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/* 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 */
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