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| author | Hou Wenlong <houwenlong.hwl@antgroup.com> | 2023-06-09 12:45:31 +0300 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-11-13 14:23:27 +0300 |
| commit | 5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4 (patch) | |
| tree | 40ef340dd4cb669c419f31e696a5c9066218b3de /arch/x86/include/asm/paravirt_types.h | |
| parent | b85ea95d086471afb4ad062012a4d73cd328fa86 (diff) | |
| download | linux-5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4.tar.xz | |
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
Diffstat (limited to 'arch/x86/include/asm/paravirt_types.h')
| -rw-r--r-- | arch/x86/include/asm/paravirt_types.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 772d03487520..e1bfb719fca3 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -5,7 +5,7 @@ #ifndef __ASSEMBLY__ /* These all sit in the .parainstructions section to tell us what to patch. */ struct paravirt_patch_site { - u8 *instr; /* original instructions */ + s32 instr_offset; /* original instructions */ u8 type; /* type of this instruction */ u8 len; /* length of original instruction */ }; @@ -263,11 +263,11 @@ extern struct paravirt_patch_template pv_ops; #define _paravirt_alt(insn_string, type) \ "771:\n\t" insn_string "\n" "772:\n" \ ".pushsection .parainstructions,\"a\"\n" \ - _ASM_ALIGN "\n" \ - _ASM_PTR " 771b\n" \ + " .align 4\n" \ + " .long 771b-.\n" \ " .byte " type "\n" \ " .byte 772b-771b\n" \ - _ASM_ALIGN "\n" \ + " .align 4\n" \ ".popsection\n" /* Generate patchable code, with the default asm parameters. */ |