Messages in this thread | | | Date | Wed, 10 Jan 2018 21:50:16 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/alternatives: Fix optimize_nops() checking |
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On Wed, Jan 10, 2018 at 12:20:40PM -0800, Linus Torvalds wrote: > No, that's not valid. That could never work anyway. The ".long 2f" > would be the absolute address in the alternative section, but opcode > E9 takes a relative 32-bit offset.
Ah, right, doh. I remember now. We used to do those jmps by computing the relative offset:
From: 090a3f615524c3f75d09fdb37f15ea1868d79f7e - .section .altinstr_replacement,"ax" -1: .byte 0xeb /* jmp <disp8> */ - .byte (copy_page_rep - copy_page) - (2f - 1b) /* offset */
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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