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2016-02-28Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A rather largish series of 12 patches addressing a maze of race conditions in the perf core code from Peter Zijlstra" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Robustify task_function_call() perf: Fix scaling vs. perf_install_in_context() perf: Fix scaling vs. perf_event_enable() perf: Fix scaling vs. perf_event_enable_on_exec() perf: Fix ctx time tracking by introducing EVENT_TIME perf: Cure event->pending_disable race perf: Fix race between event install and jump_labels perf: Fix cloning perf: Only update context time when active perf: Allow perf_release() with !event->ctx perf: Do not double free perf: Close install vs. exit race
2016-02-28Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixlet from Thomas Gleixner: "A trivial printk typo fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Fix trivial typo in printk() message
2016-02-25Merge tag 'trace-fixes-v4.5-rc5-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "Another small bug reported to me by Chunyu Hu. When perf added a "reg" function to the function tracing event (not a tracepoint), it caused that event to be displayed as a tracepoint and could cause errors in tracepoint handling. That was solved by adding a flag to ignore ftrace non-tracepoint events. But that flag was missed when displaying events in available_events, which should only contain tracepoint events. This broke a documented way to enable all events with: cat available_events > set_event As the function non-tracepoint event would cause that to error out. The commit here fixes that by having the available_events file not list events that have the ignore flag set" * tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix showing function event in available_events
2016-02-25Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: - Two fixes for compatibility with the ACPI 6.1 specification. Without these fixes multi-interface DIMMs will fail to be probed, and address range scrub commands to find memory errors will give results that the kernel will mis-interpret. For multi-interface DIMMs Linux will accept either the original 6.0 implementation or 6.1. For address range scrub we'll only support 6.1 since ACPI formalized this DSM differently than the original example [1] implemented in v4.2. The expectation is that production systems will only ever ship the ACPI 6.1 address range scrub command definition. - The wider async address range scrub work targeting 4.6 discovered that the original synchronous implementation in 4.5 is not sizing its return buffer correctly. - Arnd caught that my recent fix to the size of the pfn_t flags missed updating the flags variable used in the pmem driver. - Toshi found that we mishandle the memremap() return value in devm_memremap(). * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: nvdimm: use 'u64' for pfn flags devm_memremap: Fix error value when memremap failed nfit: update address range scrub commands to the acpi 6.1 format libnvdimm, tools/testing/nvdimm: fix 'ars_status' output buffer sizing nfit: fix multi-interface dimm handling, acpi6.1 compatibility
2016-02-25perf: Robustify task_function_call()Peter Zijlstra
Since there is no serialization between task_function_call() doing task_curr() and the other CPU doing context switches, we could end up not sending an IPI even if we had to. And I'm not sure I still buy my own argument we're OK. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.340031200@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Fix scaling vs. perf_install_in_context()Peter Zijlstra
Completely reworks perf_install_in_context() (again!) in order to ensure that there will be no ctx time hole between add_event_to_ctx() and any potential ctx_sched_in(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.279399438@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Fix scaling vs. perf_event_enable()Peter Zijlstra
Similar to the perf_enable_on_exec(), ensure that event timings are consistent across perf_event_enable(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.218288698@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Fix scaling vs. perf_event_enable_on_exec()Peter Zijlstra
The recent commit 3e349507d12d ("perf: Fix perf_enable_on_exec() event scheduling") caused this by moving task_ctx_sched_out() from before __perf_event_mask_enable() to after it. The overlooked consequence of that change is that task_ctx_sched_out() would update the ctx time fields, and now __perf_event_mask_enable() uses stale time. In order to fix this, explicitly stop our context's time before enabling the event(s). Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Fixes: 3e349507d12d ("perf: Fix perf_enable_on_exec() event scheduling") Link: http://lkml.kernel.org/r/20160224174948.159242158@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Fix ctx time tracking by introducing EVENT_TIMEPeter Zijlstra
