[mirror_ubuntu-hirsute-kernel.git] / arch / x86 / include / asm / fsgsbase.h

/* 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 */
Commit	Line	Data
b1378a56 CB	1	/* SPDX-License-Identifier: GPL-2.0 */
b1378a56 CB	2	#ifndef _ASM_FSGSBASE_H
ec3a9418	3	#define _ASM_FSGSBASE_H
b1378a56 CB	4
	5	#ifndef __ASSEMBLY__
	6
	7	#ifdef CONFIG_X86_64
	8
	9	#include <asm/msr-index.h>
	10
b1378a56	11	/*
ec3a9418	12	* Read/write a task's FSBASE or GSBASE. This returns the value that
b1378a56	13	* the FS/GS base would have (if the task were to be resumed). These
ec3a9418 IM	14	* work on the current task or on a non-running (typically stopped
ec3a9418 IM	15	* ptrace child) task.
b1378a56	16	*/
ec3a9418 IM	17	extern unsigned long x86_fsbase_read_task(struct task_struct *task);
ec3a9418 IM	18	extern unsigned long x86_gsbase_read_task(struct task_struct *task);
87ab4689 CB	19	extern void x86_fsbase_write_task(struct task_struct *task, unsigned long fsbase);
87ab4689 CB	20	extern void x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase);
b1378a56 CB	21
	22	/* Helper functions for reading/writing FS/GS base */
	23
	24	static inline unsigned long x86_fsbase_read_cpu(void)
	25	{
	26	unsigned long fsbase;
	27
	28	rdmsrl(MSR_FS_BASE, fsbase);
ec3a9418	29
b1378a56 CB	30	return fsbase;
	31	}
	32
b1378a56 CB	33	static inline unsigned long x86_gsbase_read_cpu_inactive(void)
	34	{
	35	unsigned long gsbase;
	36
	37	rdmsrl(MSR_KERNEL_GS_BASE, gsbase);
ec3a9418	38
b1378a56 CB	39	return gsbase;
	40	}
	41
87ab4689 CB	42	static inline void x86_fsbase_write_cpu(unsigned long fsbase)
	43	{
	44	wrmsrl(MSR_FS_BASE, fsbase);
	45	}
	46
	47	static inline void x86_gsbase_write_cpu_inactive(unsigned long gsbase)
	48	{
	49	wrmsrl(MSR_KERNEL_GS_BASE, gsbase);
	50	}
b1378a56 CB	51
	52	#endif /* CONFIG_X86_64 */
	53
	54	#endif /* __ASSEMBLY__ */
	55
	56	#endif /* _ASM_FSGSBASE_H */