Re: [patch] sound: fix bootup crash in snd_gus_interrupt()

[Takashi Iwai]

At Tue, 16 Oct 2007 07:58:09 +0200,
Ingo Molnar wrote:
> 
> Subject: sound: fix bootup crash in snd_gus_interrupt()
> From: Ingo Molnar <mingo@xxxxxxx>
> 
> when simulating a storm of fake GUS interrupts (without actually owning 
> this venerable piece of ISA hardware) the driver falls over (crashes) in 
> two ways:
> 
> 1) spinlocks being initialized too late:
> 
> INFO: trying to register non-static key.
> the code is fine but needs lockdep annotation.
> turning off the locking correctness validator.
>  [<401058ca>] show_trace_log_lvl+0x1a/0x30
>  [<401064b2>] show_trace+0x12/0x20
>  [<401064d6>] dump_stack+0x16/0x20
>  [<4014a72b>] __lock_acquire+0xcfb/0x1030
>  [<4014aac0>] lock_acquire+0x60/0x80
>  [<40721a68>] _spin_lock_irqsave+0x38/0x50
>  [<4058fc12>] snd_gf1_i_look8+0x22/0x60
>  [<405906fe>] snd_gus_interrupt+0x13e/0x270
>  [<401548e8>] handle_IRQ_event+0x28/0x60
>  [<40155cc1>] handle_fasteoi_irq+0x71/0xe0
>  [<40107238>] do_IRQ+0x48/0xa0
>  [<401051fe>] common_interrupt+0x2e/0x40
>  [<40156822>] register_handler_proc+0x92/0xf0
>  [<401550c2>] setup_irq+0xe2/0x190
>  [<40155224>] request_irq+0xb4/0xd0
>  [<4058f524>] snd_gus_create+0x124/0x3c0
>  [<40aa4087>] snd_gusclassic_probe+0x2a7/0x4b0
>  [<403f5eff>] isa_bus_probe+0x1f/0x30
>  [<403f1944>] driver_probe_device+0x84/0x190
>  [<403f1a58>] __device_attach+0x8/0x10
>  [<403f0e63>] bus_for_each_drv+0x53/0x80
>  [<403f1b1b>] device_attach+0x8b/0x90
>  [<403f0dd8>] bus_attach_device+0x48/0x80
>  [<403efdbd>] device_add+0x45d/0x5a0
>  [<403eff12>] device_register+0x12/0x20
>  [<403f60c3>] isa_register_driver+0xb3/0x140
>  [<40aa3dd2>] alsa_card_gusclassic_init+0x12/0x20
>  [<40a665c3>] kernel_init+0x133/0x310
>  [<401054a7>] kernel_thread_helper+0x7/0x10
>  =======================
> 
> 2) callback functions not being filled in yet:
> 
> BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
>  printing eip:
> 00000000
> *pde = 00000000
> Oops: 0000 [#1]
> SMP DEBUG_PAGEALLOC
> CPU:    0
> EIP:    0060:[<00000000>]    Not tainted VLI
> EFLAGS: 00010002   (2.6.23 #37)
> EIP is at 0x0
> eax: 7fe94000   ebx: 7fe94000   ecx: 00000000   edx: 00000226
> esi: 00000000   edi: 00000005   ebp: 7ff87c28   esp: 7ff87bf4
> ds: 007b   es: 007b   fs: 00d8  gs: 0000  ss: 0068
> Process swapper (pid: 1, ti=7ff86000 task=7ff84000 task.ti=7ff86000)
> Stack: 40590683 408424a9 408db87c 00000029 40787406 00000064 00000046 ff000000 
>        000000ff 00000001 7faefaf0 00000000 00000005 7ff87c40 401548e8 00000000 
>        40a52000 7faefaf0 00000005 7ff87c58 40155cc1 40a52030 00000005 00000000 
> Call Trace:
>  [<401058ca>] show_trace_log_lvl+0x1a/0x30
>  [<4010598b>] show_stack_log_lvl+0xab/0xd0
>  [<40105b7c>] show_registers+0x1cc/0x2d0
>  [<40105d96>] die+0x116/0x240
>  [<4011d7bb>] do_page_fault+0x18b/0x670
>  [<40721d22>] error_code+0x72/0x80
>  [<401548e8>] handle_IRQ_event+0x28/0x60
>  [<40155cc1>] handle_fasteoi_irq+0x71/0xe0
>  [<40107238>] do_IRQ+0x48/0xa0
>  [<401051fe>] common_interrupt+0x2e/0x40
>  [<401a344e>] proc_create+0x3e/0x120
>  [<401a3733>] proc_mkdir_mode+0x23/0x50
>  [<401a376f>] proc_mkdir+0xf/0x20
>  [<40156864>] register_handler_proc+0xd4/0xf0
>  [<401550c2>] setup_irq+0xe2/0x190
>  [<40155224>] request_irq+0xb4/0xd0
>  [<4058f524>] snd_gus_create+0x124/0x3c0
>  [<40aa4087>] snd_gusclassic_probe+0x2a7/0x4b0
>  [<403f5eff>] isa_bus_probe+0x1f/0x30
>  [<403f1944>] driver_probe_device+0x84/0x190
>  [<403f1a58>] __device_attach+0x8/0x10
>  [<403f0e63>] bus_for_each_drv+0x53/0x80
>  [<403f1b1b>] device_attach+0x8b/0x90
>  [<403f0dd8>] bus_attach_device+0x48/0x80
>  [<403efdbd>] device_add+0x45d/0x5a0
>  [<403eff12>] device_register+0x12/0x20
>  [<403f60c3>] isa_register_driver+0xb3/0x140
>  [<40aa3dd2>] alsa_card_gusclassic_init+0x12/0x20
>  [<40a665c3>] kernel_init+0x133/0x310
>  [<401054a7>] kernel_thread_helper+0x7/0x10
>  =======================
> Code:  Bad EIP value.
> EIP: [<00000000>] 0x0 SS:ESP 0068:7ff87bf4
> Kernel panic - not syncing: Fatal exception in interrupt
> 
> with these things fixed, i get the expected "no such hardware" result 
> from the driver initialization:
> 
>  Calling initcall 0x40aa3dc0: alsa_card_gusclassic_init+0x0/0x20()
>  ALSA sound/isa/gus/gusclassic.c:136: [0x220] check 1 failed - 0xff
>  initcall 0x40aa3dc0: alsa_card_gusclassic_init+0x0/0x20() returned 0.
>  initcall 0x40aa3dc0 ran for 133 msecs: 
>  alsa_card_gusclassic_init+0x0/0x20()
> 
> Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

Thanks, I queued it up to ALSA tree now.


Takashi
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