Currently any ctx_sched_in() call will re-start the ctx time tracking, this means that calls like: ctx_sched_in(.event_type = EVENT_PINNED); ctx_sched_in(.event_type = EVENT_FLEXIBLE); will have a hole in their ctx time tracking. This is likely harmless but can confuse things a little. By adding EVENT_TIME, we can have the first ctx_sched_in() (is_active: 0 -> !0) start the time and any further ctx_sched_in() will leave the timestamps alone. Secondly, this allows for an early disable like: ctx_sched_out(.event_type = EVENT_TIME); which would update the ctx time (if the ctx is active) and any further calls to ctx_sched_out() would not further modify the ctx time. For ctx_sched_in() any 0 -> !0 transition will automatically include EVENT_TIME. For ctx_sched_out(), any transition that clears EVENT_ALL will automatically clear EVENT_TIME. These two rules ensure that under normal circumstances we need not bother with EVENT_TIME and get natural ctx time behaviour. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.100446561@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Cure event->pending_disable racePeter Zijlstra
Because event_sched_out() checks event->pending_disable _before_ actually disabling the event, it can happen that the event fires after it checks but before it gets disabled. This would leave event->pending_disable set and the queued irq_work will try and process it. However, if the event trigger was during schedule(), the event might have been de-scheduled by the time the irq_work runs, and perf_event_disable_local() will fail. Fix this by checking event->pending_disable _after_ we call event->pmu->del(). This depends on the latter being a compiler barrier, such that the compiler does not lift the load and re-creates the problem. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.040469884@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Fix race between event install and jump_labelsPeter Zijlstra
perf_install_in_context() relies upon the context switch hooks to have scheduled in events when the IPI misses its target -- after all, if the task has moved from the CPU (or wasn't running at all), it will have to context switch to run elsewhere. This however doesn't appear to be happening. It is possible for the IPI to not happen (task wasn't running) only to later observe the task running with an inactive context. The only possible explanation is that the context switch hooks are not called. Therefore put in a sync_sched() after toggling the jump_label to guarantee all CPUs will have them enabled before we install an event. A simple if (0->1) sync_sched() will not in fact work, because any further increment can race and complete before the sync_sched(). Therefore we must jump through some hoops. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.980211985@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Fix cloningPeter Zijlstra
Alexander reported that when the 'original' context gets destroyed, no new clones happen. This can happen irrespective of the ctx switch optimization, any task can die, even the parent, and we want to continue monitoring the task hierarchy until we either close the event or no tasks are left in the hierarchy. perf_event_init_context() will attempt to pin the 'parent' context during clone(). At that point current is the parent, and since current cannot have exited while executing clone(), its context cannot have passed through perf_event_exit_task_context(). Therefore perf_pin_task_context() cannot observe ctx->task == TASK_TOMBSTONE. However, since inherit_event() does: if (parent_event->parent) parent_event = parent_event->parent; it looks at the 'original' event when it does: is_orphaned_event(). This can return true if the context that contains the this event has passed through perf_event_exit_task_context(). And thus we'll fail to clone the perf context. Fix this by adding a new state: STATE_DEAD, which is set by perf_release() to indicate that the filedesc (or kernel reference) is dead and there are no observers for our data left. Only for STATE_DEAD will is_orphaned_event() be true and inhibit cloning. STATE_EXIT is otherwise preserved such that is_event_hup() remains functional and will report when the observed task hierarchy becomes empty. Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Fixes: c6e5b73242d2 ("perf: Synchronously clean up child events") Link: http://lkml.kernel.org/r/20160224174947.919845295@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Only update context time when activePeter Zijlstra
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.860690919@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Allow perf_release() with !event->ctxPeter Zijlstra
In the err_file: fput(event_file) case, the event will not yet have been attached to a context. However perf_release() does assume it has been. Cure this. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.793996260@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Do not double freePeter Zijlstra
