linux/arch/x86/include/asm/fsgsbase.h

57 lines
1.3 KiB
C

/* 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 */