Re: [LKP] [dmi] PANIC: early exception 0e rip 10:ffffffff81899e6b error 9 cr2 ffffffffff240000

[Yuanhan Liu]

On Fri, Nov 07, 2014 at 08:44:40AM +0100, Ard Biesheuvel wrote:
> On 7 November 2014 08:37, Yuanhan Liu <yuanhan.liu@xxxxxxxxxxxxxxx> wrote:
> > On Fri, Nov 07, 2014 at 08:17:36AM +0100, Ard Biesheuvel wrote:
> >> On 7 November 2014 06:47, LKP <lkp@xxxxxx> wrote:
> >> > FYI, we noticed the below changes on
> >> >
> >> > https://git.linaro.org/people/ard.biesheuvel/linux-arm efi-for-3.19
> >> > commit aacdce6e880894acb57d71dcb2e3fc61b4ed4e96 ("dmi: add support for SMBIOS 3.0 64-bit entry point")
> >> >
> >> >
> >> > +-----------------------+------------+------------+
> >> > |                       | 2fa165a26c | aacdce6e88 |
> >> > +-----------------------+------------+------------+
> >> > | boot_successes        | 20         | 10         |
> >> > | early-boot-hang       | 1          |            |
> >> > | boot_failures         | 0          | 5          |
> >> > | PANIC:early_exception | 0          | 5          |
> >> > +-----------------------+------------+------------+
> >> >
> >> >
> >> > [    0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000036fffffff] usable
> >> > [    0.000000] bootconsole [earlyser0] enabled
> >> > [    0.000000] NX (Execute Disable) protection: active
> >> > PANIC: early exception 0e rip 10:ffffffff81899e6b error 9 cr2 ffffffffff240000
> >> > [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.18.0-rc2-gc5221e6 #1
> >> > [    0.000000]  0000000000000000 ffffffff82203d30 ffffffff819f0a6e 00000000000003f8
> >> > [    0.000000]  ffffffffff240000 ffffffff82203e18 ffffffff823701b0 ffffffff82511401
> >> > [    0.000000]  0000000000000000 0000000000000ba3 0000000000000000 ffffffffff240000
> >> > [    0.000000] Call Trace:
> >> > [    0.000000]  [<ffffffff819f0a6e>] dump_stack+0x4e/0x68
> >> > [    0.000000]  [<ffffffff823701b0>] early_idt_handler+0x90/0xb7
> >> > [    0.000000]  [<ffffffff823c80da>] ? dmi_save_one_device+0x81/0x81
> >> > [    0.000000]  [<ffffffff81899e6b>] ? dmi_table+0x3f/0x94
> >> > [    0.000000]  [<ffffffff81899e42>] ? dmi_table+0x16/0x94
> >> > [    0.000000]  [<ffffffff823c80da>] ? dmi_save_one_device+0x81/0x81
> >> > [    0.000000]  [<ffffffff823c80da>] ? dmi_save_one_device+0x81/0x81
> >> > [    0.000000]  [<ffffffff823c7eff>] dmi_walk_early+0x44/0x69
> >> > [    0.000000]  [<ffffffff823c88a2>] dmi_present+0x180/0x1ff
> >> > [    0.000000]  [<ffffffff823c8ab3>] dmi_scan_machine+0x144/0x191
> >> > [    0.000000]  [<ffffffff82370702>] ? loglevel+0x31/0x31
> >> > [    0.000000]  [<ffffffff82377f52>] setup_arch+0x490/0xc73
> >> > [    0.000000]  [<ffffffff819eef73>] ? printk+0x4d/0x4f
> >> > [    0.000000]  [<ffffffff82370b90>] start_kernel+0x9c/0x43f
> >> > [    0.000000]  [<ffffffff82370120>] ? early_idt_handlers+0x120/0x120
> >> > [    0.000000]  [<ffffffff823704a2>] x86_64_start_reservations+0x2a/0x2c
> >> > [    0.000000]  [<ffffffff823705df>] x86_64_start_kernel+0x13b/0x14a
> >> > [    0.000000] RIP 0x4
> >> >
> >>
> >> This is most puzzling. Could anyone decode the exception?
> >> This looks like the non-EFI path through dmi_scan_machine(), which
> >> calls dmi_present() /after/ calling dmi_smbios3_present(), which
> >> apparently has not found the _SM3_ header tag. Or could the call stack
> >> be inaccurate?
> >>
> >> Anyway, it would be good to know the exact type of the platform,
> >
> > It's a Nehalem-EP machine, wht 16 CPU and 12G memory.
> >
> >> and
> >> perhaps we could find out if there is an inadvertent _SM3_ tag
> >> somewhere in the 0xF0000 - 0xFFFFF range?
> >
> > Sorry, how?
> >
> 
> That's not a brand new machine, so I suppose there wouldn't be a
> SMBIOS 3.0 header lurking in there.
> 
> Anyway, if you are in a position to try things, could you apply this
> 
> --- a/drivers/firmware/dmi_scan.c
> +++ b/drivers/firmware/dmi_scan.c
> @@ -617,7 +617,7 @@ void __init dmi_scan_machine(void)
>                 memset(buf, 0, 16);
>                 for (q = p; q < p + 0x10000; q += 16) {
>                         memcpy_fromio(buf + 16, q, 16);
> -                       if (!dmi_smbios3_present(buf) || !dmi_present(buf)) {
> +                       if (!dmi_present(buf)) {
>                                 dmi_available = 1;
>                                 dmi_early_unmap(p, 0x10000);
>                                 goto out;
> 
> and try again?

kernel boots perfectly with this patch applied.

	--yliu

> That is the only change that is relevant to the non-EFI
> code path which this machine appears to take, so if this fixes things,
> that would be valuable information even if it doesn't tell us exactly
> what is going wrong.
> 
> Thanks,
> Ard.
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