x86/alternatives: Add comment about noinstr expectations

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/20250411054105.2341982-53-mingo@kernel.org

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 231b2acbe3601140eac99f5e2f730d1a100223db..604dd608d2816076bf28b2d4e6495073f9dfeb8b 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2447,6 +2447,11 @@ static struct smp_text_poke_array {
 
 static DEFINE_PER_CPU(atomic_t, text_poke_array_refs);
 
+/*
+ * These four __always_inline annotations imply noinstr, necessary
+ * due to smp_text_poke_int3_handler() being noinstr:
+ */
+
 static __always_inline bool try_get_text_poke_array(void)
 {
        atomic_t *refs = this_cpu_ptr(&text_poke_array_refs);