xref: /openbmc/linux/arch/arm/include/asm/syscall.h (revision a9ebfc40)
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 	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 
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 
40 static inline bool in_oabi_syscall(void)
41 {
42 	return __in_oabi_syscall(current);
43 }
44 
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 
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 
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 
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 
71 #define SYSCALL_MAX_ARGS 7
72 
73 static inline void syscall_get_arguments(struct task_struct *task,
74 					 struct pt_regs *regs,
75 					 unsigned long *args)
76 {
77 	args[0] = regs->ARM_ORIG_r0;
78 	args++;
79 
80 	memcpy(args, &regs->ARM_r0 + 1, 5 * sizeof(args[0]));
81 }
82 
83 static inline int syscall_get_arch(struct task_struct *task)
84 {
85 	/* ARM tasks don't change audit architectures on the fly. */
86 	return AUDIT_ARCH_ARM;
87 }
88 
89 #endif /* _ASM_ARM_SYSCALL_H */
90