On Thu, 2012-10-25 at 17:05 -0700, Greg Kroah-Hartman wrote: > 3.6-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Jacob Shin <[email protected]> > > commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream. > > On systems with very large memory (1 TB in our case), BIOS may report a > reserved region or a hole in the E820 map, even above the 4 GB range. Exclude > these from the direct mapping. > > [ hpa: this should be done not just for > 4 GB but for everything above the > legacy > region (1 MB), at the very least. That, however, turns out to require > significant > restructuring. That work is well underway, but is not suitable for > rc/stable. ] [...] > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -919,8 +919,21 @@ void __init setup_arch(char **cmdline_p) > > #ifdef CONFIG_X86_64 > if (max_pfn > max_low_pfn) { > - max_pfn_mapped = init_memory_mapping(1UL<<32, > - max_pfn<<PAGE_SHIFT); > + int i; > + for (i = 0; i < e820.nr_map; i++) { > + struct e820entry *ei = &e820.map[i]; > + > + if (ei->addr + ei->size <= 1UL << 32) > + continue; > + > + if (ei->type == E820_RESERVED) > + continue; > + > + max_pfn_mapped = init_memory_mapping( > + ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr, > + ei->addr + ei->size);
Is it safe to assume that the e820 entries are sorted? If not, this assignment needs to be conditional. Ben. > + } > + > /* can we preseve max_low_pfn ?*/ > max_low_pfn = max_pfn; > } -- Ben Hutchings Never attribute to conspiracy what can adequately be explained by stupidity.
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