In case of: err_file: fput(event_file), we'll end up calling perf_release() which in turn will free the event. Do not then free the event _again_. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.697350349@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25perf: Close install vs. exit racePeter Zijlstra
Consider the following scenario: CPU0 CPU1 ctx = find_get_ctx(); perf_event_exit_task_context() mutex_lock(&ctx->mutex); perf_install_in_context(ctx, ...); /* NO-OP */ mutex_unlock(&ctx->mutex); ... perf_release() WARN_ON_ONCE(event->state != STATE_EXIT); Since the event doesn't pass through perf_remove_from_context() because perf_install_in_context() NO-OPs because the ctx is dead, and perf_event_exit_task_context() will not observe the event because its not attached yet, the event->state will not be set. Solve this by revalidating ctx->task after we acquire ctx->mutex and failing the event creation as a whole. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.626853419@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-24tracing: Fix showing function event in available_eventsSteven Rostedt (Red Hat)
The ftrace:function event is only displayed for parsing the function tracer data. It is not used to enable function tracing, and does not include an "enable" file in its event directory. Originally, this event was kept separate from other events because it did not have a ->reg parameter. But perf added a "reg" parameter for its use which caused issues, because it made the event available to functions where it was not compatible for. Commit 9b63776fa3ca9 "tracing: Do not enable function event with enable" added a TRACE_EVENT_FL_IGNORE_ENABLE flag that prevented the function event from being enabled by normal trace events. But this commit missed keeping the function event from being displayed by the "available_events" directory, which is used to show what events can be enabled by set_event. One documented way to enable all events is to: cat available_events > set_event But because the function event is displayed in the available_events, this now causes an INVALID error: cat: write error: Invalid argument Reported-by: Chunyu Hu <chuhu@redhat.com> Fixes: 9b63776fa3ca9 "tracing: Do not enable function event with enable" Cc: stable@vger.kernel.org # 3.4+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-23devm_memremap: Fix error value when memremap failedToshi Kani
devm_memremap() returns an ERR_PTR() value in case of error. However, it returns NULL when memremap() failed. This causes the caller, such as the pmem driver, to proceed and oops later. Change devm_memremap() to return ERR_PTR(-ENXIO) when memremap() failed. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-02-22Merge tag 'trace-fixes-v4.5-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Two more small fixes. One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the stack made by the stack tracer. As the stack tracer scans the entire kernel stack, KASAN triggers seeing it as a "stack out of bounds" error. As the scan is looking at the contents of the stack from parent functions. The NOCHECK() tells KASAN that this is done on purpose, and is not some kind of stack overflow. The second fix is to the ftrace selftests, to retrieve the PID of executed commands from the shell with '$!' and not by parsing 'jobs'" * tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing, kasan: Silence Kasan warning in check_stack of stack_tracer ftracetest: Fix instance test to use proper shell command for pids
2016-02-20Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "A handful of CPU hotplug related fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Plug potential memory leak in CPU_UP_PREPARE perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug state perf/core: Remove bogus UP_CANCELED hotplug state perf/x86/amd/uncore: Plug reference leak
2016-02-20kernel/resource.c: fix muxed resource handling in __request_region()Simon Guinot
In __request_region, if a conflict with a BUSY and MUXED resource is detected, then the caller goes to sleep and waits for the resource to be released. A pointer on the conflicting resource is kept. At wake-up this pointer is used as a parent to retry to request the region. A first problem is that this pointer might well be invalid (if for example the conflicting resource have already been freed). Another problem is that the next call to __request_region() fails to detect a remaining conflict. The previously conflicting resource is passed as a parameter and __request_region() will look for a conflict among the children of this resource and not at the resource itself. It is likely to succeed anyway, even if there is still a conflict. Instead, the parent of the conflicting resource should be passed to __request_region(). As a fix, this patch doesn't update the parent resource pointer in the case we have to wait for a muxed region right after. Reported-and-tested-by: Vincent Pelletier <plr.vincent@gmail.com> Signed-off-by: Simon Guinot <simon.guinot@sequanux.org> Tested-by: Vincent Donnefort <vdonnefort@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-19Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge fixes from Andrew Morton: "10 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: slab: free kmem_cache_node after destroy sysfs file ipc/shm: handle removed segments gracefully in shm_mmap() MAINTAINERS: update Kselftest Framework mailing list devm_memremap_release(): fix memremap'd addr handling mm/hugetlb.c: fix incorrect proc nr_hugepages value mm, x86: fix pte_page() crash in gup_pte_range() fsnotify: turn fsnotify reaper thread into a workqueue job Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread" mm: fix regression in remap_file_pages() emulation thp, dax: do not try to withdraw pgtable from non-anon VMA
