1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Access to user system call parameters and results
4 *
5 * See asm-generic/syscall.h for descriptions of what we must do here.
6 */
7
8 #ifndef _ASM_ARM_SYSCALL_H
9 #define _ASM_ARM_SYSCALL_H
10
11 #include <uapi/linux/audit.h> /* for AUDIT_ARCH_* */
12 #include <linux/elf.h> /* for ELF_EM */
13 #include <linux/err.h>
14 #include <linux/sched.h>
15
16 #include <asm/unistd.h>
17
18 #define NR_syscalls (__NR_syscalls)
19
20 extern const unsigned long sys_call_table[];
21
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)22 static inline int syscall_get_nr(struct task_struct *task,
23 struct pt_regs *regs)
24 {
25 if (IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT))
26 return task_thread_info(task)->abi_syscall;
27
28 if (task_thread_info(task)->abi_syscall == -1)
29 return -1;
30
31 return task_thread_info(task)->abi_syscall & __NR_SYSCALL_MASK;
32 }
33
__in_oabi_syscall(struct task_struct * task)34 static inline bool __in_oabi_syscall(struct task_struct *task)
35 {
36 return IS_ENABLED(CONFIG_OABI_COMPAT) &&
37 (task_thread_info(task)->abi_syscall & __NR_OABI_SYSCALL_BASE);
38 }
39
in_oabi_syscall(void)40 static inline bool in_oabi_syscall(void)
41 {
42 return __in_oabi_syscall(current);
43 }
44
syscall_rollback(struct task_struct * task,struct pt_regs * regs)45 static inline void syscall_rollback(struct task_struct *task,
46 struct pt_regs *regs)
47 {
48 regs->ARM_r0 = regs->ARM_ORIG_r0;
49 }
50
syscall_get_error(struct task_struct * task,struct pt_regs * regs)51 static inline long syscall_get_error(struct task_struct *task,
52 struct pt_regs *regs)
53 {
54 unsigned long error = regs->ARM_r0;
55 return IS_ERR_VALUE(error) ? error : 0;
56 }
57
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)58 static inline long syscall_get_return_value(struct task_struct *task,
59 struct pt_regs *regs)
60 {
61 return regs->ARM_r0;
62 }
63
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)64 static inline void syscall_set_return_value(struct task_struct *task,
65 struct pt_regs *regs,
66 int error, long val)
67 {
68 regs->ARM_r0 = (long) error ? error : val;
69 }
70
syscall_set_nr(struct task_struct * task,struct pt_regs * regs,int nr)71 static inline void syscall_set_nr(struct task_struct *task,
72 struct pt_regs *regs,
73 int nr)
74 {
75 if (nr == -1) {
76 task_thread_info(task)->abi_syscall = -1;
77 /*
78 * When the syscall number is set to -1, the syscall will be
79 * skipped. In this case the syscall return value has to be
80 * set explicitly, otherwise the first syscall argument is
81 * returned as the syscall return value.
82 */
83 syscall_set_return_value(task, regs, -ENOSYS, 0);
84 return;
85 }
86 if ((IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT))) {
87 task_thread_info(task)->abi_syscall = nr;
88 return;
89 }
90 task_thread_info(task)->abi_syscall =
91 (task_thread_info(task)->abi_syscall & ~__NR_SYSCALL_MASK) |
92 (nr & __NR_SYSCALL_MASK);
93 }
94
95 #define SYSCALL_MAX_ARGS 7
96
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned long * args)97 static inline void syscall_get_arguments(struct task_struct *task,
98 struct pt_regs *regs,
99 unsigned long *args)
100 {
101 args[0] = regs->ARM_ORIG_r0;
102 args++;
103
104 memcpy(args, ®s->ARM_r0 + 1, 5 * sizeof(args[0]));
105 }
106
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,const unsigned long * args)107 static inline void syscall_set_arguments(struct task_struct *task,
108 struct pt_regs *regs,
109 const unsigned long *args)
110 {
111 memcpy(®s->ARM_r0, args, 6 * sizeof(args[0]));
112 /*
113 * Also copy the first argument into ARM_ORIG_r0
114 * so that syscall_get_arguments() would return it
115 * instead of the previous value.
116 */
117 regs->ARM_ORIG_r0 = regs->ARM_r0;
118 }
119
syscall_get_arch(struct task_struct * task)120 static inline int syscall_get_arch(struct task_struct *task)
121 {
122 /* ARM tasks don't change audit architectures on the fly. */
123 return AUDIT_ARCH_ARM;
124 }
125
126 #endif /* _ASM_ARM_SYSCALL_H */
127