From 095b8303f3835c68ac4a8b6d754ca1c3b6230711 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 14 Aug 2023 13:44:30 +0200 Subject: x86/alternative: Make custom return thunk unconditional There is infrastructure to rewrite return thunks to point to any random thunk one desires, unwrap that from CALL_THUNKS, which up to now was the sole user of that. [ bp: Make the thunks visible on 32-bit and add ifdeffery for the 32-bit builds. ] Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230814121148.775293785@infradead.org --- arch/x86/kernel/alternative.c | 4 ---- arch/x86/kernel/cpu/bugs.c | 2 ++ 2 files changed, 2 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 2dcf3a06af09..099d58d02a26 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -687,10 +687,6 @@ void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) #ifdef CONFIG_RETHUNK -#ifdef CONFIG_CALL_THUNKS -void (*x86_return_thunk)(void) __ro_after_init = &__x86_return_thunk; -#endif - /* * Rewrite the compiler generated return thunk tail-calls. * diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 6c04aef4b63b..3bc0d149eacd 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -63,6 +63,8 @@ EXPORT_SYMBOL_GPL(x86_pred_cmd); static DEFINE_MUTEX(spec_ctrl_mutex); +void (*x86_return_thunk)(void) __ro_after_init = &__x86_return_thunk; + /* Update SPEC_CTRL MSR and its cached copy unconditionally */ static void update_spec_ctrl(u64 val) { -- cgit v1.2.3