From: Borislav Petkov (AMD) <bp@alien8.de>
Date: Tue, 30 Jan 2024 10:59:40 +0000 (+0100)
Subject: x86/alternatives: Optimize optimize_nops()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c3a3cb5c3d893d7ca75c773ddd107832f13e7b57;p=linux.git

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
---

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 4b3378c715182..67dd7c371d28a 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);