xref: /linux/arch/arm/include/asm/syscall.h (revision ffb1e76f4f32d2b8ea4189df0484980370476395) 
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 
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 	return task_thread_info(task)->abi_syscall & __NR_SYSCALL_MASK;
29 }
30 
31 static inline bool __in_oabi_syscall(struct task_struct *task)
32 {
33 	return IS_ENABLED(CONFIG_OABI_COMPAT) &&
34 		(task_thread_info(task)->abi_syscall & __NR_OABI_SYSCALL_BASE);
35 }
36 
37 static inline bool in_oabi_syscall(void)
38 {
39 	return __in_oabi_syscall(current);
40 }
41 
42 static inline void syscall_rollback(struct task_struct *task,
43 				    struct pt_regs *regs)
44 {
45 	regs->ARM_r0 = regs->ARM_ORIG_r0;
46 }
47 
48 static inline long syscall_get_error(struct task_struct *task,
49 				     struct pt_regs *regs)
50 {
51 	unsigned long error = regs->ARM_r0;
52 	return IS_ERR_VALUE(error) ? error : 0;
53 }
54 
55 static inline long syscall_get_return_value(struct task_struct *task,
56 					    struct pt_regs *regs)
57 {
58 	return regs->ARM_r0;
59 }
60 
61 static inline void syscall_set_return_value(struct task_struct *task,
62 					    struct pt_regs *regs,
63 					    int error, long val)
64 {
65 	regs->ARM_r0 = (long) error ? error : val;
66 }
67 
68 #define SYSCALL_MAX_ARGS 7
69 
70 static inline void syscall_get_arguments(struct task_struct *task,
71 					 struct pt_regs *regs,
72 					 unsigned long *args)
73 {
74 	args[0] = regs->ARM_ORIG_r0;
75 	args++;
76 
77 	memcpy(args, &regs->ARM_r0 + 1, 5 * sizeof(args[0]));
78 }
79 
80 static inline void syscall_set_arguments(struct task_struct *task,
81 					 struct pt_regs *regs,
82 					 const unsigned long *args)
83 {
84 	regs->ARM_ORIG_r0 = args[0];
85 	args++;
86 
87 	memcpy(&regs->ARM_r0 + 1, args, 5 * sizeof(args[0]));
88 }
89 
90 static inline int syscall_get_arch(struct task_struct *task)
91 {
92 	/* ARM tasks don't change audit architectures on the fly. */
93 	return AUDIT_ARCH_ARM;
94 }
95 
96 #endif /* _ASM_ARM_SYSCALL_H */
97