2016-02-19tracing, kasan: Silence Kasan warning in check_stack of stack_tracerYang Shi
When enabling stack trace via "echo 1 > /proc/sys/kernel/stack_tracer_enabled", the below KASAN warning is triggered: BUG: KASAN: stack-out-of-bounds in check_stack+0x344/0x848 at addr ffffffc0689ebab8 Read of size 8 by task ksoftirqd/4/29 page:ffffffbdc3a27ac0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x0() page dumped because: kasan: bad access detected CPU: 4 PID: 29 Comm: ksoftirqd/4 Not tainted 4.5.0-rc1 #129 Hardware name: Freescale Layerscape 2085a RDB Board (DT) Call trace: [<ffffffc000091300>] dump_backtrace+0x0/0x3a0 [<ffffffc0000916c4>] show_stack+0x24/0x30 [<ffffffc0009bbd78>] dump_stack+0xd8/0x168 [<ffffffc000420bb0>] kasan_report_error+0x6a0/0x920 [<ffffffc000421688>] kasan_report+0x70/0xb8 [<ffffffc00041f7f0>] __asan_load8+0x60/0x78 [<ffffffc0002e05c4>] check_stack+0x344/0x848 [<ffffffc0002e0c8c>] stack_trace_call+0x1c4/0x370 [<ffffffc0002af558>] ftrace_ops_no_ops+0x2c0/0x590 [<ffffffc00009f25c>] ftrace_graph_call+0x0/0x14 [<ffffffc0000881bc>] fpsimd_thread_switch+0x24/0x1e8 [<ffffffc000089864>] __switch_to+0x34/0x218 [<ffffffc0011e089c>] __schedule+0x3ac/0x15b8 [<ffffffc0011e1f6c>] schedule+0x5c/0x178 [<ffffffc0001632a8>] smpboot_thread_fn+0x350/0x960 [<ffffffc00015b518>] kthread+0x1d8/0x2b0 [<ffffffc0000874d0>] ret_from_fork+0x10/0x40 Memory state around the buggy address: ffffffc0689eb980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4 ffffffc0689eba00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 >ffffffc0689eba80: 00 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00 ^ ffffffc0689ebb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0689ebb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 The stacker tracer traverses the whole kernel stack when saving the max stack trace. It may touch the stack red zones to cause the warning. So, just disable the instrumentation to silence the warning. Link: http://lkml.kernel.org/r/1455309960-18930-1-git-send-email-yang.shi@linaro.org Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching fixes from Jiri Kosina: - regression (from 4.4) fix for ordering issue, introduced by an earlier ftrace change, that broke live patching of modules. The fix replaces the ftrace module notifier by direct call in order to make the ordering guaranteed and well-defined. The patch, from Jessica Yu, has been acked both by Steven and Rusty - error message fix from Miroslav Benes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: ftrace/module: remove ftrace module notifier livepatch: change the error message in asm/livepatch.h header files
2016-02-18devm_memremap_release(): fix memremap'd addr handlingToshi Kani
The pmem driver calls devm_memremap() to map a persistent memory range. When the pmem driver is unloaded, this memremap'd range is not released so the kernel will leak a vma. Fix devm_memremap_release() to handle a given memremap'd address properly. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-17ftrace/module: remove ftrace module notifierJessica Yu
Remove the ftrace module notifier in favor of directly calling ftrace_module_enable() and ftrace_release_mod() in the module loader. Hard-coding the function calls directly in the module loader removes dependence on the module notifier call chain and provides better visibility and control over what gets called when, which is important to kernel utilities such as livepatch. This fixes a notifier ordering issue in which the ftrace module notifier (and hence ftrace_module_enable()) for coming modules was being called after klp_module_notify(), which caused livepatch modules to initialize incorrectly. This patch removes dependence on the module notifier call chain in favor of hard coding the corresponding function calls in the module loader. This ensures that ftrace and livepatch code get called in the correct order on patch module load and unload. Fixes: 5156dca34a3e ("ftrace: Fix the race between ftrace and insmod") Signed-off-by: Jessica Yu <jeyu@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Petr Mladek <pmladek@suse.cz> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-17perf/core: Plug potential memory leak in CPU_UP_PREPAREThomas Gleixner
