From: Andy Lutomirski <l...@kernel.org> We currently have CPU 0's GDT at the top of the GDT range and higher-numbered CPUs at lower addresses. This happens because the fixmap is upside down (index 0 is the top of the fixmap).
Flip it so that GDTs are in ascending order by virtual address. This will simplify a future patch that will generalize the GDT remap to contain multiple pages. Signed-off-by: Andy Lutomirski <l...@kernel.org> Reviewed-by: Borislav Petkov <b...@suse.de> Reviewed-by: Thomas Gleixner <t...@linutronix.de> Cc: Borislav Petkov <b...@alien8.de> Cc: Borislav Petkov <bpet...@suse.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Hansen <dave.han...@intel.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/3966a6edf6fd45deca4cf52a9b9276402499dda9.1511497875.git.l...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/include/asm/desc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index 4011cb03ef08..95cd95eb7285 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -63,7 +63,7 @@ static inline struct desc_struct *get_current_gdt_rw(void) /* Get the fixmap index for a specific processor */ static inline unsigned int get_cpu_gdt_ro_index(int cpu) { - return FIX_GDT_REMAP_BEGIN + cpu; + return FIX_GDT_REMAP_END - cpu; } /* Provide the fixmap address of the remapped GDT */ -- 2.14.1
