diff options
| author | Christoph Lameter <cl@linux.com> | 2014-03-22 12:49:47 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2014-04-03 15:14:28 +1100 |
| commit | 2b8bfa62f651d7b614cd221a6afdbd65e8178346 (patch) | |
| tree | fc3db7f1dd4d3446a906fd9663db579b3349b2b0 /kernel | |
| parent | 58806f31d1e16f9389c4a15c4bd3dd5fa6fe88c1 (diff) | |
modules: use raw_cpu_write for initialization of per cpu refcount.
The initialization of a structure is not subject to synchronization. The
use of __this_cpu would trigger a false positive with the additional
preemption checks for __this_cpu ops.
So simply disable the check through the use of raw_cpu ops.
Trace:
[ 0.668066] __this_cpu_write operation in preemptible [00000000] code: modprobe/286
[ 0.668108] caller is __this_cpu_preempt_check+0x38/0x60
[ 0.668111] CPU: 3 PID: 286 Comm: modprobe Tainted: GF 3.12.0-rc4+ #187
[ 0.668112] Hardware name: FUJITSU CELSIUS W530 Power/D3227-A1, BIOS V4.6.5.4 R1.10.0 for D3227-A1x 09/16/2013
[ 0.668113] 0000000000000003 ffff8807edda1d18 ffffffff816d5a57 ffff8807edda1fd8
[ 0.668117] ffff8807edda1d48 ffffffff8137359c ffff8807edda1ef8 ffffffffa0002178
[ 0.668121] ffffc90000067730 ffff8807edda1e48 ffff8807edda1d88 ffffffff813735f8
[ 0.668124] Call Trace:
[ 0.668129] [<ffffffff816d5a57>] dump_stack+0x4e/0x82
[ 0.668132] [<ffffffff8137359c>] check_preemption_disabled+0xec/0x110
[ 0.668135] [<ffffffff813735f8>] __this_cpu_preempt_check+0x38/0x60
[ 0.668139] [<ffffffff810c24fd>] load_module+0xcfd/0x2650
[ 0.668143] [<ffffffff816dd922>] ? page_fault+0x22/0x30
[ 0.668146] [<ffffffff810c3ef6>] SyS_init_module+0xa6/0xd0
[ 0.668150] [<ffffffff816e4fd3>] tracesys+0xe1/0xe6
Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/module.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/module.c b/kernel/module.c index 29f7790eaa14..11869408f79b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -640,7 +640,7 @@ static int module_unload_init(struct module *mod) INIT_LIST_HEAD(&mod->target_list); /* Hold reference count during initialization. */ - __this_cpu_write(mod->refptr->incs, 1); + raw_cpu_write(mod->refptr->incs, 1); return 0; } |