If CPU_UP_PREPARE is called it is not guaranteed, that a previously allocated and assigned hash has been freed already, but perf_event_init_cpu() unconditionally allocates and assignes a new hash if the swhash is referenced. By overwriting the pointer the existing hash is not longer accessible. Verify that there is no hash assigned on this cpu before allocating and assigning a new one. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20160209201007.843269966@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug stateThomas Gleixner
If CPU_DOWN_PREPARE fails the perf hotplug notifier is called for CPU_DOWN_FAILED and calls perf_event_init_cpu(), which checks whether the swhash is referenced. If yes it allocates a new hash and stores the pointer in the per cpu data structure. But at this point the cpu is still online, so there must be a valid hash already. By overwriting the pointer the existing hash is not longer accessible. Remove the CPU_DOWN_FAILED state, as there is nothing to (re)allocate. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20160209201007.763417379@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17perf/core: Remove bogus UP_CANCELED hotplug stateThomas Gleixner
If CPU_UP_PREPARE fails the perf hotplug code calls perf_event_exit_cpu(), which is a pointless exercise. The cpu is not online, so the smp function calls return -ENXIO. So the result is a list walk to call noops. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20160209201007.682184765@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17sched/deadline: Fix trivial typo in printk() messageSteven Rostedt
It's "too much" not "to much". Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Juri Lelli <juri.lelli@arm.com> Cc: Jiri Kosina <trivial@kernel.org> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160210120422.4ca77e68@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-14Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull lockdep fix from Thomas Gleixner: "A single fix for the stack trace caching logic in lockdep, where the duplicate avoidance managed to store no back trace at all" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/lockdep: Fix stack trace caching logic
2016-02-11mm: fix pfn_t vs highmemDan Williams
The pfn_t type uses an unsigned long to store a pfn + flags value. On a 64-bit platform the upper 12 bits of an unsigned long are never used for storing the value of a pfn. However, this is not true on highmem platforms, all 32-bits of a pfn value are used to address a 44-bit physical address space. A pfn_t needs to store a 64-bit value. Link: https://bugzilla.kernel.org/show_bug.cgi?id=112211 Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Stuart Foster <smf.linux@ntlworld.com> Reported-by: Julian Margetson <runaway@candw.ms> Tested-by: Julian Margetson <runaway@candw.ms> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-11kernel/locking/lockdep.c: convert hash tables to hlistsAndrew Morton
Mike said: : CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i. e : kernel with CONFIG_UBSAN_ALIGNMENT fails to load without even any error : message. : : The problem is that ubsan callbacks use spinlocks and might be called : before lockdep is initialized. Particularly this line in the : reserve_ebda_region function causes problem: : : lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES); : : If i put lockdep_init() before reserve_ebda_region call in : x86_64_start_reservations kernel loads well. Fix this ordering issue permanently: change lockdep so that it uses hlists for the hash tables. Unlike a list_head, an hlist_head is in its initialized state when it is all-zeroes, so lockdep is ready for operation immediately upon boot - lockdep_init() need not have run. The patch will also save some memory. lockdep_init() and lockdep_initialized can be done away with now - a 4.6 patch has been prepared to do this. Reported-by: Mike Krinkin <krinkin.m.u@gmail.com> Suggested-by: Mike Krinkin <krinkin.m.u@gmail.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix BPF handling of branch offset adjustmnets on backjumps, from Daniel Borkmann. 2) Make sure selinux knows about SOCK_DESTROY netlink messages, from Lorenzo Colitti. 3) Fix openvswitch tunnel mtu regression, from David Wragg. 4) Fix ICMP handling of TCP sockets in syn_recv state, from Eric Dumazet. 5) Fix SCTP user hmacid byte ordering bug, from Xin Long. 6) Fix recursive locking in ipv6 addrconf, from Subash Abhinov Kasiviswanathan. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: bpf: fix branch offset adjustment on backjumps after patching ctx expansion vxlan, gre, geneve: Set a large MTU on ovs-created tunnel devices geneve: Relax MTU constraints vxlan: Relax MTU constraints flow_dissector: Fix unaligned access in __skb_flow_dissector when used by eth_get_headlen of: of_mdio: Add marvell, 88e1145 to whitelist of PHY compatibilities. selinux: nlmsgtab: add SOCK_DESTROY to the netlink mapping tables sctp: translate network order to host order when users get a hmacid enic: increment devcmd2 result ring in case of timeout tg3: Fix for tg3 transmit queue 0 timed out when too many gso_segs net:Add sysctl_max_skb_frags tcp: do not drop syn_recv on all icmp reports ipv6: fix a lockdep splat unix: correctly track in-flight fds in sending process user_struct update be2net maintainers' email addresses dwc_eth_qos: Reset hardware before PHY start ipv6: addrconf: Fix recursive spin lock call
