tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Access to user system call parameters and results
4 *
5 * Copyright IBM Corp. 2008
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
7 */
8
9#ifndef _ASM_SYSCALL_H
10#define _ASM_SYSCALL_H 1
11
12#include <uapi/linux/audit.h>
13#include <linux/sched.h>
14#include <linux/err.h>
15#include <asm/ptrace.h>
16
17extern const sys_call_ptr_t sys_call_table[];
18extern const sys_call_ptr_t sys_call_table_emu[];
19
20static inline long syscall_get_nr(struct task_struct *task,
21 struct pt_regs *regs)
22{
23 return test_pt_regs_flag(regs, PIF_SYSCALL) ?
24 (regs->int_code & 0xffff) : -1;
25}
26
27static inline void syscall_rollback(struct task_struct *task,
28 struct pt_regs *regs)
29{
30 regs->gprs[2] = regs->orig_gpr2;
31}
32
33static inline long syscall_get_error(struct task_struct *task,
34 struct pt_regs *regs)
35{
36 unsigned long error = regs->gprs[2];
37#ifdef CONFIG_COMPAT
38 if (test_tsk_thread_flag(task, TIF_31BIT)) {
39 /*
40 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
41 * and will match correctly in comparisons.
42 */
43 error = (long)(int)error;
44 }
45#endif
46 return IS_ERR_VALUE(error) ? error : 0;
47}
48
49static inline long syscall_get_return_value(struct task_struct *task,
50 struct pt_regs *regs)
51{
52 return regs->gprs[2];
53}
54
55static inline void syscall_set_return_value(struct task_struct *task,
56 struct pt_regs *regs,
57 int error, long val)
58{
59 set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);
60 regs->gprs[2] = error ? error : val;
61}
62
63static inline void syscall_get_arguments(struct task_struct *task,
64 struct pt_regs *regs,
65 unsigned long *args)
66{
67 unsigned long mask = -1UL;
68 unsigned int n = 6;
69
70#ifdef CONFIG_COMPAT
71 if (test_tsk_thread_flag(task, TIF_31BIT))
72 mask = 0xffffffff;
73#endif
74 while (n-- > 0)
75 if (n > 0)
76 args[n] = regs->gprs[2 + n] & mask;
77
78 args[0] = regs->orig_gpr2 & mask;
79}
80
81static inline void syscall_set_arguments(struct task_struct *task,
82 struct pt_regs *regs,
83 const unsigned long *args)
84{
85 unsigned int n = 6;
86
87 while (n-- > 0)
88 if (n > 0)
89 regs->gprs[2 + n] = args[n];
90 regs->orig_gpr2 = args[0];
91}
92
93static inline int syscall_get_arch(struct task_struct *task)
94{
95#ifdef CONFIG_COMPAT
96 if (test_tsk_thread_flag(task, TIF_31BIT))
97 return AUDIT_ARCH_S390;
98#endif
99 return AUDIT_ARCH_S390X;
100}
101
102static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
103{
104 return false;
105}
106
107#endif /* _ASM_SYSCALL_H */