Messages in this thread | | | From | "Yu, Fenghua" <> | Subject | RE: [3.9-rc1] Bug in bootup code or debug code? | Date | Wed, 13 Mar 2013 15:22:43 +0000 |
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> -----Original Message----- > From: Tetsuo Handa [mailto:penguin-kernel@I-love.SAKURA.ne.jp] > Sent: Wednesday, March 13, 2013 6:24 AM > To: Yu, Fenghua; hpa@linux.intel.com > Cc: linux-kernel@vger.kernel.org > Subject: Re: [3.9-rc1] Bug in bootup code or debug code? > > Tetsuo Handa wrote: > > Tetsuo Handa wrote: > > > Hello. > > > > > > I can boot linux-next-20130205 using kernel config at > > > http://I-love.SAKURA.ne.jp/tmp/config-3.8-rc6-next-20130205 . > > > But I get VMware's virtual machine kernel stack fault (hardware > reset) as soon > > > as kernel is loaded if CONFIG_DEBUG_VIRTUAL=y is added to the > config above. > > > > > > Since I don't get kernel stack fault if CONFIG_DEBUG_VIRTUAL=y is > added to > > > kernel config generated by "make allnoconfig", I guess something is > wrong with > > > code which is executed at very early stage of bootup. > > > > > > Any clue? > > > > > > Regards. > > > > > > > This bug is not yet fixed as of 3.9-rc1. > > Should I run git bisect? > > > > Regards. > > > > I found the location of "hardware reset" trigger. > > It is __pa_symbol(&boot_params) call, for I don't encounter "hardware > reset" if > I remove the "//" from below debug patch. > > This bug is not yet fixed as of 3.9.0-rc2-00188-g6c23cbb . > > --- a/arch/x86/kernel/microcode_intel_early.c > +++ b/arch/x86/kernel/microcode_intel_early.c > @@ -741,7 +741,9 @@ load_ucode_intel_bsp(void) > #ifdef CONFIG_X86_32 > struct boot_params *boot_params_p; > > + //while (1); > boot_params_p = (struct boot_params *)__pa_symbol(&boot_params); > + while (1); > ramdisk_image = boot_params_p->hdr.ramdisk_image; > ramdisk_size = boot_params_p->hdr.ramdisk_size; > initrd_start_early = ramdisk_image;
Tetsuo and Dave,
That's the place where we suspected to cause the problem.
My question is: how to access global variable in linear mode in virtualization? __pa_symbol() is not a problem for native.
Thanks.
-Fenghua
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