[PATCH] x86/alternative: Align insn bytes vertically

From: Borislav Petkov
Date: Tue Jun 01 2021 - 15:37:36 EST


From: Borislav Petkov <bp@xxxxxxx>

For easier inspection which bytes have changed.

For example:

feat: 7*32+12, old: (__x86_indirect_thunk_r10+0x0/0x20 (ffffffff81c02480) len: 17), repl: (ffffffff897813aa, len: 17)
ffffffff81c02480: old_insn: 41 ff e2 90 90 90 90 90 90 90 90 90 90 90 90 90 90
ffffffff897813aa: rpl_insn: e8 07 00 00 00 f3 90 0f ae e8 eb f9 4c 89 14 24 c3
ffffffff81c02480: final_insn: e8 07 00 00 00 f3 90 0f ae e8 eb f9 4c 89 14 24 c3

No functional changes.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/kernel/alternative.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 75c752b0628c..227c4a8b145a 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -273,8 +273,8 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
instr, instr, a->instrlen,
replacement, a->replacementlen);

- DUMP_BYTES(instr, a->instrlen, "%px: old_insn: ", instr);
- DUMP_BYTES(replacement, a->replacementlen, "%px: rpl_insn: ", replacement);
+ DUMP_BYTES(instr, a->instrlen, "%px: old_insn: ", instr);
+ DUMP_BYTES(replacement, a->replacementlen, "%px: rpl_insn: ", replacement);

memcpy(insn_buff, replacement, a->replacementlen);
insn_buff_sz = a->replacementlen;
--
2.29.2