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From: Borislav Petkov <bp@alien8.de>
To: X86 ML <x86@kernel.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 3/4] x86/alternatives: Optimize optimize_nops()
Date: Tue, 30 Jan 2024 11:59:40 +0100	[thread overview]
Message-ID: <20240130105941.19707-4-bp@alien8.de> (raw)
In-Reply-To: <20240130105941.19707-1-bp@alien8.de>

From: "Borislav Petkov (AMD)" <bp@alien8.de>

Return early if NOPs have already been optimized.

Signed-off-by: Borislav Petkov (AMD) <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 2dd1c7fe0949..68ee46c379c1 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);
-- 
2.43.0


  parent reply	other threads:[~2024-01-30 11:00 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-30 10:59 [PATCH 0/4] x86/alternatives: Do NOPs optimization on a temporary buffer Borislav Petkov
2024-01-30 10:59 ` [PATCH 1/4] x86/alternatives: Use a temporary buffer when optimizing NOPs Borislav Petkov
2024-02-13 15:36   ` [tip: x86/alternatives] " tip-bot2 for Borislav Petkov (AMD)
2024-04-09 17:11   ` tip-bot2 for Borislav Petkov (AMD)
2024-01-30 10:59 ` [PATCH 2/4] x86/alternatives: Get rid of __optimize_nops() Borislav Petkov
2024-02-13 15:35   ` [tip: x86/alternatives] " tip-bot2 for Borislav Petkov (AMD)
2024-04-09 17:11   ` tip-bot2 for Borislav Petkov (AMD)
2024-01-30 10:59 ` Borislav Petkov [this message]
2024-02-13 15:35   ` [tip: x86/alternatives] x86/alternatives: Optimize optimize_nops() tip-bot2 for Borislav Petkov (AMD)
2024-04-09 17:11   ` tip-bot2 for Borislav Petkov (AMD)
2024-01-30 10:59 ` [PATCH 4/4] x86/alternatives: Sort local vars in apply_alternatives() Borislav Petkov
2024-02-13 15:35   ` [tip: x86/alternatives] " tip-bot2 for Borislav Petkov (AMD)
2024-04-09 17:11   ` tip-bot2 for Borislav Petkov (AMD)
2024-01-31 16:17 ` [PATCH 0/4] x86/alternatives: Do NOPs optimization on a temporary buffer Paul Gortmaker
2024-01-31 16:25   ` Borislav Petkov

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