On Mon, Feb 08, 2016 at 02:49:24PM -0800, Yang Shi wrote: > BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917 > in_atomic(): 1, irqs_disabled(): 128, pid: 383, name: sh > Preemption disabled at:[<ffff800000124c18>] kgdb_cpu_enter+0x158/0x6b8 > > CPU: 3 PID: 383 Comm: sh Tainted: G W 4.1.13-rt13 #2 > Hardware name: Freescale Layerscape 2085a RDB Board (DT) > Call trace: > [<ffff8000000885e8>] dump_backtrace+0x0/0x128 > [<ffff800000088734>] show_stack+0x24/0x30 > [<ffff80000079a7c4>] dump_stack+0x80/0xa0 > [<ffff8000000bd324>] ___might_sleep+0x18c/0x1a0 > [<ffff8000007a20ac>] __rt_spin_lock+0x2c/0x40 > [<ffff8000007a2268>] rt_read_lock+0x40/0x58 > [<ffff800000085328>] single_step_handler+0x38/0xd8 > [<ffff800000082368>] do_debug_exception+0x58/0xb8 > Exception stack(0xffff80834a1e7c80 to 0xffff80834a1e7da0) > 7c80: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7e40 ffff8083 001bfcc4 ffff8000 > 7ca0: f2000400 00000000 00000000 00000000 4a1e7d80 ffff8083 0049501c ffff8000 > 7cc0: 00005402 00000000 00aaa210 ffff8000 4a1e7ea0 ffff8083 000833f4 ffff8000 > 7ce0: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7ea0 ffff8083 001bfcc0 ffff8000 > 7d00: 4a0fc400 ffff8083 00005402 00000000 4a1e7d40 ffff8083 00490324 ffff8000 > 7d20: ffffff9c 00000000 92c23ba0 0000ffff 000a0000 00000000 00000000 00000000 > 7d40: 00000008 00000000 00080000 00000000 92c23b8b 0000ffff 92c23b8e 0000ffff > 7d60: 00000038 00000000 00001cb2 00000000 00000005 00000000 92d7b498 0000ffff > 7d80: 01010101 01010101 92be9000 0000ffff 00000000 00000000 00000030 00000000 > [<ffff8000000833f4>] el1_dbg+0x18/0x6c > > This issue is similar with 62c6c61("arm64: replace read_lock to rcu lock in > call_break_hook"), but comes to single_step_handler. > > This also solves kgdbts boot test silent hang issue on 4.4 -rt kernel. > > Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxx> Acked-by: Will Deacon <will.deacon@xxxxxxx> Will -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html