aka "initialize worker". While "INIT" in the macro names stands for the noun "INITIALIZER" aka "worker initializer". + INIT() macros are used only in DEFINE() macros + init() functions are used close to the other kthread() functions. It looks much better if all the functions use the same scheme. + There will be also kthread_destroy_worker() that will be used close to kthread_cancel_work(). It is related to the init() function. Again it looks better if all functions use the same naming scheme. + there are several precedents for such init() function names, e.g. amd_iommu_init_device(), free_area_init_node(), jump_label_init_type(), regmap_init_mmio_clk(), + It is not an argument but it was inconsistent even before. [arnd@arndb.de: fix linux-next merge conflict] Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kthread: rename probe_kthread_data() to kthread_probe_data()Petr Mladek3-4/+4
Patch series "kthread: Kthread worker API improvements" The intention of this patchset is to make it easier to manipulate and maintain kthreads. Especially, I want to replace all the custom main cycles with a generic one. Also I want to make the kthreads sleep in a consistent state in a common place when there is no work. This patch (of 11): A good practice is to prefix the names of functions by the name of the subsystem. This patch fixes the name of probe_kthread_data(). The other wrong functions names are part of the kthread worker API and will be fixed separately. Link: http://lkml.kernel.org/r/1470754545-17632-2-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11scripts/tags.sh: enable code completion in VIMMathieu Maret1-1/+2
Vim, with the omnicppcomplete(#1) plugin, can do code completion using information build by ctags. Add flags needed by omnicppcomplete(#2) to have completion on member of structure. 1: https://github.com/vim-scripts/omnicppcomplete 2: https://github.com/vim-scripts/OmniCppComplete/blob/master/doc/omnicppcomplete.txt#L93 Link: http://lkml.kernel.org/r/20160830191546.4469-1-mathieu.maret@gmail.com Signed-off-by: Mathieu Maret <mathieu.maret@gmail.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mappingCatalin Marinas7-9/+83
Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a physical address to a virtual one using __va(). However, such physical addresses may sometimes be located in highmem and using __va() is incorrect, leading to inconsistent object tracking in kmemleak. The following functions have been added to the kmemleak API and they take a physical address as the object pointer. They only perform the corresponding action if the address has a lowmem mapping: kmemleak_alloc_phys kmemleak_free_part_phys kmemleak_not_leak_phys kmemleak_ignore_phys The affected calling places have been updated to use the new kmemleak API. Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kdump, vmcoreinfo: report memory sections virtual addressesThomas Garnier2-0/+9
KASLR memory randomization can randomize the base of the physical memory mapping (PAGE_OFFSET), vmalloc (VMALLOC_START) and vmemmap (VMEMMAP_START). Adding these variables on VMCOREINFO so tools can easily identify the base of each memory section. Link: http://lkml.kernel.org/r/1471531632-23003-1-git-send-email-thgarnie@google.com Signed-off-by: Thomas Garnier <thgarnie@google.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Xunlei Pang <xlpang@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Kees Cook <keescook@chromium.org> Cc: Eugene Surovegin <surovegin@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ipc/sem.c: add cond_resched in exit_smeNikolay Borisov1-0/+2
In CONFIG_PREEMPT=n kernel a softlockup was observed while the for loop in exit_sem. Apparently it's possible for the loop to take quite a long time and it doesn't have a scheduling point in it. Since the codes is executing under an rcu read section this may also cause rcu stalls, which in turn block synchronize_rcu operations, which more or less de-stabilises the whole system. Fix this by introducing a cond_resched() at the beginning of the loop. So this patch fixes the following: NMI watchdog: BUG: soft lockup - CPU#10 stuck for 23s! [httpd:18119] CPU: 10 PID: 18119 Comm: httpd Tainted: G O 4.4.20-clouder2 #6 Hardware name: Supermicro X10DRi/X10DRi, BIOS 1.1 04/14/2015 task: ffff88348d695280 ti: ffff881c95550000 task.ti: ffff881c95550000 RIP: 0010:[<ffffffff81614bc7>] [<ffffffff81614bc7>] _raw_spin_lock+0x17/0x30 RSP: 0018:ffff881c95553e40 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff883161b1eea8 RCX: 000000000000000d RDX: 0000000000000001 RSI: 000000000000000e RDI: ffff883161b1eea4 RBP: ffff881c95553ea0 R08: ffff881c95553e68 R09: ffff883fef376f88 R10: ffff881fffb58c20 R11: ffffea0072556600 R12: ffff883161b1eea0 R13: ffff88348d695280 R14: ffff883dec427000 R15: ffff8831621672a0 FS: 0000000000000000(0000) GS:ffff881fffb40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b3723e020 CR3: 0000000001c0a000 CR4: 00000000001406e0 Call Trace: ? exit_sem+0x7c/0x280 do_exit+0x338/0xb40 do_group_exit+0x43/0xd0 SyS_exit_group+0x14/0x20 entry_SYSCALL_64_fastpath+0x16/0x6e Link: http://lkml.kernel.org/r/1475154992-6363-1-git-send-email-kernel@kyup.com Signed-off-by: Nikolay Borisov <kernel@kyup.com> Cc: Herton R. Krzesinski <herton@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ipc/msg: avoid waking sender upon full queueDavidlohr Bueso1-10/+43
