Messages in this thread | | | Date | Wed, 10 Dec 2014 16:46:58 -0800 | Subject | Re: [PATCH, 3.18] sleeping function called from invalid context | From | Daniel J Blueman <> |
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Gah. I had some non-temporal copy changes in the wrong tree. I'll check with a definitely clean tree and follow up if it still occurs.
On 10 December 2014 at 16:37, Andy Lutomirski <luto@amacapital.net> wrote: > Adding Rik, who is probably the most recent person to have looked at > the disaster fondly known as "FPU". > > On Wed, Dec 10, 2014 at 4:25 PM, Daniel J Blueman <daniel@quora.org> wrote: >> With 3.18, I was seeing a significant number of allocation warnings >> from load_elf_binary call paths [1]. >> >> Allocating FPU state atomically [2] does prevent potentially sleeping >> while atomic, but probably isn't the correct fix. Anyone familiar with >> this area? >> >> -- [1] >> >> BUG: sleeping function called from invalid context at mm/slub.c:1240 >> in_atomic(): 1, irqs_disabled(): 0, pid: 29016, name: dmesg >> INFO: lockdep is turned off. >> Preemption disabled at:[<ffffffff8114625f>] handle_mm_fault+0x5ff/0x8a0 >> >> CPU: 122 PID: 29016 Comm: dmesg Tainted: G W 3.18.0-test #6 >> Hardware name: Supermicro AS -1042G-LTF/H8QGL, BIOS DS3.5a 11/13/2014 >> ffffffff8203b81b ffff886fdf62f888 ffffffff81b942e8 0000000000000007 >> 0000000000000000 ffff886fdf62f8b8 ffffffff8109ac4c 0000000000000000 >> 0000000000000010 ffff8807df84bc00 00000000000000d0 ffff886fdf62f908 >> Call Trace: >> [<ffffffff81b942e8>] dump_stack+0x4f/0x7c >> [<ffffffff8109ac4c>] __might_sleep+0x164/0x250 >> [<ffffffff8116372b>] kmem_cache_alloc+0xeb/0x138 >> [<ffffffff8100e0e1>] init_fpu+0x71/0xb0 >> [<ffffffff81003966>] math_state_restore+0xce/0x208 >> [<ffffffff8100437b>] do_device_not_available+0x2b/0x60 >> [<ffffffff81ba70f5>] device_not_available+0x15/0x20 >> [<ffffffff81487102>] ? copy_page+0x12/0x33 > > wtf? I don't see any fpu state being accessed in copy_page. > > Can you disassemble "[<ffffffff81487102>] ? copy_page+0x12/0x33"? > > --Andy > >> [<ffffffff8109edb9>] ? get_parent_ip+0x11/0x58 >> [<ffffffff8109ee55>] ? preempt_count_add+0x55/0xb0 >> [<ffffffff811437a1>] ? do_cow_fault+0xe9/0x258 >> [<ffffffff8114625f>] handle_mm_fault+0x5ff/0x8a0 >> [<ffffffff81032218>] ? __do_page_fault+0xc8/0x498 >> [<ffffffff811481b9>] ? vma_gap_callbacks_rotate+0x19/0x20 >> [<ffffffff8103227d>] __do_page_fault+0x12d/0x498 >> [<ffffffff810b682e>] ? up_write+0x1e/0x48 >> [<ffffffff81148d18>] ? vma_link+0x80/0xc0 >> [<ffffffff81149cb2>] ? vma_set_page_prot+0x3a/0x60 >> [<ffffffff8114ae6e>] ? mmap_region+0x1be/0x5e0 >> [<ffffffff8103262e>] do_page_fault+0x1e/0x70 >> [<ffffffff81ba737f>] page_fault+0x1f/0x30 >> [<ffffffff81487f3e>] ? __clear_user+0x2e/0x50 >> [<ffffffff81487f22>] ? __clear_user+0x12/0x50 >> [<ffffffff81487f8a>] clear_user+0x2a/0x30 >> [<ffffffff811ca1e1>] padzero+0x21/0x30 >> [<ffffffff811cc41f>] load_elf_binary+0x8cf/0xdd0 >> [<ffffffff8117d18f>] search_binary_handler+0x7f/0x1f8 >> [<ffffffff8117ec06>] do_execve_common.isra.34+0x616/0x790 >> [<ffffffff8117eb62>] ? do_execve_common.isra.34+0x572/0x790 >> [<ffffffff8117ed93>] do_execve+0x13/0x18 >> [<ffffffff8117f070>] SyS_execve+0x20/0x30 >> [<ffffffff81ba6159>] stub_execve+0x69/0xa0 >> >> -- [2] >> >> diff --git a/arch/x86/include/asm/fpu-internal.h >> b/arch/x86/include/asm/fpu-internal.h >> index e97622f..57029ad 100644 >> --- a/arch/x86/include/asm/fpu-internal.h >> +++ b/arch/x86/include/asm/fpu-internal.h >> @@ -574,7 +574,7 @@ static inline int fpu_alloc(struct fpu *fpu) >> { >> if (fpu_allocated(fpu)) >> return 0; >> - fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL); >> + fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_ATOMIC); >> if (!fpu->state) >> return -ENOMEM; >> WARN_ON((unsigned long)fpu->state & 15); >> -- >> Daniel J Blueman > > > > -- > Andy Lutomirski > AMA Capital Management, LLC
-- Daniel J Blueman
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