x86/paravirt: Use relative reference for the original instruction offset

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Similar to the alternative patching, use a relative reference for original
instruction offset rather than absolute one, which saves 8 bytes for one
PARA_SITE entry on x86_64.  As a result, a R_X86_64_PC32 relocation is
generated instead of an R_X86_64_64 one, which also reduces relocation
metadata on relocatable builds. Hardcode the alignment to 4 now.

  [ bp: Massage commit message. ]

Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/9e6053107fbaabc0d33e5d2865c5af2c67ec9925.1686301237.git.houwenlong.hwl@antgroup.com

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This commit is contained in:

Hou Wenlong 2023-06-09 17:45:31 +08:00 • committed by Borislav Petkov (AMD)

parent b85ea95d08

commit 5c22c4726e

4 changed files with 15 additions and 13 deletions

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10

arch/x86/include/asm/paravirt.h

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8

arch/x86/include/asm/paravirt_types.h

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8

arch/x86/kernel/alternative.c

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2

arch/x86/kernel/callthunks.c

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