From 27441d76b3d6604de9162c4c24d034bcfe3249de Mon Sep 17 00:00:00 2001 From: Brian Gerst Date: Sat, 5 Sep 2026 18:55:19 -0400 Subject: [PATCH] x86/asm: Remove CR4 read fault handler Remove the fault handler from native_read_cr4() since 486 support has been removed. Signed-off-by: Brian Gerst Signed-off-by: Borislav Petkov (AMD) Link: https://patch.msgid.link/20260905225519.1002976-1-brgerst@gmail.com --- arch/x86/include/asm/special_insns.h | 13 ------------- 1 file changed, 13 deletions(-) diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index 46aa2c9c1bda..6c80f69cf62b 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -46,20 +46,7 @@ static __always_inline void native_write_cr3(unsigned long val) static inline unsigned long native_read_cr4(void) { unsigned long val; -#ifdef CONFIG_X86_32 - /* - * This could fault if CR4 does not exist. Non-existent CR4 - * is functionally equivalent to CR4 == 0. Keep it simple and pretend - * that CR4 == 0 on CPUs that don't have CR4. - */ - asm volatile("1: mov %%cr4, %0\n" - "2:\n" - _ASM_EXTABLE(1b, 2b) - : "=r" (val) : "0" (0)); -#else - /* CR4 always exists on x86_64. */ asm volatile("mov %%cr4,%0" : "=r" (val)); -#endif return val; }