linux-kernel - [PATCH v2 4/5] x86/speculation: Make mds_user_clear __ro_after

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Date: Tue,  6 Feb 2024 18:39:10 +0100
From: Valentin Schneider <vschneid@...hat.com>
To: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org,
	linux-arch@...r.kernel.org,
	x86@...nel.org
Cc: Josh Poimboeuf <jpoimboe@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Borislav Petkov <bp@...en8.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
	Ingo Molnar <mingo@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Wanpeng Li <wanpengli@...cent.com>,
	Vitaly Kuznetsov <vkuznets@...hat.com>,
	Arnd Bergmann <arnd@...db.de>,
	Jason Baron <jbaron@...mai.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ard Biesheuvel <ardb@...nel.org>,
	Frederic Weisbecker <frederic@...nel.org>,
	"Paul E. McKenney" <paulmck@...nel.org>,
	Feng Tang <feng.tang@...el.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Mike Rapoport (IBM)" <rppt@...nel.org>,
	Vlastimil Babka <vbabka@...e.cz>,
	David Hildenbrand <david@...hat.com>,
	"ndesaulniers@...gle.com" <ndesaulniers@...gle.com>,
	Michael Kelley <mikelley@...rosoft.com>,
	"Masami Hiramatsu (Google)" <mhiramat@...nel.org>
Subject: [PATCH v2 4/5] x86/speculation: Make mds_user_clear __ro_after_init

mds_user_clear is only ever enabled in:
o __init mds_select_mitigation()
o __init taa_select_mitigation()
o __init mmio_select_mitigation()

mark it as __ro_after_init.

Signed-off-by: Valentin Schneider <vschneid@...hat.com>
Acked-by: Josh Poimboeuf <jpoimboe@...nel.org>
---
 arch/x86/kernel/cpu/bugs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index bb0ab8466b919..bab36096015d8 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -112,7 +112,7 @@ DEFINE_STATIC_KEY_FALSE(switch_mm_cond_ibpb);
 DEFINE_STATIC_KEY_FALSE(switch_mm_always_ibpb);
 
 /* Control MDS CPU buffer clear before returning to user space */
-DEFINE_STATIC_KEY_FALSE(mds_user_clear);
+DEFINE_STATIC_KEY_FALSE_RO(mds_user_clear);
 EXPORT_SYMBOL_GPL(mds_user_clear);
 /* Control MDS CPU buffer clear before idling (halt, mwait) */
 DEFINE_STATIC_KEY_FALSE(mds_idle_clear);
-- 
2.43.0