Warning: This file is not a C or C++ file. It does not have highlighting.
1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
---|---|
2 | /* |
3 | * Access to user system call parameters and results |
4 | * |
5 | * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. |
6 | * |
7 | * This file is a stub providing documentation for what functions |
8 | * asm-ARCH/syscall.h files need to define. Most arch definitions |
9 | * will be simple inlines. |
10 | * |
11 | * All of these functions expect to be called with no locks, |
12 | * and only when the caller is sure that the task of interest |
13 | * cannot return to user mode while we are looking at it. |
14 | */ |
15 | |
16 | #ifndef _ASM_SYSCALL_H |
17 | #define _ASM_SYSCALL_H 1 |
18 | |
19 | struct task_struct; |
20 | struct pt_regs; |
21 | |
22 | /** |
23 | * syscall_get_nr - find what system call a task is executing |
24 | * @task: task of interest, must be blocked |
25 | * @regs: task_pt_regs() of @task |
26 | * |
27 | * If @task is executing a system call or is at system call |
28 | * tracing about to attempt one, returns the system call number. |
29 | * If @task is not executing a system call, i.e. it's blocked |
30 | * inside the kernel for a fault or signal, returns -1. |
31 | * |
32 | * Note this returns int even on 64-bit machines. Only 32 bits of |
33 | * system call number can be meaningful. If the actual arch value |
34 | * is 64 bits, this truncates to 32 bits so 0xffffffff means -1. |
35 | * |
36 | * It's only valid to call this when @task is known to be blocked. |
37 | */ |
38 | int syscall_get_nr(struct task_struct *task, struct pt_regs *regs); |
39 | |
40 | /** |
41 | * syscall_rollback - roll back registers after an aborted system call |
42 | * @task: task of interest, must be in system call exit tracing |
43 | * @regs: task_pt_regs() of @task |
44 | * |
45 | * It's only valid to call this when @task is stopped for system |
46 | * call exit tracing (due to %SYSCALL_WORK_SYSCALL_TRACE or |
47 | * %SYSCALL_WORK_SYSCALL_AUDIT), after ptrace_report_syscall_entry() |
48 | * returned nonzero to prevent the system call from taking place. |
49 | * |
50 | * This rolls back the register state in @regs so it's as if the |
51 | * system call instruction was a no-op. The registers containing |
52 | * the system call number and arguments are as they were before the |
53 | * system call instruction. This may not be the same as what the |
54 | * register state looked like at system call entry tracing. |
55 | */ |
56 | void syscall_rollback(struct task_struct *task, struct pt_regs *regs); |
57 | |
58 | /** |
59 | * syscall_get_error - check result of traced system call |
60 | * @task: task of interest, must be blocked |
61 | * @regs: task_pt_regs() of @task |
62 | * |
63 | * Returns 0 if the system call succeeded, or -ERRORCODE if it failed. |
64 | * |
65 | * It's only valid to call this when @task is stopped for tracing on exit |
66 | * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or |
67 | * %SYSCALL_WORK_SYSCALL_AUDIT. |
68 | */ |
69 | long syscall_get_error(struct task_struct *task, struct pt_regs *regs); |
70 | |
71 | /** |
72 | * syscall_get_return_value - get the return value of a traced system call |
73 | * @task: task of interest, must be blocked |
74 | * @regs: task_pt_regs() of @task |
75 | * |
76 | * Returns the return value of the successful system call. |
77 | * This value is meaningless if syscall_get_error() returned nonzero. |
78 | * |
79 | * It's only valid to call this when @task is stopped for tracing on exit |
80 | * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or |
81 | * %SYSCALL_WORK_SYSCALL_AUDIT. |
82 | */ |
83 | long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs); |
84 | |
85 | /** |
86 | * syscall_set_return_value - change the return value of a traced system call |
87 | * @task: task of interest, must be blocked |
88 | * @regs: task_pt_regs() of @task |
89 | * @error: negative error code, or zero to indicate success |
90 | * @val: user return value if @error is zero |
91 | * |
92 | * This changes the results of the system call that user mode will see. |
93 | * If @error is zero, the user sees a successful system call with a |
94 | * return value of @val. If @error is nonzero, it's a negated errno |
95 | * code; the user sees a failed system call with this errno code. |
96 | * |
97 | * It's only valid to call this when @task is stopped for tracing on exit |
98 | * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or |
99 | * %SYSCALL_WORK_SYSCALL_AUDIT. |
100 | */ |
101 | void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, |
102 | int error, long val); |
103 | |
104 | /** |
105 | * syscall_get_arguments - extract system call parameter values |
106 | * @task: task of interest, must be blocked |
107 | * @regs: task_pt_regs() of @task |
108 | * @args: array filled with argument values |
109 | * |
110 | * Fetches 6 arguments to the system call. First argument is stored in |
111 | * @args[0], and so on. |
112 | * |
113 | * It's only valid to call this when @task is stopped for tracing on |
114 | * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or |
115 | * %SYSCALL_WORK_SYSCALL_AUDIT. |
116 | */ |
117 | void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs, |
118 | unsigned long *args); |
119 | |
120 | /** |
121 | * syscall_get_arch - return the AUDIT_ARCH for the current system call |
122 | * @task: task of interest, must be blocked |
123 | * |
124 | * Returns the AUDIT_ARCH_* based on the system call convention in use. |
125 | * |
126 | * It's only valid to call this when @task is stopped on entry to a system |
127 | * call, due to %SYSCALL_WORK_SYSCALL_TRACE, %SYSCALL_WORK_SYSCALL_AUDIT, or |
128 | * %SYSCALL_WORK_SECCOMP. |
129 | * |
130 | * Architectures which permit CONFIG_HAVE_ARCH_SECCOMP_FILTER must |
131 | * provide an implementation of this. |
132 | */ |
133 | int syscall_get_arch(struct task_struct *task); |
134 | #endif /* _ASM_SYSCALL_H */ |
135 |
Warning: This file is not a C or C++ file. It does not have highlighting.