Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 1 | #ifndef _LINUX_CONTEXT_TRACKING_H |
| 2 | #define _LINUX_CONTEXT_TRACKING_H |
| 3 | |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 4 | #include <linux/sched.h> |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 5 | #include <linux/percpu.h> |
Frederic Weisbecker | 521921b | 2013-05-16 01:21:38 +0200 | [diff] [blame] | 6 | #include <linux/vtime.h> |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 7 | #include <asm/ptrace.h> |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 8 | |
| 9 | struct context_tracking { |
| 10 | /* |
| 11 | * When active is false, probes are unset in order |
| 12 | * to minimize overhead: TIF flags are cleared |
| 13 | * and calls to user_enter/exit are ignored. This |
| 14 | * may be further optimized using static keys. |
| 15 | */ |
| 16 | bool active; |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 17 | enum ctx_state { |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 18 | IN_KERNEL = 0, |
| 19 | IN_USER, |
| 20 | } state; |
| 21 | }; |
| 22 | |
Frederic Weisbecker | 521921b | 2013-05-16 01:21:38 +0200 | [diff] [blame] | 23 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 24 | #ifdef CONFIG_CONTEXT_TRACKING |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 25 | DECLARE_PER_CPU(struct context_tracking, context_tracking); |
| 26 | |
| 27 | static inline bool context_tracking_in_user(void) |
| 28 | { |
| 29 | return __this_cpu_read(context_tracking.state) == IN_USER; |
| 30 | } |
| 31 | |
| 32 | static inline bool context_tracking_active(void) |
| 33 | { |
| 34 | return __this_cpu_read(context_tracking.active); |
| 35 | } |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 36 | |
| 37 | extern void user_enter(void); |
| 38 | extern void user_exit(void); |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 39 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 40 | static inline enum ctx_state exception_enter(void) |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 41 | { |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 42 | enum ctx_state prev_ctx; |
| 43 | |
| 44 | prev_ctx = this_cpu_read(context_tracking.state); |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 45 | user_exit(); |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 46 | |
| 47 | return prev_ctx; |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 48 | } |
| 49 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 50 | static inline void exception_exit(enum ctx_state prev_ctx) |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 51 | { |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 52 | if (prev_ctx == IN_USER) |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 53 | user_enter(); |
| 54 | } |
| 55 | |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 56 | extern void context_tracking_task_switch(struct task_struct *prev, |
| 57 | struct task_struct *next); |
| 58 | #else |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 59 | static inline bool context_tracking_in_user(void) { return false; } |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 60 | static inline void user_enter(void) { } |
| 61 | static inline void user_exit(void) { } |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 62 | static inline enum ctx_state exception_enter(void) { return 0; } |
| 63 | static inline void exception_exit(enum ctx_state prev_ctx) { } |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 64 | static inline void context_tracking_task_switch(struct task_struct *prev, |
| 65 | struct task_struct *next) { } |
| 66 | #endif /* !CONFIG_CONTEXT_TRACKING */ |
| 67 | |
Frederic Weisbecker | 2d854e5 | 2013-07-12 19:02:30 +0200 | [diff] [blame] | 68 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN |
| 69 | extern void guest_enter(void); |
| 70 | extern void guest_exit(void); |
| 71 | #else |
| 72 | static inline void guest_enter(void) |
| 73 | { |
| 74 | /* |
Frederic Weisbecker | 5b206d4 | 2013-07-12 19:05:14 +0200 | [diff] [blame^] | 75 | * This is running in ioctl context so its safe |
| 76 | * to assume that it's the stime pending cputime |
| 77 | * to flush. |
Frederic Weisbecker | 2d854e5 | 2013-07-12 19:02:30 +0200 | [diff] [blame] | 78 | */ |
| 79 | vtime_account_system(current); |
| 80 | current->flags |= PF_VCPU; |
| 81 | } |
| 82 | |
| 83 | static inline void guest_exit(void) |
| 84 | { |
Frederic Weisbecker | 5b206d4 | 2013-07-12 19:05:14 +0200 | [diff] [blame^] | 85 | /* Flush the guest cputime we spent on the guest */ |
Frederic Weisbecker | 2d854e5 | 2013-07-12 19:02:30 +0200 | [diff] [blame] | 86 | vtime_account_system(current); |
| 87 | current->flags &= ~PF_VCPU; |
| 88 | } |
| 89 | #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */ |
| 90 | |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 91 | #endif |