On Fri, Nov 29, 2019 at 11:43 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > > On Tue, Nov 19, 2019 at 10:54 AM Andrey Ryabinin > <aryabinin@xxxxxxxxxxxxx> wrote: > > On 11/18/19 6:29 AM, Daniel Axtens wrote: > > > Qian Cai <cai@xxxxxx> writes: > > > > > >> On Thu, 2019-10-31 at 20:39 +1100, Daniel Axtens wrote: > > >>> /* > > >>> * In this function, newly allocated vm_struct has VM_UNINITIALIZED > > >>> * flag. It means that vm_struct is not fully initialized. > > >>> @@ -3377,6 +3411,9 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, > > >>> > > >>> setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, > > >>> pcpu_get_vm_areas); > > >>> + > > >>> + /* assume success here */ > > >>> + kasan_populate_vmalloc(sizes[area], vms[area]); > > >>> } > > >>> spin_unlock(&vmap_area_lock); > > >> > > >> Here it is all wrong. GFP_KERNEL with in_atomic(). > > > > > > I think this fix will work, I will do a v12 with it included. > > > > You can send just the fix. Andrew will fold it into the original patch before sending it to Linus. > > > > > > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > index a4b950a02d0b..bf030516258c 100644 > > > --- a/mm/vmalloc.c > > > +++ b/mm/vmalloc.c > > > @@ -3417,11 +3417,14 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, > > > > > > setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, > > > pcpu_get_vm_areas); > > > + } > > > + spin_unlock(&vmap_area_lock); > > > > > > + /* populate the shadow space outside of the lock */ > > > + for (area = 0; area < nr_vms; area++) { > > > /* assume success here */ > > > kasan_populate_vmalloc(sizes[area], vms[area]); > > > } > > > - spin_unlock(&vmap_area_lock); > > > > > > kfree(vas); > > > return vms; > > Hi, > > I am testing this support on next-20191129 and seeing the following warnings: > > BUG: sleeping function called from invalid context at mm/page_alloc.c:4681 > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 44, name: kworker/1:1 > 4 locks held by kworker/1:1/44: > #0: ffff888067c26d28 ((wq_completion)events){+.+.}, at: > __write_once_size include/linux/compiler.h:247 [inline] > #0: ffff888067c26d28 ((wq_completion)events){+.+.}, at: > arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] > #0: ffff888067c26d28 ((wq_completion)events){+.+.}, at: atomic64_set > include/asm-generic/atomic-instrumented.h:868 [inline] > #0: ffff888067c26d28 ((wq_completion)events){+.+.}, at: > atomic_long_set include/asm-generic/atomic-long.h:40 [inline] > #0: ffff888067c26d28 ((wq_completion)events){+.+.}, at: set_work_data > kernel/workqueue.c:615 [inline] > #0: ffff888067c26d28 ((wq_completion)events){+.+.}, at: > set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] > #0: ffff888067c26d28 ((wq_completion)events){+.+.}, at: > process_one_work+0x88b/0x1750 kernel/workqueue.c:2235 > #1: ffffc900002afdf0 (pcpu_balance_work){+.+.}, at: > process_one_work+0x8c0/0x1750 kernel/workqueue.c:2239 > #2: ffffffff8943f080 (pcpu_alloc_mutex){+.+.}, at: > pcpu_balance_workfn+0xcc/0x13e0 mm/percpu.c:1845 > #3: ffffffff89450c78 (vmap_area_lock){+.+.}, at: spin_lock > include/linux/spinlock.h:338 [inline] > #3: ffffffff89450c78 (vmap_area_lock){+.+.}, at: > pcpu_get_vm_areas+0x1449/0x3df0 mm/vmalloc.c:3431 > Preemption disabled at: > [<ffffffff81a84199>] spin_lock include/linux/spinlock.h:338 [inline] > [<ffffffff81a84199>] pcpu_get_vm_areas+0x1449/0x3df0 mm/vmalloc.c:3431 > CPU: 1 PID: 44 Comm: kworker/1:1 Not tainted 5.4.0-next-20191129+ #5 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014 > Workqueue: events pcpu_balance_workfn > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x199/0x216 lib/dump_stack.c:118 > ___might_sleep.cold.97+0x1f5/0x238 kernel/sched/core.c:6800 > __might_sleep+0x95/0x190 kernel/sched/core.c:6753 > prepare_alloc_pages mm/page_alloc.c:4681 [inline] > __alloc_pages_nodemask+0x3cd/0x890 mm/page_alloc.c:4730 > alloc_pages_current+0x10c/0x210 mm/mempolicy.c:2211 > alloc_pages include/linux/gfp.h:532 [inline] > __get_free_pages+0xc/0x40 mm/page_alloc.c:4786 > kasan_populate_vmalloc_pte mm/kasan/common.c:762 [inline] > kasan_populate_vmalloc_pte+0x2f/0x1b0 mm/kasan/common.c:753 > apply_to_pte_range mm/memory.c:2041 [inline] > apply_to_pmd_range mm/memory.c:2068 [inline] > apply_to_pud_range mm/memory.c:2088 [inline] > apply_to_p4d_range mm/memory.c:2108 [inline] > apply_to_page_range+0x5ca/0xa00 mm/memory.c:2133 > kasan_populate_vmalloc+0x69/0xa0 mm/kasan/common.c:791 > pcpu_get_vm_areas+0x1596/0x3df0 mm/vmalloc.c:3439 > pcpu_create_chunk+0x240/0x7f0 mm/percpu-vm.c:340 > pcpu_balance_workfn+0x1033/0x13e0 mm/percpu.c:1934 > process_one_work+0x9b5/0x1750 kernel/workqueue.c:2264 > worker_thread+0x8b/0xd20 kernel/workqueue.c:2410 > kthread+0x365/0x450 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > > Not sure if it's the same or not. Is it addressed by something in flight? > > My config: > https://gist.githubusercontent.com/dvyukov/36c7be311fdec9cd51c649f7c3cb2ddb/raw/39c6f864fdd0ffc53f0822b14c354a73c1695fa1/gistfile1.txt I've tried this fix for pcpu_get_vm_areas: https://groups.google.com/d/msg/kasan-dev/t_F2X1MWKwk/h152Z3q2AgAJ and it helps. But this will break syzbot on linux-next soon.