Re: 2.6.33 GP fault only when built with tracing

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 2010-03-18 at 16:26 -0700, Randy Dunlap wrote:
> I can build/boot 2.6.33 with CONFIG_TRACE/TRACING disabled successfully,
> but when I enable lots of tracing config options and then boot with
> ftrace=nop on the kernel command line, I see a GP fault when the parport &
> parport_pc modules are loading/initializing.

Do you see it without adding the "ftrace=nop"? The only thing that
should do is expand the ring buffer on boot up.

> 
> It happens in drivers/parport/share.c::parport_register_device(), when that
> function calls try_module_get().
> 
> If I comment out the trace_module_get() calls in include/linux/module.h,
> the kernel boots with no problems.


Interesting. Well, trace_module_get() is a TRACE_EVENT tracepoint. But
should be disabled here. It may be something to do with DEFINE_TRACE. 

(added Mathieu to Cc since he wrote that code)

> 
> [   21.852829] general protection fault: 0000 [#1] SMP 
> [   21.856321] last sysfs file: /sys/module/parport/initstate
> [   21.856321] CPU 0 
> [   21.856321] Pid: 2089, comm: modprobe Not tainted 2.6.33 #11 0HH807/OptiPlex GX620               
> [   21.856321] RIP: 0010:[<ffffffffa0437671>]  [<ffffffffa0437671>] parport_register_device+0xe4/0x48c [parport]
> [   21.856321] RSP: 0018:ffff8800765cba78  EFLAGS: 00010283
> [   21.856321] RAX: ffff10007b04a3d0 RBX: ffff88007a6a5e30 RCX: 0000000000000000
> [   21.856321] RDX: 0000000000000000 RSI: ffffffffa043d1de RDI: ffff88007a6a5e30
> [   21.856321] RBP: ffff8800765cbad8 R08: 0000000000000000 R09: 0000000000000000
> [   21.856321] R10: ffffffffa043dff8 R11: 0000000000000000 R12: ffffffffa043d1de
> [   21.856321] R13: ffffffffa043d1de R14: ffffffffa045c940 R15: 0000000000000000
> [   21.856321] FS:  00007f09cc3fb6f0(0000) GS:ffff880004a00000(0000) knlGS:0000000000000000
> [   21.856321] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [   21.856321] CR2: 0000003fb5ad62c0 CR3: 00000000764f6000 CR4: 00000000000006f0
> [   21.856321] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [   21.856321] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> [   21.856321] Process modprobe (pid: 2089, threadinfo ffff8800765ca000, task ffff88007664a3d0)
> [   21.856321] Stack:
> [   21.856321]  ffff8800765cbab8 0000000000000206 0000000000000000 ffffffff812abaf2
> [   21.856321] <0> 0000000000000000 0000000000000000 ffffffffa043d1de 00000000ffffffff
> [   21.856321] <0> ffff88007a6a5e30 ffffffffa043d1de 0000000000000000 0000000000000378
> [   21.856321] Call Trace:
> [   21.856321]  [<ffffffff812abaf2>] ? do_raw_spin_unlock+0xd7/0xe7
> [   21.856321]  [<ffffffffa043b385>] parport_open+0x12d/0x14d [parport]
> [   21.856321]  [<ffffffffa043bccf>] parport_device_id+0x2e/0xa00 [parport]
> [   21.856321]  [<ffffffff8117ab73>] ? __slab_alloc+0x560/0x5f7
> [   21.856321]  [<ffffffffa043bb06>] ? parport_daisy_init+0x55f/0x665 [parport]
> [   21.856321]  [<ffffffffa043bb06>] ? parport_daisy_init+0x55f/0x665 [parport]
> [   21.856321]  [<ffffffffa043bb53>] parport_daisy_init+0x5ac/0x665 [parport]
> [   21.856321]  [<ffffffffa0436f6d>] parport_announce_port+0x1a/0x201 [parport]
> [   21.856321]  [<ffffffffa0456848>] parport_pc_probe_port+0x13a5/0x1478 [parport_pc]
> [   21.856321]  [<ffffffffa0456c36>] parport_pc_pnp_probe+0x31b/0x358 [parport_pc]
> [   21.856321]  [<ffffffff81323b1f>] pnp_device_probe+0x11a/0x15e
> [   21.856321]  [<ffffffff81376f15>] ? driver_sysfs_add+0x61/0x9b
> [   21.856321]  [<ffffffff81377223>] driver_probe_device+0x1bc/0x339
> [   21.856321]  [<ffffffff8137743e>] __driver_attach+0x9e/0xde
> [   21.856321]  [<ffffffff813773a0>] ? __driver_attach+0x0/0xde
> [   21.856321]  [<ffffffff81376038>] bus_for_each_dev+0x83/0xdb
> [   21.856321]  [<ffffffff81376e26>] driver_attach+0x25/0x2e
> [   21.856321]  [<ffffffff81376823>] bus_add_driver+0x14c/0x367
> [   21.856321]  [<ffffffff813778e7>] driver_register+0xf8/0x1b2
> [   21.856321]  [<ffffffff81323771>] pnp_register_driver+0x28/0x31
> [   21.856321]  [<ffffffffa046380b>] parport_pc_init+0x708/0x7fa [parport_pc]
> [   21.856321]  [<ffffffffa0463103>] ? parport_pc_init+0x0/0x7fa [parport_pc]
> [   21.856321]  [<ffffffff810020d6>] do_one_initcall+0x9c/0x223
> [   21.856321]  [<ffffffff810bcfd9>] sys_init_module+0x139/0x32b
> [   21.856321]  [<ffffffff8100c732>] system_call_fastpath+0x16/0x1b
> [   21.856321] Code: 65 8b 14 25 d8 e3 00 00 41 83 3e 02 0f 84 80 00 00 00 48 ff 05 09 72 00 00 48 63 d2 49 8b 86 28 02 00 00 48 03 04 d5 b0 97 b9 81 <48> ff 00 49 8b 86 28 02 00 00 48 03 04 d5 b0 97 b9 81 48 8b 00 
> [   21.856321] RIP  [<ffffffffa0437671>] parport_register_device+0xe4/0x48c [parport]
> [   21.856321]  RSP <ffff8800765cba78>
> [   22.192206] ---[ end trace 892b5882bd1f8c3e ]---
> 
> 
> Full kernel boot log is attached.
> 
> Is this perhaps already fixed after 2.6.33?

I've never seen it. Do you have a config you can send me. I can try it
out.

Thanks,

-- Steve