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| author |  Hou Wenlong <houwenlong.hwl@antgroup.com>
| 2023-06-09 17:45:31 +0800 |
|---|---|---|
| committer |  Borislav Petkov (AMD) <bp@alien8.de>
| 2023-11-13 12:23:27 +0100 |
| commit | 5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4 (patch) | |
| tree | 40ef340dd4cb669c419f31e696a5c9066218b3de /arch/x86/kernel/alternative.c | |
| parent | Linux 6.7-rc1 (diff) | |
| download | linux-5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4.tar.gz linux-5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4.tar.bz2 linux-5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4.zip | |
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/kernel/alternative.c')
| -rw-r--r-- | arch/x86/kernel/alternative.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 73be3931e4f0..be35c8ccf826 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1431,20 +1431,22 @@ void __init_or_module apply_paravirt(struct paravirt_patch_site *start, { struct paravirt_patch_site *p; char insn_buff[MAX_PATCH_LEN]; + u8 *instr; for (p = start; p < end; p++) { unsigned int used; + instr = (u8 *)&p->instr_offset + p->instr_offset; BUG_ON(p->len > MAX_PATCH_LEN); /* prep the buffer with the original instructions */ - memcpy(insn_buff, p->instr, p->len); - used = paravirt_patch(p->type, insn_buff, (unsigned long)p->instr, p->len); + memcpy(insn_buff, instr, p->len); + used = paravirt_patch(p->type, insn_buff, (unsigned long)instr, p->len); BUG_ON(used > p->len); /* Pad the rest with nops */ add_nops(insn_buff + used, p->len - used); - text_poke_early(p->instr, insn_buff, p->len); + text_poke_early(instr, insn_buff, p->len); } } extern struct paravirt_patch_site __start_parainstructions[], |