2016-02-10bpf: fix branch offset adjustment on backjumps after patching ctx expansionDaniel Borkmann
When ctx access is used, the kernel often needs to expand/rewrite instructions, so after that patching, branch offsets have to be adjusted for both forward and backward jumps in the new eBPF program, but for backward jumps it fails to account the delta. Meaning, for example, if the expansion happens exactly on the insn that sits at the jump target, it doesn't fix up the back jump offset. Analysis on what the check in adjust_branches() is currently doing: /* adjust offset of jmps if necessary */ if (i < pos && i + insn->off + 1 > pos) insn->off += delta; else if (i > pos && i + insn->off + 1 < pos) insn->off -= delta; First condition (forward jumps): Before: After: insns[0] insns[0] insns[1] <--- i/insn insns[1] <--- i/insn insns[2] <--- pos insns[P] <--- pos insns[3] insns[P] `------| delta insns[4] <--- target_X insns[P] `-----| insns[5] insns[3] insns[4] <--- target_X insns[5] First case is if we cross pos-boundary and the jump instruction was before pos. This is handeled correctly. I.e. if i == pos, then this would mean our jump that we currently check was the patchlet itself that we just injected. Since such patchlets are self-contained and have no awareness of any insns before or after the patched one, the delta is correctly not adjusted. Also, for the second condition in case of i + insn->off + 1 == pos, means we jump to that newly patched instruction, so no offset adjustment are needed. That part is correct. Second condition (backward jumps): Before: After: insns[0] insns[0] insns[1] <--- target_X insns[1] <--- target_X insns[2] <--- pos <-- target_Y insns[P] <--- pos <-- target_Y insns[3] insns[P] `------| delta insns[4] <--- i/insn insns[P] `-----| insns[5] insns[3] insns[4] <--- i/insn insns[5] Second interesting case is where we cross pos-boundary and the jump instruction was after pos. Backward jump with i == pos would be impossible and pose a bug somewhere in the patchlet, so the first condition checking i > pos is okay only by itself. However, i + insn->off + 1 < pos does not always work as intended to trigger the adjustment. It works when jump targets would be far off where the delta wouldn't matter. But, for example, where the fixed insn->off before pointed to pos (target_Y), it now points to pos + delta, so that additional room needs to be taken into account for the check. This means that i) both tests here need to be adjusted into pos + delta, and ii) for the second condition, the test needs to be <= as pos itself can be a target in the backjump, too. Fixes: 9bac3d6d548e ("bpf: allow extended BPF programs access skb fields") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-10Merge branch 'for-4.5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - The destruction path of cgroup objects are asynchronous and multi-staged and some of them ended up destroying parents before children leading to failures in cpu and memory controllers. Ensure that parents are always destroyed after children. - cpuset mm node migration was performed synchronously while holding threadgroup and cgroup mutexes and the recent threadgroup locking update resulted in a possible deadlock. The migration is best effort and shouldn't have been performed under those locks to begin with. Made asynchronous. - Minor documentation fix. * 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Documentation: cgroup: Fix 'cgroup-legacy' -> 'cgroup-v1' cgroup: make sure a parent css isn't freed before its children cgroup: make sure a parent css isn't offlined before its children cpuset: make mm migration asynchronous
2016-02-10Merge branch 'for-4.5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fixes from Tejun Heo: "Workqueue fixes for v4.5-rc3. - Remove a spurious triggering of flush dependency warning. - Officially break local execution guarantee of unbound work items and add a debug feature to flush out usages which depend on it. - Work around CPU -> NODE mapping becoming invalid on CPU offline. The branch is young but pushing out early as stable kernels are being affected" * 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: handle NUMA_NO_NODE for unbound pool_workqueue lookup workqueue: implement "workqueue.debug_force_rr_cpu" debug feature workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs Revert "workqueue: make sure delayed work run in local cpu" workqueue: skip flush dependency checks for legacy workqueues
2016-02-10workqueue: handle NUMA_NO_NODE for unbound pool_workqueue lookupTejun Heo
