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

tip-bot2 for Borislav Petkov (AMD)
2024-04-09T17:11:31Z

Commit-ID: c3a3cb5c3d893d7ca75c773ddd107832f13e7b57
Gitweb: https://git.kernel.org/tip/c3a3cb5c3d893d7ca75c773ddd107832f13e7b57
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, 09 Apr 2024 18:15:03 +02:00

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 4b3378c..67dd7c3 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -233,6 +233,10 @@ static void noinline optimize_nops(const u8 * const instr, u8 *buf, size_t len)
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);