Blocked tasks queued in q_senders waiting for their message to fit in the queue are blindly awoken every time we think there's a remote chance this might happen. This could cause numerous (and expensive -- thundering herd-ish) bogus wakeups if the queue is still really full. Adding to the scheduling cost/overhead, there's also the fact that we need to take the ipc object lock and requeue ourselves in the q_senders list. By keeping track of the blocked sender's message size, we can know previously if the wakeup ought to occur or not. Otherwise, to maintain the current wakeup order we just move it to the tail. This is exactly what occurs right now if the sender needs to go back to sleep. The case of EIDRM is left completely untouched, as we need to wakeup all the tasks, and shouldn't be playing games in the first place. This patch was seen to save on the 'msgctl10' ltp testcase ~15% in context switches (avg out of ten runs). Although these tests are really about functionality (as opposed to performance), is does show the direct benefits of the optimization. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1469748819-19484-6-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ipc/msg: make ss_wakeup() kill arg booleanDavidlohr Bueso1-4/+4
... 'tis annoying. Link: http://lkml.kernel.org/r/1469748819-19484-4-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ipc/msg: batch queue sender wakeupsDavidlohr Bueso1-10/+20
Currently the use of wake_qs in sysv msg queues are only for the receiver tasks that are blocked on the queue. But blocked sender tasks (due to queue size constraints) still are awoken with the ipc object lock held, which can be a problem particularly for small sized queues and far from gracious for -rt (just like it was for the receiver side). The paths that actually wakeup a sender are obviously related to when we are either getting rid of the queue or after (some) space is freed-up after a receiver takes the msg (msgrcv). Furthermore, with the exception of msgrcv, we can always piggy-back on expunge_all that has its own tasks lined-up for waking. Finally, upon unlinking the message, it should be no problem delaying the wakeups a bit until after we've released the lock. Link: http://lkml.kernel.org/r/1469748819-19484-3-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ipc/msg: implement lockless pipelined wakeupsSebastian Andrzej Siewior1-93/+40
This patch moves the wakeup_process() invocation so it is not done under the ipc global lock by making use of a lockless wake_q. With this change, the waiter is woken up once the message has been assigned and it does not need to loop on SMP if the message points to NULL. In the signal case we still need to check the pointer under the lock to verify the state. This change should also avoid the introduction of preempt_disable() in -RT which avoids a busy-loop which pools for the NULL -> !NULL change if the waiter has a higher priority compared to the waker. By making use of wake_qs, the logic of sysv msg queues is greatly simplified (and very well suited as we can batch lockless wakeups), particularly around the lockless receive algorithm. This has been tested with Manred's pmsg-shared tool on a "AMD A10-7800 Radeon R7, 12 Compute Cores 4C+8G": test | before | after | diff -----------------|------------|------------|---------- pmsg-shared 8 60 | 19,347,422 | 30,442,191 | + ~57.34 % pmsg-shared 4 60 | 21,367,197 | 35,743,458 | + ~67.28 % pmsg-shared 2 60 | 22,884,224 | 24,278,200 | + ~6.09 % Link: http://lkml.kernel.org/r/1469748819-19484-2-git-send-email-dave@stgolabs.net Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ipc/sem.c: fix complex_count vs. simple op raceManfred Spraul2-55/+84
Commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") introduced a race: sem_lock has a fast path that allows parallel simple operations. There are two reasons why a simple operation cannot run in parallel: - a non-simple operations is ongoing (sma->sem_perm.lock held) - a complex operation is sleeping (sma->complex_count != 0) As both facts are stored independently, a thread can bypass the current checks by sleeping in the right positions. See below for more details (or kernel bugzilla 105651). The patch fixes that by creating one variable (complex_mode) that tracks both reasons why parallel operations are not possible. The patch also updates stale documentation regarding the locking. With regards to stable kernels: The patch is