| Date | Thu, 7 Nov 2019 10:09:34 +0100 | From | Peter Zijlstra <> | Subject | Re: [patch 7/9] x86/iopl: Restrict iopl() permission scope |
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On Wed, Nov 06, 2019 at 08:35:06PM +0100, Thomas Gleixner wrote:
Something like:
> @@ -379,7 +383,8 @@ struct tss_struct { > * byte beyond the end of the I/O permission bitmap. The extra byte > * must have all bits set and must be within the TSS limit. > */ > - unsigned long io_bitmap[IO_BITMAP_LONGS + 1];
#ifndef X86_IOPL_NONE > + unsigned long io_bitmap_map[IO_BITMAP_LONGS + 1]; #ifdef X86_IOPL_EMLATION > + unsigned long io_bitmap_all[IO_BITMAP_LONGS + 1]; #endif /* X86_IOPL_EMLATION */ #endif /* !X86_IOPL_NONE */
> } __aligned(PAGE_SIZE);
Would allow us to reclaim those 8/16K bitmaps for LEGACY/NONE kernels.
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