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 | 65f382f | 2013-07-11 19:12:32 +0200 | [diff] [blame] | 7 | #include <linux/static_key.h> |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 8 | #include <asm/ptrace.h> |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 9 | |
| 10 | struct context_tracking { |
| 11 | /* |
| 12 | * When active is false, probes are unset in order |
| 13 | * to minimize overhead: TIF flags are cleared |
| 14 | * and calls to user_enter/exit are ignored. This |
| 15 | * may be further optimized using static keys. |
| 16 | */ |
| 17 | bool active; |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 18 | enum ctx_state { |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 19 | IN_KERNEL = 0, |
| 20 | IN_USER, |
| 21 | } state; |
| 22 | }; |
| 23 | |
Frederic Weisbecker | 521921b | 2013-05-16 01:21:38 +0200 | [diff] [blame] | 24 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 25 | #ifdef CONFIG_CONTEXT_TRACKING |
Frederic Weisbecker | 65f382f | 2013-07-11 19:12:32 +0200 | [diff] [blame] | 26 | extern struct static_key context_tracking_enabled; |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 27 | DECLARE_PER_CPU(struct context_tracking, context_tracking); |
| 28 | |
| 29 | static inline bool context_tracking_in_user(void) |
| 30 | { |
| 31 | return __this_cpu_read(context_tracking.state) == IN_USER; |
| 32 | } |
| 33 | |
| 34 | static inline bool context_tracking_active(void) |
| 35 | { |
| 36 | return __this_cpu_read(context_tracking.active); |
| 37 | } |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 38 | |
Frederic Weisbecker | 2e70933 | 2013-07-10 00:55:25 +0200 | [diff] [blame] | 39 | extern void context_tracking_cpu_set(int cpu); |
| 40 | |
Frederic Weisbecker | ad65782 | 2013-07-10 02:44:35 +0200 | [diff] [blame] | 41 | extern void context_tracking_user_enter(void); |
| 42 | extern void context_tracking_user_exit(void); |
| 43 | |
| 44 | static inline void user_enter(void) |
| 45 | { |
| 46 | if (static_key_false(&context_tracking_enabled)) |
| 47 | context_tracking_user_enter(); |
| 48 | |
| 49 | } |
| 50 | static inline void user_exit(void) |
| 51 | { |
| 52 | if (static_key_false(&context_tracking_enabled)) |
| 53 | context_tracking_user_exit(); |
| 54 | } |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 55 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 56 | static inline enum ctx_state exception_enter(void) |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 57 | { |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 58 | enum ctx_state prev_ctx; |
| 59 | |
Frederic Weisbecker | ad65782 | 2013-07-10 02:44:35 +0200 | [diff] [blame] | 60 | if (!static_key_false(&context_tracking_enabled)) |
| 61 | return 0; |
| 62 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 63 | prev_ctx = this_cpu_read(context_tracking.state); |
Frederic Weisbecker | ad65782 | 2013-07-10 02:44:35 +0200 | [diff] [blame] | 64 | context_tracking_user_exit(); |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 65 | |
| 66 | return prev_ctx; |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 67 | } |
| 68 | |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 69 | static inline void exception_exit(enum ctx_state prev_ctx) |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 70 | { |
Frederic Weisbecker | ad65782 | 2013-07-10 02:44:35 +0200 | [diff] [blame] | 71 | if (static_key_false(&context_tracking_enabled)) { |
| 72 | if (prev_ctx == IN_USER) |
| 73 | context_tracking_user_enter(); |
| 74 | } |
Frederic Weisbecker | 56dd947 | 2013-02-24 00:23:25 +0100 | [diff] [blame] | 75 | } |
| 76 | |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 77 | extern void context_tracking_task_switch(struct task_struct *prev, |
| 78 | struct task_struct *next); |
| 79 | #else |
Frederic Weisbecker | 95a79fd | 2013-01-07 18:12:14 +0100 | [diff] [blame] | 80 | static inline bool context_tracking_in_user(void) { return false; } |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 81 | static inline void user_enter(void) { } |
| 82 | static inline void user_exit(void) { } |
Frederic Weisbecker | 6c1e025 | 2013-02-24 01:19:14 +0100 | [diff] [blame] | 83 | static inline enum ctx_state exception_enter(void) { return 0; } |
| 84 | static inline void exception_exit(enum ctx_state prev_ctx) { } |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 85 | static inline void context_tracking_task_switch(struct task_struct *prev, |
| 86 | struct task_struct *next) { } |
| 87 | #endif /* !CONFIG_CONTEXT_TRACKING */ |
| 88 | |
Frederic Weisbecker | 65f382f | 2013-07-11 19:12:32 +0200 | [diff] [blame] | 89 | |
| 90 | #ifdef CONFIG_CONTEXT_TRACKING_FORCE |
| 91 | extern void context_tracking_init(void); |
| 92 | #else |
| 93 | static inline void context_tracking_init(void) { } |
| 94 | #endif /* CONFIG_CONTEXT_TRACKING_FORCE */ |
| 95 | |
| 96 | |
Frederic Weisbecker | 2d854e5 | 2013-07-12 19:02:30 +0200 | [diff] [blame] | 97 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN |
Frederic Weisbecker | 48d6a81 | 2013-07-10 02:44:35 +0200 | [diff] [blame^] | 98 | static inline void guest_enter(void) |
| 99 | { |
| 100 | if (static_key_false(&context_tracking_enabled) && |
| 101 | vtime_accounting_enabled()) |
| 102 | vtime_guest_enter(current); |
| 103 | else |
| 104 | current->flags |= PF_VCPU; |
| 105 | } |
| 106 | |
| 107 | static inline void guest_exit(void) |
| 108 | { |
| 109 | if (static_key_false(&context_tracking_enabled) && |
| 110 | vtime_accounting_enabled()) |
| 111 | vtime_guest_exit(current); |
| 112 | else |
| 113 | current->flags &= ~PF_VCPU; |
| 114 | } |
Frederic Weisbecker | 2d854e5 | 2013-07-12 19:02:30 +0200 | [diff] [blame] | 115 | #else |
| 116 | static inline void guest_enter(void) |
| 117 | { |
| 118 | /* |
Frederic Weisbecker | 5b206d4 | 2013-07-12 19:05:14 +0200 | [diff] [blame] | 119 | * This is running in ioctl context so its safe |
| 120 | * to assume that it's the stime pending cputime |
| 121 | * to flush. |
Frederic Weisbecker | 2d854e5 | 2013-07-12 19:02:30 +0200 | [diff] [blame] | 122 | */ |
| 123 | vtime_account_system(current); |
| 124 | current->flags |= PF_VCPU; |
| 125 | } |
| 126 | |
| 127 | static inline void guest_exit(void) |
| 128 | { |
Frederic Weisbecker | 5b206d4 | 2013-07-12 19:05:14 +0200 | [diff] [blame] | 129 | /* Flush the guest cputime we spent on the guest */ |
Frederic Weisbecker | 2d854e5 | 2013-07-12 19:02:30 +0200 | [diff] [blame] | 130 | vtime_account_system(current); |
| 131 | current->flags &= ~PF_VCPU; |
| 132 | } |
| 133 | #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */ |
| 134 | |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 135 | #endif |