required for all kernels that include the commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") (3.10?) The alternative is to revert the patch that introduced the race. The patch is safe for backporting, i.e. it makes no assumptions about memory barriers in spin_unlock_wait(). Background: Here is the race of the current implementation: Thread A: (simple op) - does the first "sma->complex_count == 0" test Thread B: (complex op) - does sem_lock(): This includes an array scan. But the scan can't find Thread A, because Thread A does not own sem->lock yet. - the thread does the operation, increases complex_count, drops sem_lock, sleeps Thread A: - spin_lock(&sem->lock), spin_is_locked(sma->sem_perm.lock) - sleeps before the complex_count test Thread C: (complex op) - does sem_lock (no array scan, complex_count==1) - wakes up Thread B. - decrements complex_count Thread A: - does the complex_count test Bug: Now both thread A and thread C operate on the same array, without any synchronization. Fixes: 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") Link: http://lkml.kernel.org/r/1469123695-5661-1-git-send-email-manfred@colorfullife.com Reported-by: <felixh@informatik.uni-bremen.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: <1vier1@web.de> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11kcov: do not instrument lib/stackdepot.cAlexander Potapenko1-0/+1
There's no point in collecting coverage from lib/stackdepot.c, as it is not a function of syscall inputs. Disabling kcov instrumentation for that file will reduce the coverage noise level. Link: http://lkml.kernel.org/r/1474640972-104131-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11config: android: enable CONFIG_SECCOMPRob Herring1-0/+1
As of Android N, SECCOMP is required. Without it, we will get mediaextractor error: E /system/bin/mediaextractor: libminijail: prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER): Invalid argument Link: http://lkml.kernel.org/r/20160908185934.18098-3-robh@kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Amit Pundir <amit.pundir@linaro.org> Cc: Dmitry Shmidt <dimitrysh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11config: android: set SELinux as default security modeRob Herring1-0/+1
Android won't boot without SELinux enabled, so make it the default. Link: http://lkml.kernel.org/r/20160908185934.18098-2-robh@kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11config: android: move device mapper options to recommendedRob Herring2-4/+4
CONFIG_MD is in recommended, but other dependent options like DM_CRYPT and DM_VERITY options are in base. The result is the options in base don't get enabled when applying both base and recommended fragments. Move all the options to recommended. Link: http://lkml.kernel.org/r/20160908185934.18098-1-robh@kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Amit Pundir <amit.pundir@linaro.org> Cc: Dmitry Shmidt <dimitrysh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11config/android: Remove CONFIG_IPV6_PRIVACYBorislav Petkov1-1/+0
Option is long gone, see commit 5d9efa7ee99e ("ipv6: Remove privacy config option.") Link: http://lkml.kernel.org/r/20160811170340.9859-1-bp@alien8.de Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Rob Herring <robh@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11relay: Use irq_work instead of plain timer for deferred wakeupPeter Zijlstra3-11/+17
Relay avoids calling wake_up_interruptible() for doing the wakeup of readers/consumers, waiting for the generation of new data, from the context of a process which produced the data. This is apparently done to prevent the possibility of a deadlock in case Scheduler itself is is generating data for the relay, after acquiring rq->lock. The following patch used a timer (to be scheduled at next jiffy), for delegating the wakeup to another context. commit 7c9cb38302e78d24e37f7d8a2ea7eed4ae5f2fa7 Author: Tom Zanussi <zanussi@comcast.net> Date: Wed May 9 02:34:01 2007 -0700 relay: use plain timer instead of delayed work relay doesn't need to use schedule_delayed_work() for waking readers when a simple timer will do. Scheduling a plain timer, at next jiffies boundary, to do the wakeup causes a significant wakeup latency for the Userspace client, which makes relay less suitable for the high-frequency low-payload use cases where the data gets generated at a very high rate, like multiple sub buffers getting filled within a milli second. Moreover the timer is re-scheduled on every newly produced sub buffer so the timer keeps getting pushed out if sub buffers are filled in a very quick succession (less than a jiffy gap between filling of 2 sub buffers). As a result relay runs out of sub buffers to store the new data. By using irq_work it is ensured that wakeup of userspace client, blocked in the poll call, is done at earliest (through self IPI or next timer tick) enabling it to always consume the data in time. Also this makes relay consistent with printk & ring buffers (trace), as they too use irq_work for deferred wake up of readers. [arnd@arndb.de: select CONFIG_IRQ_WORK] Link: http://lkml.kernel.org/r/20160912154035.3222156-1-arnd@arndb.de [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1472906487-1559-1-git-send-email-akash.goel@intel.com Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Akash Goel <akash.goel@intel.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pps: kc: fix non-tickless system config dependencyMaciej S. Szmigiero1-1/+1
