Re: 2.6.9rc2-mm4 oops

[Andrew Morton]

Fernando Pablo Lopez-Lezcano <nando@xxxxxxxxxxxxxxxxxx> wrote:
>
> I ran into this while testing the voluntary preemption S7 patch. It
> still happens in vanilla 2.6.9rc2-mm4 (with the small patch below that
> Ingo sent me, otherwise plain rc2-mm4 would not boot). The machine is an
> athlon64 based workstation and has no floppy drive:

Thanks.   Whenever I see floppy+acpi+oops, I think "Bjorn!".

> inserting floppy driver for 2.6.8.1-1.520.1nov.rhfc2.ccrma
> Unable to handle kernel paging request at virtual address f8881920
>  printing eip:
> c0251d3d
> *pde = 37f5f067
> Oops: 0002 [#1]
> PREEMPT 
> Modules linked in: floppy(U) sg(U) dm_mod(U) uhci_hcd(U) ehci_hcd(U)
> button(U) battery(U) asus_acpi(U) ac(U) ext3(U) jbd(U) raid5(U) xor(U)
> sata_via(U) sata_promise(U) libata(U) sd_mod(U) scsi_mod(U)
> CPU:    0
> EIP:    0060:[<c0251d3d>]    Not tainted VLI
> EFLAGS: 00010246   (2.6.8.1-1.520.1nov.rhfc2.ccrma) 
> EIP is at acpi_bus_register_driver+0xd2/0x165
> eax: f8881920   ebx: f88eefe0   ecx: c03d6b40   edx: f88ebd30
> esi: ffffffed   edi: f6ed4000   ebp: c03d9460   esp: f6ed4f5c
> ds: 007b   es: 007b   ss: 0068
> Process modprobe (pid: 2119, threadinfo=f6ed4000 task=f6e71870)
> Stack: c03d94a0 f88e9126 00000015 00000014 f8870bc1 c03d94a0 f88ef280
> f6ed4000 
>        c0129ef7 c03d94a0 f88ef280 f6ed4000 c03d9460 c014dd52 00000246
> f62f29ac 
>        f6e1fc40 f6d8b8ac f6de4380 f6de43ac 00000000 b7fde008 0807a1a0
> 006a809d 
> Call Trace:
>  [<f88e9126>] acpi_floppy_init+0x16/0x50 [floppy]
>  [<f8870bc1>] floppy_init+0x11/0x600 [floppy]
>  [<c0129ef7>] printk+0x17/0x20
>  [<c014dd52>] sys_init_module+0x252/0x3b0
>  [<c0106afd>] sysenter_past_esp+0x52/0x71
> Code: 00 00 00 a1 ec 67 3e c0 c7 05 78 67 3e c0 a0 7b 3a c0 c7 05 7c 67
> 3e c0 bd 01 00 00 89 1d ec 67 3e c0 c7 03 e8 67 3e c0 89 43 04 <89> 18
> 81 3d 68 67 3e c0 3c 4b 24 1d 74 1c 68 68 67 3e c0 68 bf 
>  <6>note: modprobe[2119] exited with preempt_count 1
> Debug: sleeping function called from invalid context at
> include/linux/rwsem.h:43
> in_atomic():1, irqs_disabled():0
>  [<c0125652>] __might_sleep+0xa2/0xb0
>  [<c012d222>] do_exit+0xa2/0x980
>  [<c010775f>] die+0x2bf/0x2c0
>  [<c012a0b6>] vprintk+0x1b6/0x340
>  [<c011e1e4>] do_page_fault+0x314/0x56c
>  [<c01d8155>] sysfs_new_dirent+0x25/0x80
>  [<c01d81cd>] sysfs_make_dirent+0x1d/0x90
>  [<c0172a29>] unmap_area_pmd+0x49/0x60
>  [<c01d7d84>] sysfs_add_file+0x74/0xa0
>  [<c0172bb0>] unmap_vm_area+0x30/0x80
>  [<c0173136>] __vunmap+0xb6/0xf0
>  [<c0129cf0>] call_console_drivers+0x80/0x110
>  [<c011ded0>] do_page_fault+0x0/0x56c
>  [<c0106cf9>] error_code+0x2d/0x38
>  [<c0251d3d>] acpi_bus_register_driver+0xd2/0x165
>  [<f88e9126>] acpi_floppy_init+0x16/0x50 [floppy]
>  [<f8870bc1>] floppy_init+0x11/0x600 [floppy]
>  [<c0129ef7>] printk+0x17/0x20
>  [<c014dd52>] sys_init_module+0x252/0x3b0
>  [<c0106afd>] sysenter_past_esp+0x52/0x71
> ohci1394: $Rev: 1226 $ Ben Collins <bcollins@xxxxxxxxxx>
> 
> -- Fernando
> 
> --- linux/init/main.c.orig      
> +++ linux/init/main.c   
> @@ -435,6 +435,12 @@ static void noinline rest_init(void)
>  {
>         kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
>         numa_default_policy();
> +       /*
> +        * Re-enable preemption but disable interrupts to make sure
> +        * we dont get preempted until we schedule() in cpu_idle().
> +        */
> +       local_irq_disable();
> +       preempt_enable_no_resched();
>         unlock_kernel();
>         cpu_idle();
>  } 
> @@ -501,6 +507,7 @@ asmlinkage void __init start_kernel(void
>          * time - but meanwhile we still have a functioning scheduler.
>          */
>         sched_init();
> +       preempt_disable();
>         build_all_zonelists();
>         page_alloc_init();
>         trap_init();
> --- linux/arch/i386/kernel/entry.S.orig 
> +++ linux/arch/i386/kernel/entry.S      
> @@ -197,10 +197,8 @@ need_resched:
>         jz restore_all
>         testl $IF_MASK,EFLAGS(%esp)     # interrupts off (exception
> path) ?
>         jz restore_all
> -       movl $PREEMPT_ACTIVE,TI_preempt_count(%ebp)
>         sti
> -       call schedule
> -       movl $0,TI_preempt_count(%ebp)
> +       call preempt_schedule
>         cli
>         jmp need_resched
>  #endif
-
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