[tip: x86/alternatives] x86/alternatives: Optimize optimize_nops()

tip-bot2 for Borislav Petkov (AMD)
2024-02-13T15:36:01Z

Commit-ID: f7045230fa2933bf3b38c9c92b5ba46486ef33f9
Gitweb: https://git.kernel.org/tip/f7045230fa2933bf3b38c9c92b5ba46486ef33f9
Author: Borislav Petkov (AMD) <bp@alien8.de>
AuthorDate: Tue, 30 Jan 2024 11:59:40 +01:00
Committer: Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Tue, 13 Feb 2024 16:26:56 +01:00

x86/alternatives: Optimize optimize_nops()

Return early if NOPs have already been optimized.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240130105941.19707-4-bp@alien8.de
---
arch/x86/kernel/alternative.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index cdbece3..1ceaaab 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -233,6 +233,10 @@ static void __init_or_module noinline optimize_nops(const u8 * const instr, u8 *
if (insn_is_nop(&insn)) {
int nop = i;

+ /* Has the NOP already been optimized? */
+ if (i + insn.length == len)
+ return;
+
next = skip_nops(buf, next, len);

add_nop(buf + nop, next - nop);