CONFIG_NO_HZ currently only sets the default value of dynticks config so if PPS kernel consumer needs periodic timer ticks it should depend on !CONFIG_NO_HZ_COMMON instead of !CONFIG_NO_HZ. Otherwise it is possible to enable it even on tickless system which has CONFIG_NO_HZ not set and CONFIG_NO_HZ_IDLE (or CONFIG_NO_HZ_FULL) set. Link: http://lkml.kernel.org/r/57E2B769.50202@maciej.szmigiero.name Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Acked-by: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11mips/panic: replace smp_send_stop() with kdump friendly version in panic pathHidehiro Kawai4-1/+33
Daniel Walker reported problems which happens when crash_kexec_post_notifiers kernel option is enabled (https://lkml.org/lkml/2015/6/24/44). In that case, smp_send_stop() is called before entering kdump routines which assume other CPUs are still online. As the result, kdump routines fail to save other CPUs' registers. Additionally for MIPS OCTEON, it misses to stop the watchdog timer. To fix this problem, call a new kdump friendly function, crash_smp_send_stop(), instead of the smp_send_stop() when crash_kexec_post_notifiers is enabled. crash_smp_send_stop() is a weak function, and it just call smp_send_stop(). Architecture codes should override it so that kdump can work appropriately. This patch provides MIPS version. Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option) Link: http://lkml.kernel.org/r/20160810080950.11028.28000.stgit@sysi4-13.yrl.intra.hitachi.co.jp Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reported-by: Daniel Walker <dwalker@fifo99.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Xunlei Pang <xpang@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: "Steven J. Hill" <steven.hill@cavium.com> Cc: Corey Minyard <cminyard@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11x86/panic: replace smp_send_stop() with kdump friendly version in panic pathHidehiro Kawai5-10/+66
Daniel Walker reported problems which happens when crash_kexec_post_notifiers kernel option is enabled (https://lkml.org/lkml/2015/6/24/44). In that case, smp_send_stop() is called before entering kdump routines which assume other CPUs are still online. As the result, for x86, kdump routines fail to save other CPUs' registers and disable virtualization extensions. To fix this problem, call a new kdump friendly function, crash_smp_send_stop(), instead of the smp_send_stop() when crash_kexec_post_notifiers is enabled. crash_smp_send_stop() is a weak function, and it just call smp_send_stop(). Architecture codes should override it so that kdump can work appropriately. This patch only provides x86-specific version. For Xen's PV kernel, just keep the current behavior. NOTES: - Right solution would be to place crash_smp_send_stop() before __crash_kexec() invocation in all cases and remove smp_send_stop(), but we can't do that until all architectures implement own crash_smp_send_stop() - crash_smp_send_stop()-like work is still needed by machine_crash_shutdown() because crash_kexec() can be called without entering panic() Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option) Link: http://lkml.kernel.org/r/20160810080948.11028.15344.stgit@sysi4-13.yrl.intra.hitachi.co.jp Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reported-by: Daniel Walker <dwalker@fifo99.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Xunlei Pang <xpang@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: "Steven J. Hill" <steven.hill@cavium.com> Cc: Corey Minyard <cminyard@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11nvme: use the DMA_ATTR_NO_WARN attributeMauricio Faria de Oliveira1-1/+2
Use the DMA_ATTR_NO_WARN attribute for the dma_map_sg() call of the nvme driver that returns BLK_MQ_RQ_QUEUE_BUSY (not for BLK_MQ_RQ_QUEUE_ERROR). Link: http://lkml.kernel.org/r/1470092390-25451-4-git-send-email-mauricfo@linux.vnet.ibm.com Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Jens Axboe <axboe@fb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11powerpc: implement the DMA_ATTR_NO_WARN attributeMauricio Faria de Oliveira1-2/+4
Add support for the DMA_ATTR_NO_WARN attribute on powerpc iommu code. Link: http://lkml.kernel.org/r/1470092390-25451-3-git-send-email-mauricfo@linux.vnet.ibm.com Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Jens Axboe <axboe@fb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11dma-mapping: introduce the DMA_ATTR_NO_WARN attributeMauricio Faria de Oliveira2-0/+22
