1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun #ifndef _LINUX_CONTEXT_TRACKING_STATE_H 3*4882a593Smuzhiyun #define _LINUX_CONTEXT_TRACKING_STATE_H 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #include <linux/percpu.h> 6*4882a593Smuzhiyun #include <linux/static_key.h> 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun struct context_tracking { 9*4882a593Smuzhiyun /* 10*4882a593Smuzhiyun * When active is false, probes are unset in order 11*4882a593Smuzhiyun * to minimize overhead: TIF flags are cleared 12*4882a593Smuzhiyun * and calls to user_enter/exit are ignored. This 13*4882a593Smuzhiyun * may be further optimized using static keys. 14*4882a593Smuzhiyun */ 15*4882a593Smuzhiyun bool active; 16*4882a593Smuzhiyun int recursion; 17*4882a593Smuzhiyun enum ctx_state { 18*4882a593Smuzhiyun CONTEXT_DISABLED = -1, /* returned by ct_state() if unknown */ 19*4882a593Smuzhiyun CONTEXT_KERNEL = 0, 20*4882a593Smuzhiyun CONTEXT_USER, 21*4882a593Smuzhiyun CONTEXT_GUEST, 22*4882a593Smuzhiyun } state; 23*4882a593Smuzhiyun }; 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun #ifdef CONFIG_CONTEXT_TRACKING 26*4882a593Smuzhiyun extern struct static_key_false context_tracking_key; 27*4882a593Smuzhiyun DECLARE_PER_CPU(struct context_tracking, context_tracking); 28*4882a593Smuzhiyun context_tracking_enabled(void)29*4882a593Smuzhiyunstatic __always_inline bool context_tracking_enabled(void) 30*4882a593Smuzhiyun { 31*4882a593Smuzhiyun return static_branch_unlikely(&context_tracking_key); 32*4882a593Smuzhiyun } 33*4882a593Smuzhiyun context_tracking_enabled_cpu(int cpu)34*4882a593Smuzhiyunstatic __always_inline bool context_tracking_enabled_cpu(int cpu) 35*4882a593Smuzhiyun { 36*4882a593Smuzhiyun return context_tracking_enabled() && per_cpu(context_tracking.active, cpu); 37*4882a593Smuzhiyun } 38*4882a593Smuzhiyun context_tracking_enabled_this_cpu(void)39*4882a593Smuzhiyunstatic inline bool context_tracking_enabled_this_cpu(void) 40*4882a593Smuzhiyun { 41*4882a593Smuzhiyun return context_tracking_enabled() && __this_cpu_read(context_tracking.active); 42*4882a593Smuzhiyun } 43*4882a593Smuzhiyun context_tracking_in_user(void)44*4882a593Smuzhiyunstatic __always_inline bool context_tracking_in_user(void) 45*4882a593Smuzhiyun { 46*4882a593Smuzhiyun return __this_cpu_read(context_tracking.state) == CONTEXT_USER; 47*4882a593Smuzhiyun } 48*4882a593Smuzhiyun #else context_tracking_in_user(void)49*4882a593Smuzhiyunstatic inline bool context_tracking_in_user(void) { return false; } context_tracking_enabled(void)50*4882a593Smuzhiyunstatic inline bool context_tracking_enabled(void) { return false; } context_tracking_enabled_cpu(int cpu)51*4882a593Smuzhiyunstatic inline bool context_tracking_enabled_cpu(int cpu) { return false; } context_tracking_enabled_this_cpu(void)52*4882a593Smuzhiyunstatic inline bool context_tracking_enabled_this_cpu(void) { return false; } 53*4882a593Smuzhiyun #endif /* CONFIG_CONTEXT_TRACKING */ 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun #endif 56