When looking up the pool_workqueue to use for an unbound workqueue, workqueue assumes that the target CPU is always bound to a valid NUMA node. However, currently, when a CPU goes offline, the mapping is destroyed and cpu_to_node() returns NUMA_NO_NODE. This has always been broken but hasn't triggered often enough before 874bbfe600a6 ("workqueue: make sure delayed work run in local cpu"). After the commit, workqueue forcifully assigns the local CPU for delayed work items without explicit target CPU to fix a different issue. This widens the window where CPU can go offline while a delayed work item is pending causing delayed work items dispatched with target CPU set to an already offlined CPU. The resulting NUMA_NO_NODE mapping makes workqueue try to queue the work item on a NULL pool_workqueue and thus crash. While 874bbfe600a6 has been reverted for a different reason making the bug less visible again, it can still happen. Fix it by mapping NUMA_NO_NODE to the default pool_workqueue from unbound_pwq_by_node(). This is a temporary workaround. The long term solution is keeping CPU -> NODE mapping stable across CPU off/online cycles which is being worked on. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Len Brown <len.brown@intel.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/g/1454424264.11183.46.camel@gmail.com Link: http://lkml.kernel.org/g/1453702100-2597-1-git-send-email-tangchen@cn.fujitsu.com
2016-02-09Merge tag 'fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module fixes from Rusty Russell: "Fix for async_probe module param added in 4.3 (clearly not widely used yet), and a much more interesting kallsyms race which has been around approximately forever. This fix is more invasive, and will require some care in backporting, but I hated all the bandaids I could think of, so... There are some more coming, which are only for breakages introduced this cycle (livepatch), but wanted these in now" * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: modules: fix longstanding /proc/kallsyms vs module insertion race. module: wrapper for symbol name. modules: fix modparam async_probe request
2016-02-09workqueue: implement "workqueue.debug_force_rr_cpu" debug featureTejun Heo
Workqueue used to guarantee local execution for work items queued without explicit target CPU. The guarantee is gone now which can break some usages in subtle ways. To flush out those cases, this patch implements a debug feature which forces round-robin CPU selection for all such work items. The debug feature defaults to off and can be enabled with a kernel parameter. The default can be flipped with a debug config option. If you hit this commit during bisection, please refer to 041bd12e272c ("Revert "workqueue: make sure delayed work run in local cpu"") for more information and ping me. Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-09workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUsMike Galbraith
WORK_CPU_UNBOUND work items queued to a bound workqueue always run locally. This is a good thing normally, but not when the user has asked us to keep unbound work away from certain CPUs. Round robin these to wq_unbound_cpumask CPUs instead, as perturbation avoidance trumps performance. tj: Cosmetic and comment changes. WARN_ON_ONCE() dropped from empty (wq_unbound_cpumask AND cpu_online_mask). If we want that, it should be done when config changes. Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-09Revert "workqueue: make sure delayed work run in local cpu"Tejun Heo
This reverts commit 874bbfe600a660cba9c776b3957b1ce393151b76. Workqueue used to implicity guarantee that work items queued without explicit CPU specified are put on the local CPU. Recent changes in timer broke the guarantee and led to vmstat breakage which was fixed by 176bed1de5bf ("vmstat: explicitly schedule per-cpu work on the CPU we need it to run on"). vmstat is the most likely to expose the issue and it's quite possible that there are other similar problems which are a lot more difficult to trigger. As a preventive measure, 874bbfe600a6 ("workqueue: make sure delayed work run in local cpu") was applied to restore the local CPU guarnatee. Unfortunately, the change exposed a bug in timer code which got fixed by 22b886dd1018 ("timers: Use proper base migration in add_timer_on()"). Due to code restructuring, the commit couldn't be backported beyond certain point and stable kernels which only had 874bbfe600a6 started crashing. The local CPU guarantee was accidental more than anything else and we want to get rid of it anyway. As, with the vmstat case fixed, 874bbfe600a6 is causing more problems than it's fixing, it has been decided to take the chance and officially break the guarantee by reverting the commit. A debug feature will be added to force foreign CPU assignment to expose cases relying on the guarantee and fixes for the individual cases will be backported to stable as necessary. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 874bbfe600a6 ("workqueue: make sure delayed work run in local cpu") Link: http://lkml.kernel.org/g/20160120211926.GJ10810@quack.suse.cz Cc: stable@vger.kernel.org Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Daniel Bilik <daniel.bilik@neosystem.cz> Cc: Jan Kara <jack@suse.cz> Cc: Shaohua Li <shli@fb.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Bilik <daniel.bilik@neosystem.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Michal Hocko <mhocko@kernel.org>