Introduce the DMA_ATTR_NO_WARN attribute, and document it. Link: http://lkml.kernel.org/r/1470092390-25451-2-git-send-email-mauricfo@linux.vnet.ibm.com Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Jens Axboe <axboe@fb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11random: remove unused randomize_range()Jason Cooper2-20/+0
All call sites for randomize_range have been updated to use the much simpler and more robust randomize_addr(). Remove the now unnecessary code. Link: http://lkml.kernel.org/r/20160803233913.32511-8-jason@lakedaemon.net Signed-off-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11unicore32: use simpler API for random address requestsJason Cooper1-2/+1
Currently, all callers to randomize_range() set the length to 0 and calculate end by adding a constant to the start address. We can simplify the API to remove a bunch of needless checks and variables. Use the new randomize_addr(start, range) call to set the requested address. Link: http://lkml.kernel.org/r/20160803233913.32511-7-jason@lakedaemon.net Signed-off-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11tile: use simpler API for random address requestsJason Cooper1-2/+1
Currently, all callers to randomize_range() set the length to 0 and calculate end by adding a constant to the start address. We can simplify the API to remove a bunch of needless checks and variables. Use the new randomize_addr(start, range) call to set the requested address. Link: http://lkml.kernel.org/r/20160803233913.32511-6-jason@lakedaemon.net Signed-off-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Chris Metcalf <cmetcalf@mellanox.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11arm64: use simpler API for random address requestsJason Cooper1-6/+2
Currently, all callers to randomize_range() set the length to 0 and calculate end by adding a constant to the start address. We can simplify the API to remove a bunch of needless checks and variables. Use the new randomize_addr(start, range) call to set the requested address. Link: http://lkml.kernel.org/r/20160803233913.32511-5-jason@lakedaemon.net Signed-off-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Russell King - ARM Linux" <linux@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ARM: use simpler API for random address requestsJason Cooper1-2/+1
Currently, all callers to randomize_range() set the length to 0 and calculate end by adding a constant to the start address. We can simplify the API to remove a bunch of needless checks and variables. Use the new randomize_addr(start, range) call to set the requested address. Link: http://lkml.kernel.org/r/20160803233913.32511-4-jason@lakedaemon.net Signed-off-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Russell King - ARM Linux" <linux@arm.linux.org.uk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11x86: use simpler API for random address requestsJason Cooper2-6/+2
Currently, all callers to randomize_range() set the length to 0 and calculate end by adding a constant to the start address. We can simplify the API to remove a bunch of needless checks and variables. Use the new randomize_addr(start, range) call to set the requested address. Link: http://lkml.kernel.org/r/20160803233913.32511-3-jason@lakedaemon.net Signed-off-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11random: simplify API for random address requestsJason Cooper2-0/+34
To date, all callers of randomize_range() have set the length to 0, and check for a zero return value. For the current callers, the only way to get zero returned is if end <= start. Since they are all adding a constant to the start address, this is unnecessary. We can remove a bunch of needless checks by simplifying the API to do just what everyone wants, return an address between [start, start + range). While we're here, s/get_random_int/get_random_long/. No current call site is adversely affected by get_random_int(), since all current range requests are < UINT_MAX. However, we should match caller expectations to avoid coming up short (ha!) in the future. All current callers to randomize_range() chose to use the start address if randomize_range() failed. Therefore, we simplify things by just returning the start address on error. randomize_range() will be removed once all callers have been converted over to randomize_addr(). Link: http://lkml.kernel.org/r/20160803233913.32511-2-jason@lakedaemon.net Signed-off-by: Jason Cooper <jason@lakedaemon.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Roberts, William C" <william.c.roberts@intel.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Nick Kralevich <nnk@google.com> Cc: Jeffrey Vander Stoep <jeffv@google.com> Cc: Daniel Cashman <dcashman@android.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11rapidio/rio_cm: use memdup_user() instead of duplicating codeAlexandre Bounine1-10/+5
