On Mon, 16 Nov 2015 11:12:50 +0800 kernel test robot <ying.hu...@linux.intel.com> wrote:
> FYI, we noticed the below changes on > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > commit 08d78658f393fefaa2e6507ea052c6f8ef4002a2 ("panic: release stale > console lock to always get the logbuf printed out") > > ... > > [ 38.408623] ===================================== > [ 38.408623] [ BUG: bad unlock balance detected! ] > [ 38.408627] 4.3.0-08150-g08d7865 #1 Not tainted > [ 38.408627] ------------------------------------- > [ 38.408631] swapper/0/1 is trying to release lock (console_lock) at: > [ 38.408639] [<ffffffff811a3cb1>] panic+0x124/0x213 > [ 38.408640] but there are no more locks to release! > [ 38.408641] > [ 38.408641] other info that might help us debug this: > [ 38.408642] 2 locks held by swapper/0/1: > [ 38.408651] #0: (oom_lock){+.+...}, at: [<ffffffff811add45>] > __alloc_pages_slowpath+0x5bd/0x68d > [ 38.408656] #1: (panic_lock){......}, at: [<ffffffff811a3bd9>] > panic+0x4c/0x213 > [ 38.408657] > [ 38.408657] stack backtrace: > [ 38.408659] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.3.0-08150-g08d7865 > #1 > [ 38.408660] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > Debian-1.8.2-1 04/01/2014 > [ 38.408665] 0000000000000000 ffff8800132bba78 ffffffff8173760d > ffff8800132b4040 > [ 38.408668] ffff8800132bbaa0 ffffffff8111328c 00000000ffffffff > ffff8800132b4040 > [ 38.408670] ffffffff8406a080 ffff8800132bbb18 ffffffff8111626c > ffffffff811139d1 > [ 38.408671] Call Trace: > [ 38.408678] [<ffffffff8173760d>] dump_stack+0x4b/0x63 > [ 38.408682] [<ffffffff8111328c>] print_unlock_imbalance_bug+0xc7/0xd0 Yup, we can't have this happen. Can we instead do this? if (is_console_locked()) console_unlock(); It's racy, but more accurate than what we have now? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
