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 the GFP_KERNEL allocation in uart_startup() no longer valid..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.
That'd be me, I'm afraid. With changes in signal.git#execve2 we need to set
->flags in
start_thread() on i386 as well, not only on amd64 (where we were already doing
that).
Incremental follows, fix folded and repushed...
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 75fcad1..9e84b4f 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -190,6 +190,7 @@ start_thread(struct pt_regs *regs, unsigned long new_ip,
unsigned long new_sp)
regs->cs = __USER_CS;
regs->ip = new_ip;
regs->sp = new_sp;
+ regs->flags = X86_EFLAGS_IF;
/*
* Free the old FP and other extended state
*/
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