| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _ASM_X86_SYNC_CORE_H |
| #define _ASM_X86_SYNC_CORE_H |
| |
| #include <linux/preempt.h> |
| #include <asm/processor.h> |
| #include <asm/cpufeature.h> |
| |
| /* |
| * Ensure that a core serializing instruction is issued before returning |
| * to user-mode. x86 implements return to user-space through sysexit, |
| * sysrel, and sysretq, which are not core serializing. |
| */ |
| static inline void sync_core_before_usermode(void) |
| { |
| /* With PTI, we unconditionally serialize before running user code. */ |
| if (static_cpu_has(X86_FEATURE_PTI)) |
| return; |
| |
| /* |
| * Even if we're in an interrupt, we might reschedule before returning, |
| * in which case we could switch to a different thread in the same mm |
| * and return using SYSRET or SYSEXIT. Instead of trying to keep |
| * track of our need to sync the core, just sync right away. |
| */ |
| sync_core(); |
| } |
| |
| #endif /* _ASM_X86_SYNC_CORE_H */ |
