1 /* 2 * Access to user system call parameters and results 3 * 4 * See asm-generic/syscall.h for descriptions of what we must do here. 5 */ 6 7 #ifndef _ASM_ARM_SYSCALL_H 8 #define _ASM_ARM_SYSCALL_H 9 10 #include <linux/err.h> 11 12 extern const unsigned long sys_call_table[]; 13 14 static inline int syscall_get_nr(struct task_struct *task, 15 struct pt_regs *regs) 16 { 17 return task_thread_info(task)->syscall; 18 } 19 20 static inline void syscall_rollback(struct task_struct *task, 21 struct pt_regs *regs) 22 { 23 regs->ARM_r0 = regs->ARM_ORIG_r0; 24 } 25 26 static inline long syscall_get_error(struct task_struct *task, 27 struct pt_regs *regs) 28 { 29 unsigned long error = regs->ARM_r0; 30 return IS_ERR_VALUE(error) ? error : 0; 31 } 32 33 static inline long syscall_get_return_value(struct task_struct *task, 34 struct pt_regs *regs) 35 { 36 return regs->ARM_r0; 37 } 38 39 static inline void syscall_set_return_value(struct task_struct *task, 40 struct pt_regs *regs, 41 int error, long val) 42 { 43 regs->ARM_r0 = (long) error ? error : val; 44 } 45 46 #define SYSCALL_MAX_ARGS 7 47 48 static inline void syscall_get_arguments(struct task_struct *task, 49 struct pt_regs *regs, 50 unsigned int i, unsigned int n, 51 unsigned long *args) 52 { 53 if (i + n > SYSCALL_MAX_ARGS) { 54 unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; 55 unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; 56 pr_warning("%s called with max args %d, handling only %d\n", 57 __func__, i + n, SYSCALL_MAX_ARGS); 58 memset(args_bad, 0, n_bad * sizeof(args[0])); 59 n = SYSCALL_MAX_ARGS - i; 60 } 61 62 if (i == 0) { 63 args[0] = regs->ARM_ORIG_r0; 64 args++; 65 i++; 66 n--; 67 } 68 69 memcpy(args, ®s->ARM_r0 + i, n * sizeof(args[0])); 70 } 71 72 static inline void syscall_set_arguments(struct task_struct *task, 73 struct pt_regs *regs, 74 unsigned int i, unsigned int n, 75 const unsigned long *args) 76 { 77 if (i + n > SYSCALL_MAX_ARGS) { 78 pr_warning("%s called with max args %d, handling only %d\n", 79 __func__, i + n, SYSCALL_MAX_ARGS); 80 n = SYSCALL_MAX_ARGS - i; 81 } 82 83 if (i == 0) { 84 regs->ARM_ORIG_r0 = args[0]; 85 args++; 86 i++; 87 n--; 88 } 89 90 memcpy(®s->ARM_r0 + i, args, n * sizeof(args[0])); 91 } 92 93 #endif /* _ASM_ARM_SYSCALL_H */ 94