From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 11 Apr 2025 05:40:35 +0000 (+0200)
Subject: x86/alternatives: Remove the 'addr == NULL means forced-flush' hack from smp_text_pok... 
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=eaa24c9177c8c765ec9b9ccab392ac07ae8acda0;p=users%2Fdwmw2%2Flinux.git

x86/alternatives: Remove the 'addr == NULL means forced-flush' hack from smp_text_poke_batch_finish()/smp_text_poke_batch_flush()/text_poke_addr_ordered()

There's this weird hack used by smp_text_poke_batch_finish() to indicate
a 'forced flush':

	smp_text_poke_batch_flush(NULL);

Just open-code the vector-flush in a straightforward fashion:

	smp_text_poke_batch_process(tp_vec, tp_vec_nr);
	tp_vec_nr = 0;

And get rid of !addr hack from text_poke_addr_ordered().

Leave a WARN_ON_ONCE(), just in case some external code learned
to rely on this behavior.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-24-mingo@kernel.org
---

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index c5801b4cbb66e..16a41e29db179 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2845,12 +2845,11 @@ static bool text_poke_addr_ordered(void *addr)
 {
 	struct smp_text_poke_loc *tp;
 
+	WARN_ON_ONCE(!addr);
+
 	if (!tp_vec_nr)
 		return true;
 
-	if (!addr) /* force */
-		return false;
-
 	/*
 	 * If the last current entry's address is higher than the
 	 * new entry's address we'd like to add, then ordering
@@ -2864,6 +2863,14 @@ static bool text_poke_addr_ordered(void *addr)
 	return true;
 }
 
+void smp_text_poke_batch_finish(void)
+{
+	if (tp_vec_nr) {
+		smp_text_poke_batch_process(tp_vec, tp_vec_nr);
+		tp_vec_nr = 0;
+	}
+}
+
 static void smp_text_poke_batch_flush(void *addr)
 {
 	lockdep_assert_held(&text_mutex);
@@ -2874,11 +2881,6 @@ static void smp_text_poke_batch_flush(void *addr)
 	}
 }
 
-void smp_text_poke_batch_finish(void)
-{
-	smp_text_poke_batch_flush(NULL);
-}
-
 void __ref smp_text_poke_batch_add(void *addr, const void *opcode, size_t len, const void *emulate)
 {
 	struct smp_text_poke_loc *tp;