Messages in this thread | | | Subject | Re: [RFC 6/7] x86/asm: Remap the TSS into the cpu entry area | From | Dave Hansen <> | Date | Mon, 13 Nov 2017 11:22:44 -0800 |
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On 11/10/2017 08:05 PM, Andy Lutomirski wrote: > diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h > index fbc9b7f4e35e..8a9ba5553cab 100644 > --- a/arch/x86/include/asm/fixmap.h > +++ b/arch/x86/include/asm/fixmap.h > @@ -52,6 +52,13 @@ extern unsigned long __FIXADDR_TOP; > struct cpu_entry_area > { > char gdt[PAGE_SIZE]; > + > + /* > + * The gdt is just below cpu_tss and thus serves (on x86_64) as a > + * a read-only guard page for the SYSENTER stack at the bottom > + * of the TSS region. > + */ > + struct tss_struct tss; > }; >
Aha, and here's the place that you need sizeof(tss_struct) to be nice and page-aligned.
But why don't we just do:
char tss_space[PAGE_SIZE*something];
?
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