user/sven/linux.git/kernel/workqueue.c, branch v5.0.19

workqueue: Try to catch flush_work() without INIT_WORK().

2019-05-02T08:02:49Z

commit 4d43d395fed124631ca02356c711facb90185175 upstream. syzbot found a flush_work() caller who forgot to call INIT_WORK() because that work_struct was allocated by kzalloc() [1]. But the message INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. by lock_map_acquire() is failing to tell that INIT_WORK() is missing. Since flush_work() without INIT_WORK() is a bug, and INIT_WORK() should set ->func field to non-zero, let's warn if ->func field is zero. [1] https://syzkaller.appspot.com/bug?id=a5954455fcfa51c29ca2ab55b203076337e1c770 Signed-off-by: Tetsuo Handa Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

psi: fix aggregation idle shut-off

2019-02-01T23:46:23Z

psi has provisions to shut off the periodic aggregation worker when there is a period of no task activity - and thus no data that needs aggregating. However, while developing psi monitoring, Suren noticed that the aggregation clock currently won't stay shut off for good. Debugging this revealed a flaw in the idle design: an aggregation run will see no task activity and decide to go to sleep; shortly thereafter, the kworker thread that executed the aggregation will go idle and cause a scheduling change, during which the psi callback will kick the !pending worker again. This will ping-pong forever, and is equivalent to having no shut-off logic at all (but with more code!) Fix this by exempting aggregation workers from psi's clock waking logic when the state change is them going to sleep. To do this, tag workers with the last work function they executed, and if in psi we see a worker going to sleep after aggregating psi data, we will not reschedule the aggregation work item. What if the worker is also executing other items before or after? Any psi state times that were incurred by work items preceding the aggregation work will have been collected from the per-cpu buckets during the aggregation itself. If there are work items following the aggregation work, the worker's last_func tag will be overwritten and the aggregator will be kept alive to process this genuine new activity. If the aggregation work is the last thing the worker does, and we decide to go idle, the brief period of non-idle time incurred between the aggregation run and the kworker's dequeue will be stranded in the per-cpu buckets until the clock is woken by later activity. But that should not be a problem. The buckets can hold 4s worth of time, and future activity will wake the clock with a 2s delay, giving us 2s worth of data we can leave behind when disabling aggregation. If it takes a worker more than two seconds to go idle after it finishes its last work item, we likely have bigger problems in the system, and won't notice one sample that was averaged with a bogus per-CPU weight. Link: http://lkml.kernel.org/r/20190116193501.1910-1-hannes@cmpxchg.org Fixes: eb414681d5a0 ("psi: pressure stall information for CPU, memory, and IO") Signed-off-by: Johannes Weiner Reported-by: Suren Baghdasaryan Acked-by: Tejun Heo Cc: Peter Zijlstra Cc: Lai Jiangshan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

workqueue: Replace call_rcu_sched() with call_rcu()

2018-11-27T17:21:44Z

Now that call_rcu()'s callback is not invoked until after all preempt-disable regions of code have completed (in addition to explicitly marked RCU read-side critical sections), call_rcu() can be used in place of call_rcu_sched(). This commit therefore makes that change. Signed-off-by: Paul E. McKenney Cc: Lai Jiangshan Acked-by: Tejun Heo

watchdog: Mark watchdog touch functions as notrace

2018-08-30T10:56:40Z

Some architectures need to use stop_machine() to patch functions for ftrace, and the assumption is that the stopped CPUs do not make function calls to traceable functions when they are in the stopped state. Commit ce4f06dcbb5d ("stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE") added calls to the watchdog touch functions from the stopped CPUs and those functions lack notrace annotations. This leads to crashes when enabling/disabling ftrace on ARM kernels built with the Thumb-2 instruction set. Fix it by adding the necessary notrace annotations. Fixes: ce4f06dcbb5d ("stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE") Signed-off-by: Vincent Whitchurch Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: oleg@redhat.com Cc: tj@kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180821152507.18313-1-vincent.whitchurch@axis.com

Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2018-08-24T20:16:36Z

Pull workqueue updates from Tejun Heo: "Over the lockdep cross-release churn, workqueue lost some of the existing annotations. Johannes Berg restored it and also improved them" * 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: re-add lockdep dependencies for flushing workqueue: skip lockdep wq dependency in cancel_work_sync()

workqueue: re-add lockdep dependencies for flushing

2018-08-22T15:31:38Z

In flush_work(), we need to create a lockdep dependency so that the following scenario is appropriately tagged as a problem: work_function() { mutex_lock(&mutex); ... } other_function() { mutex_lock(&mutex); flush_work(&work); // or cancel_work_sync(&work); } This is a problem since the work might be running and be blocked on trying to acquire the mutex. Similarly, in flush_workqueue(). These were removed after cross-release partially caught these problems, but now cross-release was reverted anyway. IMHO the removal was erroneous anyway though, since lockdep should be able to catch potential problems, not just actual ones, and cross-release would only have caught the problem when actually invoking wait_for_completion(). Fixes: fd1a5b04dfb8 ("workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes") Signed-off-by: Johannes Berg Signed-off-by: Tejun Heo

workqueue: skip lockdep wq dependency in cancel_work_sync()

