x86/paravirt: Use relative reference for the original instruction offset
authorHou Wenlong <houwenlong.hwl@antgroup.com>
Fri, 9 Jun 2023 09:45:31 +0000 (17:45 +0800)
committerBorislav Petkov (AMD) <bp@alien8.de>
Mon, 13 Nov 2023 11:23:27 +0000 (12:23 +0100)
commit5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4
tree40ef340dd4cb669c419f31e696a5c9066218b3de
parentb85ea95d086471afb4ad062012a4d73cd328fa86
x86/paravirt: Use relative reference for the original instruction offset

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
arch/x86/include/asm/paravirt.h
arch/x86/include/asm/paravirt_types.h
arch/x86/kernel/alternative.c
arch/x86/kernel/callthunks.c