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SubjectRe: [PATCH 5/5] x86: if kernel .text .data .bss are not marked as E820_RAM, complain and fix
On Fri, Aug 24, 2012 at 06:23:48PM -0700, Yinghai Lu wrote:
> On Fri, Aug 24, 2012 at 4:55 PM, Jacob Shin <jacob.shin@amd.com> wrote:
> > There could be cases where user supplied memmap=exactmap memory
> > mappings do not mark the region where the kernel .text .data and
> > .bss reside as E820_RAM as reported here:
> >
> > https://lkml.org/lkml/2012/8/14/86
> >
> > Handle it by complaining, and adding the range back into the e820.
> >
> > Signed-off-by: Jacob Shin <jacob.shin@amd.com>
> > ---
> > arch/x86/kernel/setup.c | 15 +++++++++++++++
> > 1 file changed, 15 insertions(+)
> >
> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> > index 4217fb4..b84aceb5 100644
> > --- a/arch/x86/kernel/setup.c
> > +++ b/arch/x86/kernel/setup.c
> > @@ -926,6 +926,21 @@ void __init setup_arch(char **cmdline_p)
> > insert_resource(&iomem_resource, &data_resource);
> > insert_resource(&iomem_resource, &bss_resource);
> >
> > + /*
> > + * Complain if .text .data and .bss are not marked as E820_RAM and
> > + * attempt to fix it by adding the range. We may have a confused BIOS,
> > + * or the user may have incorrectly supplied it via memmap=exactmap. If
> > + * we really are running on top non-RAM, we will crash later anyways.
> > + */
> > + if (!e820_all_mapped(code_resource.start, bss_resource.end, E820_RAM)) {
> > + pr_warn(".text .data .bss are not marked as E820_RAM!\n");
> > +
> > + e820_add_region(code_resource.start,
> > + bss_resource.end - code_resource.start + 1,
> > + E820_RAM);
> > + sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
>
> this sanitze_e820_map could be spared. trim_bios_range will
> that always.

Ah. okay

>
> > + }
> > +
> > trim_bios_range();
> > #ifdef CONFIG_X86_32
> > if (ppro_with_ram_bug()) {
>
> also should use brk_limit instead of bss_resource.end. aka need to
> keep the map for brk area.

Okay.. will fix on Monday

>
> Thanks
>
> Yinghai
>



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