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