/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_FSGSBASE_H #define _ASM_FSGSBASE_H #ifndef __ASSEMBLY__ #ifdef CONFIG_X86_64 #include <asm/msr-index.h> /* * Read/write a task's FSBASE or GSBASE. This returns the value that * the FS/GS base would have (if the task were to be resumed). These * work on the current task or on a non-running (typically stopped * ptrace child) task. */ extern unsigned long x86_fsbase_read_task(struct task_struct *task); extern unsigned long x86_gsbase_read_task(struct task_struct *task); extern void x86_fsbase_write_task(struct task_struct *task, unsigned long fsbase); extern void x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase); /* Helper functions for reading/writing FS/GS base */ static inline unsigned long x86_fsbase_read_cpu(void) { unsigned long fsbase; rdmsrl(MSR_FS_BASE, fsbase); return fsbase; } static inline unsigned long x86_gsbase_read_cpu_inactive(void) { unsigned long gsbase; rdmsrl(MSR_KERNEL_GS_BASE, gsbase); return gsbase; } static inline void x86_fsbase_write_cpu(unsigned long fsbase) { wrmsrl(MSR_FS_BASE, fsbase); } static inline void x86_gsbase_write_cpu_inactive(unsigned long gsbase) { wrmsrl(MSR_KERNEL_GS_BASE, gsbase); } #endif /* CONFIG_X86_64 */ #endif /* __ASSEMBLY__ */ #endif /* _ASM_FSGSBASE_H */