On Thu, 24 Sep 2015, Jiri Kosina wrote: > > >> [ 24.705767] [<ffffffff8149287d>] dump_stack+0x7d/0xa0 > > >> [ 24.705774] [<ffffffff810cbf7a>] ___might_sleep+0x28a/0x2a0 > > >> [ 24.705779] [<ffffffff810cbc7f>] __might_sleep+0x4f/0xc0 > > >> [ 24.705784] [<ffffffff810ae8ff>] start_flush_work+0x2f/0x290 > > >> [ 24.705789] [<ffffffff810ae8ac>] flush_work+0x5c/0x80 > > >> [ 24.705792] [<ffffffff810ae86a>] ? flush_work+0x1a/0x80 > > >> [ 24.705799] [<ffffffff810eddcd>] ? trace_hardirqs_off+0xd/0x10 > > >> [ 24.705804] [<ffffffff810ad938>] ? try_to_grab_pending+0x48/0x360 > > >> [ 24.705810] [<ffffffff81917e13>] ? _raw_spin_lock_irqsave+0x73/0x80 > > >> [ 24.705814] [<ffffffff810aecf9>] __cancel_work_timer+0x179/0x260 > > This one is even more strange. It says that flush_work() is being called > from __cancel_work_timer() with IRQs disabled, but flags are explicitly > restored just one statement before that, and usbhid_close() explicitly > calls cancel_work_sync() after unconditionally enabling interrupts. > > So I am not able to make any sense of either of the traces really. > > Are you seeing this with the same .config with GCC-compiled kernel as > well?
Actually could you please provide disassembly of your __cancel_work_timer()? One explanation would be LLVM not considering local_irq_restore() a compiler memory barrier, but I am pretty sure it'll expose much more breakage if that'd be the case. -- Jiri Kosina SUSE Labs -- 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/
