Messages in this thread | | | Date | Wed, 30 Apr 2008 21:51:10 +0200 | From | Luca Tettamanti <> | Subject | [BUG] smp alternatives: sleeping function called from invalid context |
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Hello, with git current I'm seeing these warnings when bringing CPUs down:
[13794.108805] CPU0 attaching NULL sched-domain. [13794.108815] CPU1 attaching NULL sched-domain. [13794.124695] Broke affinity for irq 22 [13794.192376] CPU 1 is now offline [13794.192381] lockdep: fixing up alternatives. [13794.192389] SMP alternatives: switching to UP code [13794.192395] BUG: sleeping function called from invalid context at /home/kronos/src/linux-2.6.git/mm/slab.c:3049 [13794.192398] in_atomic():1, irqs_disabled():0 [13794.192401] 4 locks held by bash/11413: [13794.192404] #0: (&buffer->mutex){--..}, at: [<ffffffff802c638c>] sysfs_write_file+0x36/0x10c [13794.192417] #1: (cpu_add_remove_lock){--..}, at: [<ffffffff80253479>] cpu_down+0x12/0x32 [13794.192427] #2: (&cpu_hotplug.lock){--..}, at: [<ffffffff80253024>] cpu_hotplug_begin+0x36/0xa6 [13794.192435] #3: (smp_alt){--..}, at: [<ffffffff8021182f>] alternatives_smp_switch+0x63/0x1a5 [13794.192446] Pid: 11413, comm: bash Not tainted 2.6.25-64-05976-ge31a94e-dirty #68 [13794.192449] [13794.192450] Call Trace: [13794.192681] [<ffffffff80280f61>] __kmalloc+0x29/0x7d [13794.192695] [<ffffffff80276415>] __get_vm_area_node+0x9a/0x1b1 [13794.192703] [<ffffffff80209391>] clear_ti_thread_flag+0xc/0x12 [13794.192709] [<ffffffff80276585>] get_vm_area_caller+0x2b/0x2e [13794.192715] [<ffffffff8021159d>] text_poke+0xdd/0x156 [13794.192719] [<ffffffff80276cc5>] vmap+0x2d/0x5a [13794.192727] [<ffffffff8021159d>] text_poke+0xdd/0x156 [13794.192736] [<ffffffff80446f1b>] _etext+0x0/0x5 [13794.192742] [<ffffffff80211666>] alternatives_smp_unlock+0x50/0x65 [13794.192752] [<ffffffff80211934>] alternatives_smp_switch+0x168/0x1a5 [13794.192758] [<ffffffff80219439>] __cpus_weight+0x3f/0x41 [13794.192767] [<ffffffff802532b4>] _cpu_down+0x18f/0x264 [13794.192796] [<ffffffff8025348b>] cpu_down+0x24/0x32 [13794.192805] [<ffffffff8043259d>] store_online+0x29/0x67 [13794.192812] [<ffffffff802c642b>] sysfs_write_file+0xd5/0x10c [13794.192824] [<ffffffff80283cba>] vfs_write+0xa5/0xde [13794.192832] [<ffffffff80283da5>] sys_write+0x45/0x6b [13794.192842] [<ffffffff80221ed2>] ia32_sysret+0x0/0xa [13794.192857] [13794.208799] CPU0 attaching NULL sched-domain.
...and up:
[13803.369635] lockdep: fixing up alternatives. [13803.369640] SMP alternatives: switching to SMP code [13803.369645] BUG: sleeping function called from invalid context at /home/kronos/src/linux-2.6.git/mm/slab.c:3049 [13803.369648] in_atomic():1, irqs_disabled():0 [13803.369651] 4 locks held by bash/11413: [13803.369654] #0: (&buffer->mutex){--..}, at: [<ffffffff802c638c>] sysfs_write_file+0x36/0x10c [13803.369666] #1: (cpu_add_remove_lock){--..}, at: [<ffffffff8044115e>] cpu_up+0x40/0x64 [13803.369676] #2: (&cpu_hotplug.lock){--..}, at: [<ffffffff80253024>] cpu_hotplug_begin+0x36/0xa6 [13803.369686] #3: (smp_alt){--..}, at: [<ffffffff8021182f>] alternatives_smp_switch+0x63/0x1a5 [13803.369697] Pid: 11413, comm: bash Not tainted 2.6.25-64-05976-ge31a94e-dirty #68 [13803.369700] [13803.369701] Call Trace: [13803.369712] [<ffffffff80280f61>] __kmalloc+0x29/0x7d [13803.369721] [<ffffffff80276415>] __get_vm_area_node+0x9a/0x1b1 [13803.369731] [<ffffffff80209391>] clear_ti_thread_flag+0xc/0x12 [13803.369738] [<ffffffff80446f1b>] _etext+0x0/0x5 [13803.369743] [<ffffffff80276585>] get_vm_area_caller+0x2b/0x2e [13803.369749] [<ffffffff8021159d>] text_poke+0xdd/0x156 [13803.369753] [<ffffffff80276cc5>] vmap+0x2d/0x5a [13803.369763] [<ffffffff8021159d>] text_poke+0xdd/0x156 [13803.369773] [<ffffffff802118c5>] alternatives_smp_switch+0xf9/0x1a5 [13803.369795] [<ffffffff8043f29e>] native_cpu_up+0x224/0x7fc [13803.369804] [<ffffffff8043ee95>] do_fork_idle+0x0/0x20 [13803.369833] [<ffffffff80441098>] _cpu_up+0x91/0x117 [13803.369842] [<ffffffff80441175>] cpu_up+0x57/0x64 [13803.369849] [<ffffffff804325b7>] store_online+0x43/0x67 [13803.369856] [<ffffffff802c642b>] sysfs_write_file+0xd5/0x10c [13803.369867] [<ffffffff80283cba>] vfs_write+0xa5/0xde [13803.369875] [<ffffffff80283da5>] sys_write+0x45/0x6b [13803.369886] [<ffffffff80221ed2>] ia32_sysret+0x0/0xa [13803.369898] [13803.380408] Booting processor 1/1 ip 6000 [13803.389154] Initializing CPU#1 [13803.389154] masked ExtINT on CPU#1
The bug has been introduced (assuming that I'm using git blame correctly) by this commit:
commit e587cadd8f47e202a30712e2906a65a0606d5865 Author: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Date: Thu Mar 6 08:48:49 2008 -0500
x86: enhance DEBUG_RODATA support - alternatives
In both code paths - cpu_up() and cpud_down() - alternatives_smp_switch ends up calling text_poke() (via alternatives_smp_{,un}lock) with smp_alt held; then text_poke does a vmap which might sleep!
Luca -- Windows NT crashed. I'm the Blue Screen of Death. No one hears your screams.
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