2018-08-22T15:31:37Z

In cancel_work_sync(), we can only have one of two cases, even with an ordered workqueue: * the work isn't running, just cancelled before it started * the work is running, but then nothing else can be on the workqueue before it Thus, we need to skip the lockdep workqueue dependency handling, otherwise we get false positive reports from lockdep saying that we have a potential deadlock when the workqueue also has other work items with locking, e.g. work1_function() { mutex_lock(&mutex); ... } work2_function() { /* nothing */ } other_function() { queue_work(ordered_wq, &work1); queue_work(ordered_wq, &work2); mutex_lock(&mutex); cancel_work_sync(&work2); } As described above, this isn't a problem, but lockdep will currently flag it as if cancel_work_sync() was flush_work(), which *is* a problem. Signed-off-by: Johannes Berg Signed-off-by: Tejun Heo

treewide: kzalloc() -> kcalloc()

2018-06-12T23:19:22Z

The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2018-06-10T20:01:12Z

Pull SCSI updates from James Bottomley: "This is mostly updates to the usual drivers: ufs, qedf, mpt3sas, lpfc, xfcp, hisi_sas, cxlflash, qla2xxx. In the absence of Nic, we're also taking target updates which are mostly minor except for the tcmu refactor. The only real core change to worry about is the removal of high page bouncing (in sas, storvsc and iscsi). This has been well tested and no problems have shown up so far" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (268 commits) scsi: lpfc: update driver version to 12.0.0.4 scsi: lpfc: Fix port initialization failure. scsi: lpfc: Fix 16gb hbas failing cq create. scsi: lpfc: Fix crash in blk_mq layer when executing modprobe -r lpfc scsi: lpfc: correct oversubscription of nvme io requests for an adapter scsi: lpfc: Fix MDS diagnostics failure (Rx < Tx) scsi: hisi_sas: Mark PHY as in reset for nexus reset scsi: hisi_sas: Fix return value when get_free_slot() failed scsi: hisi_sas: Terminate STP reject quickly for v2 hw scsi: hisi_sas: Add v2 hw force PHY function for internal ATA command scsi: hisi_sas: Include TMF elements in struct hisi_sas_slot scsi: hisi_sas: Try wait commands before before controller reset scsi: hisi_sas: Init disks after controller reset scsi: hisi_sas: Create a scsi_host_template per HW module scsi: hisi_sas: Reset disks when discovered scsi: hisi_sas: Add LED feature for v3 hw scsi: hisi_sas: Change common allocation mode of device id scsi: hisi_sas: change slot index allocation mode scsi: hisi_sas: Introduce hisi_sas_phy_set_linkrate() scsi: hisi_sas: fix a typo in hisi_sas_task_prep() ...

Merge tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2018-06-07T00:27:14Z

Pull overflow updates from Kees Cook: "This adds the new overflow checking helpers and adds them to the 2-factor argument allocators. And this adds the saturating size helpers and does a treewide replacement for the struct_size() usage. Additionally this adds the overflow testing modules to make sure everything works. I'm still working on the treewide replacements for allocators with "simple" multiplied arguments: *alloc(a * b, ...) -> *alloc_array(a, b, ...) and *zalloc(a * b, ...) -> *calloc(a, b, ...) as well as the more complex cases, but that's separable from this portion of the series. I expect to have the rest sent before -rc1 closes; there are a lot of messy cases to clean up. Summary: - Introduce arithmetic overflow test helper functions (Rasmus) - Use overflow helpers in 2-factor allocators (Kees, Rasmus) - Introduce overflow test module (Rasmus, Kees) - Introduce saturating size helper functions (Matthew, Kees) - Treewide use of struct_size() for allocators (Kees)" * tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: treewide: Use struct_size() for devm_kmalloc() and friends treewide: Use struct_size() for vmalloc()-family treewide: Use struct_size() for kmalloc()-family device: Use overflow helpers for devm_kmalloc() mm: Use overflow helpers in kvmalloc() mm: Use overflow helpers in kmalloc_array*() test_overflow: Add memory allocation overflow tests overflow.h: Add allocation size calculation helpers test_overflow: Report test failures test_overflow: macrofy some more, do more tests for free lib: add runtime test of check_*_overflow functions compiler.h: enable builtin overflow checkers and add fallback code