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1 | /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ |
2 | #ifndef _LINUX_RSEQ_H | |
3 | #define _LINUX_RSEQ_H | |
4 | ||
5 | #ifdef CONFIG_RSEQ | |
6 | ||
7 | #include <linux/preempt.h> | |
8 | #include <linux/sched.h> | |
9 | ||
10 | /* | |
11 | * Map the event mask on the user-space ABI enum rseq_cs_flags | |
12 | * for direct mask checks. | |
13 | */ | |
14 | enum rseq_event_mask_bits { | |
15 | RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, | |
16 | RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, | |
17 | RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, | |
18 | }; | |
19 | ||
20 | enum rseq_event_mask { | |
21 | RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), | |
22 | RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), | |
23 | RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), | |
24 | }; | |
25 | ||
26 | static inline void rseq_set_notify_resume(struct task_struct *t) | |
27 | { | |
28 | if (t->rseq) | |
29 | set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); | |
30 | } | |
31 | ||
32 | void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); | |
33 | ||
34 | static inline void rseq_handle_notify_resume(struct ksignal *ksig, | |
35 | struct pt_regs *regs) | |
36 | { | |
37 | if (current->rseq) | |
38 | __rseq_handle_notify_resume(ksig, regs); | |
39 | } | |
40 | ||
41 | static inline void rseq_signal_deliver(struct ksignal *ksig, | |
42 | struct pt_regs *regs) | |
43 | { | |
44 | preempt_disable(); | |
45 | __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); | |
46 | preempt_enable(); | |
47 | rseq_handle_notify_resume(ksig, regs); | |
48 | } | |
49 | ||
50 | /* rseq_preempt() requires preemption to be disabled. */ | |
51 | static inline void rseq_preempt(struct task_struct *t) | |
52 | { | |
53 | __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); | |
54 | rseq_set_notify_resume(t); | |
55 | } | |
56 | ||
57 | /* rseq_migrate() requires preemption to be disabled. */ | |
58 | static inline void rseq_migrate(struct task_struct *t) | |
59 | { | |
60 | __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); | |
61 | rseq_set_notify_resume(t); | |
62 | } | |
63 | ||
64 | /* | |
65 | * If parent process has a registered restartable sequences area, the | |
66 | * child inherits. Unregister rseq for a clone with CLONE_VM set. | |
67 | */ | |
68 | static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) | |
69 | { | |
70 | if (clone_flags & CLONE_VM) { | |
71 | t->rseq = NULL; | |
72 | t->rseq_len = 0; | |
73 | t->rseq_sig = 0; | |
74 | t->rseq_event_mask = 0; | |
75 | } else { | |
76 | t->rseq = current->rseq; | |
77 | t->rseq_len = current->rseq_len; | |
78 | t->rseq_sig = current->rseq_sig; | |
79 | t->rseq_event_mask = current->rseq_event_mask; | |
80 | } | |
81 | } | |
82 | ||
83 | static inline void rseq_execve(struct task_struct *t) | |
84 | { | |
85 | t->rseq = NULL; | |
86 | t->rseq_len = 0; | |
87 | t->rseq_sig = 0; | |
88 | t->rseq_event_mask = 0; | |
89 | } | |
90 | ||
91 | #else | |
92 | ||
93 | static inline void rseq_set_notify_resume(struct task_struct *t) | |
94 | { | |
95 | } | |
96 | static inline void rseq_handle_notify_resume(struct ksignal *ksig, | |
97 | struct pt_regs *regs) | |
98 | { | |
99 | } | |
100 | static inline void rseq_signal_deliver(struct ksignal *ksig, | |
101 | struct pt_regs *regs) | |
102 | { | |
103 | } | |
104 | static inline void rseq_preempt(struct task_struct *t) | |
105 | { | |
106 | } | |
107 | static inline void rseq_migrate(struct task_struct *t) | |
108 | { | |
109 | } | |
110 | static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) | |
111 | { | |
112 | } | |
113 | static inline void rseq_execve(struct task_struct *t) | |
114 | { | |
115 | } | |
116 | ||
117 | #endif | |
118 | ||
119 | #ifdef CONFIG_DEBUG_RSEQ | |
120 | ||
121 | void rseq_syscall(struct pt_regs *regs); | |
122 | ||
123 | #else | |
124 | ||
125 | static inline void rseq_syscall(struct pt_regs *regs) | |
126 | { | |
127 | } | |
128 | ||
129 | #endif | |
130 | ||
131 | #endif /* _LINUX_RSEQ_H */ |