2016-02-09locking/lockdep: Fix stack trace caching logicDmitry Vyukov
check_prev_add() caches saved stack trace in static trace variable to avoid duplicate save_trace() calls in dependencies involving trylocks. But that caching logic contains a bug. We may not save trace on first iteration due to early return from check_prev_add(). Then on the second iteration when we actually need the trace we don't save it because we think that we've already saved it. Let check_prev_add() itself control when stack is saved. There is another bug. Trace variable is protected by graph lock. But we can temporary release graph lock during printing. Fix this by invalidating cached stack trace when we release graph lock. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: glider@google.com Cc: kcc@google.com Cc: peter@hurleysoftware.com Cc: sasha.levin@oracle.com Link: http://lkml.kernel.org/r/1454593240-121647-1-git-send-email-dvyukov@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-05signals: avoid random wakeups in sigsuspend()Sasha Levin
A random wakeup can get us out of sigsuspend() without TIF_SIGPENDING being set. Avoid that by making sure we were signaled, like sys_pause() does. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-03Merge tag 'trace-v4.5-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "A cleanup to the stack tracer broke stack tracing on s390. Here's a simple fix to correct that issue" * tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/stacktrace: Show entire trace if passed in function not found
2016-02-03modules: fix longstanding /proc/kallsyms vs module insertion race.Rusty Russell
For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03module: wrapper for symbol name.Rusty Russell
This trivial wrapper adds clarity and makes the following patch smaller. Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03modules: fix modparam async_probe requestLuis R. Rodriguez
Commit f2411da746985 ("driver-core: add driver module asynchronous probe support") added async probe support, in two forms: * in-kernel driver specification annotation * generic async_probe module parameter (modprobe foo async_probe) To support the generic kernel parameter parse_args() was extended via commit ecc8617053e0 ("module: add extra argument for parse_params() callback") however commit failed to f2411da746985 failed to add the required argument. This causes a crash then whenever async_probe generic module parameter is used. This was overlooked when the form in which in-kernel async probe support was reworked a bit... Fix this as originally intended. Cc: Hannes Reinecke <hare@suse.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: stable@vger.kernel.org (4.2+) Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> [minimized]
2016-02-01Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "1/ Fixes to the libnvdimm 'pfn' device that establishes a reserved area for storing a struct page array. 2/ Fixes for dax operations on a raw block device to prevent pagecache collisions with dax mappings. 3/ A fix for pfn_t usage in vm_insert_mixed that lead to a null pointer de-reference. These have received build success notification from the kbuild robot across 153 configs and pass the latest ndctl tests" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: phys_to_pfn_t: use phys_addr_t mm: fix pfn_t to page conversion in vm_insert_mixed block: use DAX for partition table reads block: revert runtime dax control of the raw block device fs, block: force direct-I/O for dax-enabled block devices devm_memremap_pages: fix vmem_altmap lifetime + alignment handling libnvdimm, pfn: fix restoring memmap location libnvdimm: fix mode determination for e820 devices
2016-01-31Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "The timer departement delivers: - a regression fix for the NTP code along with a proper selftest - prevent a spurious timer interrupt in the NOHZ lowres code - a fix for user space interfaces returning the remaining time on architectures with CONFIG_TIME_LOW_RES=y - a few patches to fix COMPILE_TEST fallout" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/nohz: Set the correct expiry when switching to nohz/lowres mode clocksource: Fix dependencies for archs w/o HAS_IOMEM clocksource: Select CLKSRC_MMIO where needed tick/sched: Hide unused oneshot timer code kselftests: timers: Add adjtimex SETOFFSET validity tests ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO itimers: Handle relative timers with CONFIG_TIME_LOW_RES proper posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper hrtimer: Handle remaining time proper for TIME_LOW_RES clockevents/tcb_clksrc: Prevent disabling an already disabled clock