1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_SYNC_CORE_H 3 #define _ASM_X86_SYNC_CORE_H 4 5 #include <linux/preempt.h> 6 #include <asm/processor.h> 7 #include <asm/cpufeature.h> 8 9 /* 10 * Ensure that a core serializing instruction is issued before returning 11 * to user-mode. x86 implements return to user-space through sysexit, 12 * sysrel, and sysretq, which are not core serializing. 13 */ 14 static inline void sync_core_before_usermode(void) 15 { 16 /* With PTI, we unconditionally serialize before running user code. */ 17 if (static_cpu_has(X86_FEATURE_PTI)) 18 return; 19 /* 20 * Return from interrupt and NMI is done through iret, which is core 21 * serializing. 22 */ 23 if (in_irq() || in_nmi()) 24 return; 25 sync_core(); 26 } 27 28 #endif /* _ASM_X86_SYNC_CORE_H */ 29