Messages in this thread | | | Date | Fri, 3 Aug 2012 17:51:51 +0800 | From | Fengguang Wu <> | Subject | Re: uart_startup: GFP_KERNEL allocation with IRQs disabled |
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On Fri, Aug 03, 2012 at 11:37:53AM +0200, Jiri Slaby wrote: > On 08/03/2012 03:46 AM, Fengguang Wu wrote: > > Hi all, > > Hi, > > > The IRQ should be disabled somewhere in the path walk, which makes > > the GFP_KERNEL allocation in uart_startup() no longer valid.. > > > > [ 0.499537] kworker/u:1 (29) used greatest stack depth: 7156 bytes left > > [ 0.500947] ------------[ cut here ]------------ > > [ 0.501445] WARNING: at /c/kernel-tests/src/stable/kernel/lockdep.c:2739 lockdep_trace_alloc+0x86/0xb2() > > [ 0.502413] Modules linked in: > > [ 0.502766] Pid: 1, comm: init Not tainted 3.5.0-01258-g1ade992 #182 > > [ 0.503419] Call Trace: > ... > > [ 0.504381] [<c1079e7d>] get_zeroed_page+0xd/0xf > > [ 0.504381] [<c10f976f>] uart_startup.part.8+0x46/0x152 > > [ 0.504381] [<c10f745f>] ? tty_port_tty_set+0x37/0x3c > > [ 0.504381] [<c10fa175>] uart_open+0xc9/0x10b > > [ 0.504381] [<c10fa0ac>] ? uart_suspend_port+0x229/0x229 > > [ 0.504381] [<c10f1bc2>] tty_open+0x26b/0x3d3 > > [ 0.504381] [<c109872a>] chrdev_open+0xf7/0x117 > > This does not make sense to me. I would not blame TTY/serial for this. > There is somebody who forgot to enable interrupts somewhere. Could you > enable DEBUG_ATOMIC_SLEEP? It might trigger earlier revealing us the > culprit.
Jiri, thanks for the info. After turning on DEBUG_ATOMIC_SLEEP, this shows up which I just reported in another email. Ah I didn't notice that it's running the same commit "x86: switch to generic sys_execve and kernel_execve"..
[ 0.408108] BUG: sleeping function called from invalid context at /c/wfg/linux/kernel/rwsem.c:47 [ 0.408966] in_atomic(): 0, irqs_disabled(): 1, pid: 1, name: init [ 0.409556] no locks held by init/1. [ 0.409929] irq event stamp: 74784 [ 0.410247] hardirqs last enabled at (74783): [<c101e4e1>] do_page_fault+0x95/0x330 [ 0.411015] hardirqs last disabled at (74784): [<c1158337>] resume_userspace+0x17/0x28 [ 0.411759] softirqs last enabled at (74726): [<c102a42e>] __do_softirq+0x109/0x12d [ 0.412011] softirqs last disabled at (74713): [<c10038f1>] do_softirq+0x5e/0xb3 [ 0.412011] Pid: 1, comm: init Not tainted 3.5.0-01258-g1ade992 #60 [ 0.412011] Call Trace: [ 0.412011] [<c1025c95>] ? console_unlock+0x340/0x36d [ 0.412011] [<c103fa89>] __might_sleep+0x159/0x161 [ 0.412011] [<c1156dc9>] down_write+0x17/0x40 [ 0.412011] [<c108c829>] sys_brk+0x21/0xe4 [ 0.412011] [<c115838d>] syscall_call+0x7/0xb
Thanks, Fengguang
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