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(tsk: 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(sig: 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 */ |
132 | |