linux-kernel - [PATCH 23/49] x86/alternatives: Simplify smp_text_poke_single() by using tp

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Message-ID: <20250328132704.1901674-24-mingo@kernel.org>
Date: Fri, 28 Mar 2025 14:26:38 +0100
From: Ingo Molnar <mingo@...nel.org>
To: linux-kernel@...r.kernel.org
Cc: Juergen Gross <jgross@...e.com>,
	"H . Peter Anvin" <hpa@...or.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Borislav Petkov <bp@...en8.de>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>
Subject: [PATCH 23/49] x86/alternatives: Simplify smp_text_poke_single() by using tp_vec and existing APIs

Instead of constructing a vector on-stack, just use the already
available batch-patching vector - which should always be empty
at this point.

This will allow subsequent simplifications.

Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/alternative.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index ffffec4597b7..70abc636b87c 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2906,8 +2906,13 @@ void __ref smp_text_poke_batch_add(void *addr, const void *opcode, size_t len, c
  */
 void __ref smp_text_poke_single(void *addr, const void *opcode, size_t len, const void *emulate)
 {
-	struct smp_text_poke_loc tp;
+	struct smp_text_poke_loc *tp;
+
+	/* Batch-patching should not be mixed with single-patching: */
+	WARN_ON_ONCE(tp_vec_nr != 0);
+
+	tp = &tp_vec[tp_vec_nr++];
+	text_poke_int3_loc_init(tp, addr, opcode, len, emulate);
 
-	text_poke_int3_loc_init(&tp, addr, opcode, len, emulate);
-	smp_text_poke_batch_process(&tp, 1);
+	smp_text_poke_batch_finish();
 }
-- 
2.45.2