On Mon, Aug 24, 2009 at 11:27 AM, Ingo Molnar<[email protected]> wrote:
>
> * Yinghai Lu <[email protected]> wrote:
>
>> Hugh Dickins wrote:
>> > I find the "mem=" boot parameter disabled in today's linux-next:
>> > reverting the tip commit below fixes that.
>> >
>> > Hugh
>> >
>> > From: Xiao Guangrong <[email protected]>
>> > Date: Thu, 20 Aug 2009 12:23:11 +0000 (+0800)
>> > Subject: x86: Fix system crash when loading with "reservetop" parameter
>> > X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fmingo%2Flinux-2.6-x86.git;a=commitdiff_plain;h=8126dec32738421afa362114337331337b4be17f
>> >
>> > x86: Fix system crash when loading with "reservetop" parameter
>> >
>> > The system will die if the kernel is booted with "reservetop"
>> > parameter, in present code, parse "reservetop" parameter after
>> > early_ioremap_init(), and some function still use
>> > early_ioremap() after it.
>> >
>> > The problem is, "reservetop" parameter can modify
>> > 'FIXADDR_TOP', then the virtual address got by early_ioremap()
>> > is base on old 'FIXADDR_TOP', but the page mapping is base on
>> > new 'FIXADDR_TOP', it will occur page fault, and the IDT is not
>> > prepare yet, so, the system is dead.
>> >
>> > So, put parse_early_param() in the front of
>> > early_ioremap_init() in this patch.
>> >
>> > Signed-off-by: Xiao Guangrong <[email protected]>
>> > Cc: [email protected]
>> > Cc: Andrew Morton <[email protected]>
>> > LKML-Reference: <[email protected]>
>> > Signed-off-by: Ingo Molnar <[email protected]>
>> > ---
>> >
>> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> > index 63f32d2..02643cc 100644
>> > --- a/arch/x86/kernel/setup.c
>> > +++ b/arch/x86/kernel/setup.c
>> > @@ -711,6 +711,11 @@ void __init setup_arch(char **cmdline_p)
>> > ? ? printk(KERN_INFO "Command line: %s\n", boot_command_line);
>> > ?#endif
>> >
>> > + ? strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
>> > + ? *cmdline_p = command_line;
>> > +
>> > + ? parse_early_param();
>> > +
>> > ? ? /* VMI may relocate the fixmap; do this before touching ioremap area */
>> > ? ? vmi_init();
>> >
>> > @@ -793,11 +798,6 @@ void __init setup_arch(char **cmdline_p)
>> > ?#endif
>> > ?#endif
>> >
>> > - ? strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
>> > - ? *cmdline_p = command_line;
>> > -
>> > - ? parse_early_param();
>> > -
>> > ?#ifdef CONFIG_X86_64
>> > ? ? check_efer();
>> > ?#endif
>>
>> yes, that patch will break other built-in command too.
>>
>> need drop that patch.
>
> done. Was nervous about the patch already:
>
> ?http://lkml.org/lkml/2009/8/21/127
>
>> also the problem was caused by vmi patch, and that commit should
>> be reverted.
>>
>> commit ae8d04e2ecbb233926860e9ce145eac19c7835dc
>> Author: Zachary Amsden <[email protected]>
>> Date: ? Sat Dec 13 12:36:58 2008 -0800
>>
>> ? ? x86 Fix VMI crash on boot in 2.6.28-rc8
>>
>> ? ? VMI initialiation can relocate the fixmap, causing early_ioremap to
>> ? ? malfunction if it is initialized before the relocation. ?To fix this,
>> ? ? VMI activation is split into two phases; the detection, which must
>> ? ? happen before setting up ioremap, and the activation, which must happen
>> ? ? after parsing early boot parameters.
>>
>> ? ? This fixes a crash on boot when VMI is enabled under VMware.
>>
>> ? ? Signed-off-by: Zachary Amsden <[email protected]>
>> ? ? Signed-off-by: Linus Torvalds <[email protected]>
>>
>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> index 9d5674f..bdec76e 100644
>> --- a/arch/x86/kernel/setup.c
>> +++ b/arch/x86/kernel/setup.c
>> @@ -794,6 +794,9 @@ void __init setup_arch(char **cmdline_p)
>> ? ? ? ? printk(KERN_INFO "Command line: %s\n", boot_command_line);
>> ?#endif
>>
>> + ? ? ? /* VMI may relocate the fixmap; do this before touching ioremap area */
>> + ? ? ? vmi_init();
>> +
>> ? ? ? ? early_cpu_init();
>> ? ? ? ? early_ioremap_init();
>>
>> @@ -880,13 +883,8 @@ void __init setup_arch(char **cmdline_p)
>> ? ? ? ? check_efer();
>> ?#endif
>>
>> -#if defined(CONFIG_VMI) && defined(CONFIG_X86_32)
>> - ? ? ? /*
>> - ? ? ? ?* Must be before kernel pagetables are setup
>> - ? ? ? ?* or fixmap area is touched.
>> - ? ? ? ?*/
>> - ? ? ? vmi_init();
>> -#endif
>> + ? ? ? /* Must be before kernel pagetables are setup */
>> + ? ? ? vmi_activate();
>>
>> ? ? ? ? /* after early param, so could get panic from serial */
>> ? ? ? ? reserve_early_setup_data();
>>
>>
>> and according to
>> http://lkml.org/lkml/2008/12/10/388
>> http://lkml.org/lkml/2008/12/10/456
>>
>> Zachary should split reserve_top_address() to two functions...
>> before sending that patch to Linus
>
> mind looking at this yourself if interested? Zachary has not been
> active for quite some time.
>
please check attached patch...
still need to make early_dbgp and early_console that would use early_ioremap?
YH