Fix coccinelle warning about duplicating existing memdup_user function. Link: http://lkml.kernel.org/r/20160811151737.20140-1-alexandre.bounine@idt.com Link: https://lkml.org/lkml/2016/8/11/29 Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com> Cc: Barry Wood <barry.wood@idt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11ptrace: clear TIF_SYSCALL_TRACE on ptrace detachAles Novak1-1/+2
On __ptrace_detach(), called from do_exit()->exit_notify()-> forget_original_parent()->exit_ptrace(), the TIF_SYSCALL_TRACE in thread->flags of the tracee is not cleared up. This results in the tracehook_report_syscall_* being called (though there's no longer a tracer listening to that) upon its further syscalls. Example scenario - attach "strace" to a running process and kill it (the strace) with SIGKILL. You'll see that the syscall trace hooks are still being called. The clearing of this flag should be moved from ptrace_detach() to __ptrace_detach(). Link: http://lkml.kernel.org/r/1472759493-20554-1-git-send-email-alnovak@suse.cz Signed-off-by: Ales Novak <alnovak@suse.cz> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: cap initial pipe capacity according to pipe-max-size limitMichael Kerrisk (man-pages)1-0/+3
This is a patch that provides behavior that is more consistent, and probably less surprising to users. I consider the change optional, and welcome opinions about whether it should be applied. By default, pipes are created with a capacity of 64 kiB. However, /proc/sys/fs/pipe-max-size may be set smaller than this value. In this scenario, an unprivileged user could thus create a pipe whose initial capacity exceeds the limit. Therefore, it seems logical to cap the initial pipe capacity according to the value of pipe-max-size. The test program shown earlier in this patch series can be used to demonstrate the effect of the change brought about with this patch: # cat /proc/sys/fs/pipe-max-size 1048576 # sudo -u mtk ./test_F_SETPIPE_SZ 1 Initial pipe capacity: 65536 # echo 10000 > /proc/sys/fs/pipe-max-size # cat /proc/sys/fs/pipe-max-size 16384 # sudo -u mtk ./test_F_SETPIPE_SZ 1 Initial pipe capacity: 16384 # ./test_F_SETPIPE_SZ 1 Initial pipe capacity: 65536 The last two executions of 'test_F_SETPIPE_SZ' show that pipe-max-size caps the initial allocation for a new pipe for unprivileged users, but not for privileged users. Link: http://lkml.kernel.org/r/31dc7064-2a17-9c5b-1df1-4e3012ee992c@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: make account_pipe_buffers() return a value, and use itMichael Kerrisk (man-pages)1-18/+18
This is an optional patch, to provide a small performance improvement. Alter account_pipe_buffers() so that it returns the new value in user->pipe_bufs. This means that we can refactor too_many_pipe_buffers_soft() and too_many_pipe_buffers_hard() to avoid the costs of repeated use of atomic_long_read() to get the value user->pipe_bufs. Link: http://lkml.kernel.org/r/93e5f193-1e5e-3e1f-3a20-eae79b7e1310@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11pipe: fix limit checking in alloc_pipe_info()Michael Kerrisk (man-pages)1-7/+13
The limit checking in alloc_pipe_info() (used by pipe(2) and when opening a FIFO) has the following problems: (1) When checking capacity required for the new pipe, the checks against the limit in /proc/sys/fs/pipe-user-pages-{soft,hard} are made against existing consumption, and exclude the memory required for the new pipe capacity. As a consequence: (1) the memory allocation throttling provided by the soft limit does not kick in quite as early as it should, and (2) the user can overrun the hard limit. (2) As currently implemented, accounting and checking against the limits is done as follows: (a) Test whether the user has exceeded the limit. (b) Make new pipe buffer allocation. (c) Account new allocation against the limits. This is racey. Multiple processes may pass point (a) simultaneously, and then allocate pipe buffers that are accounted for only in step (c). The race means that the user's pipe buffer allocation could be pushed over the limit (by an arbitrary amount, depending on how unlucky we were in the race). [Thanks to Vegard Nossum for spotting this point, which I had missed.] This patch addresses the above problems as follows: * Alter the checks against limits to include the memory required for the new pipe. * Re-order the accounting step so that it precedes the buffer allocation. If the accounting step determines that a limit has been reached, revert the accounting and cause the operation to fail. Link: http://lkml.kernel.org/r/8ff3e9f9-23f6-510c-644f-8e70cd1c0bd9@gmail.com Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Cc: <socketpair@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jens Axboe <axboe@fb.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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