| David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _ASM_FSGSBASE_H |
| 3 | #define _ASM_FSGSBASE_H |
| 4 | |
| 5 | #ifndef __ASSEMBLY__ |
| 6 | |
| 7 | #ifdef CONFIG_X86_64 |
| 8 | |
| 9 | #include <asm/msr-index.h> |
| 10 | |
| 11 | /* |
| 12 | * Read/write a task's FSBASE or GSBASE. This returns the value that |
| 13 | * the FS/GS base would have (if the task were to be resumed). These |
| 14 | * work on the current task or on a non-running (typically stopped |
| 15 | * ptrace child) task. |
| 16 | */ |
| 17 | extern unsigned long x86_fsbase_read_task(struct task_struct *task); |
| 18 | extern unsigned long x86_gsbase_read_task(struct task_struct *task); |
| 19 | extern void x86_fsbase_write_task(struct task_struct *task, unsigned long fsbase); |
| 20 | extern void x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase); |
| 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); |
| 29 | |
| 30 | return fsbase; |
| 31 | } |
| 32 | |
| 33 | static inline unsigned long x86_gsbase_read_cpu_inactive(void) |
| 34 | { |
| 35 | unsigned long gsbase; |
| 36 | |
| 37 | rdmsrl(MSR_KERNEL_GS_BASE, gsbase); |
| 38 | |
| 39 | return gsbase; |
| 40 | } |
| 41 | |
| 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 | } |
| 51 | |
| 52 | #endif /* CONFIG_X86_64 */ |
| 53 | |
| 54 | #endif /* __ASSEMBLY__ */ |
| 55 | |
| 56 | #endif /* _ASM_FSGSBASE_H */ |